Malic acid is naturally found in many tart or sour-tasting foods, such as apples, pears, tomatoes and cherries. Malic acid bound to ions or salts are known as malates. Malic acid in this form may enhance the effect of certain minerals in pharmaceuticals used to decrease fatigue, provide relief from fibromyalgia and protect the kidneys, liver and heart. Malates also play an important role in the cell’s energy-producing cycle in the body.
Malic acid is a colorless, crystalline compound that has two forms: l-malic, the natural and biologically active isomer contained in food, and d-malic, which is produced by some micro-organisms or made chemically. Responsible for the sour taste of unripe fruits, malic acid is used in the aging of wine and as an additive in hard candies and low-calorie beverages, cider and apple drinks because it keeps the natural color of juice.
Malates are negatively charged ions that combine with malic acid. The malate anion plays a key role in the citric acid, or Krebs, cycle, which is a series of metabolic reactions in organisms that produce high-energy phosphate compounds. Malic acid, produced as malates using various minerals such as magnesium, calcium and citrulline, can enhance pharmaceutical stability and improve absorption.
When a magnesium ion is attached to a malic acid molecule, the result is magnesium malate. Magnesium malate provides the benefits of a highly absorbable form of magnesium as well as malic acid in the possible treatment and pain relief associated with fibromyalgia. The University of Texas Health Science Center in San Antonio conducted a study to establish the effect of malic acid and magnesium on 24 patients with fibromyalgia. Conclusions, published in the Journal of Rheumatology, suggested that a high dose of malic acid and magnesium may improve pain and tenderness associated with fibromyalgia when taken for at least two months.
The rind of watermelon is a good source of citrulline. Citrulline, in the form of citrulline malate, may aid in enhanced performance for athletes due to its effect of reducing muscle fatigue. French researchers from Marseille studied the effects of citruilline malate on energy production in human exercising muscle. Among 18 men, those that were given citrulline malate showed a significant reduction in fatigue and had an increased synthesis of energy-producing enzymes for quicker recovery after exercise. The conclusion, published in the British Journal of Sports Medicine in 2002, was that treatment of citrulline malate promotes energy production.
Calcium malate is malic acid with calcium. Calcium malate enhances the absorption potential of calcium as compared to inorganic forms of calcium. Scientific studies by the Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food concluded that calcium citrate malate was a safe and bioavailable source of calcium in foods and supplements, according to the European Food Safety Authority.