Vitamins & Supplements

Before adding any of the supplements/vitamins below to your diet, please check with your physician for possible interference with your current medications.  Generally, the items are safe, but your complete medication list should be reviewed by your physician.

Vitamins - Courtesy of Dr. Weil

Vitamin C - 250 mg / day

  • Vitamin C - Dr. Weil currently recommends taking only 250 mg of vitamin C each day. His recommendations in the past have called for more than 1,000mg of vitamin C a day, but we now know that the body cannot use more than about 250mg a day. However, higher doses of this antioxidant, greater than 1000mg/day, may provide additional protection against increased oxidative stress, such as while recovering from illness or to address the effects of air pollution. 

Vitamin E - 400 to 800 iu / day

  • The higher dose is if you are over 40.  Use mixed tocopherols (combination of different types of Vitamin E).

  • Vitamin E is a powerful, fat-soluble antioxidant that helps protect cell membranes from damage by free radicals and prevents the oxidation of LDL (“bad”) cholesterol. It is necessary for structural and functional maintenance of skeletal, cardiac, and smooth muscle; assists in the formation of red blood cells; helps to maintain stores of vitamins A and K, iron, and selenium; and may play a protective role against heart disease, cancer and Alzheimer's disease.

Selenium - 200 mcg / day

  • Selenium is a trace mineral which functions as a cofactor for an important antioxidant exzyme system in the body called glutathione peroxidase. It has been shown in one large study to reduce the risk of secondary cancers in a group of individuals with a previous diagnosis of skin cancer. The dose used in the study was 200 mcg/day. It is important to use an organic form of the mineral like selenomethionine rather other forms. Brazil nuts are very rich in selenium; one provides about 200 mcg.

Mixed Carotenoids (Vitamin A) - 15000 IU / day

  • Include beta-carotene, alpha-carotene, lutein, zeaxanthin, and lycopene

  •  "recommend using natural forms of mixed carotenoids, such as alpha and gamma carotene along with beta-carotene, which is easily found in health food stores. Read the label to make sure it gives you lycopene, the red pigment in tomatoes that helps prevent prostate cancer, and lutein, which protects against cataracts and macular degeneration. Better brands will include other important carotenoids like astaxanthin, zeaxanthin, phytoene and phytofluene."

Folic Acid - 400 mcg / day

Calcium - 500 to 700 mg / day for women (Calcium Citrate)

  • Women - total daily intake - 1000 to 1200 mg 

  • Men - total daily intake - 500 to 600 mg, probably do not need a supplement

  • See Vitamin D below

Vitamin D - 2000 IU / day of D3 - updated 2010

  • Take with a fat containing meal to ensure absorbtion


Omega 3 fatty acids

  • Salmon and other cold water oily fish

  • walnuts and flaxseeds contain a precursor omega-3 (alpha-linolenic acid called ALA) that the body must convert to EPA and DHA.

  • Fish Oil capsules - containing no cholesterol which means distilled and free of potential contaminants

  • two critical omega-3 fatty acids, (eicosapentaenoic acid, called EPA and docosahexaenoic or DHA)

  • Decreased Omega 3s may explain the rise of such diseases as asthma, coronary heart disease, many forms of cancer, autoimmunity and neurodegenerative diseases

  • The imbalance between omega-3 and omega-6 fatty acids may also contribute to obesity, depression, dyslexia, hyperactivity and even a tendency toward violence.

