HIV-infected people live longer but are get age-related diseases hit them younger.


HIV-infected people live longer but are get age-related diseases hit them younger – The Washington Post
https://www.washingtonpost.com/national/health-science/hiv-infected-people-are-living-for-years-but-age-related-diseases-set-in-early/2018/04/13/ee26f74e-3120-11e8-8abc-22a366b72f2d_story.html?noredirect=on&utm_term=.2912fd7a9050

These ‘sea nomads’ are the first known humans to have a genetic adaptation to diving


These ‘sea nomads’ are the first known humans to have a genetic adaptation to diving
https://www.sciencealert.com/indonesian-bajau-genetic-changes-adapt-them-to-aquatic-lifestyle

Neuroscientist Claims that Adderall Is Exactly the Same As Meth.


Neuroscientist Claims that Adderall Is Exactly the Same As Meth – Awareness Act
http://awarenessact.com/neuroscientist-claims-that-adderall-is-exactly-the-same-as-meth/?=wuw

7 Things Outstanding Leaders Do Differently


7 Things Outstanding Leaders Do Differently

“A leader is best when people barely know he exists, when his work is done, his aim fulfilled, they will say: we did it ourselves.” ~ Lao Tzu

What makes some people stand out of the ordinary crowd as awesome leaders?

Why do these people live wonderful lives, while the rest just drag themselves from day to day?

7 Things Outstanding Leaders Do Differently

Great leaders shape history. Average people just get by. Greatness, however,  is simply a set of different behaviors and habits. You too can become great if you adopt them. Here’s what outstanding leaders do differently and how you can start implementing these habits into your own life.

1. They have a vision for their future

Outstanding leaders are the captains of their own boat called life. They know that the boat is following their directions and they take on the responsibility for giving those directions. They are the ones shaping the future by having a clear vision and taking 100% responsibility for whatever happens to them.

A man without a vision is like a boat without a destination. It just sails adrift in the middle of the ocean, being at the mercy of tides and waves.

All great leaders have a vision and they pursue that vision with tremendous passion. They know exactly what they want, so they are able to get others to follow them towards their desired outcome.

“Where there is no vision, the people perish.” ~ Proverbs 29:18

2. They stay true to themselves above anything else

Outstanding leaders follow their own inner guidance whenever faced with a decision. They know what’s best for them and they will do whatever they think it’s right, even in the face of adversity.

They speak their truth and they act according to what they feel to be true, even with the risk of offending others. Outstanding leaders are authentic and congruent. That’s how they gain other people’s trust so easily. They aren’t afraid to expose themselves just as they are – with both strengths and weaknesses.

They admit they are human and can make mistakes. They cherish their imperfection and use it as an asset. Above all, they value their individuality and aren’t afraid to show it, even to those who disagree.

Outstanding leaders stay true to themselves, even if others demand compliance. They know they are the only person worth appealing. They have a very strong inner validation system that guides them, so they don’t need the approval of others.

“Before you are a leader, success is all about growing yourself. When you become a leader, success is all about growing others.” ~ Jack Welch

3. They persevere in the face of obstacles

One of the most important traits of outstanding leaders is their ability to slide over setbacks and rejections. Many outstanding leaders have faced rejections before they managed to get their ideas through. Nonetheless, they persevered and succeeded.

What got them to success was their mindset. They viewed obstacles as challenges and growth opportunities, not as indicators to quit. Instead of stopping them, obstacles had the exact opposite effect: they made them even more determined to succeed and to prove they were right and others were wrong.

Great leaders don’t focus on problems and rejections. Instead, they focus on solutions and what they can learn and do better next time. They don’t take setbacks personally. They know that they are right – their internal validation system tells them that – and they do everything needed to convince the world of that fact.

4. They act with courage despite having fear

Outstanding leaders are admired for their courage. Many people who have displayed great courage have remained in history as heroes.

But what made these people different wasn’t their lack of fear. On the contrary. They felt fear just like any other human being. What set them apart was their ability to feel that fear and act despite having it.

Outstanding people have the same fears, doubts, inner conflicts and mixed emotions like everyone. But they have learned to follow their vision, no matter what they feel. They know they’re taking action for a bigger cause and that vision inspires them to keep going even in the face of fear.

It’s not that they ignore their fear. In fact, they acknowledge it – since they admit their weaknesses and are comfortable with exposing vulnerability – but they do whatever is more important for them and they don’t allow fear to paralyze them to inaction. They use fear as a catalyst that propels them in the desired direction.

