6 Cancer-Fighting Superfoods

To reduce your risk of cancer, look no further than your fridge. Many foods contain unique compounds that may have cancer-fighting properties.

For example, fruits and vegetables contain phytonutrients, chemicals that protect against germs, fungi, and other threats. Those chemicals also contain compounds that may improve human health, such as helping to prevent diseases like cancer.

Of course, no magic food can fully protect you from cancer or completely slow its growth. In fact, the American Cancer Society doesn't recommend eating specific foods but instead suggests "following a healthy eating pattern." A diet that includes high-nutrient foods, whole grains, and a variety of fruits and vegetables is an excellent place to start.

However, research suggests that some foods stand out within those groups for their cancer-fighting potential. Here are six of those gems and some foods to avoid if you're cancer-conscious.

Broccoli

All cruciferous veggies (cauliflower, cabbage, kale) contain cancer-fighting properties. Still, broccoli is the only one with a sizable amount of sulforaphane, said Jed Fahey, ScD, a nutritional biochemist at the Johns Hopkins University School of Medicine.

Lab studies suggest that sulforaphane may decrease inflammation, boost protective enzymes, and flush out cancer-causing chemicals. A study from 2017 published in Oncotarget found that sulforaphane also targeted lung cancer stem cells, which aid in tumor growth.

It's important to note, however, that no clinical studies definitively show that consuming broccoli can reduce cancer risk. More research is needed to examine the link.

Berries

All berries pack cancer-fighting phytonutrients. But black raspberries, in particular, contain very high concentrations of phytochemicals called anthocyanins. 

Anthocyanins slow the growth of premalignant cells. According to Gary D. Stoner, PhD, former chair of the Division of Environmental Health Sciences in the College of Public Health at The Ohio State University, anthocyanins keep new blood vessels from forming.

While much of Stoner's studies focused on rodents, some of his research on humans suggested that the consumption of black raspberry powder may inhibit colorectal and esophageal cancers.

Tomatoes

Tomatoes are the best dietary source of lycopene. Lycopene is a carotenoid, a type of phytonutrient, that gives tomatoes their red hue, said Richard Béliveau, PhD, chair in the prevention and treatment of cancer at the University of Québec at Montreal and author of Foods to Fight Cancer.

And that's good news because some studies suggest that lycopene may inhibit the growth of cancerous tumors and protect against prostate cancer. Studies on humans have also linked diets high in carotenoids with a decreased risk of lung and breast cancers.

But it's important to note that human studies haven't confirmed the link to prostate cancer. And as of November 2022, no study has shown that chowing down on tomatoes reduces cancer risk.

To get the most significant lycopene boost, cook your tomatoes (like in a pasta sauce). The heating process increases the amount of lycopene your body can absorb.

Walnuts

All nuts pack a nutritious punch. But walnuts may stand out for their cancer-fighting properties.

Walnuts contain bioactive compounds that some studies have found to suppress tumor growth: Omega-3 fatty acids and tocopherols (a compound with vitamin E activity). They also contain phytosterols, which are cholesterol-like molecules.

Phytosterols may block estrogen receptors in breast cancer cells, said Elaine Hardman, PhD, associate professor at Marshall University School of Medicine in Huntington, W.Va.

Hardman was the lead author of a study published in 2019 in Nutrition Research that found that after five women with breast cancer ate two ounces of walnuts a day for about two weeks, the tumor gene expression significantly changed.

The results supported Hardman and her team's hypothesis that walnuts could "suppress growth and survival of breast tumors." But the researchers warned that a large-scale clinical study would be needed to confirm the results.

Garlic

Research suggests that garlic could play a role in cancer prevention by influencing gene expression. Garlic may "turn on" genes that suppress the formation of tumors.

For example, a study published in 2015 in The Journal of Nutrition found that 17 people who ate a meal containing a teaspoon and a half of garlic activated genes involved with immune function. Those genes were also involved in destroying abnormal cells.

However, more information on the association between cancer and garlic consumption is needed. As of November 2022, studies are limited.

Beans

Beans are rich in fiber, which may reduce the risk of colorectal cancer. Lab studies suggest that beans contain cancer-fighting chemicals like phenolic acids and anthocyanins. Anthocyanins are a flavonoid that gives red and black beans their dark color.

The research examining the direct link between bean consumption and cancer risk is limited and has mixed results. Still, a couple of studies have linked the two. 

For example, a study published in 2020 in Current Developments in Nutrition found an association between a bean-rich diet and a reduced risk of developing breast cancer.

What Not To Eat and Drink

In addition to the possible cancer-preventing benefits of some foods, there are also foods you should try to avoid, said Cheryl Forberg, RD, author of Positively Ageless. 

Here are some items that may increase your risk of developing cancer.

Red and Processed Meats

Research has found that red meat and processed meats—transformed to increase shelf life or enhance flavor—may increase cancer risk.

In 2015, the World Health Organization (WHO) announced that processed meat consumption is carcinogenic. The WHO listed those meats as a potential cause of colorectal cancer. 

The WHO also reported that red meat is "probably carcinogenic" and may increase the risk of colorectal, pancreatic, and prostate cancers.

In 2021, a study published in Cancer Discovery revealed that the colorectal tumors of people with diets high in red and processed meats had a specific pattern of DNA damage. The results suggested that substances in the meat caused the damage.

Some studies suggest that chemicals formed in red meat during the cooking process may cause DNA damage. Curing meats like hot dogs and bacon by adding nitrites and nitrates may also produce carcinogenic chemicals. 

In light of the evidence against eating red and processed meats, the American Cancer Society recommended leaner protein sources such as fish, poultry, and those good-for-you beans.

Excessive Alcohol

Alcohol consumption is a significant risk factor for developing cancer. Excessive alcohol accounts for about 6% of all cancers in the United States. 

It may cause stomach cancer and is a known cause of the following cancers:

• Mouth
• Throat
• Voice box
• Esophagus
• Liver
• Colon and rectum
• Breast

Some evidence suggests that drinking any alcohol may increase the risk of developing certain cancers and recommends avoiding that beer or glass of wine altogether. 

But if you drink, women should limit intake to one a day, and men should have a maximum of two.

A Quick Review

Remember, nothing you eat—or don't eat—will eliminate your cancer risk. But a diet rich in fruits and veggies may help decrease the odds. And it may help to avoid red meat, processed meat, and excessive alcohol.