Diet after breast cancer: myths and truths revealed

With breast cancer awareness month just behind us, let’s look at the latest on the prevention of breast cancer and the recurrence thereof.

Research shows us that there is a significant improvement in breast cancer survival rates due to early detection, treatment advances and the increased awareness of dietary and lifestyle changes. We know that 60-70% of cancer recurrence cases are linked to diet and lifestyle habits – with diet contributing to 35% of cases and smoking contributing to 30% of cases.

Preventative factors for recurrence include the consumption of lean protein – especially chicken, turkey and fish; omega-3 fatty acids (found in oily fish), dairy products (high calcium intake), fibre, vegetables, foods high in Vitamin C and vitamin D.

Predisposing factors to recurrence include hydrogenated, or trans fats found in processed baked goods; a high body fat percentage and weight gain. There are high levels of hormones in fat cells (estrogen, androgens, leptin ). Estrogen is the chief fuel for breast cancer growth and leptin levels are determined by a person’s BMI.

Before age 40, women tend to store most of their fat in the hips, thighs, and buttocks. After 40, as estrogen levels drop, body fat is redistributed to the abdomen. Hormonal treatment (Tamoxafin) and steroids can contribute to weight gain. If your body shifts into menopause because of chemotherapy, there’s a tendency to gain weight.

Different types of meat appear to have different effects. Some types of meat cause more damage, damage that can lead to cancer development, to the cells than other types of meat. This means that in terms of colon cancer risk, freshly prepared chicken, other poultry, fish, lean beef, and pork are “safer” than processed meats. Processed means smoked, cured, and salted meats, such as hot dogs, sausages, salami, bologna, bratwurst, bacon, salt pork, cold cuts and lunch meat, ham, pastrami, pepperoni, smoked fish, corned beef, and jerky. It turns out that when processed, cancer-causing (carcinogenic) chemicals are created in meat. These chemicals, when eaten, increase colon cancer risk. Just as with processing of meat, cooking meat at high temperatures until very well done creates carcinogens (cancer-causing compounds). The immune system functions best when the body’s protein status is optimal – proteins are the ‘building blocks’ of cells and determines the efficacy of immune defences  and reduce cancer recurrence rate. Meat is a very good source of protein as it cannot raise blood sugar or insulin levels, and it reduces appetite.

Diets lacking in protein show reduced cell replenishment and repair, reduced number and efficacy of immune cells and increase disease risk. Diets too high in carbohydrates & fat weaken the immune system and causes weight gain and insulin resistance.

Studies link egg consumption to reduced risk of breast cancer. Choline, an essential nutrient found in foods such as eggs, is associated with a 24% reduced risk of breast cancer, according to a study supported by a grant from the US National Institutes of Health (NIH), to be published in the Federation of American Societies for Experimental Biology (FASEB) Journal’s print issue in June. In this new case-control study of more than 3 000 adult women, the risk of developing breast cancer was 24% lower among women with the highest intake of choline compared to women with the lowest intake. Women with the highest intake of choline consumed a daily average of 455 mg of choline or more, getting most of it from coffee, eggs, and skim milk. Women with the lowest intake consumed a daily average of 196 mg or less.

“Choline is needed for the normal functioning of cells, no matter your age or gender,” says Steven H. Zeisel, MD, phd, University of North Carolina, who is an author of the study and a leading choline researcher. “Increasing evidence shows that it may be particularly important for women, particularly those of child-bearing age.”

Several studies have reported that having eggs for breakfast will keep you satisfied and energetic for longer as eggs have a 50% higher satiety index than regular breakfast cereals. Eggs also contain plenty of nutrients as the fat in eggs are a good source of vitamin A, E and K. Egg yolks are also one of few foods that naturally contain vitamin D. Other nutrients, such as iron, folate and vitamin B12 can help boost your immune system and make a valuable contribution to a nutritious diet.

In recent years numerous studies have clearly demonstrated that there is no relationship between egg intake, blood cholesterol levels and the risk of coronary heart disease. Eggs are low in saturated fats and higher in the ‘heart-healthy’ mono- and poly-unsaturated fats

Studies found a relationship between low vitamin D levels and breast cancer incidence. Southern latitude countries were found to have lower rates of breast cancer incidence and death than those living at northern latitudes, and show a possible role for vitamin D in cancer prevention. One study of postmenopausal women shows that those who took vitamin D supplements for 4 years had a 60% lower incidence of cancer. Yet, it is unknown if taking vitamin D supplements after breast cancer will reduce your chances of recurrence in the future

To sum it up, moderation is the key to health. We should aim to include all food groups in our daily diet; place emphasis on vegetables and salads, as well as fruit, include lean meats and whole grains to increase our fibre intake and try to limit our fat intake by utilasing prudent cooking methods. In addition to this, limit your alcohol intake and remember that exercise is key!


Berna Harmse is a private practicing dietitian in Cape Town, she holds a MSc in Dietetics and has a special interest in oncology nutrition. She is also an external lecturer at Stellenbosch University Division of Human Nutrition.

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