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Tuesday 17 October 2017

Beet Juice Keeps Your Brain Young

Over the last five years, I’ve written an embarrassingly large number of posts about beet juice. In a world of overhyped and mostly ineffective sports supplements, beet juice is one of the very few with solid, peer-reviewed evidence of its real-world effectiveness—primarily for making endurance exercise more “efficient” (i.e., consuming less oxygen at a given pace), and for lowering resting blood pressure.

But there’s another intriguing line of research that’s been gaining traction, which is the effects of beet juice on the brain. A new study from researchers at Wake Forest University, published in the Journal of Gerontology: Medical Sciences, offers some intriguing hints that a daily shot of beet juice an hour before exercise can produce significant—and beneficial—changes in the function and organization of aging brains.



The key component of beet juice is nitrate, which is converted in the body to nitrite and then nitric oxide, which has powerful effects on the responsiveness of your blood vessels. As a result, previous research has found that beet juice can enhance the amount of oxygen reaching your brain, and can even acutely boost some aspects of cognitive function, like reaction time, when you’re fatigued.


The new study investigated the combined effects of exercise and beet juice. A group of 26 sedentary men with an average age of 65 were assigned to do six weeks of exercise along with daily shots of either beet juice or a placebo. All the men had high blood pressure, which made them more likely to benefit from the effects of beet juice on blood vessels.

The beet juice was administered in the form of Beet-It Sport Shots, which are concentrated beet juice shots that contain 560 milligrams of nitrate in each 70-milliliter (2.4-ounce) bottle. The placebos were exactly the same except that the nitrate had been removed. They took one shot per day, and timed it to be an hour before exercise on their workout days.


The exercise program was fairly simple. The participants walked on a treadmill three times a week for six weeks, building up until they were doing 50 minutes per session at a perceived effort of 12 or 13 on the Borg scale (13 corresponds to “somewhat hard”).

The researchers were interested in neuroplasticity—the brain’s ability to rewire and remake itself in response to new stimuli. And they were interested in the emerging idea that some of the physical problems of aging may reflect “invisible” problems in the central nervous system rather than just the more obvious problems like loss of muscle or aerobic fitness. To explore this possibility, they used functional magnetic resonance imaging (fMRI) before and after the trial, looking at the connections between different brain regions.


A previous study, also from Wake Forest, had found distinct differences in the “functional brain networks” of older adults depending on their level of mobility. Those who could get around quite well had better “community consistency” within the motor regions of the brain—that is, neurons within the motor region tended to be mostly connected to other neurons within the motor region.

Those who had mobility problems, on the other hand, tended to have more “secondary connections” from the motor regions to other regions of the brain, particularly areas associated with balance and other forms of self-monitoring. It’s hard to know exactly what this means at this point, but the interesting thing is that you can indeed tell the difference between mobile and mobility-impaired adults by looking at their brains.


So with this in mind, what did six weeks of exercise and beet juice (or placebo) do? It improved the “community consistency” of both groups of subjects, but the improvements were significantly greater in the group that had beet juice along with exercise. In fact, by the end of the study, the average number of red-flag-raising “secondary connections” in the beet juice group was comparable to the number in the younger control group (average age 26) from the previous study.

For those who like to see it visually, here’s a view of the average community consistency in motor areas of the brain for the two groups (BRJ is beet juice) at the beginning and end of the study:

beet juice for brain power
The thinking is that drinking beet juice means you have lots of nitrate in your body, which is then converted to nitrate and circulates throughout the bloodstream. The final step, which is converting nitrite to nitric oxide, seems to be enhanced in low-oxygen conditions—which, as it happens, are induced during hard exercise. So during your workout, as areas of your brain (among other places) start to suffer from lower oxygen levels, there’s plenty of nitrite that gets converted to nitric oxide, which in turn helps relax and dilate your blood vessels to bring more oxygen-rich blood to that site.

So is this a call to rush out and buy beet juice?

Maybe. Personally, despite all the articles I’ve written, I’ve never even tasted beet juice. Given my current running goals, and more importantly my particular motivations for racing, I’ve never really been tempted. But the associated health effects do get my attention, and have prompted me to incorporate beets (and other nitrate-rich vegetables like spinach and arugula) into my diet far more frequently than I used to.

Is that effective? From an acute running perspective, while there’s some weak evidence that you might get a boost from wolfing down 200 grams (a little less than half a pound) of beets before a run, it’s probably not a reliable bet. But for health purposes, a consistent and sustainable diet with lots of nitrate-rich food like beets seems like a reasonable bet.

Fortunately, after all this beet research, there’s one conclusion that I have 100% confidence in, even though I never would have predicted it before reading the studies: I really, really like oven-roasted beets. They’re delicious. So I’m going to keep eating them regardless of what the next study says.

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