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Posts Tagged ‘Longevity’

Researchers have found that the insulin signaling pathways in worms have a direct bearing on their lifespan. This research is particularly interesting because humans and worms share very similar insulin signaling pathways.

Over a decade ago, the first part of this research led to some positive news as researchers found that certain mutations involved in the insulin pathways can greatly extend lifespan in worms.

“In the early 90s, we discovered mutations that could double the normal life span of worms,” Kenyon said. Those mutations effected insulin signals. Specifically, a mutation in a gene known as daf-2 slowed aging and doubled life span. That longer life depended on another “FOXO transcription factor” called DAF-16 and the heat shock factor HSF-1.

Unfortunately, the recent results show that adding sugar to the worm diet has the opposite effect.

By adding just a small amount of glucose to C. elegans usual fare of straight bacteria, they found the worms lose about 20 percent of their usual life span. They trace the effect to insulin signals, which can block other life-extending molecular players.

Here is the technical aspect of the results:

In fact, glucose makes no difference to the life span of worms that lack DAF-16 or HSF-1, they show. Glucose also completely prevents the life-extending benefits that would otherwise come with mutations in the daf-2 gene.Ultimately, worms fed a steady diet containing glucose show a reduction in aquaporin channels that transport glycerol, one of the ingredients in the process by which the body produces its own glucose. “If there is not enough glucose, the body makes it with glycerol,” Kenyon explained. That glycerol has to first get where it needs to go, which it does via the aquaporin channels.

There are a few ways in which the result from studying worms affects us as humans.

A diet with a low glycemic index seems like a safe bet for now. One of the scientists was alarmed enough with the data to make serious changes to her diet:

As an aside, Kenyon says she read up on low-carb diets and changed her eating habits immediately — cutting out essentially all starches and desserts — after making the initial discovery in worms. The discovery was made several years ago, but had not been reported in a peer-reviewed journal until now.

Another area of concern is medicine. Current drugs may be offering treatment which carry as of yet unknown long term side effects. Fortunately, as is the case with anti-depressant medication, science is continually advancing to make our lives better and this research will undoubtedly result in better life saving medicines.

She says the findings may also have implications for drugs now in development for the treatment of diabetes, which are meant to block glucose production by inhibiting glycerol channels. The new findings “raise a flag” that glycerol channels might be doing something else, she says, and that drugs designed to block them might have a downside.

A long term study recently found a connection between consuming two servings of diet soda daily and a significant decline in kidney function. How do different types of artificial sugars factor into these results? Is there any connection between these two studies?

Aging in humans is far more complex than in worms.

“Although we do not fully understand the mechanism by which glucose shortens the life span of C. elegans, the fact that the two mammalian aquaporin glycerol-transporting channels are downregulated by insulin raises the possibility that glucose may have a life-span-shortening effect in humans, and, conversely, that a diet with a low glycemic index may extend human life span,” the researchers write. Kenyon also points to recent studies that have linked particular FOXO variants to longevity in several human populations, making the pathway the first with clear effects on human aging.

Glucose and the insulin signaling pathways are probably just one piece in a complex puzzle explaining the aging process. With every piece of the puzzle that gets illuminated and understood we come one step closer to allowing science an opportunity to stop aging.

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What a terrific piece of news from the scientific community:

Ogling over women’s breasts is good for a man’s health and can add years to his life, medical experts have discovered. According to the New England Journal of Medicine, “Just 10 minutes of staring at the charms of a well-endowed female is roughly equivalent to a 30-minute aerobics work-out” declared gerontologist Dr. Karen Weatherby.

Dr. Weatherby and fellow researchers at three hospitals in Frankfurt, Germany, reached the startling conclusion after comparing the health of 200 male outpatients – half of whom were instructed to look at busty females daily, the other half told to refrain from doing so. The study revealed that after five years, the chest-watchers had lower blood pressure, slower resting pulse rates and fewer instances of coronary artery disease.

