Serum Beta Carotene and Overall and Cause-Specific Mortality

Area of Science:

• Biochemistry and Molecular Biology
• Epidemiology and Public Health
• Nutritional Science

Background:

• Extensive research exists on beta carotene's health effects, but systematic examination of its association with long-term mortality, particularly cardiovascular mortality, is lacking.
• Serum concentrations of beta carotene, a vital antioxidant, are a key indicator of dietary intake and nutritional status.

Purpose of the Study:

• To investigate the association between serum beta carotene concentrations and overall mortality.
• To examine the relationship between serum beta carotene and cause-specific mortality, including cardiovascular disease, cancer, and other causes.
• To determine the strength and dose-response relationship of these associations.

Main Methods:

• Prospective serological analysis of 29,103 men from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) study.
• Serum beta carotene levels were measured using high-performance liquid chromatography.
• Long-term mortality data, including cause-specific deaths, were analyzed over 31 years of follow-up, with adjustments for major risk factors.

Main Results:

• Higher serum beta carotene levels were significantly associated with lower all-cause mortality (P_trend<0.0001).
• A significant inverse association was observed between serum beta carotene and mortality from cardiovascular disease, heart disease, stroke, cancer, respiratory disease, diabetes mellitus, injuries, and other causes (Q5 vs. Q1 hazard ratio=0.21-0.73, P_trend<0.0001).
• The association remained significant after adjusting for fruit and vegetable intake and was generally consistent across subgroups, though modified by age, smoking history, and BMI.

Conclusions:

• Elevated serum beta carotene levels are demonstrably linked to reduced overall mortality and mortality from major causes like cardiovascular disease and cancer.
• The observed dose-response relationship, robust across various risk factors, supports the importance of adequate beta carotene status for promoting longevity.
• Increased fruit and vegetable consumption is recommended to enhance beta carotene status and potentially extend lifespan.