Cancer Care Nova Scotia enewsletter masthead

Diet and Cancer – What is the connection?

“Experts believe that more than half of all human cancers are preventable through healthy lifestyle choices including a healthy diet,” said Patricia Poulsen, a clinical dietician with the Capital Health Cancer Care Program. “Diet, as well as tobacco and alcohol use and other environmental factors are believed to be major risk factors for cancer.”

Cancer AnswersAlthough there are varying opinions regarding diet and cancer prevention, the experts do agree that the following healthy eating guidelines are a good start:
• Follow a plant-based diet
• Limit high-fat foods
• Limit alcohol use
• Choose foods low in salt
• Limit sugary foods and drinks
• Increase the fiber you eat
• Maintain a healthy weight

The recommendations around a plant-based diet include: eating a minimum of 7-8 servings of fruit and vegetables a day; eating 5-10 servings of whole grains and legumes; having some vegetarian meals; and eating a variety of fruits and vegetables.

Ms. Poulsen cautions people to be careful with supplements, as many do not provide the same cancer prevention benefits as eating whole foods. She also says people need to be careful about the quantities of certain vitamins they choose to take. “Mega dosing on certain vitamins is not helpful. In fact, it can be harmful,” she said.

There has been ongoing discussion about Vitamin D and its role in lowering cancer risk. Fortified dairy products, mushrooms, fatty fish such as salmon and trout, and eggs are sources of Vitamin D. Because it is difficult for people to get the required amount of Vitamin D through food sources alone, the experts recommend that people take 1,000 IU of Vitamin D each day in the fall and winter months.

Some people may have questions about the benefits of juicing (extracting juices from fresh fruit and uncooked vegetables) to lower a person’s risk for cancer. Those promoting this idea say it reverses the natural aging process and a variety of illnesses including cancer; it enhances the immune system; and cleanses and detoxifies the body. However, Ms. Poulsen said there is no convincing evidence to support these claims.

The fat and cancer connection, by comparison, is quite convincing. High fat diets have been linked to an increased risk of cancers of the breast, colon, rectum, prostate and pancreas. To guard against this, experts recommend choosing lower fat foods; healthier fats such as olive oil, avocados and nuts; using low fat cooking methods and limiting high fat snack foods.

Similar advice is suggested in consuming sugar. People are encouraged to limit sugary drinks and foods such as candy, cakes, cookies and pastries and instead, to enjoy these foods in small amounts on special occasions. Although there is no evidence linking sugar substitutes with human cancers, animal studies do suggest that sugar substitutes increase the risk of developing bladder and brain cancers.

Another link with food and cancer is red meat and processed meat. Research shows that red meat has been linked with increased risk for colorectal, breast and prostate cancers. Processed meats tend to be very high in sodium and nitrates, which have been shown to increase a person’s risk for esophageal cancers. Recommendations include limiting the portion size of red meat to between 3 and 6 ounces and limiting the number of times per week you eat red meat; avoiding processed meats such as sausages, bacon, ham and hot dogs; substituting meat with fish or adding more vegetarian meals; and avoiding frying, broiling or grilling at high temperatures.

Many people believe that eating only organic foods, those grown without the use of artificial chemicals, lowers the risk for cancers. However, even though pesticides and herbicides are toxic and carcinogenic, there is no evidence to suggest that organic food is healthier.

“What we do know that anti-inflammatory foods can protect against cancer,” said Ms. Poulsen. “Foods in this category include: turmeric, garlic, magnesium, B-vitamins, ginger, tea, Omega 3s and foods rich in fiber.”

In eating a healthy diet, people are on the right track to maintaining a healthy weight. This is important since being overweight or obese is linked with an increased risk of developing cancer. Recommendations for losing and maintaining a healthy weight include setting realistic goals, following healthy eating guidelines, limiting the use of alcohol and exercising. Exercise has also been proven to reduce the overall risk of developing some cancers. Adults needs at least 30 minutes of moderate to vigorous activity each day.

“While we still don’t have all the answers regarding the connection between diet and cancer risk, we do know that eating a healthy diet, getting regular exercise and maintaining a healthy weight is a good start,” said Ms Poulsen. “These habits will also protect people against heart disease, stroke and diabetes, and will enhance an individual’s physical and mental health.”


© 2017 Cancer Care Nova Scotia    Sitemap | Privacy                                                                                                        Report broken links and errors to