New research finds the first evidence of a rogue protein in multiple sclerosis

In a new study published today in the journal Frontiers in Neurology, a team of researchers led by the University of Surrey, have identified a rogue protein in multiple sclerosis, which attacks the body’s central nervous system. Researchers believe this finding could pave the way for better understanding of multiple sclerosis and new treatments against neurodegenerative diseases.

Scientists have previously known that rogue proteins cause brain damage in other diseases of the brain such as Alzheimer’s, Parkinson’s and Creutzfeldt-Jakob disease.

In this study, scientists from the University of Surrey, University of Texas Medical Center and PrioCam Laboratories produced unique molecules, called antibodies, to fight against these rogue proteins. They discovered that these antibodies were able to recognise rogue proteins in Creutzfeldt-Jakob disease, as well as additional molecules associated with other neurodegenerative diseases.

The antibodies were then used to investigate whether rogue proteins existed in the brain tissue and spinal fluid of patients with . The scientists concluded that multiple sclerosis may be caused by a protein that permanently adopts a rogue state.

“Multiple sclerosis represents a substantial health burden, affecting the quality of life of many people,” said Dr Mourad Tayebi from the University of Surrey.

“Our discovery proposes a new and alternative way to conduct research into multiple sclerosis, by, for the first time, identifying a clear link to other . The results are important in redefining the molecular and cellular make-up of these diseases, and provides an important milestone in the quest for a laboratory test and an effective cure.”

Co-Senior author, Dr Monique David from the PrioCam, said, “Our research indicates that rogue proteins share a common structure and may share similar pathogenic mechanisms. This study consistently and reproducibly links the presence of abnormally shaped proteins to multiple sclerosis.”

CDC Endorses Circumcision for Health Reasons

U.S. health officials are poised to endorse circumcision as a means of preventing HIV and other sexually transmitted diseases.

The U.S. Centers for Disease Control and Prevention on Tuesday released its first-ever draft guidelines on circumcision that recommend that doctors counsel parents and uncircumcised males on the health benefits of the procedure.

The guidelines do not outright call for circumcision of all male newborns, since that is a personal decision that may involve religious or cultural preferences, Dr. Jonathan Mermin, director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, told the Associated Press.

Will Moving Help My Child’s Allergies?

But “the scientific evidence is clear that the benefits outweigh the risks,” Mermin said.

Circumcision involves the surgical removal of the foreskin covering the tip of the penis. Germs can collect and multiply under the foreskin, creating issues of hygiene.

Clinical trials, many done in sub-Saharan Africa, have demonstrated that circumcision reduces HIV infection risk by 50 percent to 60 percent, the CDC guidelines note. The procedure also reduces by 30 percent the risk of contracting herpes and human papilloma virus (HPV), two pathogens believed to cause cancer of the penis.

The guidelines do point out that circumcision has only been proven to prevent HIV and sexually transmitted diseases in men during vaginal sex. The procedure has not been proven to reduce the risk of infection through oral or anal sex, or to reduce the risk of HIV transmission to female partners.

The scientific evidence is mixed regarding homosexual sex, the guidelines say, with some studies having shown that circumcision provides partial protection while other studies have not.

Circumcision does reduce the risk of urinary tract infections in infants, according to the CDC guidelines.

The most common risks associated with the procedure include bleeding and infection.

Male circumcision rates in the United States declined between 1979 and 2010, dropping from almost 65 percent to slightly more than 58 percent, according to a CDC report issued last year.

The new draft guidelines mirror an updated policy on circumcision released by the American Academy of Pediatrics in 2012.

“The American public should take confidence that these are pretty much converging guidelines. There is no doubt that it [circumcision] does confer health benefits and there is no doubt it can be performed safely, with a less than 1 percent risk of complications,” Dr. Susan Blank, chair of the task force that authored the AAP policy statement, said Tuesday. “This is one thing a parent can do to protect the future health of their children.”

In its policy statement, the AAP declared that the health benefits are great enough that infant male circumcision should be covered by insurance, which would increase access to the procedure for families who choose it, said Blank, who is also assistant commissioner of STD Control and Prevention at the New York City Department of Health and Mental Hygiene.

