Interesting research into nitric oxide seems to indicate at least a link between positive nitric oxide and prevention of endothelial dysfunction. Endothelial dysfunction is what leads to heart disease because it's one of the (if not the main cause) causes of atherosclerosis.
Nitric oxide is something you can get from eating certain green vegetables, or from certain foods. It is also something you may be able to get from supplements but no studies have been able to prove without a doubt that supplements raise nitric oxide because as far as I know there is no blood test for nitric oxide. What seems to be true is that if you consume more green leafy vegetables, drop processed meats, processed oils, and dairy, you may be able to reduce the damage to the endothelium by naturally raising nitric oxide levels through diet.
Food sources for nitric oxide production include beets (beet juice), dark chocolate, pomegranate, spinach. A smoothie containing some, all, or any of these ingredients may increase nitric oxide.
References
Bryan, N. S. (2016). Dietary Nitrite: from menace to marvel. Functional Foods in Health and Disease, 6(11), 691-701.
Edwin Lee MD, F. A. C. E. (2016). Effects of Nitric Oxide on Carotid Intima Media Thickness: A Pilot Study. Alternative therapies in health and medicine, 22, 32.
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