Zebra shark makes world-first switch from sexual to asexual reproduction

Leonie is through with males.

A zebra shark (Stegostoma fasciatum) in Australia has become the first recorded case of a shark switching from sexual to asexual reproduction.

In April last year, Leonie gave birth to three pups called Cleo, CC, and Gemini in a Queensland aquarium. This sweet but otherwise unremarkable tale would have gone unnoticed by the science world if it weren’t for one key detail: Leonie hadn’t mated with a male shark since 2012.

Her previous breeding partner, Leo – with whom she had produced more than 20 offspring – was moved to a new tank at the aquarium in 2013. Leonie hadn’t shared a tank with any other males in that time, meaning the three pups delivered in 2016 came as something of a surprise.

“We thought she could be storing sperm but when we tested the pups and the possible parent sharks using DNA fingerprinting, we found they only had cells from Leonie,” says biomedical researcher Christine Dudgeon from the University of Queensland.

So how is this possible?

Well, sharks breeding asexually is extremely rare, but isn’t entirely unheard of.

This is possible because, beyond sexual reproduction, there’s another way that certain species can asexually reproduce, called parthenogenesis.

This process allows embryos to develop without being fertilised like they are in sexual reproduction.

 Parthenogenesis mainly occurs in plants and invertebrate animals, but these ‘virgin births’ have also been documented in vertebrate animals, including sharks and lizards.

But what makes Leonie’s case so unusual is it’s the first time scientists have seen a shark make the switch from breeding sexually to asexually.

In other circumstances where sharks have been observed to breed parthenogenetically, the animals did not have any experience with sexual reproduction, having bred asexually from maturity.

In fact, this is only the third time scientists have seen any species make the switch back to asexual reproduction from past sexual experience, with the other cases being an eagle ray and a boa constrictor, both held in captivity.

And this time around, captivity again looks to have been responsible for the change in Leonie’s circumstances.

The aquarium decided to deprive Leonie of of her mate, Leo, because they’d been producing too many offspring for the staff to handle.

“Leonie adapted to her circumstances and we believe she switched because she lost her mate. What we want to know now is could this occur in the wild and, if so, how often does it?” says Dudgeon.

“One reason why we haven’t seen it before could be because we haven’t been looking for it. It might be happening in the wild, but it’s never been recorded in this species before.”

But while the ability to breed independently could be an invaluable survival mechanism in the absence of suitable mates, it comes with its own set of problems: the resulting pups suffer in terms of genetic diversity, not picking up any of the absent male’s genes, and only receiving half of their mother’s.

“This is an extreme form of inbreeding,” Dudgeon told Casey Briggs at the ABC.

“[I]t’s unlikely to be a very good long-term strategy, because eventually they need to mix up that gene pool and increase that genetic diversity to adapt to new and ever-changing conditions.”

But in the short term, it may be that the process can preserve as much of an animal’s genetic identity as possible (if only half in total) until breeding conditions become more favourable.

“It might be a holding-on mechanism,” Dudgeon told Alice Klein at New Scientist. “Mum’s genes get passed down from female to female until there are males available to mate with.”

To find out if that’s the case, the researchers now plan to follow the pups until they reach maturity themselves, to find out if Cleo, CC, and Gemini are capable of breeding with males when their time comes.

Let’s hope so, because if they can, it would be evidence that these sharks have evolved an amazing ability to keep surviving, even when they’ve been pushed into a tight corner.

And with zebra sharks being listed as endangered on the IUCN Red List of Threatened Species, these animals need all the survival help they can get.

Complex life could have existed on Earth at least once before

We might not be the first.

Complex life might have come and gone on Earth long before the multicellular organisms we’re familiar with today arose, a new study suggests.

It’s generally thought that the evolution of complex life was a rare, once-in-4.5-billion-years event. But new research suggests that conditions were right for complex cells to evolve and die off at least once – or perhaps several times – before our lineage even got started.

 What does that mean? Billions of years ago, there could have been other complex life forms on the planet, totally unrelated to anything we see on Earth today.

But let’s backtrack for a second. Earth has been around for an estimated 4.5 billion years. Around 3.7 billion years ago, while the planet was still relatively fresh, two of the three kingdoms of life we see on Earth today – bacteria and archaea – arose.

It’s thought that these simple, single-celled organisms survived for billions of years on their own, until around 1.75 billion years ago, when the third kingdom of life, eukaryotes, appeared.

The eukaryote family tree encompasses all complex organisms on the planet, including animals (that’s us), plants, fungi, and protists.

It’s still debated exactly how eukaryotes arose, but the most accepted hypothesis is that a bacteria swallowed an archaea cell, and the two developed a symbiotic relationships that allowed them to work together to become more complex.

Eventually, the archaea became the mitochondria we see in our cells today.

 Whether that scenario is true or not, researchers think the event could only happen thanks to its timing – the reason we didn’t see eukaryotes before that is because there simply wasn’t enough oxygen in our atmosphere as yet.

Oxygen began building up billions of years ago thanks to cyanobacteria, but it took a long time – until approximately 1.6 billion years ago – to get up to levels that were suitable for complex life. Or, at least, that what we’ve always thought.

Now, a new study by the University of Washington has found evidence that there was enough oxygen in Earth’s atmosphere between 2.4 and 2 billion years ago before it dropped off again suddenly.

This suggests that the ingredients for complex life were present before the first fossil evidence of eukaryotes.

“There is fossil evidence of complex cells that go back maybe 1.75 billion years,” said astrobiologist Roger Buick. “But the oldest fossil is not necessarily the oldest one that ever lived – because the chances of getting preserved as a fossil are pretty low.”

“This research shows that there was enough oxygen in the environment to have allowed complex cells to have evolved, and to have become ecologically important, before there was fossil evidence,” he added. “That doesn’t mean that they did – but they could have.”

That last point is pretty important – we need to make it clear that no one has found fossil or DNA evidence of this earlier complex life.

What the team is saying is that the ingredients were there for it to have evolved hundreds of millions of years before the first eukaryote, but we’re still not sure if that actually that happened.

So why wouldn’t this hypothetical life have survived until today if it did evolve? The research showed that although there was an early ‘bubble’ of oxygen in the atmosphere, it crashed shortly afterwards, which would most likely have killed the lifeforms off.

To figure this out, the team analysed traces of the chemical element selenium trapped in pieces of sedimentary shale dating back between 2.4 and 2 billion years ago.

They were looking to see if the selenium had been changed by the presence of oxygen, or oxidised – a reaction that leaves a signature in the ratio of selenium isotopes stored in the rocks.

Traditionally, it was assumed that oxygen on Earth had a history of “none, then some, then a lot”, said Buick.