“The push from the academy’s point of view is to really have providers lay out for parents what are the risks, what are the benefits, and give the parents the information they need to make a decision,” Blank said. “And the academy feels strongly that since there are proven health benefits, the procedure should be covered by insurance.”

The guidelines are expected to spur a response from anti-circumcision groups.

10 foods and drinks that make dentists wary.

It’s not just chewy lollies and fizzy soft drinks that are enemies of your pearly whites. Some of the foods and drinks that can cause trouble for your teeth will probably surprise you.


Visiting the dentist isn’t a favourite pastime for most of us. But taking care with what passes your lips might mean you can be spared some unpleasant – and often costly – interventions when your next dental trip comes around.

You might know there’s a dental sting with cakes and lollies, but did you realise chips, ice, curries, popcorn and wine can also cause havoc in your mouth?

Dr Peter Alldritt, chair of the Australian Dental Association’s oral health committee, shares 10 common food and drink items that many of us aren’t aware are potential troublemakers in the tooth department.

1. Diet soft drinks – They’re tempting for those wanting to sip on something sweet without the kilojoule hit of regular soft drinks. But while there’s no sugar to cause tooth decay, like regular soft drinks and even fruit juice, diet soft drinks still have high acid levels that can erode tooth enamel. This can lead to exposure of the inner tooth layer, causing pain and sensitivity, and it can also cause cavities. Brushing straight after drinking isn’t wise either as the acid can soften enamel, making it easier to brush away. If you must drink diet drinks, swish your mouth with water afterwards to wash the acid away. You could also sip them through a straw to minimise contact with your teeth.

2. Potato chips – They might start out crunchy but once chewed, they turn into a soft mess that can lodge and linger in the tiniest crevices on and between your teeth. What’s more, while we think of them as savoury, most chips are actually quite high in sugar Alldritt says, which means their tendency to stick around on your teeth is even more of a problem.

3. Ice – Do you get to the end of your ice-chilled drink and find those remaining ice cubes irresistible? Plenty of us do. But while sucking them is fine, biting them is not. Ice is so hard that biting it can easily chip off enamel or crack your teeth. If you can’t trust yourself to stop at sucking an ice cube, don’t take it into your mouth in the first place. Finish your drink and move it away from temptation.

4. Dried Fruit – Fruit is healthy and packed with vitamins and other nutrients. But suck the moisture out of it and you’re left with a sticky product made up of concentrated sugar entwined with bits of fibre that make it stick to the surface of your teeth. Also, some dried fruits, such as dried mangoes and craisins (dried cranberries), often have extra sugar added to boot. Eat dried fruit in moderation and brush well afterwards. But generally fresh fruit is a better choice.

5. Popcorn and corn on the cob – It’s made from popped corn kernels, so it can’t be too bad, right? Except when the popcorn is coated with coloured sugar dust or sticky toffee. Then it’s a “sugar bomb”, Alldritt says. Popcorn with no added sugar is dentally speaking, not a bad snack. That’s as long as you take care to floss out any bits that wedge between your teeth and don’t bite on any unpopped kernels, which can cause cracks and breaks in teeth. Biting into corn on the cob should also be approached with caution if you have crowns or large fillings on your front teeth, as the focused pressure may damage these. (You can always cut the kernels off the cob to eat them.)

6. Sports drinks – Sports drinks along with energy drinks are highly acidic and many are also high in sugar. An acid attack that can erode the enamel on your teeth generally lasts for around 20 minutes. Every time you take a sip of the drink, the acid damage begins all over again. Bear in mind too that unless you’re having a fairly long and intense workout, you probably don’t need the extra fuel and electrolytes a sports drink provides anyway.

7. Muesli bars – They look healthy with all those nuts, grains and oats. But the substance holding all that together into a bar is generally sugar, Alldritt says. The sugar makes every bite sticky, and it hangs around the grooves of your teeth a long time.

8. Wine – Wine – especially sparkling and white wine – contains erosive acid, which can soften the protective hard enamel on teeth. This acid can also leave teeth more vulnerable to staining, which can be a problem for those who enjoy red wine along with other heavily pigmented foods and drinks such as curries, coffee and tea. Alcohol, in general, causes dehydration, which means your mouth will have less of the saliva that protects your teeth from decay. It’s worth noting that heavy alcohol consumption is a risk factor for oral cancer.

