|In contrast, participants that ate two or more servings of fish each week showed a 31 per cent decreased risk of developing the disease.
According to Dr. Sheila Bingham, principal investigator of the EPIC-Norfolk study at the MRC Dunn Human Nutrition Unit in Cambridge, the different outcomes may be due to how fish and red meat interact differently in the body.
“Probably fish contains oils which may be protective whereas red meat (not white meat) seems to result in the formation of substances in the body which may damage DNA.”
Researchers estimate that more than 30 per cent of cancers are diet related and therefore preventable. In the case of bowel cancers, some argue that diet factors increase to 80 per cent.
“The two principal reasons for cancer at different organs having different associations with diet are twofold. First, the actual exposures to dietary constituents differ. So for breast cancer, diet probably acts indirectly, through the effect of diet on circulating hormone levels, whereas for the large bowel, the mucosa is directly exposed to those components of the diet, which are not absorbed earlier. Secondly, the environments under which a tumor might develop vary. So in the stomach, which is exposed to most dietary constituents, a major factor that determines the propensity of the stomach to develop a tumor is chronic h.pylori infection…The reason why the large bowel appears more related to diet than other organs is simply because exposures to the large bowel mucosa are mostly diet related,” says Dr. Nick Day of the EPIC-Norfolk team and professor of epidemiology, Strangeways Research Laboratory, University of Cambridge.
Though no diet can promise perfect health, Dr. Bingham advises people to reduce red meat consumption:
- Eat at least two portions of fish per week.
- One portion should be of the oily, polyunsaturated omega-3 fatty acid variety.
- Follow a heart-healthy eating plan. Says Dr.Bingham: “Current guidelines for prevention of cancer and heart disease are essentially the same. i.e., eat more plant products such as whole grain cereals, vegetables, fruit, cut down on saturated fats found in red meats and dairy products (unless low fat).”
Dr. Day is quick to point out the significance of the combination of healthy diet and an active lifestyle.
“I doubt if one should speak of a ‘safe’ diet. I think at the moment all one can say is that some dietary patterns seem less safe than others. Furthermore, for each individual the consequences of their dietary intake will be affected by their level of physical activity.”
What we eat isn’t the only concern when it comes to maintaining healthy bowels. Other factors thought to play a role in developing colorectal cancer are obesity, lack of exercise, smoking and excessive alcohol use. Age is the primary concern, however—according to the American Cancer Society ninety per cent of cases are diagnosed after age 50.