Two articles on BBC news today with some developments on CR and a profile of a CRer.

Gene clue to longevity uncovered
http://news.bbc.co.uk/1/hi/sci/tech/6612411.stm

The mystery of how eating less boosts longevity is closer to being solved.
Studies have shown that severe calorie restriction markedly extends lifespan in mice and many other species - but the reasons for this remained elusive.

But now US research on nematode worms, published in Nature, has uncovered a gene linked to this unusual effect. In the future, the find could lead to drugs that mimic the consequences of calorie restriction but negate the need for severe fasting regimes.

Sweet-spot

The life-lengthening properties of reducing calorie intake were first discovered in the 1930s, when laboratory rodents fed a severely reduced diet were found to outlive their well-fed peers. Since then, this effect has been observed on organisms as diverse as yeast, flies, worms and dogs. The consequences for humans of cutting calorie intake by about 60% while maintaining levels of vital nutrients are still unclear, although this extreme diet has a number of followers.

Andrew Dillin, an author of the paper and an associate professor at the Salk Institute for Biological Studies, said: "If you reduce food too much, you go towards starvation and live less long. If you overeat you will succumb to obesity and have a short lifespan. Dietary restriction is really a sweet-spot between the two.

"But for 72 years, we have not known how it works."

A study using nematode worms (Caenorhabditis elegans) revealed that a gene called pha-4 played a key role. The team found worms that had their pha-4 genes removed showed no enhanced longevity while on the restricted diet. But they discovered that the opposite experiment - over-expressing levels of pha-4 in the worms - increased longevity when on the restricted diet.

"This is the first gene we have found that is absolutely essential to the longevity response to dietary restriction," explained Dr Dillin.

"We finally have genetic evidence to unravel the underlying molecular programme required for increased longevity in response to calorie restriction."

Feast or famine

Although the study was carried out on worms, the finding could also be important for other species. Mammals, including humans, possessed genes that were highly similar to the pha-4 gene, explained Dr Dillin.

These genes play a key role in development, and then in later life in the regulation of glucagon, a hormone that has a major role in maintaining glucose levels in blood - especially during fasting. In fact, scientists believe the life-increasing effect of dietary restriction may be linked to boosting chances of survival through times of food scarcity.

"Pha-4 may be the primordial gene to help an animal overcome stressful conditions to live a long time through dietary restriction conditions," explained Dr Dillin.

Parallels?

Scientists now plan to look at the gene in other species.

Should the longevity link also apply to humans, it could open the door to the development of drugs that mimic the effects of calorie restriction while allowing people to maintain their normal diet, the scientists said.

Professor Richard Miller of the Institute of Gerontology at the University of Michigan, commented: "It is really hard to guess whether the connections that we see between the pha-4 system and calorie restriction in worms will have parallels in mammals, whose repertoire of responses to various forms of long- and short-term food shortages are far more complex than those of worms.

"But the Dillin paper provides both motivation to look and also clues about where to look. I think it's likely to be influential, even if the implications for mammals do eventually turn out to be a cul-de-sac - which they might or might not."

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Extreme dieting: Eat less, live longer?
http://news.bbc.co.uk/1/hi/sci/tech/6617113.stm



Scientists believe they are a step close to working out why an extremely restrictive diet boosts longevity. This well-documented calorie-cutting phenomenon has been seen in many species, from yeast to mice to dogs.

Although the effects of "calorie restriction" in humans are as yet unknown, some are undertaking this in a bid to live longer. Here, Bob Cavanaugh, managing director of the Calorie Restriction Society, tells the BBC News website about his diet:

I've been doing calorie restriction for six years. When I was 53, I had a physical and found out my blood cholesterol level was very high. My doctor wanted to try and control it with diet before resorting to drugs, and I was all in favour of that. I had read a book about calorie restriction and ageing back in 1988, and was convinced by the science, so I decided to try it. I use software to work out what to eat everyday. I believe without it, it is impossible to have proper nutrition.

You weigh your food, and it works out the calories, the ratio of fat, carbohydrate and protein and the breakdown of vitamin, minerals and amino acids, then runs a nutritional profile of what you eat throughout the day. On an average day, I eat 1,800 calories. Younger people can restrict their calories more severely, but I've been told that, based on lab animal evidence, I have already accumulated years of damage to my mitochondria (the powerhouses of the cells), so I utilise my food less efficiently than a younger person.

On a typical day, I will eat an oatmeal-based recipe for breakfast, which is about 455 calories and it gives me about half of my daily nutrients. I don't eat lunch - after this breakfast I just don't feel hungry - so that leaves me about 1,350 calories for my evening meal, which is a lot. If you are smart, by eating small portions of meat and small quantities of starchy things, that leaves an enormous amount of room for fruit and vegetables. You wind up eating quite a large meal and it is very filling, nutritious and satisfying.

