How your diet can affect your cancer risk

According to the American Cancer Society (ACS), cancer is the second leading cause of death in both men and women across the United States, just behind heart disease.

Much early research conducted by ACS prioritized prevention, searching for a "magic bullet," or a select few foods that, when eaten at a consistent rate, could prevent healthy cells from developing into cancerous ones. And cancer epidemiologist Nigel Brockton and other researchers have long studied links between dietary patterns and cancer risks.

For example, researchers have found that high fiber intake, conscious weight management, such as dietary changes and exercise, and prioritizing immune health by integrating more vitamins and minerals into your diet can all reduce your risk of cancer, Fuchs reports.

Additional research shows that adopting a better diet can reduce the average person's cancer risk by up to 9%, while having a lean body weight can reduce this risk by up to an additional 8%.

But attempting to prevent cancer with "magic bullet" foods, in any case, doesn't cover the full scope of risk factors. "[T]he full dietary package is what matters," Brockton said. "It's much more important than individual foods."

6 foods that can reduce your risk of cancer

1. Fiber-rich carbs

According to research, whole foods that contain plenty of fiber can help reduce cancer risk.

However, in cases where carbs are consumed, many Americans opt for highly processed instant oatmeal, pita bread, white rice, and refined, flour-based pastas, which contain little to no fiber.

Instead, researchers say swapping these highly processed foods for whole plant foods like beans, lentils, and other high-fiber legumes can help support a healthier weight, thus reducing the risk of cancer.

"It's important to keep weight within your normal BMI range throughout life," said Kala Visvanathan, a Johns Hopkins medical oncologist and cancer epidemiologist. "Data show that even 10 pounds less can help bring down cancer risk."

This doesn't mean you have to forego your favorite low-fiber carbs, researchers say. Instead, they suggest combining them with other high-fiber carbs. This way, you can enjoy the flavors you love, only higher in protein and fiber.

2. True plant-based proteins

Where the typical American dinner plate contains a large cut of red meat with a helping of buttery, starchy sides like mashed potatoes and peas, it raises multiple red flags for cancer risk.

"We see a very consistent association between higher red meat consumption and higher cancer risk," Brockton said. This is because steak is high in a form of iron that can cause chronic inflammation and damage the digestive system over time, placing consumers at a higher risk of colorectal cancer.

Brockton and the American Institute for Cancer Research recommend reducing red meat intake to 12-18 ounces per week. They also recommend completely cutting out processed meats, such as deli meats, which are "more carcinogenic than red meat."

4. Nuts and unsweetened dried fruits

High sugar consumption is also linked to increased cancer risk, experts say, and these high sugar levels are often found in ultra-processed snacks, such as chickpea chips and vegan protein bars, that are labeled and sold as "plant-based."

The levels of refined flours and sugars in these products, including some yogurts, provide little nutritional value. Regularly eating foods with added sugars can also increase blood sugar and related hormones, which can cause cancer cells to develop over time.

Researchers say to ease off of these snack options, and instead opt for lower sugar yogurts, trail mix without candy, and other snacks that are higher in healthy oats and grains.

Almonds and walnuts have vitamin E and antioxidant levels, and research shows that eating 28 grams of nuts per day has been linked to lowered risks of developing and dying from cancer.  

5. Coffees and teas

Instead of opting for sodas or alcoholic beverages, researchers suggest Americans reach for coffees or teas.

"There's basically no safe threshold for alcohol," said Teresa Fung, a nutrition researcher at Simmons University. "It increases the risk of cancer in the entire digestive system, from the mouth to the colon, and breast and liver cancer as well."

Brockton added that, "if you have soda in your everyday life, that is the first one to eliminate. It's the easiest win, with a big impact" on cancer risk.

While more research is needed, current studies have found that coffee and tea may have anti-carcinogenic properties.

6. Natural sauces and seasonings

Everyday sauces, seasonings, and condiments, such as mayonnaise, are ultra-processed and may increase your cancer risk if you consume them regularly.

Rather than relying on ultra-processed sauces or seasonings, health experts recommend using healthier, more natural ingredients. Some flavorful sauces or seasonings that also contain cancer-fighting nutrients include tomato sauces, olive oil, vinegar, citrus zest, shallots, garlic, or flaxseed.

Overall, while living a "perfect life" doesn't guarantee perfect health, there are ways you can substantially reduce your risk of cancer. You'll "delay cancer until your 80s or 90s instead of your 40s or 50s," Brockton said. "That's a totally different proposition."