Food for Thought
It has been nearly 100 years since scientists first reported that caloric restriction could slow aging and extend life span in rodents. The same holds true for other research model species, including yeast, worms, flies and fish.
“There’s an evolutionarily ancient link between nutrients, the conditions in the environment, and the aging process,” says Kristopher Burkewitz, PhD, assistant professor of Cell and Developmental Biology at Vanderbilt. “And it makes a lot of sense. If things are scarce, it’s not a good investment to spend energy on growing and reproducing. Instead, there’s reprogramming at a variety of biological levels to put energy into taking care of things, lasting through the tough times.
“Dietary restriction works great (to extend life span), but it’s hard to tell people to do that.”
Laura Niedernhofer, MD’98, PhD’96, director of the Institute on the Biology of Aging and Metabolism at the University of Minnesota, agrees.
“Who in their right mind is going to cut their calories by 40%?” she says.
It might be possible to achieve similar results with dietary modifications like intermittent fasting (fasting every other day, for example) or compressed eating (consuming calories in the shortest window of time possible in a 24-hour period).
“There’s a huge investment by the NIA (National Institute on Aging) right now to study different ways to modulate nutrient intake to extend good health and longevity,” Niedernhofer says.
Most studies to date have been short (weeks to months), with the longest lasting two years: not long enough to learn about long-term effects.
“To really know that dietary interventions work in humans, we’re talking about decades-long studies,” says Rafael Arrojo e Drigo, PhD, assistant professor of Molecular Physiology and Biophysics.
The studies also need to consider a multitude of factors including genetics, sex, environment and lifestyle factors, he adds.
“And how do you know it’s working? What are the measurements that you can make on someone that will actually tell you that biological age versus chronological age is changing?”
For now, there isn’t enough evidence to recommend a particular type of fasting or calorie-restricting diet. Instead, researchers agree, stick to the tried-and-true recommendations to eat balanced diets of nutritious foods, exercise regularly, stay socially active, don’t smoke, drink alcohol in moderation or not at all, and get a good night’s sleep.