“Sexual excitement gets the heart pumping and improves blood circulation,” explains Dr. Weatherby. “There’s no question: Gazing at breasts makes men healthier.” “Our study indicates that engaging in this activity a few minutes daily cuts the risk of stroke and heart attack in half. We believe that by doing so consistently, the average man can extend his life four to five years.”

File this one in the “too good to be true department”.

If the story smacks of tabloid journalism, it’s because that’s precisely what it is. The text began circulating in March or April 2000, mere weeks after a very similar article appeared in the consistently misinformative Weekly World News — nor is this the first time we’ve run into baseless Internet rumors traceable to precisely that source.

It goes without saying (I hope) that it’s unwise to take medical advice from supermarket tabloids, still less from forwarded emails. Males who wish to increase their lifespans ought to consider practicing common sense as an alternative — it’s more likely to achieve the desired result than any amount of public breast ogling.

Sorry fellas, but you will not be able to justify staring based on “some scientific research you read somewhere”. Instead, take the high road and blame Leslie Bennetts style nagging for your wandering eyes – but don’t forget to look your best otherwise you won’t be able to turn her off. If you are concerned about your health don’t forget that video games are good for the heart and for the mind.

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Life Begins At 100

There are more people alive today above the age of 100, called centenarians, than ever before. The curious part of this tale is how healthy many of them are relative to their compatriots who did not live as long.

It is becoming clear that people who break through the 90-plus barrier represent a physical elite, markedly different from the elderly who typically die younger than them. Far from gaining a longer burden of disability, their extra years are often healthy ones. They have a remarkable ability to live through, delay or entirely escape a host of diseases that kill off most of their peers. Supercentenarians – people aged 110 or over – are even better examples of ageing gracefully.

Healthy is relative term for someone that old. In fact, very few people who live to be 100 are able to avoid certain chronic conditions entirely. Centenarians are divided into 3 categories regarding their health: delayers, survivors, and escapers.

Not all of the oldest old survive by delaying illness or disability, though – many soldier through it. Jessica Evert of Ohio State University in Columbus examined the medical histories of over 400 centenarians (The Journals of Gerontology Series A, vol 58, p 232). She found that those who achieve extreme longevity tend to fall into three categories. About 40 per cent were “delayers”, who avoided chronic diseases until after the age of 80. This “compression of morbidity”, where chronic illness and disability are squeezed into ever-shorter periods at the end of life, is a recent trend among ageing populations. Another 40 per cent were “survivors”, who suffered from chronic diseases before the age of 80 but lived longer to tell the tale. The final 20 per cent were “escapers”, who hit their century with no sign of the most common chronic diseases, including heart disease, cancer, diabetes, hypertension and stroke. Intriguingly, one-third of male centenarians were in this category, compared with only 15 per cent of women (see “Two paths to 100”).

There is conclusive evidence pointing to genetics as a contributing factor in such extreme longevity. Precisely how much is still being debated. Environmental factors like exercise and diet should not be dismissed even if some centenarian reports smoking 60 cigarettes a day for decades.

Scientists are working hard to uncover whatever genetic secrets are responsible for a long healthy life. Very little has been found to date.

Until recently, the only exception was ApoE, and in particular a variant of this gene known as e4, which bestows carriers with a much higher than average risk of developing Alzheimer’s and heart disease. Across the world, this unfortunate version of ApoE is about half as common in centenarians as in younger adults. Last year, a second promising candidate emerged – a variant of a gene called FOXO3A. At the University of Hawaii, a team led by Bradley Willcox, Craig’s identical twin, found that people who carried two copies of a particular form of the gene were almost three times as likely to make it to 100 than those without the variation, and also tended to start their journey into old age with better health and lower levels of stroke, heart disease and cancer (Proceedings of the National Academy of Sciences, vol 105, p 37). “There are so many false positives in this field that FOXO3A is very exciting,” says Bradley Willcox.