“But what it looks like now is, there was a period of a quarter of a billion years or so where oxygen came quite high, and then sunk back down again.”

It wouldn’t have been enough time for complex life to diversify and take hold on the planet, but it’s possible that some complex organisms could have arisen before dying off again when the oxygen crashed.

In the past, researchers had predicted that this early oxygen increase – known as the ‘oxygen overshoot’ – might have occurred, but this is the first time it has been studied in detail.

The same technique could also one day be used to measure the historic oxygen levels on Earth-like planets outside our Solar System, as a way of assessing whether they might have ever hosted life.

So what caused Earth’s oxygen levels to soar early on, only to crash again?

“That’s the million-dollar question,” said one of the researchers, Eva Stüeken, from St Andrews University in Scotland. “It’s unknown why it happened, and why it ended.”

“It is an unprecedented time in Earth’s history,” added Buick. “If you look at the selenium isotope record through time, it’s a unique interval. If you look before and after, everything’s different.”

We might never know for sure whether complex life originated and died out before the first eukaryotes, but it’s interesting to note that the conditions that paved the way for complex life on Earth might not be quite as rare or unique as we previously thought.

Natural selection is causing a decline in human ‘education genes’, say scientists

Is our species on a downwards spiral?


The genes that predispose people to attain higher levels of education have been in decline over the past 80 years, and researchers are suggesting that they’re now under negative selection, which could have a big impact on our species in the coming centuries.

A study involving more than 100,000 people in Iceland found that those who carry the genes for longer education time were less likely to have a big family, which means the smartest people in the room were actually contributing less to the Icelandic gene pool.

 “As a species, we are defined by the power of our brains. Education is the training and refining of our mental capacities,” said Kari Stefansson, CEO of Icelandic genetics firm deCODE, which ran the study.

“Thus, it is fascinating to find that genetic factors linked to more time spent in education are becoming rarer in the gene pool.”

To be clear, this does not necessarily mean that humans are getting dumber – we’re going to need a whole lot more evidence to get anywhere near a conclusion like that.

There’s also the fact that more people are getting access to education than ever before, so even if less educated people are having more offspring, non-genetic factors like more schools could counteract and even eclipse the effect.

But if we look at the trend over the course of several centuries into the future – well beyond the proliferation of schools and training access – the researchers say it could have a significant effect on our species in the long run.

“It is remarkable to report changes … that are measurable across the several decades covered by this study,” the study concludes.

“In evolutionary time, this is a blink of an eye. However, if this trend persists over many centuries, the impact could be profound.”

The researchers analysed the birth rate of 129,808 individuals born in Iceland between 1910 and 1990 who had their genomes sequenced, and compared this to their education levels.

They found that there was a genetic factor related to a person’s likelihood of attending school for longer, and came up with a ‘polygenic score‘ based on 620,000 sequence variations – or markers – in the human genome to determine an individual’s genetic propensity for education.

As the team points out, no one knows the exact mix between genetic and environmental factors that leads to someone’s education level, but previous studies have estimated that the genetic component of educational attainment can account for as much as 40 percent of the difference between individuals.

Once that polygenetic score was correlated with factors like educational attainment, fertility, and birth years, the researchers found that those with a higher genetic propensity towards more education tended to have fewer children.

They also found that the average polygenetic score has been declining at a small, but significant rate on an evolutionary timescale.

As Ian Sample reports for The Guardian, the team found a drop in IQ of about 0.04 points per decade, but if all the genetic factors that could be linked to education were taken into account, that figure would increase to 0.3 points per decade.

Interestingly, the link between a higher propensity towards more education and having fewer children wasn’t because going to university is hard, and eats into your family-raising time – the team suggests that the genes involved in education can also affect human fertility on a biological level.

Because even those who carried the genes for longer education time, but who did not actually get more education, still had fewer offspring on average than those without the genetic factor.

“Those who carried more ‘education genes’ tended to have fewer children than others,” Sample explains.

“This led the scientists to propose that the genes had become rarer in the population because, for all their qualifications, better educated people had contributed less than others to the Icelandic gene pool.”

Again, this is all speculation is only based on one country, and it’s incredibly difficult to predict what’s going to happen to humans in the distant future.

But it’s certainly something to keep an eye on, the researchers say, and if anything, highlights the importance of a continued effort towards ensuring that every human has access to education, because that can override the negative selection that appears to be in play.

“In spite of the negative selection against these sequence variations, education levels have been increasing for decades. Indeed, we control the environment in which these genetic factors play out: the education system,” Stefansson said in a press statement.

“If we continue to improve the availability and quality of educational opportunities, we will presumably continue to improve the educational level of society as a whole. Time will tell whether the decline of the genetic propensity for education will have a notable impact on human society.”

Drug-resistant “nightmare bacteria” are quickly spreading through US hospitals

Researchers have found evidence that drug-resistant superbugs, which have been labelled “nightmare bacteria”, are spreading faster and more stealthily inside US hospitals than previously thought.

In the US, the bacteria, known as carbapenem-resistant Enterobacteriaceae(CRE), infect roughly 9,300 people per year, and kill around 600. And now researchers think they might spread from person to person asymptomatically – which explains why doctors are often unable to detect it.

“While the typical focus has been on treating sick patients with CRE-related infections, our new findings suggest that CRE is spreading beyond the obvious cases of disease,” said William Hanag  from the Harvard T. H. Chan School of Public Health.

“We need to look harder for this unobserved transmission within our communities and healthcare facilities if we want to stamp it out.”

CRE are a class of drug-resistant bacteria that are even able to withstand carbapenems – last-resort drugs that are administered after all other antibiotics fail.

Enterobacteriaceae are a large-family of bacteria that include bugs such as SalmonellaE. coli, and Shigella –all of which are common causes of food poisoning and stomach bugs.

When they’re not drug-resistant, these bacteria can easily be treated by antibiotics, but antibiotic resistance has increasingly been spread within the family.

The bacteria are known to thrive in hospitals and long-term care facilities, where they evolve and pass genes back and forth over time, eventually becoming deadly CSE superbugs that drugs cannot treat, and earning the researchers’ title of “nightmare bacteria“.


An official report last week showed that a US woman has already died from one superbug – an antibiotic resistant strain of pneumonia (not a type of CSE), which was resistant to all available antibiotics in the US.

Now, Hanage and his colleagues have discovered that CSE superbugs, at least, might be spreading at a much faster rate than expected, and are starting to avoid our normal ‘surveillance’ methods by spreading asymptomatically.

“You know the phrase ‘Shutting the stable door after the horse has bolted?’ The horse has not only bolted, the horse has had a lot of ponies, and they’re eating all our carrots,” Hanage told Helen Branswell at Stat News.

