Food and cancer: Is there a link?

There is no firm evidence that any single food causes cancer. But a dietitian who surveyed studies done in the past decade says science is consistent on this point — eat your vegetables and fruits for better health.

Laura Pasut is president of Nutridata Consulting Service, based in Barrie, Ontario.

She reviewed 29 cancer studies which included red meat as well as other foods. Her report is published by the Beef Information Centre.

Pasut says all the studies used different approaches, so it’s hard to make comparisons and confirm that any one food caused cancer.

The most consistent link showed a decrease in colon and breast cancer when people ate more fruits and vegetables.

Pasut says many people avoid red meat because of fears it’s linked to colon cancer.

“Years ago, it was suggested that too much fat in the diet caused cancer. Much of the fat in our diet is hidden and the obvious sources were from animal products. So in some early studies, there seemed to be a link between fat and cancer or meat and cancer. But as other studies came out, that link wasn’t clear. And so there are now a few studies at show a link, and many studies that don’t show a link.”

She says part of the problem is a lack of duplicate test methods in different studies.

“The researchers might refer to red meat — which meant just beef. Other times, the term red meat included lamb, pork, processed sausages, all sorts of things. And animal fat could also refer to lard used in baking.”

Pasut says she isn’t alone in finding it difficult to confirm which foods might be cancer culprits.

“There’s actually a large report from the World Cancer Research Fund. They looked at 4500 studies. And the main conclusion that they came up with was that there wasn’t sufficient vegetables and fruit in our diet.”

Pasut says her review should help consumers and professionals who have to answer questions about cancer and diet.

“What happens is that a research group might look at a particular food or food group and then report their findings. The problem is that when the public reads this one article, they automatically go out and think, okay, I can’t eat that food.”

“And that could actually be more dangerous, because the foods from our four food groups are extremely important in providing nutrients. We need them all for a balanced diet, and that includes meat.”

She says red meat is one of the main sources for some key nutrients, such as absorbable iron.

“This is especially important for women. In addition, red meat has key B vitamins, as well as zinc and protein. So it’s very difficult to eliminate a food and expect to have a healthy diet.”

Pasut also says that many of the studies she surveyed were American and didn’t automatically apply to Canadians.

“We don’t have a lot of studies in Canada. But the few we do have show some key differences. First of all, we eat differently than Americans. We consume more vegetables and fruits. We eat less meat.”

“I think Canadians in general have a healthier diet. But there’s lots of room for improvement. We still need to increase our fruits and vegetables.”

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The estimates are that 20 to 30 per cent of all cancers may be related to what you eat. And another 30 to 40 per cent of all cancers may be related to the combination of poor diet, overweight and exercise.

Colon cancer has the strongest link to dietary risk factors. The Beef Information Centre offers this advice on diet and cancer:

*Each day, enjoy a variety of foods from all food groups, including lots of vegetables and fruits.

*Use lean cuts of meat, poultry and fish. For red meat, choose round and sirloin steaks, and rump, sirloin tip or round roasts.

*When cooking, trim fat from meat and remove skin from poultry.

*Choose lower fat choices from the other food groups—low fat milk and dairy products.

*Be aware of hidden fats in foods such as commercial muffins, cream or cheese sauces and salad dressings.