Nitrates and Nitrites

You may have heard of nitrates and nitrites but not have the foggiest about what on earth they actually are.

Dietary nitrate is often used by individuals as a performance nutrition supplement - most commonly in the form of Beet It shots. However, nitrates are present in a variety of foods, such as beetroot and green leafy vegetables (spinach, rocket).

After ingesting these foods containing nitrates, the nitrate interacts with enzymes in the saliva and is converted to the storage form nitrite, which is stored and transported around the body in the bloodstream.

During periods of low oxygen availability nitrite can be converted to nitric oxide, which is a vasodilator that increases blood flow and oxygen to the muscles. Thus, supplementing with nitrates increases the concentration of nitrite in the blood reducing resting blood pressure. Further, studies have demonstrated that nitrate supplementation can enhance exercise performance, in some instances, during submaximal exercise.

The reason Beet It shots are preferred is because it provides a more reliable and concentrated form of nitrate compared to obtaining it via foodstuffs. Beetroot juice containing 8mmol nitrate - which would be two 70ml Beet It shots, was found to be effective in improving exercise efficacy and performance. These effects were not greater when a higher dosage was ingested and some studies have displayed effective results using 5-6mmol in certain individuals. Effects are likely to be greater if consumed over several consecutive days prior to a competition, however, acute effects can been seen if consumed 2-3 hours before the competition.

NITRATE... but doesn't that have a bad name?

It is important not to confuse nitrate with nitrite. Whilst nitrates are considered to be safe and are slowly converted in our bodies to nitrite, direct consumption of nitrites can be toxic.

Nitrites manufactured in our mouth and subsequently swallowed, can react with acids in the stomach to form nitrosamines - some of which are carcinogenic and have been linked with bowel cancer. The formation of these nitrosamines, requires amines - a chemical related to ammonia found abundantly in protein rich food. Nitrosamines can also be created directly via cooking at high temperatures. Hence why processed meats, such as bacon, are often given a bad name - protein-rich product cooked at a high temperature. Consuming nitrates from vegetable sources (which are not rich in protein), enables the body to convert them to nitrites and it has been shown that the high vitamin, polyphenol and fibre content of vegetables can reduce nitrosamine formation. Thus, why there have been no observed links between nitrites from vegetables and cancers.

It is also important to note that nitrites are only one element in processed meats contributing to an increased risk of bowel cancer and cooking method can be a big influencing factor. Further, the relative risk of processed meats in the development of cancer is quite small.

Fun-fact: research has shown that use of anti-bacterial mouthwash can cause a huge decline in the oral manufacture of nitrites.