Urinary tract infections (UTIs) affect 8 million to 10 million Americans, mostly women, each year. The culprit: the bacteria E. coli. Neglect may allow a UTI to spread to the bladder (where it causes cystitis), or kidneys: possibly life-threatening.

The good news: medical experts recognize that a diet change and avoiding certain risk factors may help fight off UTIs.

According to the Mayo Foundation for Medical Education and Research, about 20% of women experience UTI at least once, and many suffer recurrences. Sexually active women tend to incur more UTIs because of anatomical vagaries: the bladder sits just above the vagina, while the urethra, a structure from the bladder to the outside, protrudes in a tubelike ridge down the top part of the vagina to just above the vaginal opening. This structure allows sexual intercourse to push infecting bacteria into the urethra. Women's vulnerability to UTI also derives from their short urethras which are located near the rectum, a main source of UTI germs. These tubes provide an easy path to a bacterial home in the bladder.

Another risk booster: pelvic exams which may increase chances of UTI. A 1996 study conducted at the University of Illinois at Chicago and reported in the Archives of Family Medicine (1996;5:357-360) found that 43% of women with UTIs had received a pelvic examination within the two months preceding infection. Only 16% of the uninfected had been examined.

Bladder infections can occur frequently in postmenopausal women due to thinning and drying of the vaginal lining. And mid-life women are not immune. "With the loss of estrogen support, the urethra becomes less flexible and elastic and, like the vagina, it can become easily irritated after sexual intercourse and, thus, much more prone to infection," reports Susan Lark, MD, in her book, Women's Health Companion: Self Help Nutrition Guide and Cookbook (Celestial Arts). "As women age, the lower urinary tract also stops manufacturing anti-adherence factors, which help to prevent bacteria from attaching to the bladder wall."

Every woman should keep her own "female" botanicals on hand to help boost her immune system when she is at high risk of developing a bladder infection. These include:

Cranberry: This immune-boosting, vitamin C-rich berry prevents germs from invading the lining of the urinary tract. A 1994 study of 153 elderly women conducted by researchers at the Harvard Medical School and published in the Journal of the American Medical Association (1994:271: 751-4) showed that cranberry juice may keep harmful bacteria at reduced levels. More recently, a study by Amy B. Howell, PhD, and a team at Rutgers University found that cranberries contain a type of condensed tannin, a chemical compound called proanthocyanidins, that seemed to stunt the growth of E. coli, preventing it from adhering to the walls of the bladder and kidneys.

"However, once you have an infection, cranberry juice cannot eradicate the bacteria. So drinking cranberry juice may be helpful in preventing an infection, but not in treating an existing one," according to Larrian Gillespie, MD, in her book You Don't have to Live with Cystitis (Avon Books).

Drinking two glasses of juice a day can help if you're UTI-prone. To avoid the sugar added to cranberry juice, concentrated cranberries are available in a gel-cap form.

Echinacea: This North American herb bolsters immune function and is believed to possess antiseptic and antiviral properties which may rev up the white blood cells that fight infection, reports John Cammarta, MD, in his book A Physician's Guide To Herbal Wellness (Chicago Review Press).

While cranberry is most commonly recommended for prevention, other herbs can also kill bacteria and are diuretic. These include:

Barberry: "The chemical berberine found in this herb is an impressive infection fighter. Studies show it kills the bacteria responsible for urinary tract infections," says author Jim O'Brien in his book Herbal Cures for Common Ailments (Globe).

O'Brien recommends making a tea with one half teaspoon of powdered root bark, then put it on low boil for 30 minutes. "The taste is unpleasant, so you may wish to add natural sweeteners and flavorings."

Uva-ursi: contains the ingredient arbutin, which fights germs in the urinary tract. "In addition," adds O'Brien, "the herb contains several diuretics that help flush the urinary tract, leading to faster healing. It also has several tannins, which act as powerful astringents drying out swollen, infected tissue. A third property of uva-ursi is allantoin, which promotes the growth of new cells."

"For this herb to be effective you must not eat or drink anything of acidic nature, such as citrus fruits or juices. Don't even take vitamin C supplements while using it," cautions O'Brien.

Coping With Pain
In her book Herbal Remedies for Women (Prima), medical herbalist Amanda McQuade Crawford offers an herbal recipe to help restore the urinary tract's normal pH. Herbal Formula I calls for 4 ounces of uva-ursi leaf, three ounces of marshmallow leaf, two ounces of yarrow flower (omit during pregnancy) and one ounce (or to taste) cinnamon bark. Steep the herbs for 10 to 20 minutes, then strain through bamboo or wire mesh. Drink 2 to 5 cups daily for 10 days. Crawford advocates drinking one to two cups per day for a week to 10 days after all symptoms have disappeared.

Diet Strategies
Urologist Gillespie has found that women with cystitis may notice certain foods and beverages (such as alcohol and acidic foods) exacerbate problems of pain and burning. Gillespie recommends cystitis sufferers avoid foods like apple juice, apples, apricots, melon, carbonated drinks, spicy foods, citrus fruits, coffee, ginger, grapes, guava, lemon juice, peaches, pineapple, plums, rhubarb, strawberries, tea, tomatoes and vinegar.

Limit refined sugar: this nutrient may stunt immune reactions. Most importantly, you can lower the risk of UTIs by drinking liquids. Water helps flush bacteria from the body so drink at least 6 to 8 eight-ounce glasses of filtered water daily.