Inverse relationship between fat intake and blood lead levels in the Korean adult population in the KNHANES 2007-2009

Objectives: Blood lead levels (BLLs) in the Korean adult population are about twofold higher than those in the US adult population, which may be related to nutrient intake. We examined which nutritional factors might be associated with decreased BLL. Methods: This study was based on Korean National Health and Nutrition Examination Survey data obtained over 3. years (2007-2009) using a rolling sampling design involving a complex, stratified, multistage, probability-cluster survey of a representative sample of the non-institutionalized civilian population of South Korea. Results: A multiple regression analysis after controlling for covariates indicated that dietary fat and protein were significant opposite predictors of BLL in five different models; fat and protein intake had negative and positive associations with BLL, respectively. Covariates used in the analysis were sex, age, regional area, education level, smoking and drinking status, hypertension, use of antihypertensive drugs, diabetes, use of antidiabetic drugs, use of cholesterol-lowering drugs, hemoglobin level, and exposure to chemical substances during daily life. Intake levels of other nutrients, such as dietary fiber, carbohydrates, and calcium, did not show any significant effect on BLL. Gender was also an important predictor: BLL was significantly higher in men than women. However, total femur T-score, which represents bone mass, was unaffected by BLL. When calculating adjusted predicted marginal values of blood lead according to dietary fat percentage, BLL was lower by 5.3% and 8.0% in men when fat intake was increased from 10% to 20% and 25%, respectively. This effect of fat intake on BLL was minimal in women. Conclusion: The accumulation of body stores of lead from lead exposure may be reduced by increasing dietary fat consumption to 25% of energy intake, especially in men. However, this must be weighed against possible cardiovascular risks of higher fat diets.