Scientists at the University of Colorado in Boulder, where I earned my M.A. and Ph.D., are doing some cutting-edge research to test a new nutritional compound that mimics caloric restriction (CR). It has been known for some time that CR, or eating less, prompts the body to age more slowly. Professor Doug Seals, director of CU Boulder’s Integrative Physiology of Aging Laboratory, observed that from a public health perspective, caloric restriction is not a practical strategy. People generally don’t like to severely limit their food intake, and this practice can be dangerous to one’s health.
So instead, researchers are testing a compound called nicotinamide riboside (NR) to see if it can extend “healthspan,” or the period of life in which we have good physical and cognitive function. Seals’ team has already shown that NR can improve blood pressure and reduce arterial stiffness (a risk factor for cardiovascular disease and cognitive impairments) in older adults. His lab has received a $2.5 million, five-year grant from the National Institute on Aging, and is using it to study about 100 more adults to assess the compound’s impact on the heart, brain and body. In the new study the participants will be divided into two groups, with half taking 1,000 mg per day of NR for three months and half taking a placebo. During the duration of the study, the researchers will measure participants’ vascular health, blood flow to the brain, and changes in cognition and physical fitness. Daniel Craighead, a postdoctoral researcher heading up the CU Boulder NR study, said that if the NR compound proves successful, it could be something people could take to improve their cardiovascular health and enjoy more healthy years of life. He views it as a very promising and safe nutraceutical that activates some of the same biological pathways that caloric restriction does.
Another approach being investigated involves forms of intermittent fasting as another potential approach to mimic CR and delay aging. “Time-restricted feeding,” or eating only within an eight-hour window of the day, might also kick-start some of the same cellular-defense mechanisms as constant dieting. In a study to be published in the aging research journal GeroScience, researchers reported finding that six weeks of time-restricted feeding improved blood glucose control and increased endurance exercise capacity in healthy adults ages 55-79. The other exciting finding from this study is that 85 percent of the participants were able to adhere to the eight-hour eating window.
This science is still in its early stages, and Seals notes that it’s too early to recommend supplements or fasting with any certainty to aging adults.