By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

“SMELLY SWEAT” COULD RESULT FROM DIET, POOR HYGIENE OR OTHER CAUSE

Question: I'm a 42-year old male. Over the past couple of weeks I've noticed the smell of my underarm sweat has changed from “normal” to a sort of onion type of smell. I am not a dirty person, and I am horrified and totally embarrassed by this. There are no other symptoms. I don’t feel any changes in me on the whole. Hope you can help.

Answer: Generally, sweat, itself, is odorless until it mixes with the bacteria on the surface of your body. Sweating is a very normal bodily function with the primary purpose of cooling the body. Hence, when you are in hot weather or exercise strenuously, you tend to perspire.

Since you’ve noticed this just recently and describe the odor as sort of an “onion type of smell,” the first thing I might suspect is a change in your diet. Onions are one food that has been implicated as a possible cause of diet-induced body odor. Others foods that might cause body odor problems for some people include garlic, curry, certain spicy foods, coffee and alcohol. The reason onions and garlic can be problematic, for instance, is that they contain oils that are odorous when they are excreted through the skin. Caffeine and alcohol are problems because they can act to increase sweating.

Before I answer your question more fully, it would help if I told you a little about the two distinctly different kinds of sweat that the human body produces. Only one of these types of sweat is a major contributor to body odor problems. Most sweat comes from eccrine glands located throughout the body. This type of sweat is produced by heat stimulation and by emotional factors. It’s 99 percent water and has almost no smell at all. The other kind of sweat does smell. It comes from the apocrine glands that are located primarily in the underarm area -- but are also found about the ears, nipples, navel and genital region. They are stimulated solely by your emotions -- especially stress and sexual stimulation -- and produce a thicker, slightly milky liquid.

The reason apocrine sweat smells is because it’s composed of complex organic molecules that are quickly decomposed by the bacteria on the skin. Further, the underarm environment is ideally suited for the growth of this bacteria. It’s warm and supplied with additional moisture from eccrine sweat glands that are also located there.

Type of sweat and diet are, however, only two issues that affect the smell of sweat. Other common cause of body odor are emotional factors -- like stress and anxiety -- as well as bad hygiene, antibiotics, certain other medications and caffeine consumption. Also, certain underlying medical illnesses -- such as diabetes and cancer -- can cause body odor problems.

Once you are sure there is no underlying medical condition causing your body odor, the next thing you should do is to adjust your diet. Try eliminating caffeine, alcohol and the foods I mentioned previously. If this doesn’t solve your problem, there are still some things you can try.

Charcoal or chlorophyll tablets can help eliminate body odor, as can sage tea. Using powder to keep moist underarm areas dry, can help decrease odors. Some antiperspirants that contain aluminum chloride will stop excessive sweating.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.