To figure out how rapidly CRE was diversifying and spreading, the team analysedover 250 samples from hospitalised patients in three different Boston-based facilities and one in California.

When finished, they found that CRE populations were way more diverse than previously thought, meaning that drug-resistant genes had spread more rapidly and easily between the strains than expected.

The team called it a “riot of diversity“.

Sometimes the species they found didn’t even carry the genes known to supress carbapenems, but  were still able to survive them, suggesting that they’ve found new ways to avoid these antibiotics that we don’t even know about yet.

“There are many different ways in which they can be resistant,” Hanage told Stat News.

To make things worse, the team wasn’t able to see a clear pattern of transmission for these CRE strains – the resistance seemed to be spreading even without any obvious cases of illness or infection.

“The best way to stop CRE making people sick is to prevent transmission in the first place,” Hanage said.

“If it is right that we are missing a lot of transmission, then only focusing on cases of disease is like playing Whack-a-Mole; we can be sure the bacteria will pop up again somewhere else.”

The team hypothesises that these transmissions might be happening from person to person asymptomatically, though they will need to carry out further studies to verify this is the case.

Why the Mediterranean Diet Is so Successful

The Mediterranean diet is one that has managed to maintain popularity through changing fads, and for good reason. A number of studies have confirmed its health benefits — most of which are likely due to it being low in sugars, moderate in protein and high in fresh fruits and vegetables, along with healthy fats.

Story at-a-glance

  • A number of studies have confirmed the health benefits of a Mediterranean-style diet — most of which are likely due to it being low in sugars, moderate in protein and high in fresh fruits and vegetables, along with healthy fats
  • Eating a Mediterranean-style diet has been linked to a number of health benefits, including prevention and reversal of metabolic syndrome, improved cardiovascular health and reduced risk for stroke
  • Other benefits include reduced risk of adult acne, rheumatoid arthritis, Parkinson’s, Alzheimer’s disease and cancer, and improved overall health and longevity

Contrary to popular belief, there’s actually no single “Mediterranean diet.” At least 16 countries border the Mediterranean Sea, and dietary habits vary from country to country due to differences in culture, ethnic background, religion and agricultural production.

That said, a primary hallmark of a Mediterranean-style diet is a focus on whole, minimally processed foods. The emphasis on fresh vegetables alone makes it far healthier than the standard American diet, which is very high in processed foods.

Health Benefits Associated With a Mediterranean-Style Diet

Eating a Mediterranean-style diet has been linked to a number of health benefits, including:

Prevention and/or reversal of metabolic syndrome, a cluster of risk factors for heart disease and diabetes.

One review of 35 clinical trials found it helped reduce belly fat and high blood pressure, elevate HDL cholesterol and improve blood sugar levels, compared to those who ate a low-fat diet.1

Improved cardiovascular health and a significantly reduced risk of stroke — effects linked to higher amounts of animal-based omega-3 fats (primarily from fish).2,3

According to recent research, marine animal-based omega-3 may lower your risk of heart disease even if you’re already at increased risk due to high levels of low-density lipoprotein (LDL) cholesterol and/or triglycerides.4,5

Higher levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from seafood or supplements was associated with a 16 percent lower risk of heart disease in those with high triglycerides, and a 14 percent reduced risk in those with high LDLs.

Reduced risk of acne in adult women. According to recent research, adult women who ate fresh fruits, vegetables and fish less than four days a week had double the risk of adult acne.6,7

Reduced risk of rheumatoid arthritis,8 Parkinson’s, Alzheimer’s disease and cancer.9

Improved overall health and longevity. In one study, women who closely followed a Mediterranean-style diet in their 50s and 60s were 46 percent more likely to live past the age of 70 without chronic illness or cognitive problems.10

Mediterranean Diet Linked to Healthier Brain

Overall, the Mediterranean diet is one of the best conventional diets for brain and heart health. For example, research has shown diets rich in healthy fats from nuts, avocados and olive oil may boost memory and cognition in older adults.11,12

Previous research has also suggested a Mediterranean diet may lower your odds of Alzheimer’s disease, but it wasn’t clear whether the diet was responsible, or if people who eat this way also make many other healthier lifestyle choices that decrease their risk.

In an effort to shed more light on the potential links between diet and cognition, the researchers randomly assigned nearly 450 seniors with risk factors for cardiovascular disease — such as overweight, high blood pressure and/or high cholesterol — to follow one of three diets:13,14

  • A Mediterranean diet supplemented with 1 liter of extra virgin olive oil per week
  • A Mediterranean diet supplemented with 30 grams of nuts a day
  • A low-fat diet

Brain function tests were conducted before and after the study. Those following a Mediterranean diet with supplemental nuts showed significant improvement in memory, while those who got supplemental olive oil experienced significantly improved cognition.

The low-fat group, on the other hand, experienced a significant decrease in both memory and cognitive function.

Older Adults Suffer Less Brain Shrinkage on Mediterranean Diet

More recently, scientists found that a Mediterranean-style diet also helps reduce age-related brain shrinkage in older adults. As reported by the LA Times:15

“In a group of 562 Scots in their 70s, those whose consumption patterns more closely followed the Mediterranean diet experienced, on average, half the brain shrinkage that was normal for the group as a whole over a three-year period …

The researchers used the food-frequency surveys to divide the group into two — those who at least approximated a Mediterranean-style diet and those who came nowhere close.

Even though many in the Med-diet group were far from perfect in their adherence, the average brain-volume loss differed significantly between the two groups.”

Your Brain Needs Healthy Fats for Optimal Function

Results such as these certainly make sense when you consider how important healthy fats are for your brain function. After all, your brain is composed of at least 60 percent fat — the most important of which is DHA, found in seafood such as clean fish and krill oil. That said, it’s important to choose your seafood wisely.

What you’re looking for are fish high in healthy fats, such as omega-3, while also being low in mercury and other environmental pollutants. Good choices include smaller fatty fish like sardines, anchovies and herring.

As a general rule, the lower on the food chain the fish is, the less likely it is to contain harmful levels of contaminants. Many of these smaller fish also contain higher amounts of omega-3, so it’s a win-win. Wild-caught Alaskan salmon is another healthy choice. If you avoid fish, it’s important to take a high-quality omega-3 supplement such as krill oil.

Besides fish, other examples of beneficial fats that your body (and your brain in particular) needs for optimal function include avocado, organic grass-fed raw butter, clarified butter called ghee, olives, organic virgin olive oil and coconut oil, nuts like pecans and macadamia and free-range eggs.

