Word travels fast on the Internet. As stories fly from inbox to inbox, they gain momentum and news sometimes blurs with fiction. A few years ago, an email began circulating that gave many readers reason to pause. It read:
"I just got information from a health seminar that I would like to share. The leading cause of breast cancer is the use of antiperspirant. Yes, ANTIPERSPIRANT. Most of the products out there are an anti-perspirant/deodorant combination so go home and check your labels."
The email went on to explain how antiperspirant prevents the body from "purging toxins," which, when trapped, find their way into the lymph nodes, where they concentrate and contribute to the cellular changes that lead to cancer. Meanwhile, on the Web, several sites featured stories about a supposed link between antiperspirants and Alzheimer's disease.
To the millions of Americans who use antiperspirants daily, these e-mails and Web stories came as a big shock. Like many other people, you may have wondered: Is the product I've been applying to my body every day for years really putting my health at risk?
WebMD put the question to several experts, and discovered that the rumors about antiperspirants don't stand up to the science.
The Origins of Antiperspirant Fears
Most antiperspirant worries center on the active ingredient -- an aluminum-based compound that temporarily plugs the sweat ducts and prevents you from perspiring.
Typically, antiperspirants are coupled with a deodorant, which contains the pleasant scent that stops you from stinking. They may also contain a number of inactive ingredients.
Let's look at where the health worries over antiperspirants got their start, and what the research has to say about these products:
Antiperspirants and Cancer
A few studies in recent years have theorized that aluminum-based antiperspirants may increase the risk for breast cancer.
According to the authors of these studies, most breast cancers develop in the upper outer part of the breast -- the area closest to the armpit, which is where antiperspirants are applied. The studies suggest that chemicals in antiperspirants, including aluminum, are absorbed into the skin, particularly when the skin is nicked during shaving. These studies claim that those chemicals may then interact with DNA and lead to cancerous changes in cells, or interfere with the action of the female hormone estrogen, which is known to influence the growth of breast cancer cells.
Considering that one out of every eight women will develop breast cancer at some point in her lifetime, the idea that antiperspirants might somehow contribute to the disease is a pretty serious claim.
Yet experts say the claims don't hold up to scrutiny. "There is no convincing evidence that antiperspirant or deodorant use increases cancer risk," Ted S. Gansler, MD, MBA, director of medical content for the American Cancer Society, said in an e-mail interview.
Gansler says many of the studies that have been conducted were flawed, and even though a few detected chemicals from antiperspirants in breast tissue, they didn't prove that those chemicals had any effect on breast cancer risk. In fact, one well-designed study comparing hundreds of breast cancer survivors with healthy women, as well as a review of all available studies on the subject, found no evidence that antiperspirants increase the risk of breast cancer.
Worrying about antiperspirants shouldn't distract women from addressing the real breast cancer risks, Gansler says, especially the ones they can control, like eating healthy, getting regular exercise, and limiting alcohol.
Antiperspirants and Alzheimer's Disease
Back in the 1960s, a few studies found high levels of aluminum in the brains of people with Alzheimer's disease. The research suddenly called into question the safety of everyday household items such as aluminum cans, antacids, and antiperspirants.
But the findings of these early studies weren’t replicated in later research, and experts have essentially ruled out aluminum as a possible cause of Alzheimer's.
"There was a lot of research that looked at the link between Alzheimer's and aluminum, and there hasn't been any definitive evidence to suggest there is a link," says Heather M. Snyder, PhD, senior associate director of medical and scientific relations for the Alzheimer's Association.
According to the experts interviewed for this story, the aluminum in antiperspirants doesn't even typically make its way into the body.
"The aluminum salts do not work as antiperspirants by being absorbed in the body. They work by forming a chemical reaction with the water in the sweat to form a physical plug... which is deposited in the sweat duct, producing a blockage in the areas that it's applied," says David Pariser, MD, professor of dermatology at Eastern Virginia Medical School and past president of the American Academy of Dermatology. "Even [with] nicks from shaving, the amount is so negligible that it doesn't make a whole lot of scientific sense."
Antiperspirants and Kidney Disease
Concerns about antiperspirants and kidney disease were first raised many years ago, when dialysis patients were given a drug called aluminum hydroxide to help control high phosphorus levels in their blood. Because their kidneys weren't functioning properly, their bodies couldn't remove the aluminum fast enough, and it began accumulating. Scientists noticed that dialysis patients who had these high aluminum levels were more likely to develop dementia.
As a result, the FDA requires antiperspirant labels to carry a warning that reads, "Ask a doctor before use if you have kidney disease." Yet this warning is only meant for people whose kidneys are functioning at 30% or less.
In reality, it's almost impossible to absorb enough aluminum through the skin to harm the kidneys. "Unless you eat your stick or spray it into your mouth, your body can't absorb that much aluminum," says nephrologist Leslie Spry, MD, FACP, spokesperson for the National Kidney Foundation.
Other Antiperspirant Ingredients
An aluminum-based compound is the active ingredient in antiperspirants, and the one that's most often connected with antiperspirant worries. But what about the inactive ingredients? Do they pose any risk?
One common antiperspirant component -- a group of chemicals called parabens -- has been linked to breast cancer, but that link is questionable, at best. Although parabens have estrogen-like qualities, they are much weaker than the natural estrogens found in the body.
A 2004 study did find a high concentration of parabens in breast cancer tumors, but the study didn't determine whether the parabens actually caused breast cancer, or if those parabens came from antiperspirants. Pariser says cancer isn't an issue with parabens, although some people can have an allergic reaction to the preservative. Most antiperspirants/deodorants on the market today don't even contain parabens.
Antiperspirants: Should You Worry?
In short: No. There is no real scientific evidence that aluminum or any of the other ingredients in these products pose any threat to human health.
"These products can be used with high confidence of their safety. They've been used for many years, and there's no evidence that suggests a problem," says John Bailey, PhD, chief scientist with the Personal Care Products Council, the trade association that represents the cosmetic and personal care products industry.
Antiperspirants have no proven impact on the risk of diseases like breast cancer and Alzheimer's. "Breast cancer and Alzheimer's are two complicated diseases which are difficult to associate with one singular cause, such as antiperspirant/deodorant use," Paul Pestano, MS, research analyst with the Environmental Working Group, said in an e-mail interview.
So why do the rumors about antiperspirant use and disease persist?
"The Internet, by its very nature, is a great medium for recycling old issues over and over again," Bailey says. "And I think there is a tendency for some people to use these scare tactics to their own advantage."
"Part of the reason that the discussion about aluminum and Alzheimer's disease continues to be a topic is Alzheimer's is a devastating disease, and people want to know why their relative has this disease, and they want an easy answer," Snyder says.
She says there are no easy answers when it comes to Alzheimer's. The factors that may reduce your risk of getting the disease -- such as being physically active, eating a healthy diet, and staying mentally engaged -- don't involve antiperspirants. The same goes for reducing your cancer risk.
Even though the evidence doesn't support a connection between antiperspirants and diseases like cancer and Alzheimer's, if you're still worried about using them, Pestano advises reading the product labels and learning about the ingredients they contain.
If you'd prefer to go natural, you could try an aluminum-free antiperspirant alternative, or even rub items from your kitchen -- such as tea or lemon -- under your arms. Just be warned: The resulting aromas and wet spots could cause your friends to flee. "A lot of people may want to try things, but if they want to be dry, then they need to use an antiperspirant," Pariser says.