The Correct Combination Of Proteins Is Decisive For Healthy Aging, Not Reducing The Calories In Our Diet
A new study of the Max Planck Institute for Biology of Ageing could help to understand the positive effect of dietary restriction on healthy ageing. Previous evidence from different organisms (fruit flies and mice) have shown that dietary restriction increases longevity, but with a potential negative side effect of diminished fertility. So the female fruit fly reproduces less frequently with a reduced litter size on a low calorie diet, but its reproductive span lasts longer. This is the result of an evolutionary trait, as scientists believe: essential nutrients are diverted towards survival instead of reproduction. (Nature, December 3, 2009)
Researchers from the newly founded Max Planck Institute for Biology of Ageing in Cologne have studied whether health benefit stem from a reduction in specific nutrients or calorie intake in general by manipulating the diet of female fruit flies. The fruit flies were fed a diet of yeast, sugar and water, but with differing amounts of key nutrients, such as vitamins, lipids and amino acids. The scientists were able to show that longevity and fertility are affected by a combination of the type and amount of amino acids; whilst varying the amount of the other nutrients had little or no effect. Furthermore, the researchers found out in previous studies that levels of a particular amino acid – methionine – were crucial to increasing lifespan without decreasing fertility. By carefully manipulating the balance of amino acids, both lifespan and fertility were maximised. For the first time, this indicates that it is possible to extend lifespan without wholesale dietary restriction and without lowering reproductive capacity. Read more
Pleasant Dietary Habits Are Necessary For Health
Japanese research group led by Professor Yasuhiko Minokoshi and Dr. Tetsuya Shiuchi, scientists at the National Institute for Physiological Sciences, NIPS, Japan, found that meals stimulated with sweet taste and motivated with its anticipation regularly activates “orexin” in the brain and it stimulates muscle glucose metabolism via the sympathetic nervous system, thereby reducing blood glucose level in mice. They report their finding in Cell Metabolism published on Dec 2, 2009.
The research group focused on the function of “orexin” neurons in brain. Orexin is a kind of brain hormones related to sleep/wakefulness and food intake. They found that orexin released in the brain from “orexin” neurons activates glucose metabolism in muscle but not adipose tissue in mice through the preferential activation of the sympathetic nervous system. Furthermore, they found that a pleasant meal with sweet taste stimulation and its anticipation activates orexin neurons and curbs the rise of blood glucose level by activating muscle metabolism via the sympathetic nervous system. Read more