Studies involving the use of caloric restriction for significantly improved health and longevity have been ongoing for about the last 75 years. Most of these studies have involved species such as worms, fruit flies, mice and dogs due to their shorter life spans. Although some degree of benefit, often enormous benefit relating to the impact of caloric restriction has been shown in every species studied, some degree of skepticism existed as to whether such dietary restriction would be of similar benefit to primates such as us.
In July of 2009 the eagerly awaited results of a twenty year study on the effects of caloric restriction on primates were finally published in the journal, Science (2009 Jul 10; 325(5937): 201-204).
Two groups of Rhesus monkeys (selected for their strong similarity to us) were studied. One group of Rhesus monkeys were allowed to eat as much as they wanted and the other group was given a sufficiently nutrient dense diet with 30% fewer calories than they would normally consume. Twenty years later only 63% of the monkeys that ate as much as they wanted were still alive. 37% of them had died due to age related causes (heart disease, cancer or diabetes).
And the caloric restriction group?
Fully 87% were still alive and only 13% had died–and of these only 5 of the 14 individuals died of age related causes! The rest died from complications of anesthesia, gastric bloat, endometriosis or injury.
Even the researchers themselves were blown away by these results and confidently speculated that these findings would have considerable implications for combating aging and disease in humans.
Of all monkeys that survived–the remaining two groups of monkeys even looked considerably different from one another. Each group had aged very, very differently.
Throughout their lives the calorically restricted group maintained superior health and aging-related biomarkers in every area: brain health, metabolic health and rate, insulin sensitivity and cardiovascular vitality. The caloric restriction group enjoyed a 3-fold reduction in age-related disease!! Also, they lost fat weight but maintained healthy levels of lean tissue mass. They additionally retained greater brain volume (which normally shrinks with age and glycation) but more than that they retained superior cognitive function. The cardiovascular disease rate of the caloric restricted group was fully half the rate of the control group. 40% of the control group developed diabetes (or pre-diabetes). Not ONE single monkey in the calorically restricted group developed either.
Photos from the study, shown here, present examples of age-matched individuals from the two groups. The contrast is visually striking. Stunning, even. The caloric restricted monkeys looked almost literally half the age of the controls:
Example of a control group monkey is shown on the left (AB) and a calorically restricted monkey on the right (CD)–both are exactly the same age
The study was designed, of course, well before Cynthia Kenyon’s work was published or anything related to mTOR–both of which have added richly to the understanding behind the mechanisms of just why caloric restriction is so effective, so one can only imagine how much more might have been accomplished with that awareness in mind.
FYI–Among the most common misconceptions about monkeys and apes, incidentally, is that they are vegan animals. They are better adapted to making use of plants in some ways than we are, but they also readily eat the same things we eat. ALL monkeys and apes are known to eat meat–and many even hunt for meat. The one notable exception is the mountain gorilla…and even they get some insects in their diet. Monkeys and apes are omnivores and, like us, will eat whatever might be available to them in their environment. Some even catch and eat fish (crazy, but true)! One of the reasons Rhesus monkeys were selected for this particular study, in fact, is because of their pronounced similarity to us, even in terms of diet. For more reading about this particular aspect of things I can recommend the book, “The Hunting Apes: Meat Eating and the Origins Of Human Behavior” by Craig B. Stanford.
Recent Human Longevity Research
There are actually other recent studies, too, showing significant health benefit where caloric restriction in actual humans is concerned. A newly released study in the Journal of Applied Research, Clinical Experience of a Diet Designed To Reduce Aging (Ron Rosedale, MD, E.C. Westman, MD, MHS, J.P. Konhilas, PhD; Vol 9, No. 4, 2009) demonstrated in the context of an outpatient medical clinic that a diet high in fat (unlimited quantity), adequate in protein (50-80 grams per day) and very low in carbohydrate, with some added multi-vitamin and mineral supplementation (together with 2,000 mg/day L-carnitine, 400 mg alpha lipoic acid, 100 mg CoQ10, and 1 TBSP cod liver oil) led to significant improvement in recognized serum factors related to the aging process (glucose, insulin, leptin and triglycerides). Patients were told to eat when they were hungry. The results also included a significant loss of adipose body weight, a significant reduction in systolic and diastolic blood pressure, and a reduction in levels of leptin, insulin, fasting glucose, and free T3 (with TSH levels and creatinine largely unchanged). Despite the predominance of fat in the diet, serum triglycerides were also greatly reduced.
Another area of human longevity research getting a lot of publicity these days involves manipulating the length of something called “telomeres”. Telomeres are sequences of nucleic acids extending from the ends of chromosomes and act to maintain chromosomal integrity. Every time our cells divide telomeres are shortened, leading to cellular damage and cellular death associated with aging. Scientists (at Geron Corporation) discovered that the key element in rebuilding our disappearing telomeres is the “immortalizing” enzyme telomerase, an enzyme found only in germ cells and cancer cells. Telomerase appears to repair and replace telomeres manipulating the “clocking” mechanism that controls the life span of dividing cells. Drug companies, of course, are looking for ways to enhance telomerase any way they can. In fact, look for up-coming supplements and possibly “life extension” related medications claiming to do just this. What they won’t tell you, however, is that caloric restriction also preserves telomere length. You don’t have to wait for a questionable drug to come out or go broke buying hyped “designer supplements”.
Of course, it’s easy to restrict overall calories with lab animals, as they have no choice in the matter. It is quite another matter to try and restrict overall caloric intake when you’re driving past 15 fast food joints on your way home, are surrounded by constant advertisement and have a refrigerator and cupboards full of food at your ravenous fingertips. UNLESS, of course, you apply the caloric restriction model in a way that does not leave you hungry–which is exactly what Primal Body-Primal Mind tells you how to do. Just follow the simple, most basic dietary guidelines outlined in my book to eat optimally well while feeling fully satisfied, live healthier, longer–and even save some real money along the way!
The most basic guideline to remember is this: greatly restrict or eliminate sugar and starch (preferably eliminating gluten completely), keep your protein intake adequate (roughly the RDA–44-56 g/day or 0.8 g/kg of ideal body weight) amounting to approximately 6-7 ounces of organic grass fed/wild caught meat/seafood total per day, eat as many fibrous “above ground”/non-starchy vegetables and greens as you like and eat as much fat (from fattier cuts of meat or fish, nuts, seeds, avocados, coconut, butter/ghee, olives, olive oil…etc) as you need to satisfy your appetite.
The bottom line here is that natural dietary fat is not at all our enemy–and that in the absence of dietary carbohydrate and with adequate protein can result in a far more satisfying, longer and healthier life overall. Simple, delicious and satisfying. No hunger or feelings of deprivation needed…and all the benefits of supporting a longer and healthier life while saving you money.
If you do nothing from my book other than what was outlined in the paragraph above your health and well being will change remarkably–and chances are you will age much more gracefully and live longer.
And that’s no monkey business.