A study has recently been published that some are interpreting to mean a calorie-restricted diet could slow the aging process, but this is a significant misrepresentation of what the findings are actually showing. Yes, the study looked at the effects of a caloric restriction on mice and, yes, these mice did live longer and showed some signs associated with reduced aging, but that’s where the similarities end. While the idea that diet and exercise could have anti-aging effects and prolong lifespan is nothing new and may be valid, this particular study is not a good piece of evidence for that argument.
Caloric Restriction Diet: Summary
The mice used in this study were from a strain that had a lifespan of about four-to-six months due to deficiencies in a DNA repair gene, which caused accelerated aging. When the mice were started on a 30% calorie-reduced diet at around seven-to-nine weeks into their life, their average lifespan went up by 180% to 200%. When the mice were only given the restricted diet from six-to-twelve weeks of age and then feed whatever they liked after, they only lived four-to-six weeks longer than the control. Aside from the longer lifespan, the mice fed the caloric restricted diets retained 50% more neurons in their brains and held on to full motor function longer.
The key thing to keep in mind when looking at this study is that the mice strains involved are designed to age rapidly. They are used to mimic the conditions of progeroid syndromes, a type of rare genetic condition that causes accelerated aging and the various associated effects on the neuromuscular systems.
What This Means
The results of animal studies do not always translate to human effects and this is particularly true when dealing with dietary influences. Past studies with different animals or even different strains of mice have shown caloric restrictions to improve, shorten, or have no effects on lifespan. There are also limited ways to safely test a caloric restricted diet in humans. Aside from problems relating to how hard it is to stick to such a diet, the significant drop in calories can negatively impact the immune system, among other problems.
This study suggests that caloric restrictions may help improve or lengthen the lifespan of people suffering from progeroid syndromes and should be followed up on in that regard. As far as the idea that it proves low-calorie diets can slow the aging process in general goes, however, that is sadly the result of over-interpretation or misunderstanding by other reporters.
Vermeij, W., et al., “Restricted diet delays accelerated ageing and genomic stress in DNA-repair-deficient mice,” Nature, 2016; 10.1038/nature19329.