  • NCCAM -  Summary of Key Findings:

  • The polyunsaturated fatty acids alpha-linolenic acid (ALA) and linoleic acid (LA) must come from the diet because they cannot be made by the body. ALA, an omega-3 fatty acid, is converted in the body to the fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). LA, an omega-6 fatty acid, is converted to the fatty acid arachidonic acid (AA).
  • Most American diets provide more than 10 times as much omega-6 than omega-3 fatty acids. There is general agreement that individuals should consume more omega-3 and less omega-6 fatty acids to promote good health. Good sources of ALA are leafy green vegetables, nuts, and vegetable oils such as canola, soy, and especially flaxseed. Good sources of EPA and DHA are fish and organ meats. LA is found in many foods, including meat, vegetable oils (e.g., safflower, sunflower, corn, soy), and processed foods made with these oils.
  • EPA and DHA are metabolized through the same biochemical pathways as AA. EPA and AA are precursors for hormone-like agents known as eicosanoids. It is not known whether a desirable ratio of omega-6 to omega-3 fatty acids exists or to what extent high intakes of omega-6 fatty acids interfere with any benefits of omega-3 fatty acid consumption.
  • Impact on cardiovascular disease: According to both primary and secondary prevention studies, consumption of omega-3 fatty acids, fish, and fish oil reduces all-cause mortality and various CVD outcomes such as sudden death, cardiac death, and myocardial infarction. The evidence is strongest for fish and fish oil supplements.
  • Impact on heart function: Animal and isolated organ/cell culture studies demonstrate that omega-3 fatty acids affect cellular functions involved in ensuring a normal heart rate and coronary blood flow.
  • Impact on CVD risk factors: Fish oils can lower blood triglyceride levels in a dose-dependent manner. Fish oils have a very small beneficial effect on blood pressure and possible beneficial effects on coronary artery restenosis after angioplasty and exercise capacity in patients with coronary atherosclerosis.
  • Impact on asthma: No conclusions could be drawn about the value of omega-3 fatty acid supplements in the prevention or treatment of asthma for adults or children other than the fact that they have an acceptable safety profile.
  • Impact on other conditions: Omega-3 fatty acids can reduce joint tenderness and need for corticosteroid drugs in rheumatoid arthritis. Data are insufficient to support conclusions about the effects of omega-3 fatty acids on inflammatory bowel disease, renal disease, systemic lupus erythematosus, bone density, and diabetes.
  • Impact on cognitive function: The quantity and strength of evidence is inadequate to conclude that omega-3 fatty acids protect cognitive function with aging or the incidence or clinical progression of dementia (including Alzheimer's disease), multiple sclerosis, and other neurological diseases.
  • Impact on organ transplantation: No conclusive evidence suggests specific benefits of omega-3 fatty acid supplementation on any outcome in any form of organ transplantation. However, available studies are small, have methodological problems, and may not fully apply to current transplantation procedures.
  • Safety: Adverse events related to consumption of fish-oil or ALA supplements are generally minor and typically gastrointestinal in nature (such as diarrhea). They can usually be eliminated by reducing the dose or discontinuing the supplement.
Conclusion: The health effects of omega-3 fatty acids require further investigation. Each report provides recommendations on specific research needs and how to improve the quality of future studies.


  • Fresh garlic better than dried, the more the better in your diet

  • Lowers blood pressure, lowers cholesterol, raises HDL

  • Strong antioxidant, stimulates the immune system, strong antiseptic

  • NCCAM -

    What It Is Used For

  • 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.

How It Is Used

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

  • 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.
  • 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 a study on the safety and effectiveness of three garlic preparations (fresh garlic, dried powdered garlic tablets, and aged garlic extract tablets) for lowering blood cholesterol levels. NCCAM studies are also looking at how garlic interacts with certain drugs and how it can thin blood.

Side Effects and Cautions

  • 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.
  • Tell your health care providers about any herb or dietary supplement you are using, including garlic. This helps to ensure safe and coordinated care.

Ginger - Fresh, crystallized ginger, dried capsules (1 - 2 gms / day with meals)

  • Improves protein digestion, antinausea, strong anti-inflammatory, GI tract protectorant

  • Ginger, the familiar spice, has a number of remarkable properties that recommend it for home use. It is a good treatment for nausea and motion sickness as well as a natural anti-inflammatory that is worth trying in all cases of arthritis, bursitis, and other musculoskeletal ailments. It tones the cardiovascular system and reduces platelet aggregation, as aspirin does.

