Drinking a beetroot juice supplement before exercising allows the brains of older adults to perform more efficiently, essentially mirroring the mechanisms of younger brains, according to a new study at Wake Forest University.
Beets naturally contain high levels of dietary nitrate, which is converted to nitrite and then nitric oxide when consumed. Nitric oxide increases blood flow in the body, and multiple studies have shown it can improve exercise performance in people of various ages.
“Nitric oxide is a really powerful molecule. It goes to the areas of the body which are hypoxic, or needing oxygen, and the brain is a heavy feeder of oxygen in your body,” said W. Jack Rejeski, study co-author, Thurman D. Kitchin Professor and Director of the Behavioral Medicine Laboratory in the Department of Health & Exercise Science.
One of Rejeski’s former undergraduate students, Meredith Petrie, was the lead author on the paper.
The findings, published in the peer-reviewed Journals of Gerontology: Medical Sciences, add to the growing body of evidence that our diets, particularly as we age, are vitally important to the maintenance of our brain health and functional independence.
The study involved 26 men and women aged 55 and older who were not regular exercisers, had high blood pressure, and took no more than two medications for high blood pressure. Three times a week for six weeks, they drank a beetroot juice supplement called Beet-It Sport Shot one hour before a moderately intense, 50-minute walk on a treadmill. Half of the participants received Beet-It containing 560 mg of nitrate; the others received a placebo Beet-It with very little nitrate.
“We knew, going in, that a number of studies had shown that exercise has positive effects on the brain,” said Rejeski. “But what we showed in this brief training study of hypertensive older adults was that, as compared to exercise alone, adding a beet root juice supplement to exercise resulted in brain connectivity that closely resembles what you see in younger adults.”
The study is the first to investigate the combined effects of exercise and beetroot juice on functional brain networks in the motor cortex and secondary connections between the motor cortex and the insula, which support mobility, Rejeski said.
When you exercise, the brain’s somatomotor cortex, which processes information from the muscles, sorts out the cues coming in from the body. Exercise should strengthen the somatomotor cortex. So consuming beetroot juice just before exercise delivers even more oxygen to the brain and creates an excellent environment for strengthening the somatomotor cortex.
Post-exercise analysis showed that, although the study groups had similar levels of nitrate and nitrite in the blood before drinking the juice, the beetroot juice group had much higher levels of nitrate and nitrite than the placebo group after exercise.