Caloric restriction for living longer

     

    Since a young age, the majority of us have been told to eat all of our food so that we could live long and healthy lives. Scientists have now found that this belief may not be completely true. It is important to first note that the theory of aging is still highly debated, with its two main theories being, an accumulation of free radicals which cause aging, and the rate of living theory which states that larger animals live longer than smaller animals due to slower metabolic rates. 

    Since a slower metabolic rate is thought to be correlated with a long life, it would make complete sense that a calorie deficit would increase lifespan. As a person reduces their food intake it will also reduce their metabolic rate. A decrease in the metabolic rate would then be correlated with a longer life. Looking at the second theory of aging, scientists have also found that multiple species are known to produce less free radical when in a calorie deficit which in turn may also delay aging in an organism. With that being said, no matter which theory is correct, we see that among rhesus monkeys restricting calories improves health and increases lifespan (Kumlien 2017). Although this was an incredible study that showed promising results, it is not the first study to suggest a caloric deficit. In 1935, Clive McCay, found that rats who had a severely restricted diets lived 33% longer than the expected life span (Grabski 2020). Lastly, scientist at the salk institute in California conducted a study with rats where a control group ate whatever they liked and the second group had a calorie deficit of 30%. This was maintained for 9 months which is the equivalent of 20 human years. Researchers concluded that 57% of age-related changes in the cells of normal rats were not seen in rats that were on a calorie deficit (Neuro 2020). 

    Although the majority of these studies have shown promising results, some scientists fear that a long-term caloric deficit could do more harm than good. One argument is that the control groups in the majority of these studies are allowed to eat as much as they want. Grabski argues that this may cause the control group to consume more calories than needed which in turn leads to weight gain and poorer overall health (Grabski 2020). 

    Research studies on caloric deficits are still fairly new and have not been examined enough to give a definitive answer. One limitation in this research is the ability to control the diets of human subjects as it may be much harder to control than in animals. Eating at a caloric deficit may show promising results but there may be better alternatives while the science is still being researched. 

References: 

“Calorie Restriction Lets Monkeys Live Long and Prosper.” News, 17 Jan. 2017, news.wisc.edu/calorie-restriction-lets-monkeys-live-long-and-prosper/.

FeaturedPsychology·October 22, 2020·2 min read, et al. “Eat Less, Live Longer.” Neuroscience News, 28 Feb. 2020, neurosciencenews.com/caloric-restriction-longevity-15812/.

Jan Wolitzky, et al. “Can Calorie Restriction Extend Your Lifespan?” Science in the News, 2 Aug. 2020, sitn.hms.harvard.edu/flash/2020/can-calorie-restriction-extend-your-lifespan/.