  • The root of this plant has been used in cooking and in some cultures to treat nausea, vomiting, and certain other medical conditions. It is being studied in the treatment of nausea and vomiting caused by cancer chemotherapy. Latin name: Zingiber officianale.

  • NCCAM -

    What It Is Used For

  • Ginger is used in Asian medicine to treat stomach aches, nausea, and diarrhea.
  • Many digestive, antinausea, and cold and flu dietary supplements sold in the United States contain ginger extract as an ingredient.
  • Ginger is used to alleviate postsurgery nausea as well as nausea caused by motion, chemotherapy, and pregnancy.
  • Ginger has been used for rheumatoid arthritis, osteoarthritis, and joint and muscle pain.

How It Is Used

The underground stems of the ginger plant are used in cooking, baking, and for health purposes. Common forms of ginger include fresh or dried root, tablets, capsules, liquid extracts (tinctures), and teas.

What the Science Says

  • Studies suggest that the short-term use of ginger can safely relieve pregnancy-related nausea and vomiting.
  • Studies are mixed on whether ginger is effective for nausea caused by motion, chemotherapy, or surgery.
  • It is unclear whether ginger is effective in treating rheumatoid arthritis, osteoarthritis, or joint and muscle pain.
  • NCCAM-funded investigators are studying:
    • Whether ginger interacts with drugs, such as those used to suppress the immune system.
    • Ginger's effect on reducing nausea in patients on chemotherapy.
    • The general safety and effectiveness of ginger's use for health purposes, as well as its active components and effects on inflammation.

Side Effects and Cautions

  • Few side effects are linked to ginger when it is taken in small doses.
  • Side effects most often reported are gas, bloating, heartburn, and nausea. These effects are most often associated with powdered ginger.
  • Tell your health care providers about any herb or dietary supplement you are using, including ginger. This helps to ensure safe and coordinated care.


  • Arthritis, tendinitis, bursitis; it acts as an antioxidant and anti-inflammatory agent

  • In rare instances, daily use over extended period of time can cause stomach upset and/or heartburn; do not use if you have gallstones or a bile duct dysfunction; if pregnant, do not use without your doctor's approval.

  • Look for products standardized for 95% curcuminoids. Products made by New Chapter containing curcumin are highly recommended. For cooking, brightly colored and aromatic powder is best.

  • 400 to 600 mg of extracts (tablets or capsules) three times per day or as directed on product. Dried spice is not effective for treating conditions.

  • NCCAM 

  • What It Is Used For

  • In traditional Chinese medicine and Ayurvedic medicine, turmeric has been used to aid digestion and liver function, relieve arthritis pain, and regulate menstruation.
  • Turmeric has also been applied directly to the skin for eczema and wound healing.
  • Today, turmeric is used for conditions such as heartburn, stomach ulcers, and gallstones. It is also used to reduce inflammation, as well as to prevent and treat cancer.

How It Is Used

Turmeric's finger-like underground stems (rhizomes) are dried and taken by mouth as a powder or in capsules, teas, or liquid extracts. Turmeric can also be made into a paste and used on the skin.

What the Science Says

  • There is little reliable evidence to support the use of turmeric for any health condition because few clinical trials have been conducted.
  • Preliminary findings from animal and laboratory studies suggest that a chemical found in turmeric--called curcumin--may have anti-inflammatory and anticancer properties, but these findings have not been confirmed in people.
  • NCCAM-funded investigators are studying the active chemicals in turmeric and their effects--particularly anti-inflammatory effects--in people to better understand how turmeric might be used for health purposes.

Side Effects and Cautions

  • Turmeric is considered safe for most adults.
  • High doses or long-term use of turmeric may cause indigestion.
  • In animals, high doses of turmeric have caused liver problems. No cases of liver problems have been reported in people.
  • People with gallbladder disease should avoid using turmeric as a dietary supplement, as it may worsen the condition.
  • Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.