FOXO3A is involved in several signalling pathways that are conserved across animal species. It controls the insulin/IGF-1 pathway, which influences how our bodies process food. It also controls genes that protect cells from highly reactive oxygen radicals – molecules often thought to drive human ageing through the cumulative damage they wreak on DNA. FOXO3A could even protect against cancer by encouraging apoptosis, whereby compromised cells commit suicide. The variant of FOXO3A associated with longevity is much more prevalent in 100-year-olds even than in 95-year-olds, which clearly demonstrates the value of studying the centenarian genome.

As was discussed earlier in regards to Alzheimer’s disease, it is interesting to note that men who survive to be 100 are in better shape than women.

Men, meanwhile, have the double disadvantage of being both more prone to risky behaviours throughout their lives and more likely to succumb to chronic illnesses as they age. This means that men who do make it to their century must depend more on genetic trump cards to see them through.

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The Center for Disease Control released new data for 2007 (based on 90% of all USA death certificiates) showing that mortality rates dropped again (by over 2%) to 760/100,000 population. It’s been dropping for the past 8 years, and viewed longer term is half of what it was 60 years ago. Interestingly death rates from heart disease dropped a staggering 5% and even cancer dropped 2%.

We consider that factual information to be good news, yet we are faced with a contradiction here because America is fatter than ever.

We are told to be prepared for an epidemic of diabetes, high blood pressure, elevated blood lipids because of this. Every doc has seen blood sugar drop, blood pressure lowered, lipids come down in people with any/all of the above when they are able to lose a significant amount of weight.

However, the theory which says America should be suffering health problems and increased mortality because of increased obesity is quite wrong.

So why are death rates dropping and people living longer? Something must be wrong with the model — it’s pretty hard to quarrel with the data as being inadequate. Certainly the increased incidence of obesity should have produced something by this time (it started 30 years ago).

It is an interesting question, and a few ideas are proposed. This is not an exhaustive list by any means.

  • People may be in engaging in more/ higher quality exercise.
  • Fewer people are regular smokers.
  • Better, more well informed doctors.
  • Better drugs on the market.

We are not the only ones to notice the bogus nature of the BMI, and some other people have proposed alternatives based on the fact that a group of people of equal height and weight can have very different mortality rates.

Also, when taking into account people who are skinny because they smoke a lot, there is still no indication that being overweight increases mortality.

Linking, for the first time, causes of death to specific weights, they report that overweight people have a lower death rate because they are much less likely to die from a grab bag of diseases that includes Alzheimer’s and Parkinson’s, infections and lung disease. And that lower risk is not counteracted by increased risks of dying from any other disease, including cancer, diabetes or heart disease.

The BMI is bogus. It bears repeating again and again because we still live in a system which judges your health, and thereby your insurance premiums based on this nonsense. Private insurance companies can be mandated to change this by Congress but the CDC and others enjoy the convenience provided by simply using national BMI data.

If the government is using statistically invalid data to judge the health of Americans, can we trust them with actually running the healthcare system? Why should we trust a proposed system of hugely increased cost and responsibilities by officials who can’t bother getting the basic things right?

Many public officials have been holding town hall meetings recently to try and sell the proposed healthcare legislation to the public. Take a few moments and read this compilation of important questions which need to be answered by the President and Congress before any healthcare reform bill gets voted into law.

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Speaking at APA’s 117th Annual Convention, Steven Blair, PED, called Americans’ physical inactivity “the biggest public health problem of the 21st century.”

Quick, raise your hand if you snickered when you read the word biggest because you were picturing just how big and fat Americans are. Now take your raised hand and slap yourself across the face for being so insensitive.

We kid.

Really though, there are surely much bigger global problems relating to health, especially in regards to disease control, access to clean water, nutritional deficiencies, etc.

