Herbs at a Glance: Garlic, Soy, and Cranberry
Garlic 101
Garlic's most common uses as a dietary supplement are for high cholesterol,
heart disease, and high blood pressure. Garlic is also used to prevent certain
types of cancer, including stomach and colon cancers. Garlic cloves can be
eaten raw or cooked. They may also be dried or powdered and used in tablets and
capsules. Raw garlic cloves can be used to make oils and liquid extracts.
What the Science Says about Garlic
Some evidence indicates that taking garlic can slightly lower blood cholesterol
levels. Studies have shown positive effects for short-term (1 to 3 months) use.
However, a study The National Center for Complementary and Alternative Medicine
(NCCAM) funded on the safety and effectiveness of fresh garlic, dried powdered
garlic tablets, and aged garlic extract tablets for lowering blood cholesterol
levels found no effect.
Preliminary research suggests that taking garlic may slow the development of atherosclerosis (hardening of the arteries), a condition that can lead to heart disease or stroke.
Evidence is mixed on whether taking garlic can slightly lower blood pressure. Some studies suggest consuming garlic as a regular part of the diet may lower the risk of certain cancers. However, no clinical trials have examined this. NCCAM is supporting studies looking at how garlic interacts with certain drugs and how it can thin blood.
Side Effects and Cautions for Garlic
Garlic appears to be safe for most adults. Side effects include breath and body
odor, heartburn, upset stomach, and allergic reactions. These side effects are
more common with raw garlic. Garlic can thin the blood (reduce the ability of
blood to clot) in a manner similar to aspirin. This effect may be a problem
during or after surgery. Use garlic with caution if you are planning to have
surgery or dental work, or if you have a bleeding disorder. A cautious approach
is to avoid garlic in your diet or as a supplement for at least 1 week before
surgery.
Garlic has been found to interfere with the effectiveness of saquinavir, a drug used to treat HIV infection. Its effect on other drugs has not been well studied.
Remember: It is important to inform your health care providers about any herbal or dietary supplement you take. This helps to ensure safe and coordinated care.
For more information, visit: http://nccam.nih.gov/health/garlic/index.htm
Soy 101
Soy has been common in Asian diets for thousands of years. It is found in
modern American diets as a food or food additive. Soybeans, the high-protein
seeds of the soy plant, contain isoflavones-compounds similar to the female
hormone estrogen.
People use soy products to prevent or treat a variety of health conditions, including high cholesterol levels, menopausal symptoms such as hot flashes, osteoporosis (a condition in which bones become thin and brittle), memory problems, high blood pressure, breast cancer, and prostate cancer.
What the Science Says About Soy
Research suggests that daily intake of soy protein may slightly lower levels of
LDL ("bad") cholesterol. Some studies suggest that soy isoflavone
supplements may reduce hot flashes in women after menopause. However, the
results have been inconsistent. There is not enough scientific evidence to
determine whether soy supplements are effective for any other health uses.
Side Effects and Cautions for Soy
Soy is considered safe for most people when used as a food or when taken for
short periods as a dietary supplement. Minor stomach and bowel problems such as
nausea, bloating, and constipation are possible. Allergic reactions such as
breathing problems and rash can occur in rare cases.
The safety of long-term use of soy isoflavones has not been established. Evidence is mixed on whether using isoflavone supplements, over time, can increase the risk of endometrial hyperplasia (a thickening of the lining of the uterus that can lead to cancer). Studies show no effect of dietary soy on risk for endometrial hyperplasia.
Soy's possible role in breast cancer risk is uncertain. Until more is known about soy's effect on estrogen levels, women who have or who are at increased risk of developing breast cancer or other hormone-sensitive conditions (such as ovarian or uterine cancer) should be particularly careful about using soy and should discuss it with their health care providers.
Remember: It is important to inform your health care providers about any herbal or dietary supplement you take. This helps to ensure safe and coordinated care.
For more information, visit: http://nccam.nih.gov/health/soy/
Cranberry 101
Cranberry is used in foods and in herbal products. Historically, cranberry
fruits and leaves were used for a variety of problems, such as wounds, urinary
disorders, diarrhea, diabetes, stomach ailments, and liver problems. Recently,
cranberry products have been used in the hope of preventing or treating urinary
tract infections or infections that can lead to stomach ulcers, or to prevent
dental plaque. Cranberry has also been reported to have antioxidant and
anticancer activity.
What the Science Says About Cranberry
Some studies testing cranberry products for their ability to prevent urinary
tract infections have shown promise, however, cranberry products have not been
adequately tested to see if they can be used to help treat an existing urinary
tract infection.
Research shows that components found in cranberry may prevent bacteria, such as E. coli, from clinging to the cells along the walls of the urinary tract and causing infection. The National Center for Complementary and Alternative Medicine (NCCAM), the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Institute for Dental and Craniofacial Research are funding studies to understand whether and how cranberry might work to prevent urinary tract infection and the formation of dental plaque.
Side Effects and Cautions for Cranberry
Eating cranberry products in food amounts appears to be safe, but drinking
excessive amounts of juice could cause gastrointestinal upset or diarrhea.
People who think they have a urinary tract infection should see a health care
provider for proper diagnosis and treatment. Cranberry products should not be
used to treat infection.
Remember: It is important to inform your health care providers about any herbal or dietary supplement you take. This helps to ensure safe and coordinated care.
For more information, visit: http://nccam.nih.gov/health/cranberry/
Source: National Center for Complementary and Alternative Medicine (NCCAM), National Institutes of Health
