Should People With Breast Cancer Take Resveratrol?
Key Takeaways
There’s not enough evidence in people to support the use of resveratrol to fight cancer or reduce side effects of cancer treatment.
Resveratrol can act like estrogen, which could drive the growth of estrogen receptor-positive breast cancer.
Resveratrol may cause kidney failure in people with multiple myeloma.
Resveratrol is a chemical naturally found in food, mainly in the skin of grapes. It’s found in red wine and grape juice, as well as blueberries, cranberries, peanuts, pistachios, and chocolate.
Resveratrol is a type of phytochemical called a polyphenol, or an antioxidant from plants. Antioxidants fight oxidative stress, which causes damage to cells and DNA. Oxidative stress raises the risk of cancer.
Some people take high doses of resveratrol as a supplement for heart and brain health and to protect against cancer. Resveratrol supplements are available in powders, capsules, and more.
What the research shows
Only a few small studies have tested the effects of resveratrol in people with cancer. When studies are too small, there is a high risk that their results are due to chance — not due to the effects of resveratrol.
Anti-cancer effects
One small study of 20 people with colorectal cancer found that taking four or eight grams of resveratrol per day slowed the growth of colorectal cancer cells. Another study of nine people with colorectal cancer that had spread to the liver found that those who took five grams of resveratrol per day for two weeks had more cancer cells in the liver die compared to those people given a placebo.
But other studies have found that resveratrol doesn’t affect cancer. A study of 112 men with prostate cancer recurrence found that taking 0.5 grams or 4 grams of grape skin (which contains resveratrol) per day did not change PSA doubling time, a marker of prostate cancer progression. This means it didn’t affect how fast prostate cancer grew.
Cell and animal studies
Cell and animal studies are a critical early step in research. But you can’t draw conclusions about how things will work in people based on these studies alone. For example, many lab studies in cells and animals show that resveratrol may disrupt the growth and spread of cancer cells and promote cancer cell death. Other studies in animals suggest the supplement can boost the effectiveness of chemotherapy and radiation, while reducing side effects. For example, resveratrol may be able to reduce gastrointestinal side effects and toxic side effects on the heart from chemotherapy drugs.
But studies of people haven’t found the same results. This may be because the human body doesn’t absorb resveratrol well. The body probably breaks down and clears resveratrol too quickly for it to have much of an effect. Researchers are working on ways to tweak the chemical so it sticks around longer in the body and gets to higher levels in cells.
Estrogen-positive breast cancer
Researchers are also using cell and animal studies to test the interactions between resveratrol — which is similar to the sex hormone estrogen — and breast cancer cells. Specifically, they’re looking at whether resveratrol may help or hurt the growth of breast cancer. Some of these studies suggest that resveratrol halts estrogen receptor-positive breast cancer growth and limits breast cancer from spreading into nearby tissues. But other lab studies show that resveratrol can act like estrogen (or have an even stronger effect than estrogen) and lead to faster-growing HER2-positive and estrogen receptor-positive breast cancer and more tumors in the same animal.
Heart health
There have only been a few studies in people that have looked at how resveratrol affects the heart. These studies have had positive results. They show that the supplement may improve cholesterol, blood pressure, and other risk factors for heart disease.
Safety, side effects, and risks
Resveratrol can be dangerous to some people. A study in 24 people with multiple myeloma was ended early because five people developed kidney failure. The study authors think the risk of kidney failure from resveratrol is limited to people with multiple myeloma, who are already at a higher risk of it.
At high doses — more than about 2.5 grams per day— resveratrol can cause gastrointestinal symptoms like nausea, vomiting, and diarrhea.
Resveratrol may also not be safe for some people with breast cancer. In some cases, resveratrol seems to act like estrogen, which could promote the growth of estrogen receptor-positive breast cancer. But more research is needed to know for sure.
Resveratrol may interact with some drugs, such as blood thinners. Always talk to your doctor before starting a new supplement.
Is it OK for people with breast cancer to take resveratrol?
For now, there’s no good reason to take a resveratrol supplement for cancer, especially not breast cancer. If you’re considering taking resveratrol or any other supplement, talk to your doctor first.
However, getting resveratrol from food is safe for people with breast cancer, and foods containing it should be included in a well-balanced diet, in part for their antioxidant properties.