Drinking a beetroot juice supplement before working out makes the brain of older adults perform more efficiently, mirroring the operations of a younger brain, according to a new study by scientists at Wake Forest University.
“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. “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.”
While continued work in this area is needed to replicate and extend these exciting findings, they do suggest that what we eat as we age could be critically important to the maintenance of our brain health and functional independence.
Rejeski is Thurman D. Kitchin Professor and Director of the Behavioral Medicine Laboratory in the Department of Health & Exercise Science. 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. One of his former undergraduate students, Meredith Petrie, was the lead author on the paper.
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, Rejeski said.
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 mg of nitrate; the others received a placebo Beet-It with very little nitrate.
Beets contain a high level of dietary nitrate, which is converted to nitrite and then nitric oxide (NO) when consumed. NO 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 Rejeski.
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, combining beetroot juice with 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 has 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.
This research is among the latest in a series of findings concerning the effects of beets on health:
- Drinking beet juice can 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. This was the first study to link beet consumption and blood flow to the brain. (See more below on this study!)
- A daily does 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.
- Consuming whole beets improved running performance among fit adults, according to a 2012 study in the Journal of the Academy of Nutrition and Dietetics.
- Beetroot juice helped chronic obstructive pulmonary disease (COPD) patients increase exercise time, according to a 2015 Wake Forest study published in Nitric Oxide: Biology and Chemistry.
Blood pressure dropped after drinking beetroot juice, according to a study published in Hypertension in 2008.
Beets and blood flow to the brain
The original 2010 beet study that became the impetus to continue researching beets came from Wake Forest University and was published in Nitric Oxide: Biology and Chemistry found that beet juice increases blood flow to the brain and can help ward off dementia.
“There have been several very high-profile studies showing that drinking beet juice can lower blood pressure, but we wanted to show that drinking beet juice also increases perfusion, or blood flow, to the brain,” said Daniel Kim-Shapiro, director of Wake Forest University’s Translational Science Center; Fostering Independence in Aging. “There are areas in the brain that become poorly perfused as you age, and that’s believed to be associated with dementia and poor cognition.”
High concentrations of nitrates are found in beets, as well as in celery, cabbage and other leafy green vegetables like spinach and some lettuce. When you eat high-nitrate foods, good bacteria in the mouth turn nitrate into nitrite. Research has found that nitrites can help open up the blood vessels in the body, increasing blood flow and oxygen specifically to places that are lacking oxygen.
In this study, the first to find a link between consumption of nitrate-rich beet juice and increased blood flow to the brain, Translational Science Center researchers looked at how dietary nitrates affected 14 adults age 70 and older over a period of four days.
On the first day, the study subjects reported to the lab after a 10-hour fast, completed a health status report, and consumed either a high- or low-nitrate breakfast. The high-nitrate breakfast included 16 ounces of beet juice. They were sent home with lunch, dinner and snacks conforming to their assigned diets.
The next day, following another 10-hour fast, the subjects returned to the lab, where they ate their assigned breakfasts. One hour after breakfast, an MRI recorded the blood flow in each subject’s brain. Blood tests before and after breakfast confirmed nitrite levels in the body.
For the third and fourth days of the study, the researchers switched the diets and repeated the process for each subject.
The MRIs showed that after eating a high-nitrate diet, the older adults had increased blood flow to the white matter of the frontal lobes – the areas of the brain commonly associated with degeneration that leads to dementia and other cognitive conditions.
“I think these results are consistent and encouraging – that good diet consisting of a lot of fruits and vegetables can contribute to overall good health,” said Gary Miller, associate professor in the Department of Health and Exercise Science and one of the senior investigators on the project.