The Biochemical Benefits of Vegan Diets by Jerry Brainum 10/22

 

 

In a previous article in this issue of Applied Metabolics, I discussed whether a person over age 40 can develop muscle while consuming a vegan diet. But that raises the question of why anyone would even consider embarking on a vegan diet. Numerous websites and YouTube videos attest to the health benefits associated with consuming a plant-based diet. But one problem with such sources is that they tend to cherry-pick research that backs up the many health claims touted about vegan nutrition. Indeed, some of the more militant vegan advocates infer that those who consume animal foods are facing a myriad of possible health problems that even include a shortened life span. That of course implies that consuming a vegan diet will extend the human lifespan. The only eating style shown to extend lifespan involves a caloric restriction (CR) that involves reducing daily caloric intake by at least 30% of total calories. This style of eating was initially found to boost the lifespan of animals in the 1930s, and subsequent studies over the years showed that it worked for various animal species ranging from rodents to fish to dogs. That led some researchers to suggest that it would work for primates, including humans. The only primate thus far studied for the effect of CR have been monkeys, and the results are mixed. However, CR does provide a number of benefits that are conducive to longevity, such as decreased body fat, lower resting insulin levels, and lower resting glucose levels.

Although there is no human evidence that following a stringent CR style of eating will work for humans as it does for animals, some humans have chosen to become human guinea pigs and follow severely calorie-restricted diets. People on these eating regimes claim to feel younger and show some of the same beneficial health changes observed in monkeys on CR. But they all look, without exception, gaunt and are devoid of muscle mass.  This isn't hard to understand since their low-calorie intake makes getting enough protein nearly impossible, and the fatigue they feel makes undergoing intense exercise also not possible. So they are in a state of semi-catabolism. Since recent studies show that a loss of muscle mass is closely associated with increased mortality, this raises the question of whether the other health benefits imparted by calorie restrictions will outweigh the negative effects of having too little muscle mass. Many scientists think that CR will provide little or no longevity benefits, certainly not more than engaging in such measures as not smoking and drinking excessively and maintaining lower body fat levels, all of which are possible without having to starve yourself. Even worse: recent rodent studies show that CR will only produce a life extension effect when started early in life. Rodents who began CR eating regimes during the rodent equivalent of middle age had no life extension benefits from CR at all. Other . . .