9. Low-fat yoghurts – We tend to think of dairy foods as good for our teeth, but the low-fat varieties often contain a lot of added sugar. “The only way they can make yoghurt tasty with so much fat taken out of it is to bump up the sugar content,” Alldritt says. “And often the amount they add is outrageous. The result is a product that’s a disaster for teeth.” Some low-fat yoghurts have less sugar than others though, so check the labels. You could also consider choosing natural yoghurt and adding fresh fruit yourself for a bit of sweetness.

10. Bottled water – Bottled water is very popular. But when it comes to your teeth, the water that comes out of your tap is almost certainly a better choice. In fact, the Australian Dental Association says tap water should be the primary drink of choice for all of us. That’s because in most areas of Australia, tap water contains fluoride – a natural mineral that strengthens tooth enamel and protects against decay. Bottled water in comparison does not contain the amount of fluoride needed to protect your teeth. Choosing tap water will also save you a bundle as bottled costs around 2000 times more.

Artificial intelligence could spell end of human race – Stephen Hawking

Artificial intelligence could spell end of human race – Stephen Hawking
Technology will eventually become self-aware and supersede humanity, says astrophysicist

Prof Stephen Hawking has been in partnership with Intel for over 25 years.

Stephen Hawking
The development of artificial intelligence could spell the end of the human race, Professor Stephen Hawking has said.

The famous astrophysicist said he believed technology would eventually become self-aware and supersede humanity, as it developed faster than biological evolution.

Hawking told the BBC: “The primitive forms of artificial intelligence we already have, have proved very useful. But I think the development of full artificial intelligence could spell the end of the human race.”

Hawking – who as a result of his motor neurone disease is almost totally paralysed – also spoke of how he had received a “life-changing upgrade” to the computer software that allows him to communicate.

Hawking now uses a system that incorporates predictive text, allowing him to type twice as quickly as before and send emails ten times faster.

“I was finding it very difficult to continue to communicate effectively and so do the things I love to do,” he told a press conference in London for the launch of the new Intel software platform.

“With the improvements made, I am now able to write much faster and that means I can continue to give lectures, write papers and books, and, of course, speak with my family and friends more easily.

“Medicine has not been able to cure me, so I rely on technology to help me communicate and live,” he said.

Hawking has chosen to retain his familiar, slightly robotic sounding voice despite being offered something more natural.

“We are pushing the boundaries of what is possible through technology – without it I would not be able to speak to you today,” he said. “Intel’s research and development is bringing about changes in the world and in the way that disabled people can communicate.”


Hawking has been in partnership with Intel for over 25 years. His MND is related to amyotrophic lateral sclerosis. He was diagnosed in 1963, when he was 21, and given just two years to live. He turned 72 on 8 January 2014.

This is the first upgrade to his communications system for nearly 20 years. “I hope it will serve me well for the next 20 years,” he said.

The new ease with which Hawking speaks belies the effort he needs to expend to create even the simplest sentence. In order to be heard, he must first write a sentence using only a single muscle in his cheek, which is then sent to a voice processor.

To use the Intel software, an infrared sensor attached to his glasses allows Hawking to control the software by moving the muscle in his cheek. As he selects letters, predictive text offers him options for completing the word, which speeds up the process.

Using these predictions, he now needs to key only about 15-20 percent of the characters in any document. It has doubled his writing speed, which had gradually fallen to less than a word a minute after he lost the use of his hands and had to give up using a hand switch.

The software will be released to developers and researchers in January 2015, and will be made freely available to anyone who wishes to download it.

“Opening a document used to take 3-4 minutes. The new system uses a specific icon and takes about 10 seconds,” said Lama Nachman, principal engineer and project Leader at Intel. She spent many hours working with Hawking as he tested the software.

“I think he likes finding the bugs,” said Nachman, describing how he would smile every time he found a glitch in their Windows-based software.

“This software has the ability to help a much larger community of disabled people. So, to make that happen we decided to open-source the software. We are going to offer it for free to people from January next year,” said Nachman.