It’s also important to avoid sugars and processed grains. Research from the Mayo Clinic shows diets rich in carbohydrates are associated with an 89 percent increased risk for dementia, while high-fat diets are associated with a 42 percent reduced risk.16

Omega-3 Is Important for Other Psychiatric Conditions as Well

Animal-based omega-3 in combination with vitamin D has also been shown to improve cognitive function and behavior associated with certain psychiatric conditions, including ADHD, bipolar disorder and schizophrenia — in part by regulating your brain’s serotonin levels.17,18,19

The omega-3 fat EPA reduces inflammatory signaling molecules in your brain that inhibit serotonin release from presynaptic neurons, thereby boosting your serotonin levels. DHA — which is an important structural component of your brain cells — also has a beneficial influence on serotonin receptors by increasing their access to serotonin.

Other diets shown to be particularly beneficial for brain health include the DASH and the MIND diets,20 the latter of which emphasizes fruits and vegetables, especially leafy greens and berries, whole grains, nuts, olive oil, beans, poultry and fish, while limiting red meat, cheese, butter, sweets and fried foods.

What these three diets have in common is an emphasis on whole foods, particularly fresh fruits and vegetables, and at least SOME healthy fats. Considering the importance of eating real food, it’s not so surprising that the DASH diet, Mediterranean diet and MIND diet rank No.1, 2 and 3 respectively as the best overall diets for good health, according to a panel of health experts.21

Benefits of the DASH Diet

The DASH diet in particular has been shown to be quite effective for lowering your risk of hypertension. However, I believe the real reason for this effect is not due to the reduction in salt but rather the reduction in processed foods, which is high in fructose.22,23 As your insulin and leptin levels rise in response to net carbs, it causes your blood pressure to increase.

Excess fructose promotes hypertension to a far greater degree than excess salt. One 2010 study24 discovered that those who consumed 74 grams or more per day of fructose (the equivalent of about 2.5 sugary drinks) had a 77 percent greater risk of having blood pressure levels of 160/100 mmHg (stage 2 hypertension). Consuming 74 grams or more of fructose per day also increased the risk of a 135/85 blood pressure reading by 26 percent, and a reading of 140/90 by 30 percent.

Elevated uric acid levels are also significantly associated with hypertension (by inhibiting nitric oxide in your blood vessels), and fructose elevates uric acid. In fact, uric acid is a byproduct of fructose metabolism. So, by eliminating excess sugar and fructose from your diet, you effectively address root issues that contribute to high blood pressure.

I recommend keeping your total fructose consumption below 25 grams per day. If you’re insulin resistant (about 80 percent of Americans are), have high blood pressure, diabetes, heart disease or other chronic disease, you’d be wise to limit your fructose to 15 grams or less per day, until your condition has normalized.

As for the issue of salt (which the DASH diet restricts), it’s important to realize that salt is actually essential for maintaining and regulating blood pressure. The key is to use the right kind of salt. Ideally, replace all processed table salt with a natural unprocessed version, such as Himalayan salt, which contains a variety of trace minerals your body actually needs.

Part of the DASH diet’s effectiveness for hypertension may also have to do with the fact that it focuses on vegetables, which helps improve your sodium-to-potassium ratio. Your body needs potassium to maintain proper pH levels in your body fluids, and it plays an integral role in regulating your blood pressure. It’s actually possible that potassium deficiency may be a greater contributor to hypertension than excess sodium (but not likely a greater factor than fructose).

Mediterranean Diet May Cut Your Heart Disease Risk by Nearly One-Third

The importance of healthy fats cannot be overstated in my view. Fats are important for so many biological processes, especially those related to your brain and heart function. In the case of the latter, a Spanish trial,25 which included nearly 7,450 volunteers between the ages of 55 and 80, was stopped early for ethical reasons as the low-fat control group was deemed to be at a dangerous disadvantage.

The participants had all been diagnosed with high risk of cardiovascular disease, but were asymptomatic at the outset of the study. Participants were followed for a median of 4.8 years. The volunteers were randomly divided into three groups (two intervention groups and one control):

  • Mediterranean diet rich in fresh vegetables, fruits, seafood, whole grains and mono-unsaturated fats, very low in meat and dairy and supplemented with 30 grams (1.05 ounces) of nuts per day (15 grams walnuts, 7.5 grams almonds and 7.5 grams hazelnuts)
  • Mediterranean diet (as above) supplemented with 50 milliliters (1.7 ounces) of virgin olive oil per day instead of nuts
  • Low-fat diet (control)

There were no calorie restrictions for any of the groups, nor was physical activity promoted or required. Compliance with olive oil and nut consumption was tested via blood and urine analysis. The primary end point was a composite of myocardial infarction, stroke and death from cardiovascular causes. Secondary end points were stroke, myocardial infarction, death from cardiovascular causes and death from any cause.

Remarkably, in less than five years, the two intervention groups achieved a 30 percent relative risk reduction for cardiovascular disease, and stroke reduction was an impressive 49 percent. No wonder they felt the trial had to be stopped for ethical reasons!

Sadly, low-fat diets remain among the most accepted diets in the medical community, both for weight management and cardiac health. There’s no telling how many millions of people have prematurely died from this fatally flawed and scientifically-refuted advice.

Are You Eating Enough Fish?

According to the latest report26 by the National Oceanic and Atmospheric Administration (NOAA), Americans increased their seafood consumption by nearly 1 pound per person in 2015, to an average of 15.5 pounds per year, or just over 4.75 ounces per week.

That’s the largest increase in seafood consumption in two decades, yet we still fall short of dietary recommendations, which call for 8 ounces of seafood per week. Ideally, aim for two to three servings of fish like salmon or sardines, anchovies, mackerel and herring each week, to obtain healthy levels of omega-3. Avoid canned tuna, mackerel, swordfish, grouper, marlin, orange roughy, snapper and halibut, as they have some of the highestlevels of contamination.

For more information about mercury in fish, see the Mercury Policy Project’s website, “Mercury and Fish: The Facts.”27 They have a helpful guide you can print out for reference.28 A 2015 article in Investigate West also addressed this issue, and includes a guide to how many meals per week you can safely eat based on any given seafood’s contamination level.29

Why Higher Fish Consumption Is Likely Part of Mediterranean Diet’s High Success Rate

Besides omega-3 fats and other valuable nutrients, fish is also a good source of high-quality protein. However, most fish contain only HALF of the protein found in beef and chicken, and this is actually a very good thing. While we do need protein for muscle, bone and hormone health, eating more than your body actually needs can stimulate your mammalian target of rapamycin (mTOR) — a pathway that plays an important role in many cancers, among other things.

