Gene 'controls body fat levels'

reposted from bbc

Gene 'controls body fat levels'

Obesity may be at least partly in the genes

A single gene can keep in check the tendency to pile on fat, scientists have shown.

The University of Texas team manipulated the gene, called adipose, to alter the amount of fat tissue laid down by fruit flies, worms and mice.

If the same effect could be achieved in humans, which also carry the gene, it is hoped it could lead to new ways to fight obesity and diabetes.

The study is published in the journal Cell Metabolism.

Maybe if you could affect this gene, even just a little bit, you might have a beneficial effect on fat Dr Jonathan Graff University of Texas

Lead researcher Dr Jonathan Graff said: "From worms to mammals, this gene controls fat formation.

"It could explain why so many people struggle to lose weight, and suggests an entirely new direction for developing medical treatments that address the current epidemic of diabetes and obesity.

"Maybe if you could affect this gene, even just a little bit, you might have a beneficial effect on fat."

The adipose gene was discovered in fat fruit flies more than 50 years ago, but scientists had not pinned down its exact role.

The Texas team used several methods to turn the gene on and off at different stages of the animals' lives and in various parts of their bodies.

Their work suggested that

the gene acts as a high-level master switch that tells the body whether to accumulate or burn fat.

Health impact

Mice with experimentally increased adipose activity ate as much or more than normal mice.

However, they were leaner, had diabetes-resistant fat cells, and were better able to control insulin and blood-sugar metabolism.

In contrast, animals with reduced adipose activity were fatter and less healthy, and had diabetes.

The researchers also showed that gene activity could be turned up or down, not just on or off.

Dr Graff said this increased the potential to manipulate its effect to treat obesity.

The next step will be to probe further the exact mechanisms by which the gene exerts its control.

Dr David Haslam, clinical director of the National Obesity Forum, warned that

it could take many years to develop genetic treatments for obesity.

In the meantime, he said, the only way to tackle the problem effectively was to encourage people to eat healthily and take exercise.

"I don't want patients coming to me saying: 'It's not what I eat, it's all in my genes'," he said.

"Don't give my patients another excuse to be victims."

End of Aging -The Next Great Paradigm Shift?

reposted from Daily Galaxy

September 05, 2007

End of Aging -The Next Great Paradigm Shift?

In his new non-fiction Amazon bestseller, Ending Aging, Aubrey de Grey, champions recent progress in genetics and calorie-restricted diets in laboratory animals that hold forth the promise that someday science will enable us to exert total control over our own biological aging and substantially slow down the aging process.

Aubrey de Grey is convinced that he has formulated the theoretical means by which human beings might live thousands of years -- indefinitely, in fact.

Like Francis Bacon, de Grey has never stationed himself at a laboratory bench to attempt a ­single hands-on experiment, at least not in human biology. He is a computer scientist who has taught himself natural science, and has set himself toward the goal of transforming the basis of what it means to be human.

Dr. de Grey, who holds a rare University of Cambridge degree on this basis of publications rather than classwork, believes that the key biomedical technology required to eliminate aging-derived debilitation and death entirely is now within reach —technology that would not only slow but periodically reverse age-related physiological decay, leaving us biologically young into an indefinite future—is now within reach.

In Ending Aging, Dr. de Grey and his research assistant Michael Rae describe the details of this biotechnology. They explain that the aging of the human body, similar to the aging of man-made machines, results from an accumulation of various types of damage. And, as with machines, this damage can periodically be repaired, leading to indefinite extension of the machine’s fully functional lifetime.

By demystifying aging and its postponement for the nonspecialist reader, de Grey and Rae systematically dismantle the fatalist presumption that aging will forever defeat the efforts of medical science.

The most realistic way to combat aging, de Gray suggests, is to rejuvenate the body at the molecular and cellular level, removing accumulated damage and restoring us to a biologically younger state. Comprehensive rejuvenation therapies can feasibly postpone age-related frailty and disease indefinitely, greatly extending our lives while eliminating, rather than lengthening, the period of late-life frailty and debilitation.

"The real issue," de Grey writes, "surely, was not which metabolic processes cause aging damage in the body, but the damage itself. Forty-year-olds have fewer healthy years to look forward to than twenty-year-olds because of differences in their molecular and cellular composition, not because of the mechanisms that gave rise to those differences. How far could I narrow down the field of candidate causes of aging by focusing on the molecular damage itself?"

Removing the causes of aging-related deaths will also eliminate all the suffering that aging inflicts on most people in the last years of their lives. Aging kills 100,000 people a day. Social concerns about the effects of defeating aging are legitimate but don’t outweigh the merits of saving so many lives and alleviating so much suffering.

