The truth about body odor

Body odor might not be the sexiest topic I’ve ever written about, but it’s a fact of life, especially here in South Florida.

Fortunately for the world at large, deodorants and antiperspirants are part of our daily routines, but body odor can be a stubborn problem. I recently came across information about the root cause of body odor, and you may be surprised at what I uncovered.

What causes body odor?

While most of us view it as a sign of bad hygiene, on a biological level it may be our immune system’s way of attracting mates. In addition to oil and sweat glands, our skin is home to apocrine glands that become active after puberty. These glands are concentrated in areas where there is hair (i.e. the underarms, genitals and even the scalp) and the hair serves as a diffuser for the scent.

Men’s apocrine glands are larger than women’s, and they become more active in times of nervousness or excitement. (Perhaps you’ve noticed that stress sweat smells different than it’s-hot-outside sweat.)

Research shows that body odor seems to have at least a partial genetic component. This helps explain why Asians tend to have less body odor than Caucasians and African Americans.

One study compared the scents of left and right armpits. In most cases, both smell the same, except in left-handed males, whose left armpits tend to smell more “masculine and intense.”

As mentioned earlier, body odor plays a role in attracting mates. Some studies show that women are attracted to the smell of men whose body odor contains proteins that are different than their own. This may ensure that their offspring will be better able to fight off disease.

Birth control pills can alter body odor perception, and women who take them may choose less biologically compatible mates.

One’s gender and sexual preference affects their perception of body odor.

Studies show that body odor can affect perceptions of facial attractiveness. Unpleasant odors make women rate men as less attractive.

Diet plays a role in body odor. Asparagus, curry, cumin and other potent spices give body odor a distinct smell. Another study found than men who eat red meat have a less pleasant body odor than those who don’t.

If you want your armpits to smell like maple syrup, you can try taking fenugreek supplements.

As if I weren’t already a big enough fan of antioxidants, they may help with body odor as well. One study found that resveratrol inhibited body odor by blocking androgen (male hormone) receptors. This same study also found that a variety of herbs have the ability to suppress odor, but many of these have strong odor of their own, so I don’t recommend them as a substitute for deodorant.

How to improve body odor

We’re all familiar with antiperspirants, which work by blocking sweat ducts. One main ingredient, aluminum salts, has antibacterial properties, but they are also acidic, which can be irritating. Zinc salts found in antiperspirants help absorb odor and may block dihydrotestosterone (a male hormone that may increase body odor). Manganese salts absorb odor and kill bacteria. Some products also incorporate antibacterial ingredients like triclosan to prevent odor.

But deodorants and antiperspirants aren’t always strong enough. In these cases, dermatologists have a variety of other treatments that can help body odor. Botox is FDA-approved for hyperhidrosis (excessive sweating), and just a few injections about every six months decreases sweat production.

This story was originally published August 20, 2012 at 9:00 PM with the headline "The truth about body odor."