Nitric Oxide (NO) is a gas produced by the body naturally and involved in many biological processes. NO is best known for its role in the cardiovascular system [1].
It is an essential cofactor that interacts with enzymes within the blood vessel causing the in the vascular smooth muscle to relax, and thus, lowering the blood pressure [2]. NO also prevent platelet activation and limits the attachment of white blood cells to the artery walls, avoiding the formation of plaque and reducing the risk of atherosclerosis [3]. NO also helps the regulate the heart contraction, allowing the heart to pump blood into circulation and protects against heart attack [4].
NO discovery with its associating biological functions in the cardiovascular system has led to the award of the Nobel Prize in Physiology or Medicine in 1998 [5]. Further research also discovered that NO involves in many other biochemical reactions within the body. For example, NO modulates the immune system towards the control of inflammation, infectious pathogens and tumours, as well as preventing autoimmune processes [6]. The degeneration of NO production in the body can lead to many chronic conditions, including chronic heart failure, diabetes, circulatory shock, chronic inflammatory diseases, cancer, and neurodegenerative disorders [7].
NO is a highly reactive gas and thus it only presents in the cells for a brief while. An essential approach to ensuring healthy NO production is through proper diet. Regular intake of food rich in nitrate provides the base ingredient for the conversion of nitrate into NO through many biochemical pathways [8]. Plant-based foods are the best source for nitrate, and thus, not surprisingly, a diet rich in vegetables and fruits are the best diet for prevention of chronic degenerative diseases [9].
Here are six plant-based foods that can increase NO production in the body and should be part of any healthy diet.
1. Rocket
Rocket has the highest content of nitrate at 2597 mg/kg according to a study that compared the nitrate contents in green leafy vegetables [10]. Rocket is also a good source of antioxidants and anticancer molecules such as glucosinolates and other sulphur compounds [11]. So, make sure to eat more rocket in the salad!
2. Spinach
Spinach’s nitrate content is second only to rocket (2137 mg/kg) [10]. A study that compared eating a high nitrate diet with spinach (845 mg nitrate/day) compared to a low nitrate diet with asparagus (0.6 mg nitrate/day) found that the high nitrate diet can significantly reduce blood pressure just after seven days [12].
3. Beetroot
A study that tested the NO concentration in the blood of 38 healthy volunteers found that drinking 70ml of beetroot juice can immediately increase the NO concentration in blood by about 20% after 45 minutes [13]. Furthermore, another study showed that sprint performance of army cadets improved after taking beetroot juice for 15 days [14]. For this reason, beetroot juice has become not only a health drink but also a trendy sports drink as it is known to increase performance.
4. Pomegranate
Pomegranate is a rich source of potent flavonoid antioxidants. It was also known to prevent the disappearance of NO by bind to other superoxide anions. A study found pomegranate juice is more potent than grape juice, blueberry juice, red wine, ascorbic acid (vitamin C), and DL-alpha-tocopherol (vitamin E) in its antioxidant effect. The study showed that pomegranate juice could protect NO against oxidative destruction [15].
5. Garlic
Garlic is a particularly rich source of sulphur compounds, which have enormous potentials to prevent and treat disease. Garlic was shown to be more effective than onions and leeks in the release of NO in an animal study [16]. Known to be an effective natural medicine for hypertension, the antihypertensive effect of garlic is achieved through the improvement of the NO synthase activity in the cells [17]. Hence, regular intake of garlic in diet is recommended for its health-promoting effects.
6. Dark chocolate
Dark chocolate is rich in epicatechin, a flavanol compound that can increase the bioactivity of NO to relax the blood vessel and lower blood pressure [18]. These effects were investigated in a study that compared two groups of volunteers with prehypertension. One group of 16 participants took 30g/day of dark chocolate, and another equal-sized group took only 25g/day of white chocolate. After 15 days, the dark chocolate group had significantly higher NO level in blood and lower systolic blood pressure [19]. Hence, be sure to go for dark chocolate, instead of sugar-laden white chocolate if one wants to avoid chronic diseases.
Conclusion
NO is an essential gaseous chemical that can relax blood vessel, lower blood pressure, and prevent not only cardiovascular diseases but also many chronic inflammatory conditions such as diabetes and cancer. Rocket, spinach, beetroot, pomegranate, garlic and dark chocolate are six plant-based foods that can increase the body production of NO to maintain good health. Be sure to include them in your diet!
References
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