Exhilaration

Contrary to popular belief you are not hungry on this diet, and I feel excellent. When I started the diet when I was 53, I felt like I was starting to get on in years and didn't quite have the vim and vigour I used to have. But starting calorie restriction, that exhilaration that I used to experience in youth returned and my whole sense of well-being returned to levels I experienced as a child. It really made me feel like I got my life back. In terms of health, my cholesterol level has really dropped, I now weigh 150lb, and I haven't had any illnesses at all - not even a cold.

My motivation for doing calorie restriction was two-fold. One was to reduce my risk of age-related diseases such as heart disease - with the cholesterol level I had. I was in line for this. And the prospect of extending your lifespan is very appealing - although I guess you have to be somewhat narcissistic to think you are worth living a lot longer than anyone else.

I can see this having some truth to it. When we eat, we spend something like 80% of our energy JUST digesting the food. If we eat less, energy can go toward body upkeep instead. Maybe we are even more efficient at digesting, extracting more vitamins, minerals and energy when there is less food.

Oh, yay! Another CRonbie thread. What is the name of this board again?

Atkins Diet & Low Carbohydrate
Weight-Loss Support?

what does CR stand for again?

Its not low fat, its not low protein, its not high protein, its not high carb, its not low carb. Its stands for eating less calories! Precisely what many here on these boards are doing. You think that people here that lose weight aren't eating some form of a CR diet? From what I've read, Low carb, atkins results in a 40% reduction in calories, without the calorie counting. I'd call that CR

So hostile, pathetic.

The difference, Matt, is that those who are restricting calories via low carb primarily in the goal of weight loss don't plan to do it forever and seem to be far less obsessed with calories than the average CR devote'.

I love the name of your plan... is there a book on it I can pick up???

Nope. Just take what a vegan wouldn't eat and make that most of your diet. The other 5% is the occasional fruit or vegetable. The only place it falls flat is ice cream.

I think the animosity comes from the idea of restricting calories meaning eating less food. Spending less time at the table. Obsessing less over food. Heresy! How dare you tell me how much and what kind of food to eat!

Unfortunately cronies sometimes trade one obsession for another: too little food. When I was really into Atkins, I loved it because I could pig out constantly (on meat) and still lose weight. That's not exactly dealing with obsession. It's using a gimmick to avoid dealing with the obsession. I know you're supposed to switch from mostly meat to a mix of healthy carbs, veggies, whatever. But my guess is few do that. It's easier to pig out til the weight is lost, then go back to eating junk, then repeat the cycle once the weight comes back.

The article mentions 'the sweet spot'. That magical amount of food to keep you lean yet healthy. It's something I've been seeking for a long time.

Wow! More worm studies! How... how... unenlightening! I think the fella got one thing spot on though, from the original article ...



Kind regards

Why does one have to be "worth" more to deserve to live longer? I think everybody should try to live as long as they can in the best health possible. Worth and deserving have nothing to do with that.

Thanks Woah! Hope they do more studies on IF as well.

Yes worm studies, worms do have the same genes, same pathways and both function in similar ways in humans and all organisms from small to big respond to cr in similar way. Lower organism work is quite important.

I understand now, mutant.
http://forum.lowcarber.org/showthread.php?t=333760

Well, one of those CR videos you linked to indicated that the CR monkeys were aggressive to the point of biting people. All the work is important, right?

No, all monkeys have their own personalities and do not seem to be altered by CR.

Watch 23 - 30 minutes in the video below and the guy that actually is involved in the study explains

http://video.google.com/videoplay?d...ience+of+living

Well, some buddhists believe it's because we absorb the 'karma' of everything we eat, so less food is better, and less consciousness in the food is better. (Or perhaps measured differently. In one of the funniest quips of all time, the Dalai Llama was once asked something like, "but aren't plants, like carrots, alive too? Don't they, too, 'scream' when killed when eaten?" and he said something like, "Yes. But not nearly so loudly." The sense of humor in that man just kills me. Last I heard he does eat some meat now and then anyway.)

One thing I find interesting: have these studies been done with comparative body size? For example, would jane, a 4'11 asian woman, vs. john, a 6'4 swedish male, who probably have a huge difference in daily caloric needs, is it that Jane would be expected to live longer because she ingests less calories, even if both ingested what each needed? Could this relate in part to why women often on average lived longer than men? Or is it only per-body size, e.g., if Jane ate 100% of her BMR calories and john ate 95% he'd be expected to live longer even though that was twice the food?

If a person ate more than a few hundred calories less than their BMR daily need as we measure it today, they'd end up fat, in reduced metabolic mode; bodybuilders try not to reduce very much, and increase exercise instead, to lose fat. In that case, it seems like the individual would gradually reduce body fat percentage to insanely low. In the studies, what's killing off the subjects at the end? 'cause for example most contagious illnesses like flu are far more likely to kill people with low body fat which would suggest the opposite. I don't believe that people die of old age, it's always "something" even though that may be "system wide degradation" or something.

I have a hard time extrapolating worm studies to humans personally.

PJ