Blood vessels -- your arteries, veins and capillaries -- are responsible for carrying blood throughout the body. When blood vessels are dilated, or opened, more blood can be carried through the body, which improves oxygen and nutrient delivery and often results in lowered blood pressure. Diet can have a significant effect on the health of blood vessels, including the fact that specific components of foods stimulate nitric oxide production -- a compound responsible for the dilation of blood vessels.
Another substance that gets converted to nitric oxide in the body is L-arginine, an amino acid or building block of protein. But L-arginine's effect on vasodilation, or dilation of the blood vessels, is not so straightforward. A study of 2,284 adults followed for an average of 4.7 years found that L-arginine from plant-based foods was specifically related to improved blood pressure and reduced heart disease risk. However, L-arginine from animal sources increased heart disease and high blood pressure risk, according to a report published in the March 2016 issue of "Nutrition and Metabolism." Plant sources of L-arginine include:
-- Soybeans, tofu and other soy products.
-- Nuts, especially almonds and black walnuts.
-- Legumes such as chickpeas and lentils.
-- Seeds, particularly pumpkin, sesame and chia seeds.
Dietary nitrate can also be converted to nitric oxide in the body. A review article published in the August 2011 issue of "European Journal of Nutrition" summarized that fruits and vegetables high in nitrates have a beneficial effect on vasodilation. Most dietary nitrates come from plant sources, commonly found in the following foods:
-- Chinese cabbage.
Dietary flavonoids are a diverse group of naturally occurring substances found in plants. Also responsible for the vivid colors of fruits and vegetables, the beneficial health properties of flavonoids are often linked to their antiinflammatory properties. But flavonoids also play a role in dilation of blood vessels. A review published in the August 2008 issue of "Journal of Nutrition" concluded the flavonoids in tea have vasodilation effects, as this flavonoid also stimulates nitric oxide production. According to this review, and by this same mechanism, cocoa and dark chocolate have also been shown to dilate blood vessels. Nitric oxide release is also stimulated by the flavonoids in red wine, according to research published in the September 2002 issue of "Circulation."
A healthy diet is the cornerstone for maintaining healthy blood vessels. The Mediterranean diet pattern and the traditional Japanese diet are both considered beneficial to heart health. Authors of an article published the March 2013 issue of "British Journal of Clinical Pharmacology" suggest the benefits of these dietary patterns are in part related to their high fruit and vegetable content -- foods that are also high in L-arginine, dietary nitrate and flavonoids. Plant-based or well-planned vegetarian diets that emphasize whole grains, legumes, nuts, seeds, fruits and vegetables are also rich in foods that stimulate nitric oxide production -- and have the potential to dilate blood vessels.
Warnings and Precautions
If you have any questions regarding heart health and how to keep blood vessels healthy, speak with your doctor. For a healthy eating plan and personalized nutrition recommendations, speak with a registered dietitian. Although plant chemicals such as L-arginine and flavonoids are linked to dilated blood vessels, supplements do not always have the same effects as natural foods, nor do they replace the synergy of the whole diet. In addition, supplements have the potential to interact with certain medications, so talk with a doctor prior to starting a new supplement. Always seek immediate medical attention for any symptoms related to heart disease.
Reviewed by: Kay Peck, MPH, RD