Associations between dietary diversity and dyslipidemia among Japanese workers: cross-sectional study and longitudinal study findings

The aim of this study was to determine the associations between dietary diversity and risk of dyslipidemia in Japanese workers.

The cross-sectional study included 1399 participants aged 20–63 years and the longitudinal study included 751 participants aged 20–60 years in 2012–2013 (baseline) who participated at least once from 2013 to 2017 with cumulative participation times of 4.9 times. Dietary intake was assessed using a food frequency questionnaire, and dietary diversity score (DDS) was determined using the Quantitative Index for Dietary Diversity. Dyslipidemia was diagnosed when at least one of the following conditions was met: hypertriglyceridemia, high LDL-cholesterol, low HDL-cholesterol, high non-HDL-cholesterol, and a history of dyslipidemia. Multivariable logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for dyslipidemia with control of confounding factors in cross-sectional analysis. Generalized estimating equations were used for calculating the ORs (95% CI) for dyslipidemia in the follow-up period according to the DDS at baseline with control of confounding factors in longitudinal analysis.

Cross-sectional analysis showed that the highest DDS reduced the odds of dyslipidemia in men (OR [95% CI] in Tertile 3: 0.67 [0.48–0.95], p value = 0.023). In longitudinal analysis, a moderate DDS reduced the risk of dyslipidemia (OR [95% CI] in Tertile 2: 0.21 [0.07–0.60], p value = 0.003) in women.

The results of cross-sectional analysis in this study suggest that the higher diversity of diet might reduce the presence of dyslipidemia in men and the results of longitudinal analysis suggest that a moderate DDS might reduce the risk of dyslipidemia in women. Further studies are needed since the results of cross-sectional and longitudinal analyses in this study were inconsistent.