Baltimore, United States (Web Desk): A recent research has revealed that fasting or severely restricting calories on a periodic basis may actually make us healthier and smarter than if we get the standard three square meals a day we've long been told are the road to optimal health.
Mark P. Mattson, chief of the laboratory of neurosciences at the National Institute on Aging in Baltimore, said, "Energy restriction - intermittent fasting in particular but also calorie restriction, [which is] reducing the amount of calories in a meal but still eating regular meals - they both enhance the ability of nerve cells to cope with stress. Particularly during aging, there's a lot of evidence that individual nerve cells are under a lot of stress in the form of reduced ability to generate energy to support their function."
Nerve cells are also subject to oxidative stress - damage caused by free radicals. Free radicals are molecules that enter the body and can damage cells - these molecules are what many scientists now believe cause aging. Antioxidants, which we get from many plant sources, can help reduce the damage these molecules cause, and some may potentially slow down the aging process. But Mattson says that may not be the only way to counteract the normal aging process, or at least slow it down.
Mattson's work has consistently shown that by stressing our bodies with intermittent fasting and calorie restriction, we're actually aiding our cells' ability to fend off the damage caused by free radicals. It may seem counterintuitive: Why would the body be healthier without food than with it? Mattson and his team are taking the long view in assessing this hypothesis by assessing these claims through an evolutionary lens.
"Our ancestors and other animals in their normal environment had to compete for food availability and limited resources such that they would have to go extended time periods without food. For example, if it's a carnivore, they'd have to track down prey and kill it. So it's very common for animals and also our ancestors in the not-too-distant past to go a day or two or sometimes even more without eating." In that scenario, it would not serve a hunter well if his powers of cunning took a hit just because he was hungry. Therefore, Mattson says the human brain has evolved to withstand periods of fasting while retaining a high level of brain function.
"If you think about it, if the brain is not working well when an individual is fasting, [our ancestors are] not going to be very good at competing with other individuals to obtain food and survive and pass their genes on." Our ancestors who had an edge in this arena were the ones who were able to withstand periods without food, and therefore were able to reproduce. "We think that it makes sense that fasting improves brain function," Mattson summarizes.
Animal studies have backed up this hypothesis, showing that fasting can protect nerve cells. Mattson says experimental models have also shown that fasting may help prevent Alzheimer's disease and Parkinson's disease.
But fasting isn't the only way to achieve these results; Mattson says fasting mimics exercise in how it benefits the brain. In both exercise and fasting, the brain increases production of brain-derived neurotrophic factor (BDNF), a protein that encourages new brain cells to thrive. Several studies have shown that BDNF plays a critical role in learning and memory and that these levels decline in the human brain during aging. By boosting these levels through exercise or fasting, older adults can almost trick the brain into thinking it's younger. "We think keeping levels of BDNF up during aging will sustain cognitive functions, learning and memory ability," he says.