It has been known for a long time that calorie restriction (code word for eating less) makes us live longer – this was known as the Albanian paradox. Being a poor country, deficient in a decent diet, we would have expected Albanians to have had short lives, when in fact they were among the longest lived people on earth.

Life-extending hormone bolsters the body’s immune function

Yale School of Medicine News, 01/12/2016

A hormone that extends lifespan in mice by 40 percent is produced by specialized cells in the thymus gland, according to a new study by Yale School of Medicine researchers. The team also found that increasing the levels of this hormone, called FGF21, protects against the loss of immune function that comes with age. Published online in the Proceedings of the National Academy of Sciences on Jan. 11, the study’s findings have future implications for improving immune function in the elderly, for obesity, and for illnesses such as cancer and type–2 diabetes. Dixit added that FGF21 is produced in the liver as an endocrine hormone. Its levels increase when calories are restricted to allow fats to be burned when glucose levels are low. FGF21 is a metabolic hormone that improves insulin sensitivity and also induces weight loss; therefore it is being studied for its therapeutic effects in type–2 diabetes and obesity. Dixit said further studies will focus on understanding how FGF21 protects the thymus from aging, and whether elevating FGF21 pharmacologically can extend the human healthspan and lower the incidence of disease caused by age–related loss of immune function. “We will also look to developing a way to mimic calorie restriction to enhance immune function without actually reducing caloric intake.”