5. They anticipate obstacles and find solutions

Outstanding leaders have a plan. They don’t just jump into things unprepared. They carve out a path towards their goal. Furthermore, they attempt to predict what can go wrong on their path, so that they can be prepared for any situation.

But they don’t start thinking of all the things that can work out badly and find ways to counter them. It would consume too much energy and time. Besides, one can think of a million reasons why things could go wrong. That’s not the purpose.

Outstanding leaders have learned to use their common sense and anticipate challenges. They do that by observing how things work and relate to another. They have a realistic view and avoid over- or underestimating their current circumstances. They don’t get too excited, nor do they become paranoid. They succeed in looking at circumstances, situations, and people and seeing them just as they are.

Their ability to think clearly and not be limited by beliefs allows them to accurately anticipate obstacles and find solutions in advance.

6. They spend time on things which matter most

Outstanding leaders are very efficient. And they have the exact same 24 hours per day like everyone else does. The difference is in their ability to manage time.

Outstanding leaders spend the most time on those activities which matter to them and bring them greatest fulfillment. Since they have a vision with a plan, they know exactly what to do to make it a reality. So they invest energy in making things happen and in creating a meaningful life.

On the flip side, average people spend time in activities which distract their attention and don’t bring them any long-term gains. They just seek instant gratification and pleasure as much as possible.

Outstanding leaders will often sacrifice short-term pleasure for long term gain because they know that’s where real happiness comes from. They have learned to delay their gratification while keeping an eye on the vision and taking massive action which brings them closer to living their dreams.

“Management is about arranging and telling. Leadership is about nurturing and enhancing.” ~ Tom Peters

7. They are constantly improving

Outstanding leaders don’t settle for what they have. They seek to constantly expand themselves, they are continuously learning new skills and developing their abilities. Outstanding leaders are perpetual students and they never get tired of learning.

They also never stop dreaming and setting goals for themselves. They have a permanent vision of how their ideal life looks like and they are always updating this image, as soon as they get close to reaching it.

Outstanding leaders set very high standards for themselves. Whenever they’re close to reaching their goals, they set new ones, so they can keep moving further and further. They are expanding and growing and constantly seeking new challenges to face and new ways to push their comfort zone.

Unlike average people who settle for comfort, outstanding leaders embrace challenges, because they know these are the prerequisites for lasting growth and satisfaction.

“The growth and development of people is the highest calling of leadership.” ~ Harvey Firestone

Your turn

Take one step at a time and make these changes permanent in your life. What will you do starting today to become an outstanding leader? I really want to know what are your thoughts on this. You can share your insights by joining the conversation in the comment section below :)

 

Sharing is caring!

Metastatic visceral calcification identified by bone scanning.


Abstract

The scintigraphic abnormalities with radionuclide bone scanning observed in a patient with metastatic breast carcinoma associated with hypercalcaemia are described. Abnormal uptake of 99mTc-pyrophosphate was noted in the lungs, stomach, myocardium, kidneys, and thyroid, indicating metastatic visceral calcification. A scan performed 72 h later when she was normocalcaemic showed marked reduction in the accumulation in the myocardium and thyroid. In a further scan, 18 months later, no extraosseous uptake was present. A review of 26 reported cases of visceral metastatic calcification with scintigraphic abnormalities indicates that the changes in this patient were more widespread and that in only two of the previous cases similar total resolution had been observed. The reasons for the discrepancy between the incidence of visceral calcification on autopsy and on scintigraphic examination are discussed in relation to the aetiological factors. It is concluded that bone scanning offers a useful method for identifying visceral calcification, except when associated with uncomplicated renal failure, and is valuable in detecting this abnormality in patients with hypercalcaemia and in the assessment of response to therapy.

Learning to Live in Alignment with Your Life Purpose


Learning-to-Live-in-Alignment-with-Your-Life-Purpose

“Your life has an inner purpose and an outer purpose. Inner purpose concerns Being and is primary. Outer purpose concerns doing and it is secondary. Your inner purpose is to awaken. It is as simple as that. You share that purpose with every other person on the planet – because it is the purpose of humanity. Your inner purpose is an essential part of the purpose of the whole, the universe and its emerging intelligence. Your outer purpose can change over time. It varies greatly from person to person. Finding and living in alignment with the inner purpose is the foundation for fulfilling your outer purpose. It is the basis for true success. Without that alignment, you can still achieve certain things through effort, struggle, determination, and sheer hard work or cunning. But there is no joy in such endevor, and it invariably ends in some form of suffering.” ~ Eckhart Tolle

The world we live in nowadays and the way we spend most of our time keep many of us from reflecting on the meaning of life, from contemplating on the reason of our existence and from getting to know who we truly are deep down inside.