In fact, Valter Longo, Ph.D.,30 — a professor of biological science at the University of California and a well-known longevity researcher — believes the reduced protein content in fish may be one reason why the Mediterranean diet is linked to life extension and reduced risk for chronic disease. In essence, those who eat more fish than red meat automatically get far less protein, thereby preventing the excessive stimulation of mTOR.

For Health and Longevity, Be Sure to Optimize Your Omega-3

If you do not eat this amount of fish on a weekly basis, consider taking a daily omega-3 supplement such as krill oil. As for dosage, the amount of omega-3s you need depends on your body size, age, health status, the type of omega-3 and more. Your best bet is to get an omega-3 index test. This test measures the omega-3 in your red blood cells, which is really the only way to determine if you’re getting enough from your diet or supplements. Your index should be above 8 percent.

While there’s no set recommended standard dose of omega-3 fats, some health organizations recommend a daily dose of 250 to 500 milligram (mg) of EPA and DHA for healthy adults. Higher amounts (upwards of 1,000 to 2,000 mg of EPA and DHA daily) are typically recommended for the prevention of memory loss, depression and heart disease.

If you’re pregnant or breastfeeding, your body will likely require additional omega-3 fats. The American Dietetic Association and Dietitians of Canada recommend pregnant and lactating women (along with all adults) consume at least 500 mg of omega-3s, including EPA and DHA, daily.

Other Vital Reasons Why Mediterranean-Style Diet Is a Good Choice

Aside from the important dietary components mentioned above, there are at least three other lifestyle factors that contribute to the benefits achieved by those actually living in the Mediterranean countries. The obvious one is that these are subtropical countries and most people are able to achieve a healthy level of sun exposure, as the opportunities to go outside with minimal clothing on are far more frequent than for most of us living in the U.S.

The other two are related in that they are social variable. There is less reliance on cars and automated tasks that allow them to walk and be more active and mobile than many of us in the U.S. Additionally, there is an important social component to most meals that is typically not encountered in the U.S.

Is There Something Better Than the Mediterranean Diet?

If you are healthy and have an ideal body fat percentage, then the dietary choices discussed above are a sound choice, especially if you integrate the other variables discussed in the section above.

But the sad reality is that well over 80 percent of those in the U.S. do not fit this profile, as they are either overweight, have cancer, heart disease, diabetes, autoimmune or neurodegenerative diseases. If this applies to you or someone you love, then I firmly believe you need to teach your body to burn fat as its primary fuel before you engage in this type of diet.

My new book, “Fat for Fuel,” discusses how to radically limit your carb and protein intake while integrating periods of feast and famine cycling, which will help your body regain its ability to burn fat as its primary fuel. Once you normalize your weight and other conditions, and your body has regained the capacity to burn fat as your primary fuel, then it makes loads of sense to shift to a Mediterranean diet.

The Role of Selenium in Cellular Health and Cancer Prevention

Micronutrients are incredibly important and vital to your health, but are you getting enough, and perhaps even more importantly, the right form? Mark Whitacre, Ph.D., is a leading expert on one of the most important micronutrients, selenium.

Story at-a-glance

  • At the cellular level, selenium is an active component of glutathione peroxidase, which has potent antioxidant properties and serves as a first line of defense against build-up of harmful free radicals in your cells
  • By reducing free radicals, selenium also helps reduce your risk of cancer. Studies show higher selenium levels can cut your risk of prostate cancer by as much as 63 percent, and lung and colon cancer by about 50 percent
  • For cancer prevention, the recommended dosage is 200 mcg of SelenoExcell® high selenium yeast per day. Avoid exceeding 400 mcg per day as toxicity may be an issue

Selenium is a trace element a Swedish chemist, Baron Jöns Jacob Berzelius, discovered almost 200 years ago. Today, modern scientists recognize it as an essential mineral for human health, with potent anti-inflammatory, antiviral and anti-cancer activity.

There are fewer than 100 selenium Ph.D. biochemists in the world. Whitacre received his master’s degree in nutrition at Ohio State University in Columbus, Ohio, in the late 1970s — a time when selenium was quickly becoming a hot topic.

“After I finished my master’s degree at Ohio State, I went to Cornell University to get my Ph.D. in nutritional biochemistry and to study under Gerald F. Combs Jr.[,Ph.D., who] was probably the leading authority in selenium research, and probably still is,” Whitacre says.

During his Ph.D. research at Cornell in selenium biochemistry, Whitacre researched the biochemical role of selenium in pancreatic cells. At the time, researchers were just starting to discover the biological necessities for selenium.

Selenium in Health and Disease Prevention

Selenium serves two very important and interrelated roles:

  1. At the cellular level, selenium is an active component of glutathione peroxidase, an enzyme that converts hydrogen peroxide to water. Glutathione peroxidase has potent antioxidant properties, and serves as a first line of defense against build-up of harmful free radicals in your cells.
  2. Selenium also plays an important role in the prevention of cancer. One of the reasons people get cancer is because of excessive free radical production. By reducing free radicals, selenium helps reduce your risk of cancer.

Excessive Iron + Selenium Deficiency = Bad News

Excessive iron can throw a wrench in the works here. By causing a Fenton reaction in the inner mitochondria, iron then reacts with hydrogen peroxide to form hydroxyl free radicals — the most dangerous type of free radicals known.

These excess free radicals can damage mitochondrial DNA, proteins and cell membranes and lead to dysfunction and ultimately premature death of the mitochondria.

This is why I recommend getting your iron level tested once a year, and to maintain a level between 20 and 80 nanograms per milliliter (ng/mL), and ideally between 40 and 60 ng/mL.

While anemia (low iron) can be a serious problem it is easily treated with iron supplementation. The vast majority of people actually have too much iron. The only people who typically do not are premenopausal women and children.

As a result of that excess iron, hydroxyl free radicals are catalyzed, and the situation is further worsened if you’re selenium deficient. A great example of the danger of high iron is thalassemia, a genetic condition that causes intrinsically high levels of iron.

I inherited this from my dad, who also has it. He developed hemochromatosis, (iron overload), which led to bronze diabetes — a specific subset of type 1 diabetes that results when high iron oxidizes your pancreatic islet cells.

Check Your Iron Levels Annually

As noted by Whitacre:

“Excessive iron does create some challenges. Actually, my Ph.D. thesis, looking at the biochemical role of selenium in the pancreatic cell … [showed that] chicks with selenium deficiency get pancreatic fibrosis …

Basically, once [the chicks were] 21 to 28 days [old], when they were selenium deficient on a purified diet, they wouldn’t survive at all … Most of that damage we saw early on — the earliest damage we can detect — was mitochondrial membrane [damage].

We could see the degeneration of that mitochondrial membrane … basically, the peroxide oxidizing and attacking those lipids … [The mitochondrial membrane] is really one of the areas that’s impacted first … because of the generation of free radicals inside the mitochondria.”

