Dietary Habits and Incidence of Metabolic Syndrome among Middle-aged Japanese Male Workers

Total, low-fat, and full-fat dairy consumption and risk of metabolic syndrome among workers

BACKGROUND & AIM

Dairy products may play a beneficial role against metabolic syndrome; however, epidemiological evidence is scarce in Asian populations, who consume less dairy than Western populations. We prospectively investigated the association between dairy product intake, both overall and by fat content, and metabolic syndrome in a Japanese working population.

METHODS

Participants were 1014 workers (aged 19-68 years) without metabolic syndrome at baseline who completed a 3-year follow-up survey. Dietary intake was assessed using a validated self-administered diet history questionnaire. Metabolic syndrome was defined according to the Joint Interim Statement (JIS) criteria. Multiple logistic regression was used to estimate the odds ratio of metabolic syndrome according to tertile of total, low-fat, and full-fat dairy product intake with adjustment for covariates.

RESULTS

At the 3-year follow-up, 66 (6.5%) workers were newly identified as having metabolic syndrome. A trend towards decreased odds of developing metabolic syndrome was observed among those in the highest tertile of total and full-fat dairy product intake: multivariable-adjusted odds ratio for the highest versus lowest tertile was 0.54 (95% CI 0.26-1.12; P for trend = 0.094) for total dairy products and 0.50 (95% CI 0.24-1.05; P for trend = 0.038) for full-fat dairy products. Low-fat dairy intake was not associated with metabolic syndrome.

CONCLUSIONS

Our results suggest that higher intake of full-fat, but not low-fat, dairy products may be associated with a lower risk of metabolic syndrome among Japanese.

Relationship between number of metabolic syndrome components and dietary factors in middle-aged and elderly Japanese subjects

Metabolic syndrome (MetS) represents a cluster of risk factors for atherosclerosis and is considered a risk factor for cardiovascular disease. The role of diet in the etiology of MetS is poorly understood, especially among Asian subjects. This cross-sectional study assessed the relationship between diet and the number of MetS components among Japanese men (n=609) and women (n=631). Mean (s.d.) age and body mass index were 57.1 (12.1) years and 22.8 (2.8) kg m(-2) for men and 55.5 (12.0) years and 22.0 (3.0) kg m(-2) for women, respectively. Diet was assessed by a 3-day dietary record that included photographs: 16 nutrients, 11 food groups, and energy % of protein and dietary fat were selected as a dietary index. The definition of MetS was based on modified National Cholesterol Education Program, Adult Treatment Panel III criteria, and the number of clustering MetS components was calculated by adding the presence of each five MetS components. A total of 61 men (10.0%) and 46 women (7.3%) were determined to have MetS. After adjusting for age, energy intake, alcohol intake, smoking status and physical activity, a lower intake of vitamin B6 and dietary fiber in men, and lower intake of calcium, milk and dairy products and higher intake of cereal in women were related to the number of MetS components. These results suggest that some dietary factors were related to the number of MetS components among community-dwelling Japanese men and women.