Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Higher fruit and vegetable consumption was found to be “positively associated with muscle power” in adolescents, but that’s not who really needs it. What about the “consumption of fruit and vegetables and risk of frailty” in the elderly? Higher “[fruit and vegetable] consumption was associated with…lower…frailty” as well, “in a dose-response manner”—meaning more fruit, less frailty, and more vegetables, too. But these were all observational studies, which can’t alone prove cause and effect.

What happens when you put foods to the test? Well, “no positive influence…ingesting chia-seed oil on human running performance,” but there was an effect found for “spinach supplementation on exercise-induced oxidative stress.” And, by spinach supplementation, they meant they just gave some guys some fresh raw spinach leaves—one gram per kilo. So, like a quarter of a bunch a day for two weeks, and then they had them run a half-marathon. And, they found that “chronic daily oral supplementation of spinach”—uh, meaning like eating a salad—”has alleviating effects on known markers of oxidative stress and muscle damage.”

Here’s what happens when you run a half-marathon without spinach: a big spike in oxidative stress, blood malondealdehyde levels, that stay up hours or even days later. In the spinach group, the before-and-after two weeks of spinach doesn’t seem to make much of a difference. But, put the body under pressure, and then you can really see the difference. Your body is better able to deal with the stress.

And, if you look at the resulting muscle damage, as measured by creatine kinase leakage from your muscles (an enzyme that should be in your muscles, not leaking out into your blood), you start out at about 100, and go up to 200 after the half-marathon. Right after, two hours later. But, it’s the next day where you really feel it—that delayed-onset muscle soreness, with CK levels reaching 600 before coming back down. That’s without spinach, though. On spinach, you get a similar immediate post-race bump, but it’s that next day where spinach really shines. You don’t get the same next-day spike. So, for a competitive athlete, that quicker recovery may get you back training harder sooner. They attribute this to “the anti-inflammatory effects of spinach.”

Same with black currant juice. After some hardcore weight lifting, muscle damage indicators go up and stay up, whereas the same lifting, drinking berries, and it goes up, but comes right back down. But, these were just measures of a biomarker of muscle soreness. What about actual soreness?

If you look at the effects of tart cherry juice “on recovery following prolonged, intermittent” sprints in soccer players, you see the same kind of reduction in biomarkers of inflammation—but, more importantly, less resulting muscle soreness. Here’s the soreness reported in the days afterwards in the placebo group. Only about half in the cherry group. Then, they measured maximum voluntary isometric contractions of the leg muscles, which understandably took a hit in the days after the intense workout, but not in the cherry group.

They conclude “that participants who supplemented with [a tart cherry concentrate] were able to maintain greater functional performance.” But, that was testing like how high can you vertically jump. They didn’t actually see if they played soccer any better. But, this study on purple grape juice actually showed “an ergogenic effect in recreational runners by promoting increased time-to-exhaustion,” where you ramp people up on a treadmill and see how long they can go before collapsing. After a month of drinking a grape Kool-Aid type placebo control drink, no real change in performance, but a whopping 15% improvement in the real grape group, who hung on for another 12 minutes.

These studies used juice, so they could make a matched placebo control drink. But, you can buy Concord grapes fresh, or tart cherries fresh, frozen, or water-packed in a can. I mix them with oatmeal, cocoa, and mint leaves for a chocolate-covered-cherry type sensation. You may want to try that for a few days before participating in your next big sporting event.

Please consider volunteering to help out on the site.