Research has shown approximately 25 percent to 35 percent of American adults are inactive, Blair said, meaning that they have sedentary jobs, no regular physical activity program and are generally inactive around the house or yard. “This amounts to 40 million to 50 million people exposed to the hazard of inactivity,” Blair said in an interview.

Putting the hyperbole aside, it is an often accepted and mistaken bit of common knowledge that weight can determine a person’s health. Many young men and women diet and exercise with the goal of changing their weight to a particular amount, and are occasionally briefly successful. Others do not exercise, or do so rarely, but are not considered overweight so it is assumed that they are healthy.

One follow-up study of 40,842 longitudinal study participants showed poor fitness level accounted for about 16 percent of all deaths in both men and women. The percentage was calculated by estimating the number of deaths that would have been avoided if people had spent 30 minutes a day walking.

The reality is that everyone should make it a goal to be physically active to at least a moderate level. Cardiovascular exercises in particular seem to be strongly correlated with longevity and better health, physical and mental,  well into old age. Most people should stay away from exercise extremes such as marathon running because the damage incurred (to the joints, for example) and risk of injury are not worth the health benefits.

Blair also highlighted the benefits of exercise on the mind, referring to recent emerging evidence that activity delays the mind’s decline and is good for brain health overall.

Diet alone cannot make a person healthy. Appetite control is regulated in a complex way by the body, and is very difficult to fight against for any reasonable period of time. Should you be one of those people with a slow metabolism and a hearty appetite, make sure you put extra time and effort into exercising.

Obviously, since this was presented at an APA function there was a role in all this for psychologists.

“I believe psychologists can help develop better lifestyle change interventions to help people be more active via the Internet and other technological methods.”

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Can someone’s personality have an effect on their overall health and longevity? It seems that the answer is “yes”, since a connection between being an extrovert and having low levels of interleukin 6, an inflammatory chemical, has been discovered.

…extraversion is a personality trait with three parts: a tendency toward happy thoughts, a desire to be around others and “dispositional energy,” a sense of innate vigor or active engagement with life (“I’m bursting with energy; my life is fast-paced”).

While the first two extrovert qualities were not found to track with inflammation, the current study found increases in “dispositional activity” came with statistically significant decreases in IL-6 (p = .001). P values measure the weight that should be attributed to a finding, with values less than .05 usually deemed significant.

On average, women and minorities have higher levels than white males. Chemicals such as interleukin 6 increase in concentration as result of stress. Long term exposure to various sources of stress takes a toll on an individual’s organs and can result in poor health and early death.

“If this aspect of personality drives inflammation, dispositional energy and engagement with life may confer a survival advantage,” Chapman said. “But we don’t know if low dispositional activity is causing inflammation, or inflammation is taking its toll on people by reducing these personality tendencies, so we must be cautious in our interpretation of this association.”

A cynic may look at all the data and simply conclude that an extroverted personality is one which participates in the world, meaning, someone who likely getting plenty of exercise and doing physical activity. There is a strong connection between proper exercise and longer, healthier life, so everyone could gain these benefits by getting fit.

“Beyond physical activity, some people seem to have this innate energy separate from exercise that makes them intrinsically involved in life,” Chapman said. “It will be fascinating to investigate how we can increase this disposition toward engagement.

Of course, there’s probably more to it.

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Fascinating stuff, definitely worth checking out if you have an interest in longevity research. It’s not very long, and will give you a general idea of what’s going on in this field.

Gregory Stock is a biophysicist, best-selling author, biotech entrepreneur, and the director of the Program on Medicine, Technology and Society at UCLA’s School of Medicine. He has written extensively on the implications for society, medicine and business of the human genome project and associated developments in molecular genetics and bioinformatics. His interests lie in the scientific and evolutionary as well as ethical, social and political implications of today’s revolutions in the life sciences and in information technology and computers.

The following transcript of Gregory Stock’s presentation at the Methuselah Foundation symposium entitled “Aging: The Disease, The Cure, The Implications” has been corrected and approved by the speaker. Video is also available.

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