Transcript: “Veg-Table” Dietary Nitrate Scoring Method
What is the optimal timing and dose of nitrate-containing vegetables? In terms of timing for improving athletic performance, everyone’s different; so, basically two to three hours before a competition is about as specific as we can get.
How much borscht do we have to have for breakfast? To date, most studies have used a narrow range of doses; so, it’s not clear if it’s a matter of the more, the better, or if there’s a ceiling, or a threshold amount. So, they put it to the test. They set up folks on an exercise bike, and had them furiously cycle until they dropped. They made it about eight minutes after drinking a placebo, and after one shot of beetroot juice, about a quarter of a cup, they may or may not have gained a few seconds, but drinking a half cup gave them like a full extra minute, but drinking even more didn’t seem to offer additional benefit.
That half cup or so of beet juice corresponds to eight units of nitrate; so, four didn’t significantly work, and 16 did no better than eight. So, eight appears to be the sweet spot for improving athletic performance. What about for lowering blood pressure? Same thing. Four units—the triangles—may have helped a little, but eight worked better, and about equally well as 16. A ten point drop in blood pressure may not sound like a lot, but may translate into dropping heart attack risk 25% and stroke risk 35%.
But, beet juice is perishable and hard to find. What about V8 juice, which has both beet and spinach juice? It must not have much, because you’d have to drink 19 quarts a day to hit the target.
Straight beet juice is nitrate packed, but it’s a processed food. How many actual beets, or green leafy vegetables, would one have to eat to reach the target of eight units? The British Heart Foundation put together this really helpful table that takes into account both nitrate concentration and serving size. So, a serving of anything in the high group is worth two units, a serving of medium group vegetables about a half, and low nitrate vegetables a tenth. Now, these are pretty small servings, less than three ounces, (remember, we’re trying to get up to eight a day); so, a typical 15 ounce can of beets would nail the eight unit target for the day, as would a really big salad of greens. Most people only get about a unit a day, but even vegetarians need to double their vegetable intake, and those eating organic may have to eat even more.
Organic produce may have more vitamin C, iron, magnesium, and phosphorus but tends to have fewer nitrates, since by law synthetic nitrogen fertilizers are banned from organic agriculture. Now, eating 15% more organic veggies to get the same nitrate intake is easy, but for beets, the spread can be larger. On the other hand, organic beets may have more of certain phytonutrients, like the red pigment, which may explain why the organic beet extracts had significantly higher anti-cancer effects in vitro compared to conventional beets.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
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