Siberian Ginseng (Eleutherococcus senticosus)

  • Adaptogen, stress protective, increased vitality

  • Two capsules daily unless different from manufacturer recommendations (Weil)

  • 625 mg twice a day (Mona Lisa Schulz)

  • Uses - Lethargy, fatigue, low stamina. It increases endurance and resilience to environmental stresses.

Chinese / Korean / American Ginseng (Panax ginseng, Panax quinquefolius)

  • Stimulant - Panax Ginseng, Adaptogen - Panax Quinquefolius

  • General tonic, buy capsules with standardized "ginsenoside" content

  • Improved vitality - dose - use manufacturer recommendations

  • Used regularly, ginseng increases energy, vitality and sexual vigor, improves skin and muscle tone, and builds resistance to stress.  Dr. Andrew Weil  often recommend ginseng to chronically ill patients and to those who are debilitated or lacking in vitality.

  • NCAM - What It Is Used For

    Treatment claims for Asian ginseng are numerous and include the use of the herb to support overall health and boost the immune system. Traditional and modern uses of ginseng include:

  • Improving the health of people recovering from illness
  • Increasing a sense of well-being and stamina, and improving both mental and physical performance
  • Treating erectile dysfunction, hepatitis C, and symptoms related to menopause
  • Lowering blood glucose and controlling blood pressure

How It Is Used

The root of Asian ginseng contains active chemical components called ginsenosides (or panaxosides) that are thought to be responsible for the herb's medicinal properties. The root is dried and used to make tablets or capsules, extracts, and teas, as well as creams or other preparations for external use.

What the Science Says

  • Some studies have shown that Asian ginseng may lower blood glucose. Other studies indicate possible beneficial effects on immune function.
  • To date, research results on Asian ginseng are not conclusive enough to prove health claims associated with the herb. Only a handful of large clinical trials on Asian ginseng have been conducted. Most studies have been small or have had flaws in design and reporting. Some claims for health benefits have been based only on studies conducted in animals.
  • NCCAM is supporting research studies to better understand the use of Asian ginseng. NCCAM is studying how Asian ginseng interacts with other herbs and drugs and exploring its potential to treat chronic lung infection, impaired glucose tolerance, and Alzheimer's disease.

Side Effects and Cautions

  • When taken by mouth, ginseng is usually well tolerated. Some sources suggest that its use be limited to 3 months because of concerns about the development of side effects.
  • The most common side effects are headaches and sleep and gastrointestinal problems.
  • Ginseng can cause allergic reactions.
  • There have been reports of breast tenderness, menstrual irregularities, and high blood pressure associated with ginseng products, but these products' components were not analyzed, so effects may have been due to another herb or drug in the product.
  • Ginseng may lower levels of blood sugar; this effect may be seen more in people with diabetes. Therefore, people with diabetes should use extra caution with Asian ginseng, especially if they are using medicines to lower blood sugar or taking other herbs, such as bitter melon and fenugreek, that are also thought to lower blood sugar.
  • It is important to inform your health care providers about any herb or dietary supplement you are using, including Asian ginseng. This helps to ensure safe and coordinated care.

Milk Thistle

  • Liver protectorant - two capsules twice a day or manufacturer recommendations

  • NCCAM -  

    • Milk thistle is a plant whose fruit and seeds have been used for more than 2,000 years as a treatment for liver and biliary disorders.

    • The active substance in milk thistle, silymarin, is a mixture of flavonolignans, primarily consisting of 4 isomers: silybin, isosilybin, silychristin (also known as silichristin), and silydianin (also known as silidianin). In the biological literature, silybin is referred to as silibinin.

    • Laboratory studies demonstrate that silymarin functions as a potent antioxidant, stabilizes cellular membranes, stimulates detoxification pathways, stimulates regeneration of liver tissue, inhibits the growth of certain cancer cell lines, exerts direct cytotoxic activity toward certain cancer cell lines, and may increase the efficacy of certain chemotherapy agents.

