By Deborah Kotz
(Boston.com/health) I tend to get into food ruts, eating the same fruits and vegetables every day to fill my daily quota. At the moment, blackberries, spinach, and chopped tomatoes are my faves. Yet despite my plentiful consumption of these nutritional superstars, I’m actually missing out on the variety that can help my body draw on its full array of cancer-fighting immune cells.
“When it comes to cancer prevention, there are more than just a few super foods,” said Stephanie Meyers, a registered dietitian at Dana-Farber Cancer Institute. “You really want to take it to the next level by eating a colorful array of plant foods, aiming for 16 different fruits and vegetables over the course of three days.”
Food in each of those colors contains unique chemicals or nutrients that, when eaten, trigger our digestive tracts to release specific enzymes to digest them. “There are certain enzymes that you’ll never secrete if you never eat orange colored foods,” Meyers said, “and these very same enzymes help support our immune system.”
A diet filled with a variety of colorful plant foods -- including nuts, fresh herbs and spices, olive oil, and whole grains -- not only helps boost your immune system but contains antioxidants that, on their own, neutralize cancer-causing chemicals called free radicals. “We are just now beginning to understand how these thousands of phytonutrients [plant nutrients] work together as a team to interfere with cancer as it develops.”
That doesn’t mean you’ll never get cancer, but you can help reduce your risk with a smarter diet and, as Meyers tells her cancer patients, could help keep cancer from recurring or spreading if you’ve already been diagnosed. Research hasn’t actually shown that these foods prevent cancer in people; these claims are based on cancer cells grown in petri dishes and population studies linking a high consumption of fruits and vegetables with lower cancer rates.
How to reach that sweet 16 spot over the next three days? There are dozens of plant foods to choose from, and Meyers wasn’t going to rank her top 16 -- especially since researchers are still identifying all those hidden chemicals -- but she did give me some enticing tidbits gleaned from the latest studies.
For example, apples contain the nutrient quercitin, which protects DNA in the body’s cells from damage that could lead to the development of cancer. Cranberries contain benzoic acid, which has been shown in lab studies to inhibit the growth of lung cancer, colon cancer, and leukemia cells. Pumpkin and other orange-colored fruits and vegetables are packed with carotenoid nutrients, like beta carotene, which have been linked to the prevention of colon, prostate, breast, and lung cancer.
(Note: beta carotene in pill form hasn’t been linked to cancer prevention, most likely because it doesn’t work in isolation but in synergy with a variety of nutrients.)