Supplements in the Fight Against Cancer

Medically Reviewed by Jennifer Robinson, MD on February 06, 2023
4 min read

Many people take vitamins and supplements while they are being treated for cancer; some take them to prevent cancer. Here are tips to help you shop wisely.

Cancer patients are increasingly turning to supplements to strengthen their immune systems and ease nausea from chemotherapy.

Vitamin D

Vitamin D is one of the most studied supplements for cancer prevention and treatment right now.

Antioxidants

Vitamin A, vitamin C, vitamin E, and beta-carotene contain antioxidants once thought to help prevent cancer. However, more recent studies show that high levels of these, in supplement form, may increase cases of gastrointestinal cancers, such as stomach, colon, and esophageal, in some people. However, eating foods that contain these vitamins reduces the risk of many kinds of cancer.

Fiber (Psyllium)

Dietary fiber helps ease constipation, which may be caused by some cancer medicines.

Folic Acid

Folic acid helps reduce the toxicity of the cancer drug methotrexate. However, in men, high levels of folic acid may raise the risk of prostate cancer.

Iron

Iron supplements can improve the fatigue caused by iron-deficiency anemia, which can result from chemotherapy and radiation.

Do you know how to evaluate vitamins and supplements? There are so many vitamins, supplements, and herbal extracts on the shelves. Use these tips to find out which ones may be right for you.

Safe upper limits for vitamins and minerals

When it comes to vitamins and minerals, how much should you take? Find out the safe upper limits for the vitamins you take, as well as the recommended daily allowance you may need.

Vitamin and supplement glossary: Common definitions

This glossary provides simple definitions for common terms such as antioxidants, fat soluble, or phytochemicals. Find out what the lingo really means.

Supplements for cancer: Garlic

Many studies have found that people who eat a lot of garlic are less likely to develop certain common cancers.

That garlic research has led scientists to wonder whether garlic may have cancer-treating properties as well as cancer-prevention capabilities. Although studies are not yet conclusive, there is some evidence that garlic may be useful for cancer in conjunction with medical treatments.

For starters, garlic may be beneficial for cancer patients owing to its immune-boosting abilities, which vary depending on how the garlic has been processed. Additionally, certain substances found in garlic have been shown to suppress growth and fight certain cancerous cells in the lab, including forms of breast and lung cancer.

Early studies have shown that eating garlic can decrease the risk of colorectal cancer and stomach cancer. The same benefit was not found with garlic supplements. However, preliminary prostate cancer research on men in China has shown that both eating garlic and garlic supplements may decrease the risk of prostate cancer.

Supplements for cancer: Green tea

Green tea contains substances called polyphenols that are believed to have powerful anti-cancer abilities.

Cancerous tumors rely on fast-growing networks of blood vessels to sustain their rapid growth rate. Green tea compounds may possess the ability to help slow or prevent this rapid growth.

Be aware, there are some concerns about green tea extracts and liver toxicity. Also, a recommendation of 10 to 12 cups of green tea per day would be for cancer treatment, not cancer prevention.

Drinking green tea may increase the survival rates of some cancer patients. One study of women with ovarian cancer found that women who drank green tea were more likely to survive 3 years after ovarian cancer diagnosis than women who did not drink green tea. The survival rates increased with higher consumption levels of green tea.

Supplements for cancer: Mushroom products

Extracts from mushrooms have been used in traditional Asian medicine for thousands of years. More recent scientific studies are beginning to determine reasons for their potential health-promoting actions.

For example, polysaccharides (phytochemicals) from the Ganoderma lucidum mushroom have been shown to inhibit the growth and invasiveness of some cancer cells in the laboratory, including certain forms of breast cancer.

Other fungal varieties that may exhibit anti-cancer activity include reishi, shiitake, maitake, and coriolus, or turkey tail, mushrooms.

Lentinan, a substance found in shiitake mushrooms, has been shown in the lab to inhibit the growth of human colon cancer cells in mice. This may result from lentinan's ability to inhibit some enzymes that promote the activity of cancer-causing substances called carcinogens. Beta-glucan, a compound found in maitake mushrooms, is also thought to have tumor-fighting properties, though data on these abilities is still quite limited.

Supplements for cancer: Ginger

Nausea and vomiting are two of the most common side effects of chemotherapy for cancer. These side effects can be serious. Nausea and vomiting can lead to weight loss, nutritional deficiencies, and fatigue, which can make it harder for your body to fight cancer.

There are a number of anti-nausea medications available. But some patients with cancer also find that using ginger, either alone or in conjunction with anti-nausea medicine, significantly reduces nausea and vomiting.

Supplements for cancer: L-glutamine

Peripheral neuropathy, or nerve damage, is a common side effect of certain drugs, including the widely prescribed chemotherapy drug paclitaxel.

L-glutamine, taken orally, has also been shown in one study to reduce the peripheral neuropathy associated with oxaliplatin, a chemotherapy drug used to treat colorectal cancer.