Background: Diets rich in n-6 polyunsaturated fatty acids (PUFAs) and saturated fatty acids (SFA) have been associated with increased risk of obesity and the metabolic syndrome (MetS), but the evidence is inconsistent, whereas diets high in n-3 long-chain (LC) -PUFAs are associated with lower risk. There is limited information about the association of plasma phospholipid fatty acids (FAs) with obesity and the MetS among black South Africans.
Objective: To investigate the association of dietary FAs and plasma phospholipid FA patterns, respectively, with measures of adiposity (body mass index, waist circumference, waist-to-height ratio) and the MetS in black South Africans.
Methods: Factor analysis was used to identify FA patterns from 11 dietary FAs and 26 individual plasma phospholipid FAs. Cross-sectional association of the identified patterns with measures of adiposity and the MetS was investigated. A random sample of 711 black South African adults aged 30 to 70 years (273 men, 438 women) from the North West Province was selected from the South African leg of the Prospective Urban and Rural Epidemiology (PURE) study. Sequential regression models adjusted for confounders were applied to investigate the association between dietary FAs and plasma phospholipid FA patterns with measures of adiposity and the MetS.
Results: Two patterns were derived from dietary FAs and six patterns from plasma phospholipid FAs that explained the cumulative variance of 89 and 73%, respectively. The association of FA patterns with adiposity and the MetS was weaker for dietary FA patterns than for plasma phospholipid FA patterns. The plasma phospholipid FA pattern with high loadings of saturated FAs (high-Satfat) and another with high loadings of n-3 very-long-chain PUFAs (n-3 VLC-PUFAs) were positively associated with measures of adiposity and the MetS, while patterns with positive loadings of LC monounsaturated fatty acids (n-9 LC-MUFA) and a positive loading of n-3 essential FAs (n-3 EFA) showed inverse associations with the MetS and some measures of adiposity.
Conclusion: The n-9 LC-MUFA and n-3 EFA patterns seemed to provide possible protective associations with adiposity and the MetS, whereas the high-Satfat and n-3 VLC-PUFA patterns were associated with adiposity and the MetS in our study participants. The results are reflective of the metabolic difference between overweight and obese compared to lean individuals.
Keywords: adiposity; dietary fatty acid patterns; metabolic syndrome; phospholipid fatty acid patterns; waist:height ratio.