How important is diet in cases of colon cancer? Very, if a report of a study in the August 15 issue of JAMA is to be believed. This report says that patients, who follow a diet rich in meat, desserts, fat and refined grains after being treated for and recovering from colon cancer, were three times more at risk of having the cancer reoccur, and even of dying from it. This is in comparison to patients whose diet which was termed a 'prudent diet' mainly consisting of vegetables and fruit, fish and poultry.
Although earlier research has pointed out the importance of diet and lifestyle in the chances of developing colon cancer it is only these recent studies, the scientists claim, that have concentrated on their influence in the recurrence of the disease and the chances of survival.
From Boston's Dana-Farber Cancer Institute, Jeffrey A. Meyerhardt, M.D., M.P.H., and team studied a group of 1009 patients, who, having had cancer in both, the colon and the lymph nodes (stage III colon cancer) and having undergone chemotherapy within the last two months had enrolled from 1999 to 2001. Their dietary patterns were particularly observed. The patients carefully maintained a daily record of their diets at this time.
The diets were classified either as western or prudent. Whereas the western diet typically had large portions of meat, desserts and refined greens, the prudent one was noticeably richer in vegetables and fruit, fish and poultry.
Although most subjects did not fall neatly into one category or the other, they were scored by how closely they matched them.
The patients were followed up for about five years either to check their diet and to check on the recurrence of the cancer or if they had survived it or not. It was found that the cancer had reappeared in 324 patients, of which 223 patients died from it, and that 28 had died without the real occurrence of the cancer been acknowledged.
The scientists noted that the western dietary pattern, post diagnosis, was significantly connected to the chances of the cancer recurring or of the patient dying. Compared to the other patients those consuming the prudent diet did not have any significant reoccurrence of cancer or death rates.
The benefits for those whose diets most resembled the prudent pattern were evident even after researchers considered other factors such as age, gender, degree of cancer spread to lymph nodes, level of physical activity and body mass, Investigators are not sure why the western type of diet produces poor results but speculate that it may be related to increased levels of insulin and insulin-like growth factors which have been associated to the formation and development of certain types of growths.
Meyerhardt remarked, “The message is that patients in this category can improve their prospects by avoiding certain foods …It is not really increasing the amount of fruits and vegetables, but really trying to reduce the amount of red meat intake and fatty foods and sugary, 'desserty' foods.”
Scientists from San Diego's University of California reported in their Women's Healthy Eating and Living study, however, that more important than diet was exercise and weight control . In their studies they found that women randomly assigned a super version of the prudent type of diet already described fared no better with regard to recurrences of the cancer or to death than women who simply observed a diet with five servings of fruits and veggies everyday. The real threat, these cancer nutritionists declare, is becoming or remaining overweight. The fact that their diet was also low in fat, however, seems to bear out the finding of the scientists who were referring specifically to colon cancer.
Dr. Lidia Schapira, a breast-cancer specialist at Massachusetts General, put it this way: "Even though the data are imprecise and conflicting, we can't wait to eat until better data are in."
The National Cancer Institute and Pfizer Oncology partly sponsored the study.
