To Your Health

A. Aside from ignorance about exactly how a food supplement should be used, there are several explanations for different instructions on how to take a particular food supplement.

One is that some people think that all food supplements should be taken at mealtimes because that is how it would get into our bodies if it were in food. Although this seldom does any harm, it is not necessarily the best option for every food supplement. For instance, acidophilus, the friendly bacteria that usually inhabit our GI tracts, are harmed more by the bile acid secreted at mealtimes than by stomach acid, even though stomach acid is stronger between meals than at mealtimes. Some acidophilus will survive even though the supplement is taken at mealtime, but more survive when it is taken apart from meals.

Another explanation is that some individuals have had an unusual experience with a food supplement and assume that everyone else will have that same experience. Although it is very rare, some people find that taking a glutamine supplement late in the day greatly disturbs their sleep and will recommend that people take it only early in the day. Probably this is because glutamine can be made into glutamic acid, a stimulating neurotransmitter, even though it is usually converted into gamma amino butyric acid, a calming neurotransmitter. Likewise, though glutamine seldom upsets the stomach even when it is taken between meals, someone with a bad experience taking glutamine on an empty stomach will recommend that everyone take it with food.

A better reason for differences in instructions relates to the different reasons for taking a particular supplement. If you buy glutamine from a store that specializes in bodybuilding supplements, the instructions will likely be to take glutamine in very large amounts (15 to 50 grams per day), with food. This is reasonable if your purpose for taking glutamine is to enhance muscle formation, which glutamine can do. Glutamine taken with food is more likely to join with other amino acids in the formation of muscle protein. If instead your purpose for taking glutamine is to increase the production of GABA, for its calming effects, you can use a lot less (1 to 4 grams per day), if you take it apart from food.

Glutamine has plenty of nonprotein functions aside from production of GABA. Although it is still considered a "nonessential" amino acid because we can make some, it is the primary fuel source for the cells that line the intestinal tract, and it also helps regulate acid-base balance in the body. It is the most abundant amino acid circulating in your bloodstream. Even if your body normally has enough glutamine, if it is used up too fast by extreme stress (long illness or even by vigorous exercise) your stores of glutamine could run short, and a dietary supplement can help you recover faster.

If you want to take glutamine, check with your health care provider to rule out Reye's syndrome or other rare situations in which you should not use it. As a general rule, if you are using glutamine for bodybuilding, taking it with food is an advantage. Otherwise, for its nonprotein functions it is better taken apart from food.