Increasing evidence indicates that dietary fiber and fat affect a woman’s risk of developing breast cancer.
According to a recent study, raising fiber intake from 15 to 30 grams per day reduced blood estrogen levels, an important factor contributing to the development of breast cancer. Fiber plays another critical role — fiber helps lower fat levels in the blood, by encouraging elimination of fat in the stools.
Unfortunately, most of us do not get enough fiber in our diet. The average person in the U.S. eats only 15 grams of fiber per day, even though 30 grams daily is recommended for health. Excellent sources of fiber include:
• Cooked whole grains
• Garbanzo and kidney beans
• Pears and berries
• Dried figs
Furthermore, total fat intake is associated with increased risk of breast cancer. Women who eat less fat have a lower risk of breast cancer.
According to the largest, controlled clinical study of low-fat diets performed, post-menopausal women (of the ages of 50-79) who previously had a high-fat diet and then reduced their dietary intake of fat (to represent 29% of calories) and increased their consumption of grains, fruits, and vegetables for an average period of approximately 8 years showed a 22% lower rate of occurrence of invasive breast cancer than did the women who remained on a high fat diet. Limitations of the study include:
• The average age of participants being 62 years of age. Degree of the effects of reduction of fat intake initiated at a younger age is not known.
• The average length of follow-up was only 8 years. Degree of the effects of a longer reduction of fat intake is not known.
• The amount of fat in a low-fat diet could have been decreased even further. For example, the degree of the effects of reduction of fat intake to 20% of calories is not known.
• The types of fat consumed were not determined.
New research confirms that saturated and trans fats are culprits in raising the risk several types of chronic diseases. Both of these types of fats are easily oxidized into “free radicals,” which may account for the potentially carcinogenic properties of saturated and trans fats.
Saturated fats are found in animal products such as meat and poultry, dairy foods (e.g.: whole milk, cheese, butter, and ice cream), and eggs. Coconut, palm and cottonseed oils are the only plant oils that are saturated.
When possible, try to use "good" fats found in certain vegetable oils, nuts, and fish instead. Healthy fats include polyunsaturated fats and monosaturated fats (such as olive oil and canola oil). Monosaturated fats have no association with increasing cancer incidence. Furthermore, monosaturated fats have a protective effect against heart disease.
1. R.L. Prentice. Journal of the American Medical Association. 2006; 295:629-666.
2. Harvard Medical School. Say goodbye to low fat diets? Not so fast. HEALTHbeat. 02/13/06. Accessed at www.health.harvard.edu/n.