The association between plant-based diet indices and metabolic syndrome in Iranian older adults

Background: We investigated the association between plant-based diets indices - an overall plant-based diet index; a healthful plant-based diet index; and an unhealthful plant-based diet index - and metabolic syndrome among Iranian older adults.

Aim: We aimed to examine the relationship between plant-based diet indices and metabolic syndrome.

Methods: This cross-sectional study included 178 older adults (51 men and 127 women), with a mean age of 67.04 (60-83) who were referred to health centers in Tehran, Iran. Blood and urine samples were collected to measure serum total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. We created an overall plant-based diet index, healthful plant-based diet index, and unhealthful plant-based diet index from semi-quantitative food-frequency questionnaire data. Anthropometric measures were done.

Results: Our crude model results showed that triglycerides, systolic and diastolic blood pressure, fasting blood sugar, high-density lipoprotein cholesterol, and waist circumference did not significantly differ between tertiles of plant-based diet index and healthful plant-based diet index; also triglycerides, systolic and diastolic blood pressure, fasting blood sugar, and waist circumference did not significantly differ between tertiles of unhealthful plant-based diet index, but high-density lipoprotein cholesterol significantly differed between tertiles of unhealthful plant-based diet index. After adjusting for confounders the results remained non-significant for plant-based diet index but high-density lipoprotein cholesterol was significant for healthful and unhealthful plant-based diet indices. There was also no significant association between plant-based diet index (OR: 1.11; 95% CI: 0.53-2.33), healthful plant-based diet index (OR: 0.81; 95% CI: 0.39-1.68), and unhealthful plant-based diet index (OR: 0.81; 95% CI: 0.38-1.72) with metabolic syndrome, even after adjustment for confounders.

Conclusions: Our findings showed that plant-based diets are not significantly associated with risk of metabolic syndrome in older adults. To confirm the veracity of these findings, more studies should be conducted.