    • Human clinical trials have investigated milk thistle or silymarin primarily in individuals with hepatitis or cirrhosis. No clinical trials in individuals with cancer have been published.

    • Few adverse side effects have been reported for milk thistle, but little information about interactions with anticancer medications or other drugs is available.

    • Milk thistle is available in the United States as a dietary supplement.


  • Kefir - milk or soy - excellent source of "good" bacteria

  • GI tract health and protectorant

  • Dr. Weil:  "I take acidophilus to reduce the risk of traveler's diarrhea. The dose is one tablespoon of the liquid culture or one to two capsules after meals unless the label directs otherwise. Always check the expiration date on acidophilus products. You want to be sure the bacteria in them are alive and in good condition. And be sure to protect your supply from heat. I prefer products like Culturelle that provide lactobacillus gg, a strain known to survive passage through the strong acid of the stomach."

Gingko Biloba - (NCCAM)

What It Is Used For

  • Ginkgo seeds have been used in traditional Chinese medicine for thousands of years, and cooked seeds are occasionally eaten. More recently, ginkgo leaf extract has been used to treat a variety of ailments and conditions, including asthma, bronchitis, fatigue, and tinnitus (ringing in the ears).
  • Today, people use ginkgo leaf extracts hoping to improve memory; to treat or help prevent Alzheimer's disease and other types of dementia; to decrease intermittent claudication (leg pain caused by narrowing arteries); and to treat sexual dysfunction, multiple sclerosis, tinnitus, and other health conditions.

How It Is Used

Extracts are usually taken from the ginkgo leaf and are used to make tablets, capsules, or teas. Occasionally, ginkgo extracts are used in skin products.

What the Science Says

  • Numerous studies of ginkgo have been done for a variety of conditions. Some promising results have been seen for Alzheimer's disease/dementia, intermittent claudication, and tinnitus among others, but larger, well-designed research studies are needed.
  • Some smaller studies for memory enhancement have had promising results, but a trial sponsored by the National Institute on Aging of more than 200 healthy adults over age 60 found that ginkgo taken for 6 weeks did not improve memory.
  • NCCAM is conducting a large clinical trial of ginkgo with more than 3,000 volunteers. The aim is to see if the herb prevents the onset of dementia and, specifically, Alzheimer's disease; slows cognitive decline and functional disability (for example, inability to prepare meals); reduces the incidence of cardiovascular disease; and decreases the rate of premature death.
  • Ginkgo is also being studied by NCCAM for asthma, symptoms of multiple sclerosis, vascular function (intermittent claudication), cognitive decline, sexual dysfunction due to antidepressants, and insulin resistance. NCCAM is also looking at potential interactions between ginkgo and prescription drugs.

Side Effects and Cautions

  • Side effects of ginkgo may include headache, nausea, gastrointestinal upset, diarrhea, dizziness, or allergic skin reactions. More severe allergic reactions have occasionally been reported.
  • There are some data to suggest that ginkgo can increase bleeding risk, so people who take anticoagulant drugs, have bleeding disorders, or have scheduled surgery or dental procedures should use caution and talk to a health care provider if using ginkgo.
  • Uncooked ginkgo seeds contain a chemical known as ginkgotoxin, which can cause seizures. Consuming large quantities of seeds over time can cause death. Ginkgo leaf and ginkgo leaf extracts appear to contain little ginkgotoxin.
  • It is important to inform your health care providers about any herb or dietary supplement you are using, including ginkgo. This helps to ensure safe and coordinated care.


  • NCAM -

    What It Is Used For

  • 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 Helicobacter pylori infections that can lead to stomach ulcers, or to prevent dental plaque. Cranberry has also been reported to have antioxidant and anticancer activity.

How It Is Used

The berries are used to produce beverages and many other food products, as well as dietary supplements in the form of extracts, teas, and capsules or tablets.