We’re running around like crazy people, constantly doing something, keeping ourselves busy and bragging with how hard we work, but we rarely stop to think whether all these things we are doing and all this hard work is increasing our happiness, or is amplifying the stress, anxiety, and unhappiness that is already present in our lives. 

Living in this world sometimes scares me because at times it feels as if we have forgotten how to think our own thoughts, how to have our beliefs and ideas and how to a life that we can honestly call our own. We’re copying everyone else’s behaviors and we’re doing whatever everyone else is doing, failing to realize that we weren’t born to be like everyone else. We weren’t born to do what everyone else is doing and we weren’t born to be a second rate version of someone else.

I don’t know why the world is as it is and why we care so little about honoring ourselves and living our lives with integrity but what I do know is that we are all here for a reason and those who dare to look for this reason will eventually find it. And when they do, their whole lives will be transformed and even though from the outside it will look as if they are part of the “lucky” ones, they will know that luck has nothing to do with it. And they will know that if they deserve to live a beautiful, abundant, happy and loving life, so does everyone else.

The Spice of Death: The Science behind Tainted “Synthetic Marijuana”


Experts describe how rat poison linked to a recent bleeding outbreak does its damage

The Spice of Death: The Science behind Tainted "Synthetic Marijuana"
Synthetic Marijuana, or K2.

Three people died and more than 100 have been sickened in the past few weeks after taking synthetic cannabinoids, human-made compounds that target the same brain receptors as marijuana. Symptoms documented by poison centers—first mostly in the Midwest, and now in Maryland—include unexplained bruising, coughing up blood, bleeding from the nose and gums, blood in urine and feces, and excessively heavy menstruation.

An ongoing investigation has identified a likely culprit in the blood of those affected: rat poison, specifically brodifacoum. Commonly sold in hardware stores, it is a dangerous anticoagulant that can also cause brain damage.

These are the first known instances of rat poison being found in synthetic cannabinoids—and how the toxin got there is unknown. Douglas Feinstein, a neuroscientist and brodifacoum expert developing new antidotes to this substance at the University of Illinois at Chicago, says the symptoms in these cases indicate high levels of exposure. That makes accidental contamination unlikely, he says, and suggests the poison may have been introduced deliberately. “We don’t know the exact doses these people are getting, but it’s a lot,” says Feinstein, who is hoping to analyze blood samples from those affected.* “It could have been added intentionally to prolong the high.”

That may seem like the stuff of urban legends. But Feinstein cites previous case studies, reported in the scientific literature, of drug users deliberately ingesting rat poison to stay high longer when taking marijuana or cocaine. The toxin ties up liver enzymes that metabolize drugs, extending their effects.

Feinstein—whose work is funded by the National Institutes of Neurological Disorders and Stroke’s CounterACT Program, tasked with developing countermeasures against chemical threats—added that malicious intent cannot be ruled out. He also speculated the drugs themselves could have exacerbated the poisoning if they dilated blood vessels.

Little is known about what synthetic cannabinoids themselves do to the body. Many of these compounds were developed experimentally in the 1980s by scientists studying the brain and trying to develop new analgesics. The ones now found in the U.S. are often made in China, and can be purchased online. Known by a wide variety of names including “Spice” and “K2,” they are typically sprayed on various herbs and sold as a smoking mixture, sometimes labeled as incense.

Authorities have arrested a convenience store owner in Chicago for allegedly selling some of the contaminated material linked to the current poisoning outbreak. Bruce Anderson, executive director of the Maryland Poison Center, says he was told the poisoned Maryland resident purchased the product that made them ill “at a local store.” He warns these substances are poorly understood, and can be perilous even when not tainted; the new cases comprise the latest chapter in an ongoing public health crisis, as people increasingly chase a buzz from numerous chemicals developed for scientific research and readily available on the internet or dark web. “None of these products have ever been tested on humans,” Anderson notes. “Using them is a spectacularly bad idea.”

