Primate Study Confirms Calorie Restriction Extends Life and Protects Against Age-Related DiseaseSeptember 2014
By By Paul Mcglothin and Meredith Averill
Eating less can enable you to live longer in a far healthier state.
A controversy erupted two years ago when researchers at the National Institute on Aging proclaimed that humans may not benefit by consuming fewer calories.
The media reacted by running headlines and news articles stating that how much you eat has no effect on health and longevity.
Life Extension® knew the National Institutes of Health’s findings were erroneous and published rebuttals to it.
We are pleased to report that a 2014 primate study at the University of Wisconsin showed that compared to calorie-restricted monkeys, those in the control group (not calorie restricted) were almost three times more likely to die from age-related causes.
Starting almost 80 years ago, every living organism studied—from yeast to humans—has shown the robust life-extension and disease-protection effects of calorie restriction.1,2
But in 2012, researchers from the National Institute on Aging released a controversial finding: no survival benefit from calorie restriction in their rhesus monkey study.3
If true, that would be bad news for human calorie restrictors. Monkeys age in very human-like ways: Gray hair, declining muscle strength, and thinning bones are common. Age-related diseases, like cancer and diabetes, also often occur as monkeys age.4
Fortunately, newly published results from the University of Wisconsin’s (UW) long-term study of calorie restriction in rhesus monkeys are very promising.4 The UW researchers found a significant survival benefit for calorie restriction in comparison to the non-calorie-restricted controls that were allowed to eat as much as they wanted.
Why did the two studies have such very different outcomes?
Two Calorie Restriction Studies Compared
Ben Best, in his excellent report on the European Biogerontology Conference in the May 2014 issue of this publication, analyzed differences between the two studies that would likely account for such findings.
…the UW control monkeys could eat whenever they wanted (which represents the typical human diet), whereas the NIA control monkeys received a standard allotment of food, which mildly restricted their calories. On average, there was a greater difference in body weight between the calorie-restricted and the control monkeys at UW than at the NIA. In rats, very low levels of dietary restriction have a significant effect on survival, so the NIA controls may be showing those benefits, which diminished the longevity difference between the two groups of monkeys (calorie-restricted versus controls).5
Ben Best also mentioned important differences in the carbohydrate composition between the two studies:
Although both the NIA and the UW monkeys received nearly 60% carbohydrates, the UW diet was 28.5% sucrose, whereas the NIA diet was only 3.9% sucrose. The UW protein source was lactalbumin, whereas the NIA diet included fish meal, which is rich in omega-3 fatty acids. Omega-3 fats are known to reduce cardiovascular disease.5
The NIA paper caused a media frenzy with headlines, declaring that calorie restriction doesn’t work. And calls came in to our group, the CR Way™, asking for clarification of the results. So we collaborated with the CR Society in organizing a joint meeting of scientists who study calorie restriction in rhesus monkeys and those studying long-term caloric restriction in humans.
Many important ideas were exchanged that are outside the scope of this article. But one important outcome was that the scientists plan to issue a paper analyzing the NIA and UW studies together.
For most members of LivingTheCRWay.com, the studies made little difference. Every day, we experience extraordinary results that would be common for people of much younger ages. But for millions who are influenced by headlines, the negative stories discouraged them from finding out how calorie restriction might help them live better and possibly longer.
In April 2014, the Wisconsin scientists’ paper titled “Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys,” was published.
The researchers acknowledge that their data contrasts with findings in the widely reported 2012 National Institute on Aging study; however, they emphasize an important point that Ben Best identified: The NIA control monkeys were effectively practicing modest calorie restriction because their food allotments were well controlled.
The CR Way™
If you are considering starting a calorie-restricted diet, the Wisconsin research results should be encouraging: All the monkeys in the study were adults, suggesting that you can start a calorie-restricted diet now and reap significant benefits. In fact, the study includes a helpful statistical analysis, indicating that the control animals had 2.9 times greater rate of death from age-related causes than the calorie-restricted animals.
Modest calorie restriction resonates with the CR Way™. The days are gone when human calorie restrictors practiced draconian diets that produced extremely low body weights. The CR Way™ changed that. It takes advantage of the latest scientific research, showing that activation of longevity cell signals is the important factor for slowing aging. As the rhesus monkey studies confirm, this may be as simple as keeping calorie intake moderate and choosing nutrient-dense foods. Regular moderate exercise and maintaining a happy approach to life are also important.
The Wisconsin study results support the findings of the extensive human study of elderly Okinawans who followed “modest” calorie restriction for 60 years, limiting calories by only 11%. Their average life span is the longest recorded in the world. They also experience less heart disease, cancer, diabetes, and Alzheimer’s disease. Their quality of life is better too. Many Okinawans who practice calorie restriction remain active well into their 90s and beyond.6
We see similar results among LivingTheCRWay.com members. The CR Way™ encourages moderate calorie restriction, which improves quality of life and is easy to follow.
Interestingly, both the University of Wisconsin and National Institute of Aging studies indicate that greatly extended life span may be possible from moderating calorie intake. For example, five monkeys in the NIA study—four calorie-restricted and one (mildly calorie-restricted) control monkey—lived exceptionally long lives, beyond 40 years of age, when the average age of death of monkeys in captivity is 26. Following a CR Way™-type lifestyle has produced supercentenarians, such as the famed Jiroemon Kimura, who ate small meals, didn’t smoke, and exercised by farming for 25 of his elder years, and is verified as the longest-lived (116 years) man in history.7
If you have any questions on the scientific content of this article, please call a Life Extension® Health Advisor at 1-866-864-3027.
Paul McGlothin and Meredith Averill are co-authors of The CR Way™ (HarperCollins, 2008) and they lead The CR Way™ Longevity Center. To learn more about the CR Way™ or the CR Society International, visit www.LivingTheCR Way.com or www.CRSociety.com
- McCay CM, Crowell MF, Maynard LA. The effect of retarded growth upon the length of life span and upon the ultimate body size. Nutrition. 1989 May-Jun;5(3):155-71.
- Redman LM, Ravussin E. Caloric restriction in humans: impact on physiological, psychological, and behavioral outcomes. Antiox Redox Signal . 2011;14(2):275-87.
- Mattison JA, Roth GS, Beasley TM, et al. Impact of caloric restriction on health and survival in rhesus monkeys from the NIA study. Nature. 2012 Sep 13;489(7415):318-21.
- Colman RJ , Beasley TM, Kemnitz JW, et al. Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys. Nat Commun. 2014;5:3557.
- Best B. European Biogerontology Conference in Israel. Life Extension. 2014 May;20(5):90-7.
- Willcox BJ, Willcox DC, Todoriki H, et al. Caloric restriction, the traditional Okinawan diet, and healthy aging: the diet of the world’s longest-lived people and its potential impact on morbidity and life span. Ann N Y Acad Sci. 2007 Oct;1114:434-55.
- Available at: http://www.theguardian.com/world/2013/mar/07/world-oldest-person-jiroemon-kimura. Accessed June 19, 2014.