A number of studies have shown that reducing intake of calories through fasting extended lifespan in animals, including mammals. It also protected the brain against age-associated degeneration. Intense exercise has been found to have similar effects.

But no one really knew why this protective effect occurred. In both situations (fasting and performing intense exercise) brain levels of special growth factors called BDNF and NGF increased, and there were fewer free radicals and lipid peroxidation products in the brain. But why that happened remained a mystery.

More recent studies then found that in both situations, the body produces substantially more ketones. When given to animals, ketones extend lifespan, reduce brain degeneration, and protect many tissues and organs in the body.

A considerable amount of research has shown that high glucose levels are toxic to cells, especially brain cells. This condition is called glucotoxicity.

In part, glucotoxicity occurs because high glucose levels dramatically increase the generation of free radicals and lipid peroxidation products.

High fructose corn syrup, a sweetener used in many foods and drinks, appears to be the most toxic form of glucose. The average American diet contains very high levels of sugar and other simple carbohydrates that are easily converted to sugar in the body. When combined with the equally high levels of inflammatory omega-6 oils — which are also an integral part of the typical American diet — the potential for harm is great.

Adding to the danger, high sugar levels also suppress generation of beneficial ketones. Combining intermittent fasting, regular exercise, and a diet that’s low in carbohydrates can produce optimal ketone levels.

Fortunately, as people age many eat far less than when they were younger, which increases ketosis and actually helps slow aging and diseases associated with aging. Unfortunately, those people also become deficient in many essential vitamins and minerals.

Studies show that supplying essential minerals and vitamins greatly improves the benefits of fasting and low-calorie diets. Dr. Bruce Ames has demonstrated that as people age, enzymes in the body become sluggish. Taking higher doses of vitamins can give sluggish enzymes a much needed boost.

Another benefit is that ketones reduce the inflammation that is associated with a great many diseases, including cancer, neurodegenerative diseases, and heart failure.