Do Dieting Monkeys Live Healthier and Longer Lives?Preliminary evidence from one of the largest studies of calorie-restricted diet in primates shows health benefits.
An ongoing study at the University of Wisconsin-Madison in which rhesus monkeys are being fed an extremely calorie-restricted diet gives preliminary evidence that the regime prevents age-related diseases. For decades, scientists have known that a diet of about 30-percent fewer calories than normal extends the lifespan of mice by 10 to 20 percent, reduces their incidence of cancer, and prevents the deterioration of learning and memory in the rodents (see "A Clue to Living Longer"). And similar effects have been shown in lower organisms from yeast to fruit flies. But such life extension has not been proven yet in primates.
Researchers at the Wisconsin National Primate Research Center have been studying a group of 76 rhesus monkeys, half of them on calorie restriction and half on a normal diet, for 18 years, to determine whether or not the restricted diet has the same health benefits in primates as it does in other animals. The study will likely go on for at least another decade, since the monkeys are only now entering old age. Captive rhesus monkeys usually live to around 25 years old, which is now about the average age of the monkeys in the study. An age of 40 for a rhesus monkey is similar to 120 for a human--the apparent maximum lifespan. Although there is now strong evidence that caloric restriction prevents diabetes in the primates (the disease is a major killer of captive rhesus monkeys), it's still too early to assess the diet's effects on their lifespan, according to Richard Weindruch, professor of medicine at the University of Wisconsin, who is heading up the study. But preliminary evidence suggests that the diet is preventing loss of muscle mass, arthritis, menstrual irregularities, and other signs of aging. "Over the next 10 years, survival differences will come out," predicts Ricki Colman, a scientist on the study. Meanwhile, eight of the monkeys on a normal diet have died of age-related causes such as cancer and diabetes; five on the restricted diet have died of these causes. As the monkeys enter old age, the researchers are beginning gene expression profiling on them--the first step toward finding the molecular mechanisms that connect the extreme diet to its effects in the animals. The monkeys will also undergo MRIs and be tested for mental acuity, to assess whether or not the diet prevents age-related deterioration of learning and memory. Even if a diet of 30-percent fewer calories proved to extend healthy human lifespan, however, it's unlikely that most people could be able to stick with it. (A group of individuals following such a diet, called the Calorie Restriction Society, seem to have some health benefits. See "Human Study Shows Benefits of Caloric Restriction".) Researchers studying caloric restriction in animals, including Colman, say that, in general, such a diet is "not a long-term possibility in humans." Rather, the primary goal of their study, Colman and Weindruch agree, is to learn about aging and to understand how caloric restriction changes metabolism and gene expression.
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Caloric Restriction Slows Aging in Monkeys
07/09/2009
Massachusetts Institute of Technology
Comments
Alex
10/03/2006
Posts:1
Basically, I have to question such wide-ranging benefits of low-cal diets simply because there is no place in nature where this is seen. Animals try to eat about as much as they can. If it were dramatically better for them not to do so, then why has natural selection not given instincts to all of us to stop eating at an optimal point?
Certainly over-eating is damaging, because it is so rare in nature for much food to be available. But likewise, why have not the hungriest tribes of the world not shown to the rest of us longer, healthier lives, lesser disease (yeah, right) and greater productivity?
kitk
10/04/2006
Posts:65
Worse : it's better for the species, that you die when you are not useful for your offspring anymore (Since being alive and old makes you eat the food of other reproducer).
May-be this is why we just die : to leave the room for the offspring and allows their genes to evolve.
We are kind of slaves to our genes.
Sly
10/04/2006
Posts:11
aymeric
10/04/2006
Posts:19
captainhurt
10/12/2006
Posts:2
agnes
10/12/2006
Posts:1
In addition, all the studies increased the vitamin levels of the cal. restricted group to make it even with the non-restricted group. While the amounts were the same, the amount/body mass was 25-30% different. It seems to me that this is very confounding.
It seems our Medical Societies bias against the benefits of vitamin intake is blinding them to a possible applicable result.
We should all be in shape, but be taking significantly more vitamins.
guetenburg
04/30/2007
Posts:6
Caloric restriction is not a miracle cure, but if done correctly, it could easily add 10 years of lifespan to humans.
gabrielg01
10/04/2006
Posts:405
I am asking because some human studies made the mistake to put controls on a cholesterol-dripping burger diet so what the studies actually measured was toxicity of control, rather than benefit of CR over an optimal non-CR diet.
John Schloen...
10/04/2006
Posts:1
gabrielg01
10/04/2006
Posts:405
Katie Bourza...
10/04/2006
Posts:2
Our doctors repeat a tiresome litany; lose weight, get some exercise, drink less alcohol; give up smoking; eat right; and pay your medical bills. They say this emphatically yet with no real hope because they can't live by their own advice.
What we need is a way to lose weight that doesn't require willpower or relocating to Mumbai India.