It’s important to realize that while selenium deficiency can worsen the situation, selenium will not optimize glutathione peroxidase production to the point of actually protecting you against excessive iron. So, you really need to check your iron levels and donate blood (phlebotomy), should your levels be elevated.

The Selenium-Cancer Connection

Since the 1980s, most of the selenium research has been in the area of cancer prevention. The first study was conducted by Combs, Whitacre’s thesis adviser at Cornell University.

The late Larry C. Clark, Ph.D., and former director of the Arizona Cancer Center’s epidemiology program at the University of Arizona, was another Cornell researcher.

“In 1983, which was my last year at Cornell, [Combs and Clark] started a 10-year study looking at 200 micrograms (mcg) per day of selenium supplementation using high selenium yeast compared to no supplementation …

They found … there was a 50 to 63 percent reduction in cancer rates in colon, lung and prostate, with the highest number of 63 percent rate reduction in prostate cancer …  

That was probably the first study that really looked at the impact of selenium supplementation on cancer reduction. Since that point, there’s been dozens of studies verifying that work,” Whitacre says.

“That work really emphasized … the thought that the glutathione peroxidase reducing free radical production was the biological role. There is some newer work that looks like there may possibly be another function … beyond the antioxidant role of glutathione peroxidase …

Most of the works since [then] has really been looking more at selenium form. That study used SelenoExcell high-selenium yeast, and there’s been several studies that have looked at sodium selenite [and] selenomethionine, and have not seen the same effect …  [F]orm does make a difference.

The SelenoExcell high-selenium yeast has been the most effective form. Matter of fact, selenomethionine had no effect in a very long term cancer research study published in 2011 called the SELECT trial …”

The Form of Selenium You Use Is Very Important

Interestingly, there does not appear to be a significant difference between selenium forms in regard to the amount of glutathione being produced. However, it makes a big difference when you’re looking at cancer incidence. Selenomethionine is a single amino acid where the selenium has replaced the sulfur in methionine. SelenoExcell high selenium yeast is the full protein form, and a more natural food form.

The selenium yeast gives you not just selenomethionine but also methylselenocysteine and selenocysteine. Research suggests methylselenocysteine may be the most active form in reducing cancer, and that’s the form found in high-selenium yeast. It’s not found in selenate, selenite or selenomethionine.

“When you look at the selenium bounty yeast, it does match with the selenium that you see in tuna, for example, or that you see in natural plant forms. It does match more the natural food form, which is in the complete protein form. We don’t know [whether] the protection of the protein makes it more effective, or [if it’s] the form itself that’s in the selenium yeast beyond selenomethionine.

The selenium in selenium yeast has been shown to be about 70 percent selenomethionine. But these other forms that are in the yeast form — and also in Brazil nuts — does have the methylselenocysteine and also selenocysteine that you don’t have in these other selenium forms.

It’s really thought at this stage that the mixture of these forms … like selenomethionine together with methylselenocysteine and selenocysteine, could possibly be the reason why it’s more effective than selenomethionine by itself at … 200 mcg.”

People With Higher Selenium Levels Have Lower Rates of Cancer

When it comes to food, Brazil nuts are an excellent source of selenium, and all you need is two to three per day to meet your daily requirement. Sadly, there have been no comparison studies done to assess the difference between Brazil nuts and selenium from bounty or extracted from yeast. That said:

“There have been studies showing that the lower the blood level of selenium — looking at individuals who consume foods that are higher in selenium compared to individuals who consume foods that are lower in selenium and therefore have very low selenium blood levels — [the] higher the rates of cancer. Those studies do exist,” Whitacre says.

If you use a supplement, you’ll typically find selenium combined with other antioxidants such as vitamin E. According to Whitacre, this is likely because they serve similar antioxidant functions, not because there’s any type of beneficial interactions between them, such as enhancing the absorption. For example, the SELECT trial looked at both vitamin E and selenium on cancer incidence.

That particular trial looked at the alpha form of vitamin E (alpha-tocopherol) and selenomethionine as the selenium source. Neither of these forms had an effect on cancer rates. This does not mean vitamin E and selenium are useless. It simply confirms that the devil’s in the details, so to speak. When it comes to selenium, you really should strive to get it from your whole food in order to reap maximum benefit.

Best Food Sources of Selenium

As a general rule, eating a variety of whole, unprocessed foods will naturally optimize your selenium levels (along with other important nutrients). Good food sources of selenium include:

Brazil nuts (which average about 70 to 90 micrograms per nut) Sardines Wild-caught Alaskan salmon
Pastured organic eggs Sunflower seeds Pasture-raised organic chicken and turkey
Liver (lamb or beef) Chia seeds Mushrooms

In most parts of the U.S., selenium levels in soil tend to be relatively high (northern Nebraska and the Dakotas have soil that is especially high in selenium). However, in other areas such as China, Russia, Australia, New Zealand and Europe, soil levels of selenium tend to be much lower, and if you eat food primarily grown in these areas, a high-quality selenium supplement may be beneficial. Even parts of the U.S. have been identified as selenium-deficient regions, including:

  • The Pacific Northwest
  • Parts of the Great Lakes region and east of it toward New England
  • Parts of the Atlantic Coast

If you live in one of these areas and focus your diet on locally grown foods, you may be low in selenium. You may also have low levels of selenium if you smoke cigarettes, drink alcohol, have had weight loss surgery or have Crohn’s disease or ulcerative colitis.

Dosage and Supplement Recommendations

Selenium is needed in very small, microgram amounts, which is a fraction of a milligram. More is not better here, as toxicity can become an issue. For cancer prevention, the recommended level is 200 mcg per day. Many studies have used as much as 400 mcg per day without ill effect. However, since most of the research supports the use of 200 mcg per day, and shows no significant benefits at higher amounts, I don’t recommend exceeding 200 mcg per day.

If you like Brazil nuts, eating about two to three of them per day will typically be sufficient. If you opt for a supplement, make sure to get the correct form. What you’re looking for is the high-selenium yeast form. SelenoExcell is the scientifically tested and most recommended version.

“There’s been a lot of research looking at other high-selenium yeast forms. The National Cancer Institute [NCI] required high selenium yeast — before it could be used in clinical trials — to be standardized. They … found that some of the high selenium yeast forms in the marketplace were really just taking yeast and supplementing sodium selenite. They were adulterated.

In 1998, the [NCI] signed a clinical trial agreement … with Cypress … that any cancer prevention trial that was going to use high-selenium yeast had to use the standardized form, which is SelenoExcell high-selenium yeast …

The trials that you see since that first trial published in 1996 by Clark and Combs … all the work since then, supported by the NCI, has been the SelenoExcell high-selenium yeast form. Not only does form make a difference — even [among] the high-selenium yeast forms there are some differences. I really want to emphasize that,” Whitacre says.

