Nitrate supplementation is being used widely by athletes to improve performance, although claims of benefits have not been completely proven. Nitrates can be taken in the pure chemical form, such as sodium nitrate (NaNO3) or in beetroot juice. Nitrate is converted in the body into nitrite (NO2-), which is then changed to nitric oxide (NO). The maximal benefits may be achieved at a dose of 300-500 mg of nitrate.
Caution should be exercised with the use of nitrites. Nitrates are non-toxic even at high doses; however the nitrites can be severely toxic. Nitrites can react with blood hemoglobin, causing potentially life-threatening methemogobinemia*. Nitrite salts taken by mouth can cause a dangerous drop in blood pressure. (Nitrite salts are available on the internet.)
Nitrate salts are used for the preservation of foods. Only a small amount of nitrates taken orally are converted to nitrites and are much less likely to be toxic. However, foods containing nitrates should be stored carefully to prevent the growth of bacteria which reduce the nitrates to nitrites, thereby becoming toxic.
Caution is advised with the use of nitrate and nitrite salts, but natural sources of nitrates (such as beetroot juices) aren’t dangerous.
CONCLUSION: Beetroot and beet juices reportedly have benefits of lowering blood pressure and improving athletic performance. However, the use of nitrate and nitrite salts as supplements have risks of toxicity and should be used with caution.
NOTE: *Methemoglobinemia causes a condition in which the blood can carry oxygen, but can’t release it to the tissues. There are some inherited forms of the disease.
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PMID: 21828255.
Summary #745.
