Different kinds of vegetable oils in relation to individual cardiovascular risk factors among Iranian women

Abstract

Detrimental effects of trans-fats on lipid profiles, blood pressure and plasma glucose levels have been documented by short-term clinical trials with high doses of trans-fats, but limited observational studies have considered habitual consumption of partially hydrogenated vegetable oil (PHVO) and these outcome variables, particularly hypertension. We aimed to evaluate the association of PHVO and non-hydrogenated vegetable oils (non-HVO) intake with individual cardiovascular risk factors. In a cross-sectional study of 486 Iranian adult women, usual dietary intakes were assessed, and fasting plasma glucose (FPG), lipid profiles and blood pressure were measured. PHVO (commonly used for cooking in Iran) were considered as the PHVO category. Sunflower oil, maize oil, rapeseed oil, soyabean oil and olive oil were defined as the non-HVO category. Diabetes (FPG ≥ 1260 mg/l), dyslipidaemia (based on Adult Treatment Panel III) and hypertension (based on Joint National Committee VI) were defined. The presence of 'at least one risk factor' and 'at least two risk factors' of the three major risk factors for CVD (hypertension, dyslipidaemia and diabetes) was also evaluated. After controlling for age and other potential confounders, a high consumption of HVO was associated with a greater risk of having dyslipidaemia (OR for top v. bottom quintile 5·04; 95 % CI 2·70, 9·36), hypertension (OR for top v. bottom quintile 3·03; 95 % CI 1·55, 6·10), at least one (OR for top v. bottom quintile 8·52; 95 % CI 4·41, 16·41) and at least two risk factors (OR for top v. bottom quintile 3·60; 95 % CI 1·64, 7·74), while those in the top quintile of non-HVO consumption had lower odds for all these conditions. Further adjustment for dietary intakes had little impact on these associations. Even after additional adjustment for BMI, the positive association of HVO and the inverse association of non-HVO with the above-mentioned cardiovascular risk factors remained significant, except for the association between non-HVO and hypertension that became marginally significant. No overall significant associations were found between the consumption of HVO and non-HVO and diabetes. Higher intakes of PHVO were associated with a greater risk of individual cardiovascular risk factors, while those of non-HVO were associated with a reduced risk.