Physicians' Health Study (Beta carotene component) - Physicians' Health (Beta carotene)

Description:

Beta-carotene for primary prevention of cancer and cardiovascular disease.

Hypothesis:

People who consume more fruits and vegetables containing beta carotene have somewhat lower risks of cancer and cardiovascular disease; the hypothesis was tested using beta carotene supplementation.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 22,071
Mean Follow Up: 12 years
Mean Patient Age: Not available
Female: 0

Patient Populations:

U.S. male physicians
40 to 84 years of age in 1982

Exclusions:

History of cancer (except nonmelanoma skin cancer)
Myocardial infarction (MI)
Stroke
Transient cerebral ischemia

Primary Endpoints:

Any type of malignant neoplasm except nonmelanoma skin cancer.

Secondary Endpoints:

Myocardial infarction
Stroke

Drug/Procedures Used:

Beta carotene capsules, 50mg, or placebo, taken on alternate days.

Concomitant Medications:

Aspirin, 325 mg, or placebo, taken on alternate days (opposite the beta carotene or placebo)

Principal Findings:

Capsule compliance was 78% after 12 years.

There were virtually no early or late differences in the overall incidence of malignant neoplasms or cardiovascular disease, or in overall mortality.

In the beta carotene group, 1273 men had any malignant neoplasm (except nonmelanoma skin cancer), vs. 1293 in the placebo group (relative risk, 0.98; 95% confidence interval, 0.91 to 1.06).

There were also no significant differences in the number of:
Cases of lung cancer (82 in the beta carotene group vs. 88 in the placebo group;
Deaths from cancer (386 vs. 380);
Deaths from any cause (979 vs. 968);
Deaths from cardiovascular disease (338 vs. 313);
Myocardial infarction (468 vs. 489);
Stroke (367 vs. 382);
Men with any one of the previous three end points (967 vs. 972)

Among current and former smokers, there were no significant early or late differences in any of these end points.

Interpretation:

In this trial among healthy men, 12 years of supplementation with beta carotene produced neither benefit nor harm in terms of malignant neoplasms, cardiovascular disease, or death from all causes.

References:

1. N Engl J Med 1996;334:1145-9. Final results

Clinical Topics: Prevention, Nonstatins, Diet

Keywords: Risk, Myocardial Infarction, Skin Neoplasms, Stroke, beta Carotene, Dietary Supplements, Confidence Intervals, Lung Neoplasms, Primary Prevention


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