"There are mutations in our chromosomes, of course, which cause cancer," de Grey muses. "There is glycation, the warping of proteins by glucose. There are the various kinds of junk that accumulate outside the cell (“extracellular aggregates”): beta-amyloid, the lesser-known transthyretin, and possibly other substances of the same general sort. There is also the unwholesome goo that builds up within the cell (“intracellular aggregates”), such as lipofuscin. There’s cellular senescence, the “aging” of individual cells, which puts them into a state of arrested growth and causes them to produce chemical signals dangerous to their neighbors. And there’s the depletion of the stem cell pools essential to healing and maintenance of tissue.

"And of course, there are mitochondrial mutations, which seem to disrupt cellular biochemistry by increasing oxidative stress. I had for a few years felt optimistic that scientists could solve this problem by copying mitochondrial DNA from its vulnerable spot at “ground zero,” within the free-radical generating mitochondria, into the bomb shelter of the cell nucleus, where damage to DNA is vastly rarer.

"Now, if only we had solutions like that for all of this other stuff, I mused, we could forget about the “butterfly effect” of interfering with basic metabolic processes, and just take the damage ITSELF out of the picture."

De Grey's call to action, writes Dr. Sherwin Nuland, clinical professor of surgery at Yale University School of Medicine and author of How We Die and The Art of Aging, "is the message neither of a madman nor a bad man, but of a brilliant, beneficent man of goodwill, who wants only for civilization to fulfill the highest hopes he has for its future.” An opinion darkly countered by Dr. Martin Raff, emeritus professor of biology at University College London and coauthor of Molecular Biology of the Cell: “Seems to me this man could be put in jail with reasonable cause.”

De Grey has formulated a wide-ranging plan for the comprehensive and eventually indefinite postponement of age-related physical and mental decline, named SENS (Strategies for Engineered Negligible Senescence). He is the organizer of an ongoing series of conferences and workshops that focus on the key biomedical research relevant to SENS, and he also oversees the Methuselah Foundation’s growing sponsorship of SENS research worldwide.

"For decades," de grey summarized, "my colleagues and I had been earnestly investigating aging in the same way that historians might “investigate” World War I: as an almost hopelessly complex historical tragedy about which everyone could theorize and argue, but about which nothing could fundamentally be done. Perhaps inhibited by the deeply ingrained belief that aging was “natural” and “inevitable,” biogerontologists had set themselves apart from the rest of the biomedical community by allowing themselves to be overawed by the complexity of the phenomenon that they were observing.

"To intervene in aging, I realized, didn’t require a complete understanding of all the myriad interacting processes that contribute to aging damage. To design therapies, all you have to understand is aging damage itself: the molecular and cellular lesions that impair the structure and function of the body’s tissues. Once I realized that simple truth, it became clear that we are far closer to real solutions to treating aging as a biomedical problem, amenable to therapy and healing, than it might otherwise seem."

Posted by Casey Kazan.

Related Galaxy posts:

The Story of a Biologist & the Extension of the Human Life Span
Pathway to Longevity Discovered
Can Humans Live to 1,000? Some Experts Claim We Can — Others Want to Prevent That
Darwin's Lab: Scientists on Brink of Creating Life
World's Oldest Living Microbes May Cast Light on Aging & Life on Mars
“Longevity Genes” Solve Centenarian Paradox
The "Blue Brain" & Human Consciousness -Scientists Create Artificial Brain
"Mind Children": Transhumanism & the Search For Genetic Perfection
“What is Life?” A New Breed of Robots Are Causing Scientists to Question

Video: Aubrey de Grey -Defeat of Aging

http://www.technologyreview.com/Biotech/14147/

Top Tips For Dieting (Health & Medicine: Dieting)

Top Tips For Dieting (Health & Medicine: Dieting)

you've got to work up a sweat

reposted from Guardian

The era of gentle exercise is over. It's official: you've got to work up a sweat

Polly Curtis, health correspondent
Friday August 17, 2007
The Guardian

Runners in the London Marathon. Adults are now being told they need regular vigorous exercise. Photograph: Rebecca Naden

Official advice that 30 minutes of gentle exercise a day is enough to improve your health has been revised by the scientists who first developed the international fitness guidelines.

Until now, government recommendations have suggested that people can achieve a minimum level of fitness through their normal daily routines. But amid fears that the lightest of activities such as dusting and the stroll to the car are being counted as exercise, a new study by the public health experts behind the formula concludes adults need to add jogging and twice-weekly weight training sessions if they want to cut their risk of heart disease and obesity.

