Study Reveals Dairy Lowers Blood Lipid Levels, Contradicting Fruits and Vegetables

A recent study conducted in Iran has unveiled significant findings regarding dietary impacts on blood lipid levels, specifically highlighting the role of dairy consumption. Published in BMC Research Notes on June 24, 2025, researchers discovered that dairy intake is associated with lower triglyceride levels, while fruit and vegetable consumption showed no significant effect on overall blood lipid profiles.

The cross-sectional study, which involved 19,868 participants aged 25 and older from both rural and urban areas across 30 Iranian provinces, utilized the World Health Organization's STEPwise approach to surveillance (STEPs) questionnaire to gather data on socio-demographic characteristics, medical risk factors, and lifestyle habits, including dietary intake.

According to Dr. Mehran Nouri, a lead researcher from Tehran University of Medical Sciences, the study's findings highlight an inverse relationship between dairy consumption and serum triglyceride levels. "Our research indicates that individuals consuming one and two servings of dairy products experienced a 10% and 13% reduction in triglycerides, respectively," Dr. Nouri stated. Despite these findings, the study did not find significant associations between dairy intake and total cholesterol or high-density lipoprotein cholesterol (HDL-C) levels.

In contrast, fruit and vegetable intake exhibited no meaningful impact on lipid profiles. The findings suggested that two servings of vegetables resulted in only a 2% reduction in serum triglycerides, while fruit consumption did not significantly alter triglyceride or cholesterol levels. Researchers pointed out that, traditionally, increased fruit and vegetable consumption is advocated for managing dyslipidemia through various mechanisms, including dietary fibers that bind cholesterol and bile acids.

Dr. Zohreh Ebrahimi, a co-author of the study and a nutritionist at Tehran University, emphasized that the findings challenge common dietary recommendations. "While fruits and vegetables are known for their health benefits, our study indicates they may not influence lipid profiles as significantly as previously thought," Dr. Ebrahimi noted. She added, however, that fruits and vegetables play crucial roles in weight management and overall health due to their low-calorie content, which indirectly influences lipid levels.

The study's implications are particularly relevant given the high prevalence of cardiovascular diseases linked to dyslipidemia in Iran. According to the World Health Organization (WHO), cardiovascular diseases are a leading cause of mortality in the country, making effective dietary interventions critical.

Moreover, the research underscores the need for further investigation into the mechanisms by which dairy products may influence lipid metabolism. Dr. Ebrahimi called for longitudinal and intervention studies to elucidate how different dietary components interact with lipid profiles over time.

This study adds to the growing body of literature on dietary impacts on health and reopens discussions about the role of dairy in nutrition. It also highlights a troubling trend in Iran, where average fruit and vegetable consumption remains below recommended levels, with most participants reporting less than one serving of fruit and fewer than two servings of vegetables daily. As researchers call for increased awareness and consumption of these food groups, the need for balanced dietary guidance becomes ever more critical.

In conclusion, while dairy appears to offer specific benefits in lowering triglyceride levels, the lack of significant effects from fruit and vegetable intake suggests a complex relationship between diet and lipid profiles that requires further exploration. As dietary recommendations continue to evolve, these findings may prompt a reevaluation of traditional views on the roles of dairy and plant-based foods in managing blood lipid levels and overall cardiovascular health.