Typically cheap and invisible to traditional drug screening, synthetic cannabinoids have been especially popular among the poor and incarcerated. A 2014 study flagged these chemicals as a popular drug of choice among military personnel dealing with substance abuse.

Poison control centers receive thousands of calls about synthetic cannabinoids every year, and they usually have nothing to do with rat poison. Emergency room doctors have documented a confusing array of problems among users: seizures, strokes, brain bleeding and heart attacks. In 2016 several dozen New Yorkers wound up in hospitals, unresponsive to the outside world, after reportedly using these drugs. Earlier this year dozens of U.S. soldiers and Marines were hospitalized after allegedly vaping synthetic cannabinoid oil. “The side-effect profile of these compounds is unknown,” says William Burgin, a neurologist and professor at the University of South Florida. “It’s bag of nightmares for those dealing with patients on the frontlines.”

Tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, binds to cannabinoid receptors in the brain and body rather weakly, Burgin says. But some molecules in the synthetic chemicals hold on with an iron grip; they can be hundreds of times more potent than natural pot. Their chemical structures often bear little resemblance to THC, and that is part of what makes them difficult to regulate. In 2011 the U.S. Drug Enforcement Agency banned five of the earliest such compounds to hit the streets, and in 2012 Congress passed the Synthetic Drug Abuse Prevention Act outlawing 15 chemicals. Makers responded with creative chemistry, crafting other molecules that have similar effects and thus staying one step ahead of the law, says Jeff Lapoint, director of the Division of Medical Toxicology at Kaiser Permanente San Diego Medical Center. The exact formula in the drugs recently found to be tainted with rat poison remains unclear.

“It’s like a game of Whac-A-Mole: Make one thing illegal, and the next week something new pops up,” Lapoint says. Authorities at the state level are also trying to crack down. But this is “happening in a piecemeal fashion and varies from state to state,” says Stefanie Jones, director of audience development at the Drug Policy Alliance, a nonprofit organization that advocates for drug law reform.

Lapoint says he has purchased packets of these drugs and analyzed their contents. The compounds he found within varied wildly, and he says those who choose to use them can never really have any idea what they might be putting into their bodies. “It’s like playing Russian roulette,” he says. “You don’t know what you’re getting or how much you’re getting or what these chemicals will do.”

Escape from Proxima b


A civilization in the habitable zone of a dwarf star like Proxima Centauri might find it hard to get into interstellar space with conventional rockets

Escape from Proxima b
Artist’s impression of the exoplanet Proxima Centauri b.

Almost all space missions launched so far by our civilization have been based on chemical propulsion. The fundamental limitation here is easy to understand: a rocket is pushed forward by ejecting burnt fuel gases backwards through its exhaust. The characteristic composition and temperature of the burnt fuel set the exhaust speed to a typical value of a few kilometers per second. Momentum conservation implies that the terminal speed of the rocket is given by this exhaust speed times the natural logarithm of the ratio between the initial and final mass of the rocket.

To exceed the exhaust speed by some large factor requires an initial fuel mass that exceeds the final payload mass by the exponential of this factor. Since the required fuel mass grows exponentially with terminal speed, it is not practical for chemical rockets to exceed a terminal speed that is more than an order of magnitude larger than the exhaust speed, namely a few tens of kilometers per second. Indeed, this has been the speed limit of all spacecraft launched so far by NASA or other space agencies.

By a fortunate coincidence, the escape speed from the surface of the Earth, 11 kilometers per second, and the escape speed from the location of the Earth around the sun, 42 kilometers per second, are close to the speed limit attainable by chemical propulsion. This miracle allowed our civilization to design missions, such as Voyager 1 and 2 or New Horizons, that could escape from the solar system into interstellar space. But is this fortune shared by other civilizations on habitable planets outside the solar system?

Life “as we know it” requires liquid water, which can exist on planets with a surface temperature and a mass similar to Earth. Surface heating is needed to avoid freezing of water into ice and an Earth-like gravity is needed to retain the planet’s atmosphere, which is also essential, since ice turns directly into gas in the absence of an external atmospheric pressure. Just next door to Mars, which has a tenth of an Earth mass and lost most its atmosphere long ago.

Since the surface temperature of a warm planet is dictated by the flux of stellar irradiation, the distance of the habitable zone around any arbitrary star scales roughly as the square root of the star’s luminosity. For low mass stars, the stellar luminosity scales roughly as the stellar mass to the third power. The escape speed scales as the square root of the stellar mass over the distance from the star.