There are three million people afflicted with MND and quadriplegia. The software has been designed in a modular way that makes it customisable. It could be controlled by touch, eye blinks, eyebrow movements and other gestures. This means it could be tailored to the specific needs of other users.

• This article was amended on 3 December 2014. An earlier version said that Hawking was diagnosed with MND in 1961 rather than 1963.

Vitamin supplement successfully prevents noise-induced hearing loss

Researchers from Weill Cornell Medical College and the Gladstone Institutes have found a way to prevent noise-induced hearing loss in a mouse using a simple chemical compound that is a precursor to vitamin B3. This discovery has important implications not only for preventing hearing loss, but also potentially for treating some aging-related conditions that are linked to the same protein.

Published today in Cell Metabolism, the researchers used the chemical nicotinamide riboside (NR) to protect the nerves that innervate the cochlea. The cochlea transmits sound information through these nerves to the spiral ganglion, which then passes along those messages to the brain. Exposure to loud noises damages the synapses connecting the nerves and the hair cells in the cochlea, resulting in noise-induced .

The researchers set about trying to prevent this nerve damage by giving mice NR before or after exposing them to loud noises. NR was successful at preventing damage to the synaptic connections, avoiding both short-term and long-term hearing loss. What’s more, NR was equally effective regardless of whether it was given before or after the noise exposure.

“One of the major limitations in managing disorders of the inner ear, including hearing loss, is there are a very limited number of treatments options. This discovery identifies a unique pathway and a potential drug therapy to treat noise-induced hearing loss,” says Kevin Brown, MD, PhD, an associate professor of otolaryngology-head and neck surgery at the University of North Carolina School of Medicine and first author on the paper. Brown conducted the research while at Weill Cornell.

The researchers chose NR because it is a precursor to the chemical compound nicotinamide adenine dinucleotide (NAD+), which had previously been shown by Dr. Brown and co-senior author Samie Jaffrey, MD, PhD, to protect cochlea nerve cells from injury. However, NAD+ is an unstable compound, calling into question whether it could be used out of the petri dish and in a live animal. That led the scientists to use NR instead.

Methods for synthesizing NR were recently developed by Anthony Sauve, PhD, a professor of pharmacology at Weill Cornell and co-author of the study. This resulted in quantities of NR that were sufficient to test in animals.

“NR gets into cells very readily and can be absorbed when you take it orally. It has all the properties that you would expect in a medicine that could be administered to people,” said Dr. Jaffrey, a professor of pharmacology at Weill Cornell.

Beyond just preventing hearing loss, the researchers think the results may have broader applications because of the underlying way NR protects nerve cells. The scientists showed that NR and NAD+ prevent hearing loss by increasing the activity of the protein sirtuin 3 (SIRT3), which is critically involved in the function of mitochondria, the powerhouses of the cell.

The researchers hypothesized that it was this enhancement of SIRT3 that was behind the protective properties of NR. To test this, they manipulated SIRT3 levels independently of NR to see if they could still prevent noise-induced hearing loss by administering NR. Sure enough, deleting the SIRT3 gene in mice abolished any of the protective properties of NR. The researchers also showed that a new strain of mice, generated in the lab of co-senior author Eric Verdin, MD, at the Gladstone Institutes and engineered to express high levels of SIRT3, were inherently resistant to noise-induced hearing loss, even without administration of NR.

SIRT3 decreases naturally as we age, which could partially explain aging-related hearing loss. Additionally, some individuals carry different versions of the SIRT3 genes that result in reduced enzyme activity, which may make them more susceptible to noise-induced hearing loss.

Dr. Verdin, an investigator at the Gladstone Institute of Virology and Immunology and professor of medicine at the University of California, San Francisco, says, “The success of this study suggests that targeting SIRT3 using NR could be a viable target for treating all sorts of aging-related disorders—not only hearing loss but also metabolic syndromes like obesity, pulmonary hypertension, and even diabetes.”

Scientists make enzymes from scratch


Experts say they have achieved a scientific milestone – creating enzymes out of artificial genetic material that they made in their lab.

The synthetic enzymes functioned just as well as real ones.

The work, in Nature journal, not only provides clues to the building blocks of life but also points to a new way to make therapeutic drugs for humans.

