Dieting Away Cancer?

CURE, Spring 2008, Volume 7, Issue 1

Popular in practice, macrobiotic diet lacks scientific evidence.

Dietary claims to treat cancer are everywhere. Some diets surface and are quickly dismissed by scientific data. But even with the lack of research, one diet continues to attract attention: the macrobiotic diet.

“Over the past 60 to 70 years, all kinds of cancer treatment diets have emerged, and none cure cancer. Macrobiotics is just one of these,” says Barrie R. Cassileth, PhD, chief of the integrative medicine service at Memorial Sloan-Kettering Cancer Center in New York.

Many cancer organizations, including the American Cancer Society, confirm the macrobiotic diet is not a curative therapy. People with cancer often have increased nutritional needs, and relying on any diet alone, without conventional therapy, can have severe health consequences, says the ACS.

Despite these warnings, macrobiotics continue to be one of the most popular diets for people with cancer, according to Ernest H. Rosenbaum, MD, and Isadora Rosenbaum in Everyone’s Guide to Cancer Supportive Care. This popularity can be traced back to the arrival of macrobiotics in the United States.

Japanese philosopher George Ohsawa brought macrobiotics to the United States in the 1960s, but it was his student, Michio Kushi, who popularized the macrobiotic movement by defining the lifestyle in books and opening the Kushi Institute in Boston to promote macrobiotics and to sell macrobiotic products.

Kushi espouses a philosophy that is more than just a diet—it’s a lifestyle approach that helps people maintain good health, decrease their incidence of illness, and live a harmonious life. Dietary recommendations are only part of a way of life that includes limiting exposure to radiation from television, wearing cotton clothing instead of synthetic materials, and taking time for daily reflection.

The dietary portion is largely vegetarian, describes Kushi in The Cancer Prevention Diet. About half of the daily diet consists of organically grown whole grains, such as brown rice and barley. Locally grown organic vegetables and bean or soy products, such as tofu, make up the remainder of the diet. Small portions of white-meat fish, fruit, and nuts can be consumed occasionally.

Cassileth says Kushi modified the original macrobiotic diet by adding more vegetables and nutrients. The original diet was purely based on consumption of grains and was so nutritionally poor, she says, that some people on the diet died.

Despite its popularity, no scientific evidence exists to prove a macrobiotic diet cures or prevents cancer. The Macrobiotic Diet and Flax Seed study, started in 2001 by the National Center for Complementary and Alternative Medicine, lost funding, leaving the study incomplete, says lead investigator Lawrence Kushi, ScD, associate director for epidemiology at Kaiser Permanente and the son of Michio Kushi.

Lawrence Kushi says despite the inconclusive results of his study, a macrobiotic diet has some healthy dietary elements. “If you look at macrobiotic dietary patterns, there is an increase in plant-based, high-fiber foods, and few animal foods, and those are aspects of healthy diets in general,” he says.

Other macrobiotic principles that may be beneficial for cancer prevention include increasing physical activity, avoiding pesticides, and reducing stress, Lawrence Kushi noted in “The Macrobiotic Diet in Cancer” published in The Journal of Nutrition in 2001.

No matter the diet, Cassileth says, cancer patients should always consult their health care team when making any dietary change to ensure safety and nutritional sufficiency. To address this need, many cancer centers now have dietitians on staff to advise patients.

“No diet can cure cancer,” says Cassileth, “but eating a balanced diet sufficient in proteins, vitamins, and minerals gained through foods—not through supplements—is the best treatment for everyone, whether you have cancer or not, to keep your body strong.”