The Longevity Diet

The Longevity Diet

I just finished The Longevity Diet by Valter Longo, a scientific look at how we eat. Longo is a research biologist at USC Davis School of Gerontology, where he developed the fasting-mimicking-diet (FMD). It’s one of the topics of his books, along with what to eat to live longer and other potential routes to life extension.

Early on in his career, Longo made two important discoveries. If he starved yeast, it lived twice as long. He also observed that sugar caused the yeast to age fast and die early by activating RAS and PKA genes that accelerate aging. The conclusion he drew was that if aging is a central risk factor for all major diseases, it’s smart to intervene in aging itself. How to do this is the holy grail for biogerontology, the science of the biological aging process, and potential means to stop it.

Diet is likely a factor. According to Longo, we have known for almost a hundred years that mice fed 30-40 percent fewer calories live longer and develop fewer diseases than mice on a normal calorie diet. At the same time, severe calorie restriction over extended periods can have a negative effect. Longo recommends the longevity diet, which is mostly vegan with some fish, unsaturated fats, and low sugar intake. He takes inspiration from the centenarians in the blue zones with time-restricted eating and an hour of walking a day.

What’s interesting about Longo’s diet is that he advocates low but sufficient protein at 0.8g/ kg of body weight/ day. High protein intake activates the growth hormone receptor, which in turn increases levels of insulin and insulin-like growth factor 1 (IGF-1). There’s a link between higher levels of insulin and IGF-1 and certain cancers and accelerated aging. By reducing calorie intake, especially intake of protein and sugar, you can reduce the activities of the growth hormone receptor and the gene clusters that make you age faster.

Lab mice with defects in the growth hormone receptor can live fifty percent longer than normal mice. Longo has also studied a group of Laron syndrome patients in Ecuador. Laron syndrome is caused by a mutation in the growth hormone receptors. It leads to dwarfism and a high rate of obesity in comparison with relatives on the same diet. Even though obesity is a risk factor for type 2 diabetes, not a single one of the one hundred Laron syndrome patients studied developed the disease. It appears that the inability to use growth hormone eliminates obesity’s diabetes-promoting effect. When proteins are the chief regulators of the growth hormone gene, it suggests that high protein intake may promote diabetes in part by increasing the activity of growth hormone and IGF-1.

Longo’s theories of eating relatively low protein go against popular diets like the PE and the carnivore diet. They both require a lot of meat. Some say you should watch the fat, while others eliminate the carbs. I’m still on the fence, trying not to eat too much of anything. The Longevity Diet, which is a well-written and thought-provoking read, has made me even more confused.

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