1. Wolfgang, Kelly

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A recent study found that postmenopausal women who followed a low-fat diet may have a reduced risk of death from breast cancer compared to those who followed a less-restricted diet. The clinical trial, conducted by the Women's Health Initiative (WHI), included 48,935 women between the ages of 50 and 79 years old who had never suffered from breast cancer. Results found that participants had a 21 percent lower chance of death from breast cancer compared to those not following the low-fat diet. In addition, there was a 15 percent reduction in deaths after breast cancer from any other cause.

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Low Fat, High Fruits & Vegetables

Forty percent of women who participated in the trial were randomized to the intervention and asked to lower their fat intake to 20 percent of energy, increase fruit and vegetable servings to five or more daily, and increase grain servings to six or more daily, according to the trial. It was hypothesized that participants' intake of saturated fat would decrease to 7 percent of total energy, though participants were not provided with a specific goal for that metric. The intervention also did not include a weight loss component, though women on average did lose a modest amount of weight, according to the study.


Each participant received an individualized daily fat gram goal ranging from 27 to 39 grams of fat, or about 20 percent of energy, depending on her expected total energy intake. Groups of 8-15 participants attended sessions facilitated by nutritionists to learn how to lower dietary fat intake and increase fruit, vegetable, and grain intake, the study noted. Participants were also provided guidance on how to maintain the changes.


During the first year, the study participants attended 18 group sessions and one individual session with a nutritionist. In the second session, individualized fat gram goals were introduced; in session seven, fruit, vegetable, and grain goals were adopted. In the second year of participation, the women attended quarterly maintenance sessions facilitated by nutritionists and had the opportunity to attend optional peer-led group meetings, the study noted.


Participants were asked to self-monitor and self-report their food intake throughout the study. They received a book detailing fat grams and fruit, vegetable, and grain serving equivalents for approximately 1,000 foods, according to the study. Participants also received a choice of self-monitoring tools for recording intakes, including a food diary, a fat scan where commonly eaten foods were listed for easer and faster tallying, and a variety of alternatives to meet participant needs, the study noted.



After long-term follow-up of about 20 years, 3,374 cases of breast cancer were diagnosed among participants. Women who followed the intervention diet that was low in fat and included five or more servings of fruits, vegetables, and grains had a 21 percent lower risk of death from breast cancer compared to those who continued their normal diet, according to the study. The number of women who developed invasive breast cancer after the follow-up period was 655 in the intervention group and 1,072 in the comparison group. In addition, there was a 15 percent reduction in deaths after breast cancer from any cause among those who participated in the intervention.


The trial also found that by the sixth year of the trial, fat intake among the intervention group decreased by 8.2 percent of energy intake, with additional decreases of 2.9 percent in saturated fat, 3.3 percent in monounsaturated fat, and 1.5 percent in polyunsaturated fat. Increases of 1.1 servings per day of fruits and vegetables and 0.5 servings per day of grain were also recorded. Low-density lipoprotein cholesterol levels were reduced by 3.55 mg/dL, diastolic blood pressure decreased by 0.31 mm Hg, and factor VIIc was reduced by 4.29 percent, according to the study.


An additional analysis reported by Cancer Network showed that metabolic syndrome score identified a subgroup of postmenopausal women at high risk for death from breast cancer, specifically those with 3-4 metabolic abnormalities, who are more likely to benefit from the low-fat intervention diet.


"To our review, this is the only study providing randomized clinical trial evidence that an intervention can reduce a woman's risk of dying from breast cancer," noted Rowan T. Chlebowski, MD, PhD, FASCO, Chief of the Division of Medical Oncology and Hematology at Harbor-UCLA Medical Center. "This is a dietary change that we think can be achievable by many because it represents dietary moderation."


ASCO breast cancer expert Lidia Schapira, MD, FASCO, told Cancer Network, "The important thing here is that it is worth us sticking to the message of prevention that what we eat matters. Postmenopausal women who take the time to think about and plan their diets will be taking an important step toward prevention and improving their health."


Kelly Wolfgang is a contributing writer.