Taken together, these considerations imply that the escape speed from the habitable zone of a star scales inversely with stellar mass to the power of one quarter. Paradoxically, the gravitational potential well is deeper in the habitable zone around lower mass stars. A civilization born near a dwarf star would need to launch rockets at a higher speed than we do in order to escape the gravitational pull of its star, even though the star is less massive than the Sun.

As it turns out, the lowest mass stars happen to be the most abundant of them all. It is therefore not surprising that the nearest star to the sun, Proxima Centauri, has 12 percent of the mass of the sun. This star also hosts a planet, Proxima b, in its habitable zone at a distance that is 20 times smaller than the Earth-Sun separation. The escape speed from the location of Proxima b to interstellar space is about 65 kilometers per second. Launching a rocket from rest at that location requires the fuel-to-payload weight ratio to be larger than a few billions in order for the rocket to escape the gravitational pull of Proxima Centauri.

In other words, freeing one gram’s worth of technological equipment from the position of Proxima b to interstellar space requires a chemical fuel tank that weighs millions of kilograms, similar to that used for liftoff of the space shuttle. Increasing the final payload weight to a kilogram, the scale of our smallest CubeSat, requires a thousand times more fuel than carried by the space shuttle.

This is bad news for technological civilizations in the habitable zone of dwarf stars.

Their space missions would barely be capable of escaping into interstellar space using chemical propulsion alone. Of course, the extraterrestrials (E.T.s) can take advantage, as we do, of gravitational assists by optimally designing the spacecraft trajectory around their host star and surrounding planets.

In particular, launching a rocket in the direction of motion of the planet would reduce the propulsion boost needed for interstellar escape down to the practical range of 30 kilometers per second. The E.T.s could also employ more advanced propulsion technologies, such as light sails or nuclear engines.

Nevertheless, this global perspective should make us feel fortunate that we live in the habitable zone of a rare star as bright as the sun. Not only that we have liquid water and a comfortable climate to maintain a good quality of life, but that we also inhabit a platform from which we can escape at ease into interstellar space. We should take advantage of this fortune to find real estate on extrasolar planets in anticipation of a future time when life on our own planet will become impossible.

This unfortunate fate will inevitably confront us in less than a billion years, when the sun will heat up enough to boil all water off the face of the Earth. With proper planning we could relocate to a new home by then. Some of the most desirable destinations would be systems of multiple planets around low mass stars, such as the nearby dwarf star TRAPPIST-1 which weighs 9 percent of a solar mass and hosts seven Earth-size planets.

Once we get to the habitable zone of TRAPPIST-1, however, there would be no rush to escape. Such stars burn hydrogen so slowly that they could keep us warm for ten trillion years, about a thousand times longer than the lifetime of the sun.

Slow-Motion Ocean: Atlantic’s Circulation Is Weakest in 1,600 Years


If hemisphere-spanning currents are slowing, greater flooding and extreme weather could be at hand

Slow-Motion Ocean: Atlantic's Circulation Is Weakest in 1,600 Years

In recent years sensors stationed across the North Atlantic have picked up a potentially concerning signal: The grand northward progression of water along North America that moves heat from the tropics toward the Arctic has been sluggish. If that languidness continues and deepens, it could usher in drastic changes in sea level and weather around the ocean basin.

That northward flow is a key part of the larger circulation of water, heat and nutrients around the world’s oceans. Climate scientists have been concerned since the 1980s that rising global temperatures could throw a wrench in the conveyor belt–like system, with possibly stark climatic consequences. Sea levels could ratchet upward along the U.S. east coast, key fisheries could be devastated by spiking water temperatures and weather patterns over Europe could be altered.

Such concerns had been quelled over the last decade as climate models suggested this branch of the ocean’s circulatory system was not likely to see a rapid slowdown, which would slow any consequences. But two new studies, published Wednesday in the journal Nature, suggest the recent weakening spotted by ocean sensors is not just a short-term blip, as some had thought. Rather, it is part of a longer-term decline that has put the circulation at its weakest state in centuries. The results imply climate models are missing key pieces of the puzzle, and that ill effects could be on their way.

Which pieces might be missing, though, could determine how worrying this trend is. If models are not sensitive enough to the changes going on in the North Atlantic, “that sort of puts the warning flag a little higher,” says Thomas Delworth, an ocean and climate modeler at the National Oceanic and Atmospheric Administration who was not involved in the research.

