Linda Snetselaar, PhD, RDProfessor

Interim Chair of the Department of Community and Behavioral Health

College of Public HealthUniversity of Iowa

Background15- year, $625 million national health study

funded by NHLBIFocused on chronic disease prevention in

postmenopausal women of all racesHeart diseaseBreast cancerColorectal cancerOsteoporotic fractures

161,808 women aged 50-79

WHI Sites40 clinics throughout the USThree locations in Iowa:

Iowa CityDavenportDes Moines

Two Main Study ComponentsRandomized clinical trial

3 prevention strategies-women could enroll in any or all (if eligible) Hormone therapy Dietary modification Calcium and Vitamin D

Observational studyExamines relationships between lifestyle,

health, risk factors, and disease outcomes

Hormone Therapy TrialsEstrogen plus progestinEstrogen alonePlaceboHormone groups stopped treatment early,

but all participants continued to be followed until the end of the study

Dietary Modifications (DM) TrialEvaluated impact of diet on prevention of

breast and colorectal cancer and heart diseaseLow fatHigh fruitHigh vegetableHigh grain

DM Comparison GroupFollow regular eating habits

Keep a food record a few days each year

Attend a clinic visit one time each year

Dietary Change GroupAttend 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 recordOne clinic visit per year

DM Nutrition SessionsThe 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 beyond4 nutrition classes each year1 clinic and 1 phone visit

Calcium and Vitamin D TrialEvaluated the effect of calcium and vitamin D

supplementation on osteoporotic fractures and colorectal cancer

Calcium and vitamin D supplements group

Placebo group

Observational Study GroupCompleted questionnaires reporting changes

in health and activities over time

No other required study activities

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