Oxidative dna damage levels in blood from women at high risk for breast cancer are associated with dietary intakes of meats, vegetables, and fruits

OBJECTIVE: We examined the relationship between intakes of specific foods–namely, meats, vegetables, and fruits–with levels of oxidative DNA damage in women consuming their own usual diet or a diet low in fat.

DESIGN: Blood was obtained from women who had been assigned randomly to a low-fat or nonintervention diet for 3 to 24 months. Levels of 5-hydroxymethyluracil, a type of oxidative DNA damage, were determined. Diet data were obtained from 3-day food records.

SUBJECTS/SETTING: The 21 women were participating in an outpatient clinic. All the women were healthy but had a first-degree relative with breast cancer.

INTERVENTION: The intervention was a self-selected diet with a goal of 15% of energy from fat.

MAIN OUTCOME MEASURES: Existing data on oxidative DNA damage levels were evaluated for possible relationships to foods eaten. Intakes of raw and cooked vegetables were examined separately. Meat intake was examined by type of meat (pork, beef, fish, chicken) and by cooking temperature.

STATISTICAL ANALYSES: Initial univariate analyses relied on Spearman rank correlations of each food item with DNA damage. Further analyses of the data were performed with univariate and multivariate weighted least squares regression models.

RESULTS: The model that best explained DNA damage levels was a bivariate regression model that included the intake of cooked vegetables and the sum of beef and pork intake. This model accounted for 85% of the variation in DNA damage levels among women. Preliminary results are suggestive of a positive association of DNA damage with beef and pork intake and a negative association with cooked vegetable intake.

APPLICATION: These observations, if confirmed in larger studies, suggest specific dietary changes to reduce oxidative DNA damage levels and possibly cancer risk.