 More than 1,000 years ago, an ancient Persian medical text advised for the treatment of hypertension lifestyle interventions such as avoiding meat and pastries, and recommended eating spinach. A thousand years later, researchers discovered that a single meal containing spinach could indeed reduce blood pressure thanks to its nitrate content. All green leafy vegetables are packed with this stuff, which our body can use to create nitric oxide that improves the flexibility and function of our arteries, which may be why eating our greens may be one of the most powerful things we can do to reduce our chronic disease risk. Just switching from low nitrate vegetables to high nitrate vegetables for a week can lower blood pressures by about 4 points, and the higher the blood pressure they started out with, the greater benefit they got. Four points might not sound like a lot, but even a two-point drop in blood pressure could prevent more than 10,000 fatal strokes every year here in the U.S. Potassium rich foods may also act via a similar mechanism. If we just got the minimum recommended daily intake of potassium, we might prevent 150,000 strokes every year, because potassium appears to increase the release of nitric oxide. One week of eating two bananas and a large baked potato every day significantly improved arterial function. Even a single high potassium meal containing the equivalent of two to three bananas worth of potassium can improve the function of our arteries, whereas a high sodium meal, which is to say a meal with the regular amount of salt most people eat, can impair arterial function within 30 minutes. Whereas potassium increases nitric oxide release, sodium reduces nitric oxide release, so the health of our arteries may be determined by our sodium to potassium ratio. Two slices of bacon worth of sodium in our arteries take a significant hit within 30 minutes, but add three bananas worth of potassium, and you can counteract the effects of the sodium. When we evolve, we're reading 10 times more potassium than sodium. Now the ratio is reversed, more sodium than potassium. These kinds of studies provide additional evidence that increases in dietary potassium should be encouraged. What does that mean? More beans, sweet potatoes, and leafy greens, which are like a super good double whammy, high in potassium and nitrates. This recommendation to eat spinach from the 900s, pretty impressive, though they also recommended bloodletting and abstaining from sex. So we should probably take ancient wisdom with a grain of salt, but our meals should be added salt-free.