The UK Medical Research Council team now hopes to make more complex structures that rival nature.

“Start Quote

I can see how there could be therapeutic strategies downstream if we can start to mimic nature and develop synthetic variants”

Prof Paul FreemontImperial College London

Genetic information

The ground work for the pioneering project started a couple of years ago when Dr Philipp Holliger and his team created synthetic versions of DNA and its chemical cousin RNA – the molecules that carry the basic genetic code of life.

Using these artificial XNAs as building blocks, the researchers set out to see if they could make synthetic enzymes – substances that drive a wide range of bodily functions, such as how we digest our food.

Dr Holliger explained: “Until recently, it was thought that DNA and RNA were the only molecules that could store genetic information and, together with proteins, the only biomolecules able to form enzymes.”

His team found it was possible to create enzymes from scratch using material that does not exist in nature.

Although entirely man-made, the synthetic enzymes are capable of building and breaking down molecules – just like naturally occurring ones.

test tubes

The “XNAzymes”, as the researchers call them, could jump-start simple reactions, such as cutting and joining RNA strands in a test tube.

“Start Quote

Life’s ‘choice’ of RNA and DNA may just be an accident of prehistoric chemistry”

Lead researcher Philipp Holliger

One of the XNAzymes joined XNA strands together – something that represents one of the first steps to creating a living system, say scientists.

Dr Holliger said: “Our work suggests that, in principle, there are a number of possible alternatives to nature’s molecules that will support the catalytic processes required for life. Life’s ‘choice’ of RNA and DNA may just be an accident of prehistoric chemistry.”

He said it was possible that life could be found on other planets, born from a molecular “backbone” other than DNA.

Back here on Earth, synthetic enzymes might be useful for treating human diseases such as cancer.

Dr Holliger explained that XNAs are ideally suited as a therapy.

Chemically, they are extremely hardy and, because they do not occur in nature, they can evade the body’s natural degrading enzymes.

“This might make them an attractive candidate for long-lasting treatments that can disrupt disease-related RNAs,” he said.

“And because we can modify chemistry at least to some extent to our hearts’ content, we can make tailor-made enzymes for particular purposes.”

Prof Paul Freemont, an expert in structural biology at Imperial College London, said: “I can see how there could be therapeutic strategies downstream if we can start to mimic nature and develop synthetic variants.

“What excites me more is the questions it raises about the origins of life. It provokes people to think that what we see on our planet is just one chemical possibility. It’s the pure challenge of the chemistry of life.”

Controversial DNA test comes to UK

The personal DNA test detects a range of gene variants

A personal DNA test that has sparked controversy in the US has launched in the UK.

The UK’s Medicines and Healthcare Products Regulatory Agency (MHRA) says the 23andMe spit test, which is designed to give details about a person’s health risks based on their DNA, can be used with caution.

But critics say it may not be accurate enough to base health decisions on.

The company, California-based 23andMe, stands by its test.

Backed by Google, the firm offered US customers details of health risks based on gene variants they carry.

But in November 2013, the US Food and Drug Administration (FDA)banned the company from marketing its service in the US, claiming 23andMe had failed to provide adequate information to support the claims it made about results.

A month later, the company stopped offering genetic tests related to health.

‘Think carefully’

An MHRA spokesperson said it regulated such tests in the UK to make sure they met minimum standards.

“People who use these products should ensure that they are CE marked and remember that no test is 100% reliable so think carefully before using personal genome services.

“If after using the service, you have any questions or concerns you should speak to your healthcare professional.”

She added: “If you are concerned that you have an incorrect result due to a faulty product, you can report this to MHRA at or  020 3080 7080.”

The UK Department of Health said it was behind the idea of using gene tests to guide patient care within the NHS, but echoed the MHRA advice on giving careful consideration before opting for services like the one offered by 23andMe.

The Alzheimer’s Society went a step further saying: “‘If you are worried about your memory, your GP should be the first port of call – not a home DNA testing kit. Research has identified a number of genes that may play a role in the development of dementia but we don’t know enough to use these as a diagnostic tool.”

23andMe chief executive Anne Wojcicki said: “The UK is a world leader in genomics and we are very excited to offer a product specifically for UK customers.”

