Most nutritionists agree that sugar, yeast, dairy, wheat, caffeine, nicotine, and alcohol are the main culprits because they help yeast to grow. In people with healthy immune systems, the body is usually able to fight off the excess yeast made by these products. But for people with weakened immune systems, yeast can grow out of control, leading to certain kinds of fungal infections, like oral or vaginal candidiasis, or more seriously, esophageal (in the throat/esophagus) candidiasis. To prevent this, nutritionists recommend eating as little as possible of these foods that contribute to the excess production of yeast.
Another approach is to eat larger amounts of foods that may suppress the growth of yeast. For example, garlic is believed by some nutritionists to have natural anti-fungal properties and may help to prevent candidiasis. Fresh garlic is considered best, although garlic supplements offer the advantage of reduced odors. Fresh garlic can be mixed into other foods, eaten raw after removing the dry outer skin, or minced and put into empty gelatin capsules, up to six cloves a day.
Another factor that can contribute to uncontrolled yeast growth is the use of antibiotics. Friendly bacteria are found naturally in the body and establish a healthy balance while eliminating unfriendly yeasts. These bacteria are similar to Lactobacilli, the bacteria that turn milk into yogurt. Most common antibiotics kill these bacteria which then allows yeast to grow, especially in the vagina. It is not unusual, even in people with healthy immune systems, to experience some form of candidiasis after a prolonged use of antibiotics, so it is important to use antibiotics only when truly necessary.
In order to lessen this effect from antibiotics and promote healthy bacteria in general, many nutritionists recommend adding Lactobacilli acidophilus bacteria to your diet. It can be found in yogurts and certain milks. Look for Lactobacilli acidophilus on the label. You can also take it in capsule or powder form. Tablet and non-refrigerated forms of acidophilus are not as beneficial as the bacteria have been killed by heat. The best acidophilus supplements are the ones that are refrigerated prior to purchase in order to maximize the amount of live bacteria per gram. These forms of acidophilus are available from AIDS Treatment Initiatives (ATI). ATI also carries a special acidophilus called Fem-Dophilus® for women which comes with a vaginal applicator for treating vaginal infections.
Oral candidiasis or thrush can change how you taste and enjoy foods. It can also make eating and swallowing difficult. Avoiding acidic, spicy, or hot foods as well as cigarettes, alcohol, and carbonated drinks may lessen this effect. All of these can irritate the insides of your mouth. Soft, cool, and bland foods (like oatmeal, mashed beans, applesauce) are recommended. Many people use liquid food supplements (Ensure, Boost, etc.) to ease swallowing and to keep or add weight during an oral infection.
Unfortunately, many of these supplements are high in sugars, which can promote yeast growth. If you use liquid supplements, make sure they contain mainly complex carbohydrates, are high in protein and have low-to-moderate sugar levels. It is important to remember that these products are intended to be supplements and should not replace solid food. Powdered whey protein supplements are generally higher in protein and lower in sugars and are therefore more beneficial.
There are some reports that gargling with tea tree oil diluted with water can help treat oral candidiasis. Generally these gargles (two drops of oil in a tablespoon of water) are used in the morning, at night, and after meals. They are sometimes swabbed directly on mouth sores (one drop of oil to one drop of water). Grapefruit seed extract and 1% hydrogen peroxide may also be used in a similar way, but must be more heavily diluted and should never be swallowed. However, these approaches (especially grapefruit seed extract) may irritate the mouth and promote infection. Moreover, they only address the local symptoms of yeast growth and not the underlying causes. Other supplements which may be used to treat yeast infections naturally include grapefruit seed extract in a tablet form. Also, herbal extracts containing black walnut (Juglans nigra) and wormwood (Artemisia absinthium) may be helpful. Generally, a combination of these herbs is more potent than a single herbal extract.
Overall, the best way to naturally treat and prevent fungal infections is to eat healthfully and regularly, avoid excessive sugar intake, and avoid or decrease alcohol and cigarettes.