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Drinking beetroot juice before a workout could make the brains of older adults work more efficiently, similar to a young brain. That’s the conclusion of a new study conducted at Wake Forest University.
Beetroot Juice Before Exercise in Older Adults
Researchers already knew from previous studies that exercise can have a positive effect on the brain. This study among older adults with high blood pressure shows that a combination with beetroot juice results in improved brain connectivity as seen in young adults [1]. It was the first study to demonstrate the combined effects of beetroot juice and exercise on functional brain networks in the motor cortex.
While further research is needed to confirm these conclusions, they suggest that healthy nutrition in older age may play an important role in the aging process.
The study involved 26 sedentary men and women aged 55 and older, with high blood pressure for which no medication had been used in the last two years. Half of this group received a beetroot juice supplement (“Beet-It-Sport Shot”) one hour before exercise three times a week for six weeks. This exercise consisted of 50 minutes of moderate-intensity walking on a treadmill. The other half received a placebo.
The beetroot juice contained 560 mg of nitrate. The placebo contained very little nitrate.
Beetroot Juice – Nitric Oxide (NO)
It has been known for some time that nitrate in the body can be converted into nitrite and nitrite into nitric oxide (NO)[2]. NO is a popular pre-workout although in those supplements arginine and citrulline are usually used to produce NO in the body.
The researchers refer to previous studies showing that NO improves blood flow and thus athletic performance in older adults. Jack Rejeski of Wake Forest University explains:
“NO is a powerful molecule. It goes to areas in the body that have an oxygen deficiency, and the brain is a big user of oxygen.”
The levels of nitrate and nitrite in the blood were equal before exercise, but larger afterwards in the group that had consumed beetroot juice (although it remains unclear how much of this is converted into NO). Using MRI, the researchers were able to observe the improved connections in the brain.
When you exercise, the somatomotor cortex processes impulses from the muscles. Training should therefore strengthen the somatomotor cortex as the results showed. If you then combine this with beetroot juice, more oxygen will be drawn to the brain, thereby enhancing this strengthening effect.
It should be noted that the choice was not made randomly for a test group of older adults with (untreated) high blood pressure. High blood pressure means that due to narrowing of the blood vessels, blood had difficulty finding its way through the body. NO causes dilation of the blood vessels, allowing blood and therefore oxygen to arrive more quickly and effectively where needed. The effect we see in this test group is therefore likely greater than what we would see in older adults who manage to keep their blood pressure at healthier levels.
Nitrate and Nitrite Carcinogenic?
For completeness, it is good to mention that nitrate and nitrite have long been considered toxic. Nitrite could be converted into carcinogenic nitrosamines [3,4]. Those concerns have since diminished to uncertainty about the risks in combination with protein from food such as from fish. Not enough for the Nutrition Center to give restrictive advice on intake, but enough to discourage daily intake via beetroot juice [5].
References
- Meredith Petrie, W. Jack Rejeski, Swati Basu, Paul J. Laurienti, Anthony P. Marsh, James L. Norris, Daniel B. Kim-Shapiro, Jonathan H. Burdette. Beet Root Juice: An Ergogenic Aid for Exercise and the Aging Brain. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 2016; glw219 DOI: 10.1093/gerona/glw219
- Lundberg JO, Weitzberg E, Gladwin MT. The nitrate-nitrite-nitric oxide pathway in physiology and therapeutics. Nat Rev Drug Discov. 2008 Feb;7(2):156-67. doi: 10.1038/nrd2466. Review. PubMed PMID: 18167491.
- Issenberg P. Nitrite, nitrosamines, and cancer. Fed Proc. 1976 May 1;35(6):1322-6. Review. PubMed PMID: 4342.
- Song P, Wu L, Guan W. Dietary Nitrates, Nitrites, and Nitrosamines Intake and the Risk of Gastric Cancer: A Meta-Analysis. Nutrients. 2015;7(12):9872-9895. doi:10.3390/nu7125505.
- voedingscentrum.nl/encyclopedie/nitraat.aspx
