Yeast infections usually result from an overgrowth of a species of fungus called Candida albicans. They can occur on the skin, under nails or mucous membranes of the mouth, vagina, bronchi, and lungs.
Vaginal yeast infections are one of the most common reasons that women consult healthcare professionals.
What are the symptoms of yeast infection?
Yeast infections are a type of vaginitis. The hallmark symptom of a yeast infection is itching of the external and internal genitalia, which is often associated with a white discharge that can be thick and/or curdy (like cottage cheese). Severe infections lead to inflammation of the tissue and subsequent redness, swelling, and even pinpoint bleeding.
Dietary changes that may be helpful for yeast infection
Some doctors believe that a well-balanced diet low in fats, sugars, and refined foods is important for preventing vaginal infections caused by Candida. In one preliminary trial, avoidance of sugar, dairy products, and artificial sweeteners resulted in a sharp reduction in the incidence and severity of Candida vaginitis.1 Many doctors advise women who have a yeast infection (or are predisposed to such infections), to limit their intake of sugar, fruit juices, and refined carbohydrates. For persistent or recurrent infections, some doctors recommend that fruit also be avoided.
Another trial found that dramatic increases in intake of several sugars in healthy people partially increased stool sample levels of Candida, but only in 12 out of 28 people.2
Lifestyle changes that may be helpful for yeast infection
According to one study, yeast infections are three times more common in women who wear nylon underwear or tights, than in those who wear cotton underwear.3 Additional predisposing factors for Candida infection include the use of antibiotics, oral contraceptives, or adrenal corticosteroids (such as prednisone).
Underlying health conditions that may predispose someone to Candida overgrowth include pregnancy, diabetes, and HIV infection. Allergies have also been reported to promote the development of recurrent yeast vaginitis. In a preliminary trial, when the allergens were avoided and the allergies treated, the chronic recurrent yeast infections frequently resolved.4 In most cases, sexual transmission does not play a role in yeast infection. However, in persistent cases, sexual transmission should be considered, and the sexual partner should be examined and treated.
Nutritional supplements that may be helpful for yeast infection
Lactobacillus acidophilus is a species of friendly bacteria that is an integral part of normal vaginal flora. Lactobacilli help to maintain the vaginal ecosystem by preventing the overgrowth of unfriendly bacteria and Candida. Lactobacilli produce lactic acid, which acts like a natural antibiotic.
Lactobacillus acidophilus can be taken orally in the form of acidophilus yogurt, or in capsules or powder. It can also be administered vaginally. In a controlled trial, women who consumed 8 ounces of Lactobacillus acidophilus-containing yogurt per day had a threefold decrease in the incidence of vaginal yeast infections and a reduction in the frequency of Candida colonization in the vagina.5 In another trial, women who were predisposed to vaginal Candida infection because they were HIV-positive received either Lactobacillus acidophilus vaginal suppositories, the antifungal drug, clotrimazole (e.g., Gyne-Lotrimin®), or placebo weekly for 21 months.6 Compared to those receiving placebo, women receiving Lactobacillus acidophilus suppositories had only half the risk of experiencing an episode of Candida vaginitis—a result almost as good as that achieved with clotrimazole.
Many women find relief using an acidophilus-containing yogurt douche daily for a few days or weeks, depending on the severity of the infection.7 Three capsules of acidophilus or one-quarter teaspoon of powder can be taken orally one to three times daily. Acidophilus can also be taken preventively during antibiotic use to reduce the risk of Candida vaginitis.8 9
Boric acid capsules inserted in the vagina have been used successfully as a treatment for vaginal yeast infections. One study demonstrated that 85% of women who used boric acid vaginal suppositories were cured of chronic recurring yeast vaginitis.10 These women had all previously failed to respond to treatment with conventional antifungal medicines. The suppositories, which contained 600 mg of boric acid, were inserted vaginally twice a day for two weeks, then continued for an additional two weeks if necessary. Boric acid should never be swallowed.
Are there any side effects or interactions with yeast infection?
Refer to the individual supplement for information about any side effects or interactions.
Herbs that may be helpful for yeast infection
A small, preliminary trial found that a mouthwash with diluted tea tree oil was effective in decreasing the growth of Candida albicans and in improving symptoms in AIDS patients with oral Candida infections (thrush) that had not responded to drug therapy.11 People in the study took 15 ml of the oral solution (dilution of tea tree oil was not given) four times per day and were instructed to swish it in their mouth for 30 to 60 seconds and then spit it out. For use of tea tree oil as a mouthwash, one should not exceed a 5% dilution and should be extremely careful not to swallow the solution.
Many doctors recommend that people with recurrent yeast infections take measures to support their immune system. Echinacea, which has the capacity to enhance immune function, is often used by people who suffer from recurrent infections. In one study, women who took echinacea experienced a 43% decline in the recurrence rate of yeast infections.12
The essential oil of cinnamon contains various chemicals that are believed to be responsible for cinnamon’s medicinal effects. Important among these compounds are eugenol and cinnamaldehyde. Cinnamaldehyde and cinnamon oil vapors exhibit extremely potent antifungal properties in test tubes.13 In a preliminary study in people with AIDS, topical application of cinnamon oil was effective against oral thrush.14
A test tube study demonstrated that oil of oregano, and an extract in the oil called carvacrol in particular, inhibited the growth of Candida albicans far more effectively than a commonly employed antifungal agent called calcium magnesium caprylate.15 However, clinical studies are needed to confirm these actions in humans.
Are there any side effects or interactions with yeast infection?
Refer to the individual herb for information about any side effects or interactions.