Phineas
10/04/2006
Posts:85
most animals work like hell to get enough food just to live. we humans also do, or should, work enough to balance our food intake. so if these monkeys are living in cages, being fed foods far more energy intensive than natural foods, this tells us nothing.
kitk
10/04/2006
Posts:65
captainhurt
10/12/2006
Posts:2
I enjoyed this report. The work of Dr. Rick Weindruch is especially important to me since his writings originally inspired me to begin calorie restriction twelve years ago. Some, who are not informed about the many benefits of a calorie-restricted lifestyle, may think that only a stoical few could practice calorie restriction and those who do live dreary lives, hoping for an unrealistic extension of life. Indeed, it almost seems a requirement for scientists or writers to include a phrase like the following in this article “it’s unlikely that most people could be able to stick with it.”
Your readers should know that for many successful CR practitioners “restriction” is really liberation – liberation from the idea that the amount of food intake is proportional to one’s happiness. For many of us, liberation from high-calorie intake results in living our full potential right now, with hopes for a longer life. I can state unequivocally that the health and happiness benefits are life transforming. Anyone who experiences the increased energy, the heightened cognitive capabilities, and the phenomenal health benefits of the calorie-liberation lifestyle will never want to go back to the rapid-aging way of life followed by a majority of our Society.
True, some will always take things to extremes and equate their failures with the essence of calorie restriction. But fortunately, thousands of practitioners can set the record straight. Confirming our positive experience is the visionary work of Dr. Luigi Fontana and Dr. John Holloszy (http://tinyurl.com/yxj3x9) at Washington University in Saint Louis School of Medicine with their longitudinal study on the effects of CR in humans. My wife and I are members of the 23-person cohort of the Calorie Restriction Society (www.calorierestriction.org) who are being thoroughly evaluated and compared against other cohorts. Already two well-reported papers have resulted:
Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans.
Proceedings of the National Academy of Sciences of the U. S. A..
2004 Apr 7;101(17):6659-63. Fontana L, Meyer TE, Klein S, Holloszy JO.
PMID: 15096581
Long-term caloric restriction ameliorates the decline in diastolic function in humans.
Journal of the American College of Cardiology. 2006 Jan 17;47(2):398-402.
Meyer TE, Kovacs SJ, Ehsani AA, Klein S, Holloszy JO, Fontana L.
PMID: 16412867
But perhaps the best news for health-minded folks is that in round three of the research, Dr. Fontana will be joined by Dr. Stephen Spindler (http://tinyurl.com/y97v79) and Dr Shin Imai (http://dbbs.wustl.edu/dbbs/website.nsf/RIB/107B3F3826243E9B86256D4E005B2D3A), who will explore the genetic and signal transduction aspects of calorie restriction.
We hope the results will be a beacon for all who want to live as long and healthfully as possible. To learn more use this link http://www.calorierestriction.org/ResearchOnAging.
Wishing you and your readers long health and happiness,
Paul McGlothin
VP, Research
The Calorie Restriction Society
Research@CalorieRestriction.org
pmcglothin
10/23/2006
Posts:1
I'd say: watch for the outcomes, it’s going to exciting.
(1) Minireview: the role of oxidative stress in relation to caloric restriction and longevity. Endocrinology. 2005 Sep; 146(9):3713-7. Epub 2005 May 26
(2) Caloric restriction, metabolic rate, and entropy. J Gerontol A Biol Sci Med Sci. 2004 Sep; 59(9):B902-15
(3) Aging in mouse and human systems: a comparative study. Ann N Y Acad Sci. 2006 May; 1067:66-82
Ivan Boyadzhiev, M.D.
Convex
Ivan Boyadzh...
10/27/2006
Posts:1
Simply, the answer is no. There is nothing new to report. You should compare this artticle with the many that have preceded it. The University of Wisconsin has one of the most active public relations departments I've encountered.
Studies in humans are always going to provide better data about humans than will studies in other species. Given that humans are volunarily participating in caloric restriction, the data from animal models has very little utility.
The reason that these studies continue is also a simple one: money. Weidruch's FY 2003 federal grants:
P01AG011915-10 $1,416,472 Dietary Restriction And Aging In Rhesus Macaques
P20CA103697-01 $586,000 Aging And Cancer Program
R01AG018922-03 $372,081 Gene Expression Profiling, Oxidative Stress And Aging
T32AG000213-13 $385,144 Biology Of Aging And Age-Related Diseases Training Grant
One issue that is never addressed in these UW-spin pieces is the effects of the research on the animals. In the Weindruch studies, these monkeys are individually housed for their entire lives. Individual housing is a well-recognized cause of emotional stress in rhesus monkeys closely associated with stereotypic behaviours and self-mutilation.
Is the knowledge gained from a lifetime of chronic hunger and loneliness really outweighed by the data generated?
[An aside: Just recently, the University of Wisconsin announced that they had destroyed sixty boxes of video tapes of experiments on primates at the UW. The university reported that they were destroyed 63 days following a denial of a open records request for a single tape. The WI state statutes require that requested documents be kept on hand for 60 days following a denial.]
Rick
11/02/2006
Posts:1
Elroch
03/01/2007
Posts:33
In addition, all the studies increased the vitamin levels of the cal. restricted group to make it even with the non-restricted group. While the amounts were the same, the amount/body mass was 25-30% different. It seems to me that this is very confounding.
It seems our Medical Societies bias against the benefits of vitamin intake is blinding them to a possible applicable result.
We should all be in shape, but be taking significantly more vitamins.
guetenburg
04/30/2007
Posts:6