As a veteran faculty member at the Stanford University Medical School, Dr. John Farquhar has seen thousands of patients try to beat cancer with aggressive chemotherapy treatments that “blast them with terrible side effects.” But, as the founder of Stanford’s Prevention Research Center, he believes he has helped other patients beat cancer before it starts using nature’s medicine: vegetables and fruits.
Farquhar has worked at the university for 30 years as a professor, a cardiologist and the co-founder of the Stanford Prevention Research Center. He co-teaches a popular course called “The Best Diet Ever,” (see box) in which he preaches the merits of five foods with strong anti-cancer agents: soy, onions, broccoli, tomatoes and blueberries.
“There’s still uncertainty about how important nutrition is in cancer prevention,” Farquhar said, “but I’ve found that if you deal with these specific foods, there’s evidence that they all have cancer-fighting nutrients. As opposed to genetics, nutrition is something that people can control.”
Joyce Hanna is the associate director of the Health Improvement Program at the Stanford Prevention Research Center. A 19-year Stanford faculty member and former marathon runner, she teaches “The Best Diet Ever” class with Farquhar. Hanna also counsels clients who want to engage in healthier lifestyles and oversees a program that helps cancer patients exercise and eat well during and after treatments.
Beating disease back
“One of the biggest fears cancer patients have is that their cancers may come back,” Hanna said. “Other people haven’t been diagnosed with cancer, but they’re out of shape and their doctors have warned them about risk of disease. I try to help them take small steps to improve their lifestyles. Obesity increases cancer rates, and in a lot of these cases, lifestyles are more important than genetics.”
In the 1980s, for example, U.S. Public Health Service researchers working with the Honolulu Heart Health Program determined that men who never ate tofu, or ate it only once per week, were 1.3 times more likely to be diagnosed with prostate cancer than men who ate tofu two to four times a week. They were almost three times more likely to have the disease than men who ate tofu five times a week or more.
Daily serving of soy
Scientists at the Shanghai Cancer Institute found similar results when they studied the relationship between soy intake and breast cancer rates. The Shanghai Women’s Health Study, published last year, showed the more soy protein women ate in a day, the less likely they were to be diagnosed with breast cancer. Farquhar recommends daily helpings of 8-10 grams of soy protein, which can be found in tofu, soy nuts, soy milk or edamame.
According to the Centers for Disease Control, breast cancer is the most common cancer for women in the United States, followed by lung and colorectal cancers. The list is the same for men, except that prostate cancer replaces breast cancer at the top of the list. According to Farquhar, a strategic, healthy diet can help prevent these cancers.
He recommends a daily serving of berries, especially blueberries, which deliver a high concentration of antioxidants that help prevent cell damage that occurs naturally with age. Slowing age-related cell damage helps prevents cancer and other diseases.
A study published in 2009 in the Journal of Clinical Oncology shows that tomatoes, which contain lycopene, help prevent prostate cancer. Lycopene is a strong antioxidant that may also prevent other types of cancers, so Farquhar recommends three servings of tomatoes a week for men and women.
Likewise, he suggests a daily serving of broccoli or another cruciferous vegetable like cabbage, cauliflower, kale, Brussels sprouts or bok choy. Studies have shown that the natural compounds in cruciferous vegetables may help prevent colorectal cancer.
And one serving a day from the onion family, including garlic, leeks, scallions and shallots, will deliver multiple compounds shown to have anti-cancer qualities. Farquhar noted that red onions have the added value of being a “rainbow veggie,” or a uniquely colored vegetable. Adding servings of red, yellow, orange, white or purple vegetables to the usual greens maximizes a person’s chance of getting all the micronutrients that could potentially help fight off cancer.
Farquhar cites another important factor in the diet that affects cancer rates, but this time, it’s something people shouldn’t eat in large quantities: red meat.
American Cancer Society researchers published a study in 2009 that compared rates of colon, breast and prostate cancer in different countries over the last 30 years. It showed that the incidence of cancer was much lower in nations with diets traditionally low in red meat consumption and high in fresh vegetables and fruits.
The United States, which has a diet high in meat consumption, had colon cancer rates 10 times higher than those in Peru, Thailand or India. However, these countries’ cancer rates gradually increased over 30 years. Farquhar attributes this, at least in part, to these countries becoming more economically developed and shifting toward more Westernized diets.
“There’s something going on as a nation changes diets,” Farquhar said. “There’s such a magnitude of difference.”
Farquhar says that he eats red meat about once every two months – and recently ate flank steak for the first time in 30 years. While he doesn’t expect his patients to make dietary changes that drastic, he recommends a diet that is “near vegetarian.” He suggests people switch out red meat protein for soy, fish or nuts or egg whites.
According to Farquhar, if a person eats many healthy vegetables, but still eats a lot of red meat, “the increased veggie intake would only partly remove the harmful effects of meat.”
Take small steps
When counseling overweight patients, Hanna encourages them to take small steps to build vegetables, fruit and soy protein into their daily routines.
“I tell them to focus on what they want to accomplish next week,” Hanna said. If you never buy fresh vegetables, can you try buying two? If you have fast food seven days a week, can you try to cut down to four? I always tell them they have to take small steps because radical, sudden changes lead to radical, sudden defeat.”
Top foods to cut cancer risk
Recommended Foods in Dr. Farquhar’s “Best Diet Ever”
Soy – 8-10 grams tofu, soy nuts, soy milk or edamame a day to help prevent breast and prostate cancer.
Berries – one cup per day for antioxidants to help ward off cell damage that can lead to cancer and other diseases.
Broccoli – 1/2 cup of cooked broccoli or other cruciferous veggies a day to aid in prevention of colorectal cancer.
Onions – 1/4 cup of onions, garlic, leeks or shallots for several anti-cancer agents.
Tomatoes – 1/2 cup cooked or 1 cup raw tomatoes three times a week to help prevent prostate cancer. Adding three daily servings of “rainbow vegetables” (red, orange, yellow, white, green or purple) provides even more disease-preventing micronutrients.