Table 1.

Key Studies of Lifestyle Modification on Invasive Breast Cancer Risk

Trial	Intervention	Population	Sample Size	Primary End Point	Results	Subgroups
WHI Dietary Modification Trial[35]	Lifestyle intervention: Reduction of intake of total fat to 20% of energy and increase consumption of fruits and vegetables to ≥5 servings daily and grins to ≥6 servings daily or usual diet comparison group	Postmenopausal women, aged 50–79 years, without a prior breast cancer	48,835	IBC	After median follow up of 8.1 years, non-significant 9% relative reduction in risk of IBC, HR: 0.91; 95% CI: 0.83–1.01	22% reduction among women consuming ≥36.8% of energy from fat, HR: 0.78; 95% CI: 0.64–0.95 11% reduction among ER+ tumors, HR: 0.89; 95% CI: 080–1.00 24% reduction among PR− tumors, HR: 0.76; 95% CI: 0.63–0.92
PREDIMED[39]	Lifestyle intervention: Mediterranean diet supplemented with extra virgin olive oil Lifestyle Intervention: Mediterranean diet supplemented with mixed nuts Control diet (advice to reduce dietary fat)	Women aged 60–80 years at higher risk of developing cardiovascular disease	4,282	Major cardiovascular events Pre-specified secondary endpoint: IBC	After median follow up of 4.8 years, 68% relative reduction in risk of IBC with Mediterranean diet supplemented with extra virgin olive oil, HR: 0.32; 95% CI: 0.13–0.79)	E28% reduction for each additional 5% of calories from extra virgin olive oil, HR: 0.72; 95% CI: 0.57–0.90

Abbreviations: CI, Confidence Interval; ER, Estrogen Receptor; HR, Hazard Ratio; IBC, Invasive Breast Cancer; PR, Progesterone Receptor