According to the Canadian Cancer Society, breast cancer is the most commonly diagnosed type of cancer in females. Worldwide breast cancer is the leading cause of cancer death in women . While the exact causes of breast cancer in a specific individual are unclear, it is known that it develops as a result of interactions between genetics, diet and lifestyle, and environmental exposures.
Dietary patterns can either increase or decrease your risk depending on the choices you make. Individual foods have been glamorized for their potentially cancer fighting abilities but the reality is it is more likely to be our overall dietary patterns that have the greatest influence on cancer risk rather than any specific “superfood”. What type of diet is most likely to reduce your risk of developing breast cancer?
In order to answer this question, Albuquerque et al. reviewed all epidemiological papers (studies looking at the risk of disease in a population) published until the end of 2012 that looked at breast cancer and diet patterns. They found 26 studies that met their criteria, the majority of which were conducted in Europe. If you combine all of the results they had ~ 600,000 women and ~30,000 cases of breast cancer upon which to base their conclusions.
Here are few of the key results from their report:
Vegetables, Fruits, Fish and Soy
Of the diets that focused on vegetables, fruits, grains and cereals, ten studies found a lower risk of breast cancer, one found no link between the two, and two found an increase risk and nine others didn’t reach significance.
Generally, diets including fruits, vegetables, fish (possibly chicken), soy and legumes reduced the risk of breast cancer. However, as a cautionary note, some studies found an increased risk with this dietary pattern and attributed it to a proportionally higher intake of fruits and fewer legumes or an imbalance in the ratio of polyunsaturated fatty acids to saturated fatty acids. Not to say fruit is bad but too much could upset the balance. The idea is that excessive carbohydrate intakes (especially those carbohydrates high on the glycemic index) could increase insulin levels and promote tumor growth.
The “healthy” Mediterranean diet focuses on fruit, vegetables, fish and crustaceans, chicken, olive oil, and sunflower oil. Two of the three studies found a reduced risk and one found no difference. Overall, this suggests you could hedge your bets and include these foods in your diet to reduce your risk. However, total calories consumed can influence your risk. Turns out too much food, even healthy food can be harmful.
Traditional diets obviously vary by region. Ten studies looked at the “traditional diets” and a few of the highlights are list here.
- Southern USA traditional: cooked vegetables, beans and legumes, sweet potatoes, cabbage, rice, cornbread, fried fish and chicken and low intakes of cheese, mayonnaise, salad dressing, wine, liquor and savory snacks seemed to decrease the risk.
- Mexican traditional: cheeses, meats, soups, legumes, refined grains, tomato based sauces had a lower risk.
- Brazilian traditional: rice, beans, milk products, roots and tubers was inversely associated with an increased risk.
- Asian traditional: vegetable soup, pork, dried and salted fish, fried rice, and noodles increased the risk.
“Western Diet” is the term applied to the current typical diet of Canadians and Americans. It is often high in salt, sugar, and processed food and includes red and processed meats, refined grains, potatoes and starches, snacks, sweets, fried foods and soft drinks. Twenty-four studies were identified and eight reported and increased risk, one found a reduced risk, and the remaining fifteen didn’t find any association.
Four of the six studies looking at alcoholic beverages and breast cancer found an increased risk in the groups consuming the greatest amount of alcohol.
No Baloney’s advice? There is still a lot of confusion over the best diet to reduce the risk of breast cancer; likely due to the plethora of other lifestyle factors that can confound the results. For now though, it seems prudent to increase your intake of vegetables, legumes and fish and restrict your intake of red meat, processed foods, and alcohol.
Ending on a positive note the annual statistics from the American Cancer Society shows that breast cancer rates may be declining!