Ms Wojcicki is separated from but still legally married to Sergey Brin, the co-founder of Google – which has invested millions in 23andMe.

The company had previously offered results on a customer’s risk for 254 diseases and conditions, including identifying genes linked to heart disease and breast cancer. There was also information on how individuals might respond to certain medicines.

“Start Quote

Genetic testing is an important medical tool in certain situations, but for healthy people as a way to predict common complex diseases, it’s pretty useless”

Dr Marcy DarnovskyCenter for Genetics and Society

But the FDA said the reliability of such tests had not been proven to its satisfaction. It was also worried that some customers could make life-changing decisions based solely on their results.

The UK Department of Health said the product launched in Britain was very different to the service halted by the US regulator.

“Many of the drug responses, inherited conditions and genetic health risks that were of concern in the US have been removed,” a spokesperson told BBC News.

In October, 23andMe said it would sell kits in Canada – these too contain only a handful of health-related results.

“I think a large part of it is trying to expand their markets,” said Professor Hank Greely, director of the Center for Law and the Biosciences at Stanford University in California.

“They may also want to make it clear to the public, to their investors, to their employees that they’re alive and kicking.”

What’s the plan?

Dr Marcy Darnovsky, executive director of the Center for Genetics and Society in California, said the UK and Canadian launches could be a way of placing pressure on the FDA by demonstrating that regulators in other countries found no fault with their product.

“Genetic testing is an important medical tool in certain situations, but for healthy people as a way to predict common complex diseases, it’s pretty useless,” she told BBC News.

“Most complex diseases and almost all the common ones – with some exceptions such as the BRCA 1 and 2 genes (implicated in breast cancer) – are multi-factorial with many genes and other biological, social and environmental causes.”

What happens to the data gathered by 23andMe also concerns some people. “It’s not entirely clear what their business plan is – whether they want to make money by selling kits to consumers, or whether they want to make most of their money by selling consumer data to other companies,” Prof Greely told BBC News.

But Ms Wojcicki believes the information provided to customers is empowering. “23andMe’s mission is to ensure that individuals can personally access, understand and benefit from the human genome,” she said.

Commenting on the announcement, Mark Thomas, professor of evolutionary genetics at University College London, said: “For better or worse, direct-to-the-consumer genetic testing companies are here to stay.

“One could argue the rights and wrongs of such companies existing, but I suspect that ship has sailed.”

Why are blood donors asked their sexual history?

The US Food and Drug Administration is considering lifting a ban on blood donations by men who have had sex with other men – even just once – since 1977. The blood is tested so what is the point of asking donors questions about their sexual history?

Vial of blood held by gloved hand

The ban was put in place as response to the spread of HIV and Aids in the gay community. But advances in testing and a better understanding of the disease mean the US is being urged to follow other countries, such as the UK, and allow gay men to donate blood as long if they have refrained from sex with another man for one year.

The 12-month deferral period is because it takes on average two to four weeks to pick up an HIV infection when testing blood and a couple of months to detect Hepatitis B. So the questions about a donor’s sexual history filter out potential infections – although they inevitably mean people with healthy blood are not allowed to donate.

The Answer

  • Men who have sex with men are more likely to have HIV
  • Blood is tested but it takes time to detect new infections
  • By asking questions, potential infections are filtered out

Although campaigners say they are enthusiastic about lifting the ban, they argue it does not go far enough. “Our goal is to eliminate sexual orientation from the deferral process and instead base the decision on an individual risk assessment,” says Ryan James Yesak, founder of the US National Gay Blood Drive.

He says male or female donors should instead be asked if they have had receptive anal intercourse in the last year. But Dr Steven Kleinman, senior medical adviser to the American Association of Blood Banks, says who you have sex with is a better risk indicator than what you’re doing with that person.

And in the US, he says, men who have sex with men make up the group in which HIV prevalence is highest. “Maybe the tool we use is crude – it’s not a fine scalpel but more of a sledgehammer. But if we use a fine scalpel, we might miss some people.”


