Doctors have long advised women to avoid vaginal douching because of the risk of infection and other adverse effects, but a new study suggests other feminine hygiene products may be just as harmful.

The University of Guelph-led study found that 95 per cent of almost 1,500 Canadian women surveyed about their use of over-the-counter sanitizing gels, anti-itch creams, moisturizers, sprays and wipes had used such products at least once in their lifetime.

But the study also found that women who use feminine hygiene products are three times more likely to experience some type of vaginal infection. In some cases, women purchased a product to address an existing vaginal issue.

"The study does not establish whether it is the products causing the infections or whether women are using the products in an attempt to address the infection," said principal researcher Kieran O'Doherty, a social psychologist at the Ontario university.

"However, the results do provide important evidence for strong correlations that need further research."

For example, women who used gel sanitizers — whether externally of internally — were eight times more likely to have a yeast infection and almost 20 times more likely to have reported bacterial vaginosis.

Vaginosis is caused by the overgrowth of certain bacteria, a condition that occurs when the natural balance of microbes in the vagina is disturbed.

"These products may be preventing the growth of the healthy bacteria required to fight off infection," said O'Doherty, noting that emerging evidence has linked disruption of vaginal microbial systems with health problems.

Pelvic inflammatory disease, cervical cancer, reduced fertility, ectopic and pre-term pregnancies, and bacterial and sexually transmitted infections are among the problems related to an abnormal vaginal microbiome, he said.

Our thinking here is this connects in part with double standards around what is expected of men and women in terms of personal presentation. - Kieran O'Doherty

The study, published in the journal BMC Women's Health, found that women who used vaginal moisturizers and lubricants had 2.5 times higher odds of reporting a yeast infection and 50 per cent higher odds of a urinary tract infection, or UTI, compared to those who didn't use those products.

Women using feminine washes were almost 3.5 times more likely to have reported a bacterial infection and 2.5 times more likely to have had a UTI. Feminine wipes were associated with double the risks of a UTI.

Dr. Chelsea Elwood, a reproductive infectious diseases specialist at BC Women's Hospital and Health Centre, said the study is one of the first to look at the use of these products in the Canadian context and it reaffirmed that their use is becoming more commonplace.

Elwood, who was not involved in the research, stressed that the study found an association between use of vaginal hygiene products, but can't determine whether they caused increased infections.

"So it's a bit of a chicken-and-egg conversation," she said from Vancouver.

"Did they have the yeast infection and they reached for the vaginal moisturizer because they thought it would be helpful? Or did they reach for the vaginal moisturizer daily and then got a yeast infection because it disturbed what should normally be there?

Perhaps not as benign as advertised

"This type of study can't answer that question, but it makes us think that maybe this should be explored further, and that all of these products that are advertised to women are perhaps not as benign as they are advertised to be."

As a general rule, Elwood said she recommends that patients give feminine hygiene products a miss.

"So moisturizers, anti-itch creams, wipes, douching, waxing as well as shaving, in particular, I encourage women just to leave things alone down there."

In a previous study, the Guelph researchers looked at why Canadian women might use the array of feminine hygiene offerings on the market, which the authors say represent a $2-billion industry in North America.

"One of the findings was that women often spoke about how they used these products to feel 'clean and fresh,'" a phrase that manufacturers often use to promote their goods, O'Doherty said.

"Our thinking here is this connects in part with double standards around what is expected of men and women in terms of personal presentation," he said. "And it has to do with body shaming of women.

"And these products are very cleverly designed to fit into that niche."

O'Doherty said societal and cultural attitudes have perpetrated the notion of female genitalia as unclean, leading many women to believe they need feminine hygiene products to be acceptable, especially to a sexual partner.

Some women interviewed for the previous study reported that their partners encouraged use of the products, while others said their partners were happy with them being au naturel.

Despite such assurances, he said many women reported "this very strong internal need that 'I have to be clean. I would die if there was any smell coming from me.'"

O'Doherty said corporations are profiting by marketing products that women "don't really need, but are made to feel they need. And on top of that, not only do they not need them and are paying money, they [may be] bad for their health."

His advice to women: "Think twice before buying these things."