1. Processed Meats
Processed meats like bacon, sausage, and deli meat are some of the most concerning foods when it comes to cancer risk. Tierney explains that they’re classified as Group 1 carcinogens because of additives like nitrites and the formation of "cancer-causing compounds (called N-nitroso compounds) when these meats are cooked." These compounds can damage DNA and significantly increase the risk of colorectal cancer.
As Tierney notes, plant-based proteins like beans, lentils, tofu, tempeh, nuts, and seeds, are much safer options. She recommends "minimally processed poultry or fish" instead. Plus, plant proteins "come packaged with fiber and phytonutrients that help the body naturally lower cancer risk."
2. Red Meat (Especially High-Heat Cooked)
Eating a lot of red meat—especially if it's grilled, fried, or broiled—can also increase cancer risk. Tierney explains that high-heat cooking raises exposure to heme iron and "harmful chemicals that form with high heat," which can fuel inflammation and DNA damage.
Safer alternatives include whole soy foods like tofu, tempeh, and edamame. Tierney emphasizes that these foods are "safe and even protective for hormone-related cancers," noting that research links "1–2 servings of whole soy daily" to lower breast cancer recurrence and mortality.
3. Ultra-Processed Foods
Packaged pastries, sugary cereals, fast food, processed snacks, and other pantry staples are undeniably convenient, but they come at a cost. Tierney explains that ultra-processed foods are "high in refined carbs, added sugar, salt, and unhealthy fats — and low in the nutrients your body needs to stay well." Over time, this can contribute to inflammation, unhealthy weight gain, and insulin resistance—all linked to higher cancer risk.
As Tierney puts it, these foods "crowd out fiber, antioxidants, and phytochemicals — the very things that help protect cells from damage." Instead, she recommends focusing on minimally processed whole foods like fruits, vegetables, whole grains, legumes, nuts, and seeds.
4. Alcohol
It's no secret that alcohol is a poor choice for your health. It raises cancer risk even in small amounts. According to Tierney, it increases exposure to acetaldehyde, "a known carcinogen," and can elevate estrogen levels—both of which contribute to DNA damage and tumor development. She notes that alcohol is linked to at least seven cancers, including breast and colorectal cancer.
For healthier alternatives, Tierney suggests sparkling water with citrus, herbal teas, or fun non-alcoholic mocktails made with fresh fruit and herbs. Good to know!