Selenium Is Important for Optimal Health and Cancer Prevention

The research is quite clear on this point: Making sure you’re getting enough selenium in your diet on a regular basis will help you achieve biological health and reduce your risk of cancer. Considering the fact that heart disease and cancer are both at epidemic levels in the Western world, cutting your risk by eating a few Brazil nuts or taking a high-selenium yeast supplement like SelenoExcell seems like a no-brainer.

As noted by Whitacre, many of the trials show higher blood selenium levels as a result of high selenium yeast supplementation can cut your risk of prostate cancer by as much as 63 percent, and lung and colon cancer by approximately 50 percent. Avoiding toxins and optimizing your vitamin D level, iron level and diet (reducing your net carbs and avoiding processed foods) will provide additional protection.

Faulty gene is a major cause of repeated miscarriages, say experts

Up to half of couples who suffer repeated miscarriages may be carrying a faulty gene, doctors have discovered

At least four in ten couples who suffer repeated miscarriages may be carrying a faulty gene, research has found, which can be successfully treated with drugs.

Doctors have found that a faulty gene can trigger miscarriages

Doctors have found that a faulty gene can trigger miscarriages

Fertility doctors have found that a faulty gene that can be carried by either parent can trigger miscarriages.

It is the first time it has been discovered that a gene carried by the father can cause miscarriage in the mother.

The fault causes improper blood clotting and can be treated with blood thinners such as aspirin and heparin.

One in four pregnancies ends in miscarriage but it is thought that recurrent miscarriages may be a bigger problem than infertility and may affect hundreds of thousands of couples.

Doctors at Care Fertility, the biggest private provider of IVF treatment, found the faulty gene, known as C4M2, in 44 per cent of their patients compared with just 15 per cent of the general population.

Prof Simon Fishel, managing director, said the gene could be a major cause of recurrent miscarriage.

With proper treatment the number of couples having healthy babies increased to 38 per cent, a similar proportion to other infertility patients of the same age.

The findings were published in the journal Reproductive Biomedicine Online.

The fault means the embryo is unlikely to implant in the womb and if it does it may do so insufficiently, causing late miscarriage or growth problems in the baby.

If the women is the carrier of the faulty gene she is also at risk of complications such as blood clots.

Prof Fishel, lead author on the publication, said “Very recently a new genetic marker has been found that predisposes couples to the risk of miscarriage, which we call the C4/M2 variant.

“In addition to the risk of implantation failure and miscarriage, it is linked to blood clotting disorders, pre-eclampsia and low birth weight babies.

“What I do find remarkable, is that in the population of patients studied, the man has the same chance as the woman to pass on this variant to the developing embryo and disturb successful implantation. Where the genetic variant exists, the chance of delivering a baby is reduced to one in four that of fertile couples.”

Care Fertility now intend to screen selected patients for the faulty gene so they can be treated appropriately.

Prof Fishel said: “Whilst this test is available for all patients undergoing IVF, we are focused on patients who have had recurrent miscarriage or failed implantation. The risk is the same whether the male or female carries the gene variant – so both partners need to be tested. We hope to increase the chance of pregnancy and live birth, decrease the risk of miscarriage and reduce the incidence of obstetric complications arising from this genetic mutation.”

The research found that couples with the gene who had IVF treatment without blood thinners, none had successful pregnancies. However of those with the gene who were treated, 38 per cent had successful pregnancies.

A spokesman for the Miscarriage Association said: “This adds to the growing evidence of the links between infertility and miscarriage, especially at the level of implantation.

“The study seems to show a clear difference between the affected parents who were treated and those who weren’t.

“We always welcome new research into factors that can increase the risk of miscarriage, so we’ll be looking closely at these findings with the help of our research expert advisors.”

Hope for future treatment of thousands of stroke sufferers from stem cells

Brain damage caused by strokes could be repaired thanks to a new treatment which could revolutionise the treatment for the deadly condition.

Thousands of lives a year could be changed thanks to the breakthrough by Imperial College which involves injecting a patient’s stem cells into their brain.

Colorised scanning electron microscope image of a blood clot

Colorised scanning electron microscope image of a blood clot

The treatment, that has been hailed as ‘one of the most exciting recent developments in stroke research’, gives new hope to the 152,000 who have strokes in Britain every year.

Doctors said the procedure could become routine in ten years after larger trials to examine its effectiveness in a wider group of patients.

Hopes have been raised of a future treatment to repair the damage caused by strokes after scientists found improvements in patients who had their own stem cells injected into the brain.

Lead author Dr Paul Bentley, from the Department of Medicine at Imperial College London, said: “Currently the main form of treatment is an unblocking of the blood vessel and that only helps one third of the patients who are treated and only ten per cent are eligible anyway.

“So we said what about the other 90 per cent?”

The team targeted patients who had suffered massive strokes involving a blood clot in the blood vessel in the middle of the brain. Typically there is a high mortality rate in these patients and those who survive are often severely disabled, are unable to walk, talk, feed or dress themselves.

The experimental procedure was carried out on five patients aged between 40 and 70, all of whom showed improvement over the following six months and three were living independently.

More than 152,000 people suffer a stroke in England per year and the research team said that the new procedure could eventually help most of them.

Dr Madina Kara, a neuroscientist at The Stroke Association, said: “Previous studies have shown that a type of stem cell, called CD34+ cells, shows promise to aid stroke recovery. These latest results suggest that this type of treatment could be administered safely and we’re looking forward to seeing the outcomes of further studies to see exactly how they are aiding recovery.

“This is one of the most exciting recent developments in stroke research; however, it’s still early days in stem cell research but the findings could lead to new treatments for stroke patients in the future.

“In the UK, someone has a stroke every three and half minutes, and around 58 per cenrt of stroke survivors are left with a disability.

“One of the few existing treatments which can limit brain damage caused by stroke is thrombolysis. However, this drug can only be used to treat strokes caused by blood clots and must be administered within the first 4.5 hours after a stroke. There is an urgent need for alternative treatments to help prevent the debilitating impact of stroke.”

The experimental procedure involves several stages, first the patient’s own bone marrow is harvested, which was then sent to a specialist laboratory so the specific stem cells, called CD34+ can be selected.

Then the patient undergoes a procedure in which a wire is inserted into a vein in the neck and up into the area of brain damage. Once there the stem cells are released and the wire retracted.

During the trial the whole process took half a day but it is hoped that with refinement this could be reduced.