The Atlantic meridional overturning circulation (AMOC) and the subpolar gyre, where ocean waters cool when the AMOC weakens. Credit: Nature

Running AMOC

The warm, salty waters of the tropical Atlantic cruise northward along the eastern U.S. before darting toward northwestern Europe (giving the British Isles a climate far balmier than Newfoundland at a similar latitude). As that segment of ocean flow, known as the Gulf Stream, pushes north, it cools and becomes denser and eventually sinks, forming the so-called deepwater that flows back southward along the ocean floor toward Antarctica.

This cycle, called the Atlantic Meridional Overturning Circulation (AMOC), plays a key role in moving heat around the planet as well as nutrients throughout the ocean. It also helps draw carbon dioxide from the atmosphere into the sea. In the Pacific Ocean equatorial heat is transported north and south toward both poles. But in the Atlantic “the heat is moving northward throughout the whole Atlantic Ocean,” says David Thornalley, a paleo-oceanographer at University College London and co-author of one of the new studies. The resulting heat imbalance between the Northern and Southern hemispheres determines several large climatic features, such as the latitude at which a key tropical rain belt is located, which impacts water supplies, precipitation for agriculture and the health of tropical ecosystems.

As global temperatures rise with the levels of heat-trapping gases in the atmosphere, the AMOC could be disrupted by an influx of freshwater from increasing precipitation in the North Atlantic and the melting of sea ice and glaciers on land. The added freshwater lowers the water density in the zone where deepwater forms, backing up and weakening the overall flow of the AMOC like a clogged sink. That slowdown means less heat is transported northward, leading to cooler ocean temperatures in a region below Greenland, and warmer temperatures off the U.S. east coast. That warming leads to higher sea levels along the coast and raises sea temperatures where economically valuable cold-loving species like cod and lobster live.

There are some indications the cold spot below Greenland can alter atmospheric patterns in a way that channels warm air over Europe, increasing the likelihood of sustained summer heat waves, says Levke Caesar, a PhD student at the Potsdam Institute for Climate Impact Research (PIK) and co-author of the other new study. The changing ocean temperatures from an AMOC slowdown could also potentially help lock in colder winter conditions over the eastern U.S., PIK’s Stefan Rahmstorf, a co-author of the same research, has posited, although the evidence there is not clear.

Until a little more than 10 years ago scientists did not have any direct measurements of the AMOC to see how it was actually responding to climate change. The deployment of the RAPID array of instruments (short for the U.K and U.S.–sponsored Rapid Climate Change program) across the Atlantic Basin has allowed that data to slowly trickle in, and “they’ve been revealing it is undergoing weakening,” Thornalley says. But the brief window of data offers no longer-term perspective. When that first data came in, scientists thought the weakening could be a temporary change resulting from the natural ups and downs of the climate, but were aware it could be part of a much longer decline.

Clues from the Past

To help resolve the uncertainty, the teams involved with the new studies turned to what are called paleoclimate markers, which capture past changes in Earth’s climate to see how these recent changes fit in. Thornalley and his colleagues used sediment cores collected from the ocean floor along the U.S. east coast to reveal how deep ocean currents linked to the AMOC have changed over time; stronger currents deposit larger grains of sediment. They also looked at tiny creatures fossilized in sediment cores—some of which had thrived in colder conditions, others in warmer ones—to see how ocean temperatures changed as the AMOC waxed and waned in strength. Caesar and Rahmstorf’s study used direct measurements of ocean temperatures going back to the late 19th century.

The two studies came to broadly similar conclusions: The AMOC is in a very weakened state—the most anemic it has been in the last 1,600 years, according to Thornalley’s results.

The studies differ on the timing of when that weakening began. Thornalley’s record, which spans those 1,600 years, suggests it started at the end of the little ice age, a period from about A.D. 1350 to 1850, when solar and volcanic influences depressed temperatures across the Northern Hemisphere and glaciers and ice sheets expanded. As the little ice age ended and temperatures warmed, ice melted and freshwater flooded into the North Atlantic. The results suggest the current state of the AMOC is the weakest it has been over that whole long record. Whether today’s state is just a continuation of that reaction or whether global warming has also started to chip in is not clear, he says. Caesar, meanwhile, put the turning point toward a weaker AMOC in the mid-20th century, suggesting it is due to the influence of human-caused warming. Her team’s record, however, does not extend as far back.