Blood donation around the world:

  • UK, Japan and Australia have a one-year ban on men who have had sex with another man
  • Canada has a five-year ban
  • no ban in Italy, Mexico, Poland, Portugal, Russia and Spain, but some of those countries have tougher screening questions

Can You Turn Gray Hair Back With Nutrition?

You have some control over the premature graying of your hair, and you can restore your hair color with nutrition and nutritional supplements. According to Mehmet Oz and Michael Roizen, authors of “YOU: The Owner’s Manual,” you control up to 70 percent of how fast you age by the time you are 50 years old. Talk to your doctor before making dietary changes or taking a new vitamin supplement.

Can You Turn Gray Hair Back with Nutrition?

Step 1

Take 400 to 800 mcg of folic acid, also known as vitamin B-9, every day. Folic acid is an essential nutrient for maintaining healthy methionine levels in your body. Methionine is an amino acid and one of the building blocks needed for healthy hair. Gray hair is a sign of folic acid deficiency. A folic acid supplement will also help restore healthy texture to hair.

Step 2

Eat natural foods that contain folic acid. Foods rich in folic acid include spinach, broccoli, kale, green beans and cabbage.

Step 3

Take 25 to 50 mg of para-aminobenzoic acid, also called PABA, daily. According to Huntington College of Health Sciences, your natural hair color usually restores once you correct nutritional deficiencies, particularly PABA deficiencies.

Step 4

Take a vitamin B-12 supplement daily. According to Dr. Alan Greene, even young people can have gray hair if they have a vitamin B-12 deficiency. People with digestive disorders and anemia may have a problem absorbing vitamin B-12. The dietary reference intake established for vitamin B-12 is 2.4 mcg per day for people over the age of 14.

Step 5

Eat fortified cereals and animal meats to obtain your vitamin B-12 recommendation. Linus Pauling Institute recommends that those over 50 — and others who lack the ability to absorb vitamin B-12 — eat fortified cereals each day. This ensures a daily intake of 6 to 30 mcg of vitamin B-12, in a form the body readily absorbs. Beef, chicken, pork, trout, clams and oysters are also rich in vitamin B-12.

Climate change drove mastodons to the brink

Climate change played a pivotal role in the extinction of mastodons in North America, new radiocarbon dating of fossils has revealed — though hunting by people may have been the last straw.

Mastodons are the relatives of modern elephants and were widespread across North America from 1,25,000 years ago, going extinct around 10,000 years ago. Their disappearance coincides with the arrival of early humans on the continent, and has led to the “overkill” hypothesis that they were hunted to extinction by our species.

The new results, which are published in Proceedings of the National Academy of Sciences, suggest a more nuanced sequence of events.

Grant Zazula, a palaeontologist with the Yukon Palaeontology Program, and his colleagues have dated the collection of 36 fossil teeth and bones, found in Alaska and Yukon. They used a technique that targets the collagen in bone, avoiding contaminants such as varnish and glue that were applied many years ago to strengthen the specimens.

All of the fossils were found to be older than previously thought, with most older than the 50,000-year limit of radiocarbon dating.

The team concluded that mastodons were probably only living in the Arctic and Subarctic for a short time around 1,25,000 years ago. This was an interglacial period in which Arctic regions of North America were covered in forests and wetlands.

“The residency of mastodons in the north did not last long,” said Mr. Zazula, “The return to cold, dry glacial conditions along with the advance of continental glaciers around 75,000 years ago effectively wiped out their habitats.” The depleted population of mastodons moved south to escape the advancing ice.

They were just one of dozens of large mammalian species that went extinct around 10,000 years ago. Together they are known as the megafauna and include sabretoothed tigers and giant sloths.

Adrian Lister, research leader in palaeobiology at the Natural History Museum, London, says, “This is a very nice finding. Radiocarbon dating is the best technique we have for this. It seems perfectly reasonable that climate change knocked these populations down in number and to different regions.” From this weakened position, the mastodons had little reserve to resist meat-hungry humans.

“We’re not saying that humans were uninvolved in the megafauna’s last stand 10,000 years ago, but by that time — whatever the mastodon population was down to — their range had shrunken mostly to the Great Lakes region,” said Ross MacPhee, a curator in the Department of Mammalogy at the American Museum of Natural History and a co-author on the paper.