Linda Snetselaar, PhD, RD Professor Interim Chair of the Department of Community and Behavioral Health College of Public Health University of Iowa

Background 15- year, $625 million national health study funded by NHLBI Focused on chronic disease prevention in postmenopausal women of all races Heart disease Breast cancer Colorectal cancer Osteoporotic fractures 161,808 women aged 50-79

WHI Sites 40 clinics throughout the US Three locations in Iowa: Iowa City Davenport Des Moines

Two Main Study Components Randomized clinical trial 3 prevention strategies-women could enroll in any or all (if eligible) Hormone therapy Dietary modification Calcium and Vitamin D Observational study Examines relationships between lifestyle, health, risk factors, and disease outcomes

Hormone Therapy Trials Estrogen plus progestin Estrogen alone Placebo Hormone groups stopped treatment early, but all participants continued to be followed until the end of the study

Dietary Modifications (DM) Trial Evaluated impact of diet on prevention of breast and colorectal cancer and heart disease Low fat High fruit High vegetable High grain

DM Comparison Group Follow regular eating habits Keep a food record a few days each year Attend a clinic visit one time each year

Dietary Change Group Attend nutrition sessions to: Lower fat (20% kcal from fat) Increase fruits and vegetables (> 5 servings per day) Increase grains (> 6 servings per day) Frequently keep a food record One clinic visit per year

DM Nutrition Sessions The first year 18 nutrition classes Once a week for 6 weeks Every other week for 6 weeks Once a month for 9 months 1 clinic and 1 phone visit The second year and beyond 4 nutrition classes each year 1 clinic and 1 phone visit

Calcium and Vitamin D Trial Evaluated the effect of calcium and vitamin D supplementation on osteoporotic fractures and colorectal cancer Calcium and vitamin D supplements group Placebo group

Observational Study Group Completed questionnaires reporting changes in health and activities over time No other required study activities

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