The two results are not mutually exclusive. Both records show broadly similar patterns in decline. “We think it’s quite remarkable that all the evidence is converging,” Thornalley says. But pinpointing the timing of the weakening trend would give better clues as to what is driving it as well as how quickly it is happening and how rapidly we might expect to see some of the resulting climate impacts.

Already, Thornalley says, it is clear the Gulf of Maine has its warmest temperatures in the last 1,600 years. There are also “tantalizing glimpses” of more rapid sea level rise along the U.S., he says.

The researchers are curious why climate models seem to be missing something in the AMOC process. They do not capture this past behavior and significant weakening. If the results of these studies bear out, Delworth says, it is possible the models are not sensitive enough to the changes in ocean freshwater that are happening or they are not factoring in all of the important changes that have impacted the circulation. A 2017 study that looked at what would happen if climate models did factor in that melt saw it caused a sharper response from the AMOC than had otherwise been suggested.

The greater cause for concern would be if models are incorrectly capturing the sensitivity of the system, Delworth says, because it means scientist have been underestimating how quickly the AMOC might respond. “It really depends on why the models don’t match the paleo results,” he says.

While modelers work to figure that out, Thornalley and others are trying to expand the paleoclimate record to see if the pattern they found shows up at other sites throughout the Atlantic and if they can extend it farther back in time. They are also looking for signs of how much freshwater may have triggered the weakening at the end of the little ice age.

Moving forward, the RAPID instruments will slowly help tease out the AMOC’s behavior. “It’s just that we have to wait a couple of years,” Caesar says, by which time some impacts may already be happening.

Another Nail in the Coffin for Fish Oil Supplements


More people than ever take fish oil dietary supplements—around 8% of US adults in 2012 compared with around 5% five years earlier, according to the National Center for Health Statistics. But a recent meta-analysis of 10 large clinical trials came to a disappointing conclusion: The popular capsules do little to protect patients with heart disease. The findings are at odds with advice from the American Heart Association (AHA), including a 2017 science advisory recommendation to consider fish oil supplementation for patients with a recent myocardial infarction, or heart attack.

Image description not available.

The new meta-analysis, published in JAMA Cardiology in January, looked at randomized trials of marine-derived omega-3 fatty acid supplements involving almost 78 000 participants with a history of coronary heart disease (66%), stroke (28%), or diabetes (37%). The trials lasted an average of 4.4 years and compared fish oil with placebo or no treatment in at least 500 participants.

All told, fish oil supplements did not reduce the risk of coronary heart disease deaths, nonfatal heart attacks, fatal or nonfatal strokes, revascularization procedures, or all-cause mortality among the full study population. The supplements also didn’t protect against major vascular events in any subgroups, including people with a history of heart disease, diabetes, high cholesterol, or statin use.

Parsing the effects of fish oil supplementation in prespecified disease subtypes and participant subgroups is something that wasn’t previously possible with the published data sets, said Robert Clarke, MD, a professor of epidemiology and public health medicine at the University of Oxford who led the review. Clarke’s coauthors included principal investigators from 9 out of 10 of the included trials, who provided unpublished data necessary for the meta-analysis.

“They looked every way they could to find out if there was a signal and nothing panned out,” said Lawrence J. Appel, MD, a coauthor of last year’s AHA advisory, who was not involved with the analysis.

The findings are just the latest to cast doubt on the usefulness of fish oil supplementation for major cardiovascular disease end points. Although early trials showed a substantial mortality benefit, the supplements haven’t lived up to their promise in later studies.

Two 2012 reviews of randomized trials published in JAMA and the Archives of Internal Medicine (now JAMA Internal Medicine) by separate research teams found little benefit of fish oil supplementation for heart health. A 2016 systematic review from the Agency for Healthcare Research and Quality essentially reached the same conclusion.

The authors of the new analysis concluded that it “doesn’t provide any support for the current recommendation from the American Heart Association to use omega-3 fatty acids for the prevention of fatal coronary heart disease or any coronary heart disease in people with prior vascular disease,” Clarke told JAMA.

Disappointing Landscape

Despite having coauthored the conflicting AHA advisory, Appel, who is director of the Welch Center for Prevention, Epidemiology, and Clinical Research at Johns Hopkins School of Medicine and the Bloomberg School of Public Health, said he was “not at all surprised” by the results. “After a few high-profile trials done over a decade ago, … it’s really been a pretty disappointing landscape for fish oil, which [was] sort of like the supplement du jour,” he said.