It is thought the cells work in two ways, they grow into small blood vessels which allow the brain to grow new nerves and brain tissue surrounding them and also they release anti-inflammatory chemicals which encourage tissue repair.

Doctors said there are two ways the treatment could develop for use in routine cases. The patients could do through the exact same process in the first few days following their stroke, or the chemicals that the stem cells produce could be recreated and administered to stroke victims when they first arrive at hospital.

Dr Paul Bentley said: “If we find that the is the chemicals causing most of the improvement then it would be easier to inject those.”

Dr Soma Banerjee, a lead author and Consultant in Stroke Medicine at Imperial College Healthcare NHS Trust, said: “This study showed that the treatment appears to be safe and that it’s feasible to treat patients early when they might be more likely to benefit.

“The improvements we saw in these patients are very encouraging, but it’s too early to draw definitive conclusions about the effectiveness of the therapy. We need to do more tests to work out the best dose and timescale for treatment before starting larger trials.”

Professor Nagy Habib, principal investigator of the study, from the Department of Surgery and Cancer at Imperial College London, said: “These are early but exciting data worth pursuing.

“Scientific evidence from our lab further supports the clinical findings and our aim is to develop a drug, based on the factors secreted by stem cells, that could be stored in the hospital pharmacy so that it is administered to the patient immediately following the diagnosis of stroke in the emergency room.

“This may diminish the minimum time to therapy and therefore optimise outcome. Now the hard work starts to raise funds for this exciting research.”

Dr Tim Chico, Reader in Cardiovascular Medicine at University of Sheffield and a consultant cardiologist, said: “It is important to understand that this study is only the very earliest step towards a possible new treatment for stroke and does not prove the stem cell treatment improved these patients recovery.

“A much larger trial will be needed to compare stem cell treatment with no stem cell treatment. Anyone who has seen the suffering a stroke can cause will be encouraged that doctors and scientists are continually exploring new ways to treat this devastating disease. This study is only one small piece in a very large puzzle.”

Prof Robin Lovell-Badge, Head of Developmental Genetics, at the National Institute for Medical Research, said: “This is no more than a small safety trial, with such low numbers of patients that the authors themselves state: “this proof of concept study was not designed with a control group, or powered to be able to detect efficacy”.

“Although they mention some improvement of some of the patients, this could be just chance, or wishful thinking, or due to the special care these patients may have received simply because they were in a trial. There is no evidence about mechanism from pre-clinical (animal) studies and, although it is possible that the bone marrow cells produce factors that can aid recovery, I would prefer that further research was done on this prior to any larger trial being initiated, even if the current work showed no adverse effects.”

Apple-a-day as effective as statins

Eating an apple-a-day is an effective as statins at preventing deaths from strokes and heart attacks, Oxford University scientists has discovered.

Eating an apple-a-day is an effective as statins at preventing deaths from strokes and heart attacks, Oxford University scientists has discovered.

Previous studies have shown that apples are high in soluble fibre which slows the build-up of cholesterol-rich plaque in the arteries

The original 1866 proverb states: Eat an apple on going to bed, and you’ll keep the doctor from earning his bread.

But a study from Oxford University has shown than an apple-a-day really will keep the doctor away and is as affective as statins at preventing strokes and heart attacks.

Researchers have concluded that around 8,500 deaths could be prevented every year if over-50s who are not already taking statins ate one apple each day.

Previous studies have shown that apples are high in soluble fibre which slows the build-up of cholesterol-rich plaque in the arteries.

Apples also contain antioxodiants and flavanoids which are beneficial to health and boost the immune system.

Dr Adam Briggs of the BHF Health Promotion Research Group at Oxford University said: “The Victorians had it spot on when they came up with the clear and simple public health advice, ‘An apple a day keeps the doctor away’.

“It just shows how effective little changes in diet can be.

“While no-one currently prescribed medicine should replace them for apples, we could all benefit from simply eating more fruit.

“This study shows that small dietary changes as well as increased use of statins at a popuation level may significantly reduce vascular mortality in the UK.”

Apples also have fewer side effects than statins, which can raise the risk of diabetes and muscle weakness.

Researchers looked at previous studies which demonstrated the benefits of fruit consumption for cardiovascular health and decreased mortality. They then compared that to similar mortality figures for statins.

Around 5.2 million people are currently eligible for statins in the UK.

If everyone over the age of 50 was prescribed statins it would mean an extra 17.6 million people would take the drug – and 9,400 more deaths would be prevented each year.

Researchers assumed there would only be a 70 per cent compliance rate if apples were prescribed. But they said that even at that level it would prevent 8,500 deaths a year. If there was an100 per cent take-up it could prevent more than 12,000 deaths a year.

The report authors noted: “Prescribing either an apple a day or a statin a day to everyone over 50 yeas old is likely to have a similar effect on population vascular mortality.

“Choosing apples rather than statins may avoid more than a thousands excess cases of myopathy and more than 12,000 excess diabetes diagnoses.”

The authors found the only downside to prescribing apples in stead of statins would be that the fruit currently costs more.

Dr Peter Coleman, Deputy Director of Research at The Stroke Association said: “Apples have long been known as a natural source of antioxidants and chemical compounds called flavanoids, all of which are good for our health and wellbeing.

“This study shows that, as part of a healthy diet with plenty of fresh fruit and veg, a daily apple could help to reduce the risk of stroke and heart disease.

“Whilst it is vital that those who have been prescribed the cholesterol lowering-drugs, statins, continue to take this highly effective medication, everyone can lower their risk of stroke with simple lifestyle changes, like eating a balanced diet.”

The results were published in the British Medical Journal.

Older people ‘should exercise to build muscle even into their 80s’

Older people should exercise to build their muscles even into their eighties, according to a new review which suggests it will help them with everyday tasks.

Senior man, woman, couple exercising: Older people 'should exercise to build muscle even into their 80s'

Today’s over-50s are very different to the over-50s of previous generations

Climbing the stairs, housework, walking and even washing were made easier if elderly people worked out two or three times a week, researchers found.

People lose muscle as they age, which can make daily chores more difficult.

But working out by using small weights or elastic bands can help to rebuild these muscles, a review of the available evidence shows, while the risks of developing an injury are low for older people.

Chiung-ju Liu of the Department of Occupational Therapy at Indiana University, who carried out the study, said: “Older adults seem to benefit from this type of exercise even at the age of 80, and even with some type of health condition.

“The data support the idea that muscle strength is largely improved after the training, and the impact on older adults’ daily activities can be significant.

“Simply having enough strength to do things such as carrying groceries would make a difference for senior (citizens).”

The study, published by the Cochrane Library, looked at 121 trials, involving 6,700 people over the age of 60, all of whom exercised between two and three times a week.