Alpha-lipoic acid is a fatty acid that is made naturally by the body, usually in the amounts you need to remain healthy. One of its main functions is to convert glucose into energy. It also acts as an antioxidant that cleans up the free radicals that can do irreparable damage in the body. Even though the body makes this fatty acid on its own, it can be found in a number of foods, though typically in very small amounts.
Broccoli and Greens
These vegetables are sources of alpha-lipoic acid. It is found in the chloroplasts of the vegetable's cells, which are responsible for producing energy in the broccoli plant. Spinach is a leafy green vegetable that also has a number of chloroplasts, given its dark green color. This means it has a decent amount of alpha-lipoic acid in it, not to mention a number of other beneficial nutrients.
Organ meats are particularly high in alpha-lipoic acid. Liver is not eaten as much as other animal products, but it is one of the better sources of alpha-lipoic acid. This is because it has a high concentration of mitochondria, which are responsible for producing energy in animals. Kidney and heart meats are also noted as high in alpha-lipoic acid, according to the Linus Pauling Institute.
Steak and ALA
Lean beef or steak rounds are another rich source of alpha-lipoic acid. This is also because of the large number of mitochondria found in typical cuts of this meat.
Yeast and ALA
These helpful little bacteria are responsible for making bread rise and for fermentation in beer, wine and other drinks. They also are known to be a decent source of alpha-lipoic acid, as listed by the University of Maryland Medical Center.