Durk Pearson & Sandy Shaw’s®
Life Extension NewsTM
Volume 15 No.
1 • January-February 2012
Eat Spinach and Knock Out Bluto?
What You Really Get from Spinach
You probably saw some of the old-time Popeye cartoons where Popeye, caught in the middle of a dire situation (usually involving being attacked by Bluto), produces a can of spinach, quickly opens it, and glugs it down, all while the heroic Popeye theme song is urging him on and we see his muscles suddenly bulging so he can take care of the bully, with Olive Oyl looking on adoringly.
Of course you always knew that it didn’t happen like that.
But the good news is that spinach can really deliver a punch when it comes to improved health. Green leafy vegetables, such as spinach, are among the richest sources of nitrate in the diet. A new paper reports that spinach consumed by thirty healthy volunteers recruited by newspaper ads resulted in a substantial acute augmentation of NO (nitric oxide) status and a small but significantly higher flow-mediated dilation (expansion of the brachial artery in response to nitric oxide) and a lower systolic blood pressure. “This is consistent with previous studies which demonstrated that high-dose nitrate increased plasma nitrite levels, improved endothelial function and lowered blood pressure when given in a dietary (beetroot juice or pure KNO3 capsules) form. However the level of nitrate intake tested in these studies has ranged from approximately 500 to 1500 mg/day with chronic supplementation and from 400 to 2400 mg acutely. These intakes exceed the mean dietary intake of nitrate, which is estimated to be between 0.4 and 2.6 mg/kg or 31 and 185 mg. In the current study the intake of nitrate provided by the 200g of spinach included with the lunch meal was 182 mg.” The spinach used in the study was taken from a single batch of frozen spinach from a commercial supplier and thawed before use.
One of the problems with green, leafy vegetables, though, is that nowadays much of what is available in the U.S. is imported from countries that do not have a similar level of hygienic standards for growing commercial vegetables as in the U.S. Unfortunately, California, which used to supply about 60% of all the veggies available in the U.S. has pretty well destroyed its once flourishing agricultural production due to the Federal government cutting off water to the western half of the Joaquin Valley in order to protect an “endangered” fish. According to an FDA Report entitled “Pathway to Global Safety and Quality,” between 10 and 15 percent of all food consumed in the U.S. is imported, while the U.S. Government Accountability Office (GAO) estimates that imports account for nearly two-thirds of the fruits and vegetables and 80% of seafood eaten domestically. A lot of these veggies and fruits come from places like Mexico, China, Asia, India, and Africa, where hygienic standards are far inferior to those in the U.S. and it is not uncommon for workers to urinate and defecate in the fields while picking the crop. Pathogens in green leafy vegetables cause a considerable amount of disease and even deaths in the U.S. every year.
Though Sandy is a big fan of salads that include a lot of green leafy vegetables, consideration of the risk of pathogens in raw veggies (and the possibility that this is what caused her recent bowel obstruction that required surgical correction) has resulted in her choosing to eat only cooked green leafy vegetables. While cooked lettuce (yech) is a limp, mushy turnoff, cooked spinach is (at least to Sandy) tasty and she likes it for a snack, especially with a dollop of butter-olive oil added to it.
- Bondonno et al. Flavonoid-rich apples and nitrate-rich spinach augment nitric oxide status and improve endothelial function in healthy men and women: a randomized controlled trial. Free Radic Biol Med 52:95-102 (2012)
- Ades G et al. The food safety challenge of the global food supply chain. Food Safety Magazine 17(6):34-9 (2012).