The aggressive way heart disease is treated today—with statins, β-blockers, angiotensin-converting enzyme inhibitors, and aspirin, along with procedures to restore blood flow—may largely explain why the benefit of fish oil supplements appears to have dwindled over time. Trials for the most part have tested secondary prevention, which means they included participants who were already receiving treatment.

“Once you get a heavily medicated group, it’s really hard to detect further benefit,” Appel said.

Improved diets—including greater fish consumption—may have also reduced the magnitude of effect over time. The omega-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in cold-water fish are believed to be the main drivers of cardioprotection in seafood and are the primary components in fish oil capsules.

“Most observational studies have found that adding omega-3 supplements on top of a diet with 1 to 2 servings of fish a week will have no benefit,” said Eric Rimm, ScD, director of cardiovascular epidemiology at Harvard T.H. Chan School of Public Health.

A Reasonable Treatment

The AHA advisory concluded that it was reasonable for physicians to consider prescribing fish oil to patients with a recent coronary heart disease event like a recent heart attack or with prevalent heart failure with reduced left ventricular function.

David Siscovick, MD, senior vice president for research at the New York Academy of Medicine and a professor emeritus of medicine and epidemiology at the University of Washington, chaired the advisory. Like his coauthor Appel, Siscovick wasn’t surprised by the results of the recent meta-analysis. But he said different research methods could explain the divergent conclusions in the analysis and the AHA advisory.

In addition to randomized trials, the advisory committee also considered meta-analyses and looked at outcomes for specific indications in individual studies rather than pooling the data. The 2 groups also defined cardiovascular mortality differently, Siscovick said. The meta-analysis included deaths related to revascularizations, for example, while the AHA advisory did not.

The AHA advisory committee estimated a reduction of around 10% in cardiovascular mortality among patients who experienced a recent heart attack and a 9% reduction in all-cause mortality among patients with heart failure.

“Given a potential modest effect [on] mortality, which is an important patient outcome, and little evidence of risk from the treatment with omega-3 supplements, we concluded that it was reasonable for physicians to consider treating in these two clinical indications,” Siscovick said.

He pointed out that the advisory and the meta-analysis are otherwise essentially in agreement. For example, both concluded that for patients at high risk of heart disease who haven’t developed it yet, the evidence from trials doesn’t suggest a benefit of fish oil treatment.

Siscovick’s bottom line: “Would I rewrite our advisory? The answer is no.”

More Data on the Way

Researchers are watching for the results of 4 large randomized trials of fish oil supplements currently under way that together will include more than 60 000 people.

An open question is whether healthy people should take fish oil for primary prevention of heart disease. The highly anticipated Vitamin D and Omega-3 Trial (VITAL), which involves almost 26 000 participants, is the first to test whether fish oil supplements reduce the risk of developing heart disease, stroke, and cancer in the general population. Another trial, A Study of Cardiovascular Events in Diabetes (ASCEND), will test if fish oil prevents serious vascular events in patients with diabetes who do not have arterial disease.

Clarke, however, doesn’t expect a different outcome in these trials because the omega-3 dosages are roughly the same as the average dose in his meta-analysis: around 1 g per day.

The 2 other trials—Reduction of Cardiovascular Events with EPA–Intervention Trial (REDUCE-IT) and Statin Residual Risk Reduction with EpaNova in High Cardiovascular Risk Patients with Hypertriglyceridemia (STRENGTH)—will test around 4 g of fish oil per day in patients at high risk of cardiovascular disease who have extremely high triglycerides and are already taking statins. This higher dosage is used to reduce hypertriglyceridemia but until now hasn’t been tested for end points such as heart attack, stroke, or mortality.

“Those results will be interesting,” Clarke said. In the meantime, patients with heart disease should focus on monitoring their blood pressure and blood lipids and making lifestyle and dietary changes, including eating 2 to 3 servings of seafood a week, he emphasized.

Most people in the United States, however, don’t eat that much fish. Although seafood consumption is on the rise, it still only makes up 5% of the protein in the US diet, far less than the 20% recommended by the Dietary Guidelines for Americans.

Those who don’t eat fish may be more likely to see a benefit from the supplements, Rimm said.

Source:JAMA

%d bloggers like this: