“We knew going in that a number of studies had shown that exercise has positive effects on the brain,” said W. Jack Rejeski, study co-author and Thurman D. Kitchin Professor and Director of the Behavioral Medicine Laboratory in the Department of Health & Exercise Science. “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.”
Exercise And The Brain
The study, “Beet Root Juice: An Ergogenic Aid for Exercise and the Aging Brain,” was published in the peer-reviewed Journals of Gerontology: Medical Sciences. These findings suggest that what we eat as we age could be critically important to the maintenance of our brain health and functional independence. This is the first experiment to test 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.
The study included 26 men and women age 55 and older who did not exercise, 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 the participants received Beet-It containing 560 milligrams of nitrate; the others received a placebo Beet-It with very little nitrate.
Nitric Oxide Conversion
Beets contain a high level 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,” Rejeski said.
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. 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. Combining beetroot juice with exercise delivers even more oxygen to the brain and creates an excellent environment for strengthening the somatomotor cortex.
Heart Disease Benefits
Another recent study found that dietary nitrate – a compound that dilates blood vessels to decrease blood pressure – may reduce overstimulation of the sympathetic nervous system that occurs with heart disease. The research team looked specifically at beetroot juice, a source of dietary nitrate, to explore its use as a future targeted treatment option for people with cardiovascular disease. The study, published in the American Journal of Physiology – Heart and Circulatory Physiology, is the first to study the effects of nitrate supplementation on sympathetic nerve activity.
Activation of the sympathetic nervous system – caused by increased sympathetic nerve activity – include elevated heart rate and blood pressure and blood vessel constriction. Sympathetic nerve activity (sympathetic outflow) also increases with some forms of cardiovascular disease, including high blood pressure and heart failure. The aim of the study was to show that acute nitrate supplementation using beetroot juice can decrease muscle sympathetic outflow at rest and during exercise.
Twenty young adult volunteers with an average age of 27 participated in two separate testing visits in which they blindly received either a nitrate supplement or a placebo. On both visits, the research team recorded the blood pressure, heart rate and muscle sympathetic nerve activity (MSNA) and measured muscle activity at rest and during handgrip exercise with the participants’ non-dominant hand. Measurements were recorded at the beginning of the visit and then again after the volunteers drank nitrate-rich beetroot juice or a placebo and had rested on their backs for three hours.
MSNA burst rate, denoting the frequency of nerve activity, was lower when the volunteers drank beetroot juice compared to when they drank the placebo. Sympathetic nerve activity also decreased during exercise. “Surprisingly, no differences in blood pressure were detected at rest or during exercise,” the research team noted. “These results provide proof-of-concept that dietary nitrate supplementation can modulate central sympathetic outflow and suggest that the established cardiovascular benefits [of dietary nitrate] are likely to involve a neural contribution.”
A daily dose of beetroot juice significantly improved exercise endurance and blood pressure in elderly patients with heart failure with preserved ejection fraction, according to a Wake Forest study published in the Journal of the American College of Cardiology-Heart Failure in 2016. A 2015 Wake Forest study, published in Nitric Oxide: Biology and Chemistry, stated that beetroot juice helped chronic obstructive pulmonary disease (COPD) patients increase exercise time.
Consuming whole beets improved running performance among fit adults, according to a 2012 study in the Journal of the Academy of Nutrition and Dietetics. Blood pressure dropped after drinking beetroot juice, according to a study published in Hypertension. Drinking beet juice was also found to increase blood flow to the brain in older adults, according to a 2010 study out of Wake Forest published in Nitric Oxide: Biology and Chemistry – the first study to link beet consumption and blood flow to the brain.