More than half of all adult women will have at least one vaginal
–and, surprisingly, about 20% of men experience a similar infection. Although these infections can be effectively treated with medications, for an unfortunate few they have a tendency to recur despite adequate treatment. Can eating yogurt help them avoid repeated infections?
Evidence for the Health Claim
A fungus known as
is responsible for causing yeast infections. A small amount of it is always present on the skin and mucous membrane surfaces in the body. However, when
multiplies, and the acid levels in the vagina become imbalanced, the unpleasant symptoms of a yeast infection, or
candidiasis, result. Most female yeast infection sufferers report itching and burning that may be more pronounced when urinating. Men who have candidiasis
typically complain of itching and red, bumpy skin on and around the penis.
Fermented milk products contain so-called “probiotic,” or “good” bacteria, including
lactobacillus, acidophilus, and
bifidobacterium, that compete with Candida in the genital area.
In a study conducted with 320 Finnish women, researchers found that those who ate three or more servings per week of yogurt–or in some cases, cheeses made from fermented milk–had far fewer fewer UTIs than those who did not eat yogurt or ate it only infrequently.
Several studies have found that to make a significant reduction in the occurrence of yeast infections, people need to consume at least one serving of yogurt per day. In these studies, the yogurt contained
bacteria, which is generally noted on food labels as containing “live” or “active” cultures.
Evidence Against the Health Claim
Not all studies support the claim that regular yogurt consumption reduces the risk of recurrent yeast infections, and those that do have generally been small in size. Furthermore, there is little evidence to suggest that eating lots of yogurt once symptoms appear will resolve an acute infection any quicker.
There is probably sufficient evidence to recommend the consumption of active-culture yogurt as a safe preventive treatment for women who are prone to repeated infections. It is unclear whether the same can be said for men. Women who suffer from repeated infections may wish to add yogurt to their regular diets, and have at least one serving daily. Because yeast feeds on sugar, most authorities recommend selecting low sugar or unsweetened yogurts.