The scientists, world-leaders in public health and exercise advice, say they want to clarify the fitness guidelines for healthy adults which were adopted by the World Health Organisation and later used as a template for healthy living by the UK government. Some people have misunderstood the original message and are doing too little exercise, they argue. But they go even further saying explicitly that people should do vigorous as well as moderate aerobic exercise because of the "substantial science base" that it is good for you.

The paper published in Circulation, the journal of the American Heart Association, includes authors who are influential members of the American College of Sports Medicine. They write: "There are people who have not accepted, and others who have misinterpreted, the original recommendation. Some people continue to believe that only vigorous intensity activity will improve health while others believe that the light activities of their daily lives are sufficient to promote health."

The new guidelines say:

· 30 minutes of moderate exercise a day is still the minimum, but vigorous as opposed to moderate activity should be "explicitly" recommended

· Combining days of moderate exercise with other days of vigorous exercise is better for you

· Moderate exercise should be in addition to daily activities such as casual walking, shopping or taking out the rubbish

· People should do two weight-training sessions a week

· Adults over 65 or those who are infirm during their 50s and early 60s should also do balancing exercises if they are at risk of falling and draw up appropriate exercise plans with their doctors.

"Many adults, including those who wish to improve their personal fitness or further reduce their risk of premature chronic health conditions and mortality related to physical inactivity, should exceed the minimum recommended amounts of physical activity," it says.

But their apparent change of heart exposes the dilemma facing health officials of how to encourage an increasingly overweight population to exercise without deterring them with over-ambitious programmes. Anti-obesity experts suggested that advising people to do weight-training was unrealistic.

David Haslam, chair of the National Obesity Forum, said: "If you suggested everyone here should do weight-training twice a week they wouldn't do it. They don't have the time or money for the gym, it would be an unrealistic guideline. I'd rather see healthy habits built into daily life - gyms aren't a sustainable habit."

Paul Gately, professor of exercise and obesity at Leeds Metropolitan University, said: "Scientists keep changing the goalposts but this advice is trying to provide more specific information for specific groups of people to encourage them to do appropriate exercise.

"It's the age-old problem of one-size-fits-all public health advice versus tailored programmes. People who are very overweight would have to do an hour of exercise a day just to maintain their weight if they aren't going to change their diets."

The authors include several experts who are on a high-level committee in the US which next year will announce America's new physical activity guidelines. Their revisions this month are widely expected to be adopted as official advice there. Their original recommendations in 1995 were quickly adopted by the WHO and by the UK government in 1996.

In 2004 the chief medical officer for England and Wales, Sir Liam Donaldson, republished the recommendations in his attempt to underscore the importance of more rigorous exercise and show that people could achieve the total through smaller 10-minute chunks. It was revealed then that up to two-thirds of men and three-quarters of women were failing to meet the 30-minute goal. Scotland's advice is similar to that in England and Wales.

A spokeswoman for the Department of Health said it was watching developments in the evidence about how much exercise was optimum but there were no plans at the moment to change the advice.

keep pace with the constantly changing advice on how much exercise is healthy.

reposted from Guardian

No Sweat. Never mind jogging, I can't keep pace with the constantly changing advice on how much exercise is healthy.

He can work it out: Tim Dowling being himself, only better. Photograph: David Levene.

Now they tell us: the scientists who developed the fitness guidelines for adults, the guidelines adopted by the World Health Organisation, have decided to "clarify" their advice. They would like to point out that when they where they said "moderate" exercise, they meant "vigorous", and that where they implied that a minimum level of fitness could be maintained through one's normal daily routines, they now wish to include "in addition jogging and two weight-training sessions a week". If you're not regularly breaking a sweat, they say, you're not doing enough.

This new advice come just days after the release of a study that said that even low levels of physical activity - say, three brisk walks a week - could lower the risk of heart disease in people who took no other exercise. What are we supposed to believe?

In hindsight, the old guidelines always seemed too good to be true. To suggest that doing the hoovering and using the stairs counted as exercise was to give almost everybody the idea that they were already immensely fit. People could congratulate themselves for simply negotiating the dull routine of daily existence. I had taken to including the sweat I broke into whenever a tax demand arrived as part of my overall exercise regime.

Everybody knows that maintaining fitness involves a certain amount of bother, and that improving fitness requires a degree of discomfort. If you're only walking between the sofa and the fridge, you're better off not exercising at all.

Perhaps the health officials have they taken their revisions a little too far. How many minimally fit people have been reclassified as dangerously unfit by this shift in emphasis? Lots of us do a bit of regular, actual exercise - beyond the realm of vigorous ironing or trudging to the bus stop - but how many of us do two weight-training sessions a week? I've done two weight-training sessions full stop, and it seemed like more than enough to me.

But then I don't have to worry about fitness, because I lift myself out of the bath every day, rain or shine.