What the Science Says

  • Some studies testing cranberry products for their ability to prevent urinary tract infections have shown promise. These studies have generally been small in size, and some were not randomized or controlled; therefore, the results are not conclusive.
  • 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. However, the mechanism of action of cranberry is not fully understood.
  • 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
    • Prevent the formation of dental plaque

Side Effects and Cautions

  • 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.
  • It is important to inform your health care providers about any herb or dietary supplement you are using, including cranberry. This helps to ensure safe and coordinated care.


  • NCCAM -

    What is it?

    Selenium is an essential nonmetallic trace element. L-selenomethionine is an organic form of selenium found in grains, meat, yeast, and certain vegetables and that has been used in cancer prevention clinical trials. Studies suggest that people with low selenium levels have a greater risk of developing or dying from cancer of the bladder, breast, colon, rectum, lung, and prostate.

    How does it work?

    L-Selenomethionine accumulates in the body because it is incorporated into proteins in place of the amino acid methionine. It is stored in the body and is slowly released. The body uses the nutrient selenium provided by l-selenomethionine to make antioxidant proteins, such as glutathione peroxidase and thioredexin reductase, which protect against cancer-causing free radicals. A byproduct of l-selenomethionine, methylselenol, is probably the anti-cancer form of selenium.

    What do the data show?

    A five-to-nine year safety and efficacy study tested whether selenized yeast, which is about 85 percent selenomethionine, could prevent nonmelanoma skin cancer. The study found that selenized yeast significantly reduced all cancer deaths and decreased rates of lung, prostate, and colorectal cancer. But an expert panel determined that the content, stability, and purity of selenized yeast was too variable among batches, and recommended that l-selenomethionine be used in the large scale, multi-year Selenium and Vitamin E Cancer Prevention Trial (SELECT). SELECT, launched in 2001, is the first study to look at the effects of selenium and vitamin E on the risk of prostate cancer, and to find out if either or both agents prevent prostate cancer.

Green Tea (NCCAM)

  • What It Is Used For

  • Green tea and green tea extracts, such as its component EGCG, have been used to prevent and treat a variety of cancers, including breast, stomach, and skin cancers.
  • Green tea and green tea extracts have also been used for improving mental alertness, aiding in weight loss, lowering cholesterol levels, and protecting skin from sun damage.

How It Is Used

Green tea is usually brewed and drunk as a beverage. Green tea extracts can be taken in capsules and are sometimes used in skin products.

What the Science Says

  • Laboratory studies suggest that green tea may help protect against or slow the growth of certain cancers, but studies in people have shown mixed results.
  • Some evidence suggests that the use of green tea preparations improves mental alertness, most likely because of its caffeine content. There are not enough reliable data to determine whether green tea can aid in weight loss, lower blood cholesterol levels, or protect the skin from sun damage.
  • NCCAM is supporting studies to learn more about the components in green tea and their effects on conditions such as cancer, diabetes, and heart disease.

Side Effects and Cautions

  • Green tea is safe for most adults when used in moderate amounts.
  • Green tea and green tea extracts contain caffeine. Caffeine can cause insomnia, anxiety, irritability, upset stomach, nausea, diarrhea, or frequent urination in some people. Caffeine can also raise blood pressure, and in very high doses, it can cause seizures, delirium, or irregular heart rhythms.
  • Green tea contains small amounts of vitamin K, which can make anticoagulant drugs, such as warfarin, less effective.
  • Tell your health care providers about any herb or dietary supplement you are using, including green tea. This helps to ensure safe and coordinated care.

Tea and Cancer Prevention Summary (NCCAM)

  • The antioxidants found in tea--called catechins--may selectively inhibit the growth of cancer .
  • In laboratory studies using animals, catechins scavenged oxidants before cell damage occurred, reduced the number and size of tumors, and inhibited the growth of cancer cells .
  • However, human studies have proven more contradictory, perhaps due to such factors as variances in diet, environments, and populations .
  • NCI researchers are investigating the therapeutic and preventive use of tea catechins against a variety of cancers.