Dietary fats, carbohydrates and vascular disease: Sri Lankan perspectives

Area of Science:

• Nutritional Epidemiology
• Cardiovascular Disease Research

Background:

• Sri Lanka faces high mortality rates from cardio and cerebrovascular diseases (CVD), exceeding those in many Western nations.
• Traditional markers like total fat intake and LDL cholesterol do not fully account for this increased CVD vulnerability.

Purpose of the Study:

• To investigate the underlying metabolic factors contributing to elevated CVD risk in Sri Lanka.
• To explore the role of dietary fatty acid composition and high carbohydrate intake in metabolic abnormalities.

Main Methods:

• Analysis of dietary intake, focusing on total fat, carbohydrate percentages, and fatty acid ratios (saturated/polyunsaturated).
• Assessment of traditional lipid markers (total cholesterol, LDL-c) and other metabolic indicators (triglycerides, HDL, postprandial lipids, lipoprotein particles, hyperglycemia, hyperinsulinemia, oxidative stress).

Main Results:

• Sri Lankan diets show adequate total fat (25% energy) but a high saturated/PUFA ratio (9/1) and high carbohydrate intake (65% energy).
• These dietary patterns are associated with metabolic outcomes similar to very low-fat diets, including high triglycerides, low HDL, and potentially atherogenic lipoproteins.
• Metabolic abnormalities like postprandial hyperlipidemia, hyperglycemia, hyperinsulinemia, and increased oxidative stress are likely contributors to CVD risk.

Conclusions:

• Dietary patterns high in digestible carbohydrates and saturated fat, coupled with low PUFA intake, are strongly implicated in Sri Lanka's high CVD burden.
• Novel biomarkers assessing postprandial lipemia, LDL particle size, endothelial dysfunction, inflammation, and coagulability may offer deeper insights into CVD pathogenesis in this population.