Eat less, live longer and healthier, a study suggests

Reducing your calorie intake, even just a little bit, may have a beneficial effect on longevity and good health, a new study suggests.

“Two years of modest calorie restriction reprogrammed the pathways in fat cells that help regulate the way mitochondria generate energy, the body’s anti-inflammatory responses, and potentially longevity,” says Eric Ravussin, PhD, Associate Executive Director for Clinical Science at Pennington Biomedical Research Center.  “In other words, calorie restriction rewires many of the metabolic and immune responses that boost lifespan and health span.”

The new study, published in the journal Science, used data from the longest-running calorie restriction trial in humans: Louisiana State University Pennington Biomedical’s CALERIE 2 (Comprehensive Assessment of the Long-Term Effects of Reducing Intake of Energy).

People who reduced their calorie intake by about 14 percent over two years, according to the study, generated more T cells. T cells are vital to the immune system and help slow the ageing process.

“As people age, their thymuses shrink and produce fewer T cells. As a result, older people have a harder time fighting off infections and certain cancers,” says Eric Ravussin, PhD, Associate Executive Director for Clinical Science at Pennington Biomedical Research Center.  “Calorie restriction helps prevent the thymus from shrinking so the person generates more T cells.”

Ravussin adds that an increase in T cells doesn’t only affect immunity; it is also associated with an improved ability to burn stores of fatty acids for energy. Burning stores of fatty acids for energy is a significant plus because if a person doesn’t use up this energy, there may be fat buildup in organs – which is associated with insulin resistance, obesity, type 2 diabetes and ageing.

Another important discovery by the authors is a potential treatment to lessen age-related inflammation and enhance metabolic health.

While rodent studies have shown that restricting calories by 40 percent helped them live longer, it had also shunted their growth, reproduction and immunity.

Yet calorie restriction also diminishes the levels of gene encoding platelet activating factor acetylhydrolase (PLA2G7). This is a good thing, as minimising PLA2G7 is beneficial to health – its reduction lowers age-related inflammation and improves metabolic health.

“If researchers can find a way to harness PLA2G7, they could create a treatment to extend a person’s health span, the time an individual experiences good health,” says Pennington Biomedical Executive Director John Kirwan, PhD.