A number of fruits and vegetables contain malic acid. Most of these fruits and vegetables use the process of fermentation, which is a type of natural biological reaction, to preserve them. When fermentation occurs, the malic acid is disintegrated into another acid – called the lactic acid. The gas – carbon dioxide – is also formed in the reaction. The fermentation is usually carried out by a few microorganisms – usually, bacteria. However, this fermentation can bring both benefits and harms to humans. For instance, fermentation makes wine less acidic. On the other hand, the carbon dioxide produced spoils vegetables and fruits such as cucumbers.
The preservation ability of malic acid is not just limited to fruits and vegetables. This acid also prevents the formation of bacteria in other types of foods. Other acids also kill bacteria. In addition, the higher the concentration of the acids, the faster the bacteria are killed. This concentration of acids – or, the level of acidity – is called pH. Many research studies are going on to find more about the relationship between the pH of malic acid and the deactivation of bacteria. So far, the studies have shown that malic acid has one of the lowest pH compared to other acids; however, the pH is high enough to kill the bacteria present in food, such as pathogenic bacteria and Listeria monocytogenes.
The cycle of citric acid is responsible for the formation of malic acid from foods. The same cycle also helps in the synthesis of malic acid inside the body. Malic acid plays a key role when energy is produced during aerobic condition (that is, in the presence of oxygen) and anaerobic (that is, in the absence of oxygen) condition. In the former condition, malate is oxidized to oxaloacetate and this reaction forms “reducing equivalents”. The amount of the reducing equivalents is increased in the absence of oxygen – that is, during anaerobic condition. However, the excess amount stops the naturally occurring process of glycolysis. At that point, malic acid is reduced to succinate. This eliminates the reducing equivalents from the body. As a result, glycolysis starts again and energy is continually produced. This property of malic acid is beneficial to treat Primary fibromyalgia, where the patients suffer from a lack of energy due to the presence of hypoxia.
Malic acid can also help people who exercise. That’s because there is a lack of energy after exercising and malic acid can help produce energy. The fact that a lack of malic acid can cause fatigue has been proved in many studies, including the study on rats. First of all, the studies showed that there is a lack of malate in tissues after any physical activity. Second, other elements of the cycle of citric acid do not change. The amount of mitochondrial malate, as well as energy production via mitochondrial respiration, is also increased. The malic acid is very effective in increasing the rate of production of energy and of ATP. In fact, a very small amount of malic acid leads to significant increase in the volume of mitochondrial energy produced. During the condition of hypoxia, more malic acid needs to be produced and used. However, this is extremely dangerous for the body. That is because the need for malic acid is met by the production of malic acid from the breakdown of protein in the muscles and from gluconeogenesis. This can damage the muscles as well as cause them to break down. When malic acid is taken orally, it can cause the body to perform a longer duration of physical activity. However, for this purpose, a higher amount of oxygen and carbohydrates is not used.
The importance of malic acid in the production of energy has led to a growing use of malic acid supplements in conditions of hypoxia. If the supplements are of 1200 to 2400 mg, the pain gets alleviated within a period of 48 hours. The supplements are usually taken by people who are suffering from primary fibromyalgia and by athletes. Also, they can be used by people suffering from conditions of hypoxia – like circulatory and respiratory insufficiency – that result in energy depletion. Finally, malic acid supplements can provide relieve from conditions such as Chronic Fatigue Syndrome that results from fibromyalgia.