The controversial role of B-vitamins in cardiovascular risk: An update

Area of Science:

• Cardiology
• Nutritional Science
• Epidemiology

Background:

• Cardiovascular disease is a leading cause of mortality in Western nations.
• Elevated homocysteine levels (hyperhomocysteinaemia) have been associated with atherosclerosis since 1969.
• Observational studies suggest hyperhomocysteinaemia is an independent cardiovascular risk factor.

Purpose of the Study:

• To review clinical trial findings on the 'homocysteine hypothesis'.
• To provide an updated overview of B-vitamin supplementation's effect on cardiovascular risk.
• To assess the efficacy of reducing homocysteine levels for preventing stroke, coronary heart disease, and peripheral artery disease.

Main Methods:

• Systematic review of clinical trials investigating homocysteine-lowering therapies.
• Analysis of observational studies linking homocysteine levels to cardiovascular outcomes.
• Evaluation of data on B-vitamin supplementation (folic acid) and cardiovascular events.

Main Results:

• B-vitamins, including folic acid, effectively reduce homocysteine levels.
• Clinical trials investigating the impact of homocysteine reduction on cardiovascular events have yielded inconsistent results.
• The 'homocysteine hypothesis' remains debated due to conflicting evidence.

Conclusions:

• While B-vitamins lower homocysteine, their role in reducing cardiovascular morbidity and mortality requires further clarification.
• The direct causal link between hyperhomocysteinaemia and cardiovascular disease is not definitively established by current clinical trial data.
• Further research is needed to resolve the inconsistencies in the 'homocysteine hypothesis' and its clinical implications.