After a 13-year-long study, primary findings from the Dietary Modification Trial component of the Women's Health Initiative (WHI) are being released in the upcoming "Journal of the American Medical Association" (JAMA). Emory University is one of 40 sites that participated in the WHI trials. Emory investigators and WHI study participants are available for comment on the three JAMA reports.
The intervention for the Dietary Modification Trial component was designed to promote dietary change by reducing the total fat intake of participants to 20 percent of total energy, increasing vegetable and fruit consumption to at least five servings daily, and grains to at least six servings daily.
"Despite the perceived message in the primary findings of the trial, a healthy diet continues to be important as something individuals can and should do to optimize their health," says Lawrence Phillips, MD, professor, division of endocrinology, Emory University School of Medicine, and Emory's principal investigator for the WHI. "And unlike assertions in popular books that advocate low-carb diets, the WHI diet, which was low in fat and high in carbohydrates, didn't increase the risk of obesity or metabolic syndrome."
The 48,835 WHI study participants included postmenopausal women aged 50 to 79 years of age, from diverse backgrounds and ethnicities. Forty percent of the women were assigned to the intervention arm, and 60 percent to the comparison group. Summaries for the JAMA articles are listed below.
LOW-FAT DIETARY PATTERN AND RISK OF COLORECTAL CANCER Researchers found that the intervention didn't reduce the risk of colorectal cancer in postmenopausal women during 8.1 years of follow-up. The article points out that questions remain unanswered about whether greater adherence, longer intervention, or dietary change at an earlier age would influence risks.
LOW-FAT DIETARY PATTERN AND RISK OF CARDIOVASCULAR DISEASE Dietary intervention didn't significantly reduce the risk of coronary heart disease, stroke, or cardiovascular disease (CVD) in postmenopausal women. Only modest effects were achieved on CVD risk factors, suggesting that more focused diet and lifestyle interventions may be needed.
LOW-FAT DIETARY PATTERN AND RISK OF INVASIVE BREAST CANCER Over an 8.1-year follow up period, the low-fat dietary pattern did not result in a statistically significant reduction in invasive breast cancer risk in postmenopausal women. Breast cancer incidence was nine percent lower for women in the dietary intervention group compared with women in the comparison group.
"The data aren't strong enough to recommend a low-fat dietary pattern for most women," Dr. Phillips says in regards to breast cancer risks. "However, women consuming a diet high in fat may benefit by lowering their fat intake. Women should also continue to have regular mammograms and breast exams."
Emory investigators available for comment on the JAMA reports include:
Lawrence S. Phillips, MD - Dr. Philips is the principal investigator for the WHI study being conducted at the Emory University School of Medicine. He is a professor of medicine in the division of endocrinology.
Ora Strickland, PhD, DSc (Hon.), RN, FAAN - Dr. Strickland is a professor in the department of family and community nursing at the Nell Hodgson Woodruff School of Nursing.
Dr. Strickland's research focuses primarily on measurement as well as perinatal health, women's health and minority health issues. She is a co-principal investigator for the WHI at Emory University.
Nanette Wenger, MD - Dr. Wenger is a co-investigator for the WHI at the Emory University site. She is a professor of medicine in cardiology at the Emory University School of Medicine.
If you would like to interview any of these experts or our available patients, please contact the Emory Health Sciences Communications Office at the above numbers.