Poor Diet in Adolescence Linked to Breast Cancer at Earlier Age

A poor diet during the teen and early adult years may raise a woman’s risk of developing breast cancer before menopause, according to a recent study.
Researchers from the UCLA Fielding School of Public Health in Los Angeles examined the effect of a diet associated with chronic inflammation on breast cancer. This diet—few vegetables; high in sugar-sweetened drinks, refined sugars and carbohydrates; loaded with red and processed meats—has been linked to high levels of inflammatory markers in the blood, said Karin B. Michels, professor and chair of the school’s department of epidemiology.
“Because breast cancer takes many years to arise, we were curious whether such a diet during the early phases of a woman’s life is a risk factor for breast cancer,” Michels said.
Michels and her colleagues used data from 45,204 women enrolled in the Nurses’ Health Study 2. That study examined participants’ diet at four-year intervals, beginning in 1991. During the study period, 870 of the women were diagnosed with premenopausal breast cancer and 490 were diagnosed with postmenopausal breast cancer.
Each woman’s diet was scored using a method linking diet with inflammatory markers in the blood, and the women were then divided into five groups based on their score. Those in the highest score group for adolescent diet had a 35 percent higher risk for premenopausal breast cancer.  The same analysis was done based on early adulthood diet, and researchers found those in the highest inflammatory score group had a 41 percent higher risk for premenopausal breast cancer.
“During adolescence and early adulthood, when the mammary gland is rapidly developing and is therefore particularly susceptible to lifestyle factors, it is important to consume a diet rich in vegetables, fruit, whole grains, nuts, seeds and legumes,” Michels said.
The study had two main limitations: Patients had to recall their adolescent diet years later, and researchers didn’t have adolescent or early adulthood measurements of blood markers of inflammation in this study.
Still, the study’s results are illuminating. “About 12 percent of women in the United States develop breast cancer in their lifetimes,” Michels said. “However, each woman’s breast cancer risk is different based on numerous factors, including genetic predisposition, demographics and lifestyle. Our study suggests that a habitual adolescent/early adulthood diet that promotes chronic inflammation may be another factor that impacts an individual woman’s risk.”