Secular trends in diet and risk factors for cardiovascular disease: the Framingham Study

Abstract

Objective: In this study we examined changes in dietary intake and risk factors for cardiovascular disease that occurred over three decades in a US-population-based sample.

Design: Secular trends in dietary profiles and risk factors were studied in cross-sectional samples of subjects from the Framingham Study in 1957-1960, 1966-1969, and 1984-1988.

Results: Dietary levels of cholesterol appeared to have declined considerably, whereas macronutrient and fatty acid intakes appeared to change only slightly. Men appeared to increase their saturated fat intakes from 16.4% in 1966-1969 to 17.0% in 1984-1988 (P < .01). In spite of relatively stable mean total fat intake levels, 35% to 60% of Framingham Study men and women reported decreased consumption of higher-fat animal products over the 10-year period between 1974-1978 and 1984-1988. Framingham subjects who reported modifying their diets by substituting lower-fat foods for high-fat items between 1974-1978 and 1984-1988 were more likely to achieve the guidelines of the National Cholesterol Education Program and Healthy People 2000 for dietary fat and cholesterol intake and for serum total cholesterol level. Levels of systolic and diastolic blood pressure, total and low-density lipoprotein cholesterol, and cigarette smoking were also lower in 1984-1988 than in earlier times. Compared with 1957-1960, mean body mass index and prevalence rates of overweight and hypertension were higher in 1984-1988, despite higher levels of reported physical activity.

Conclusions: The observed secular trends in diet and risk factor levels for cardiovascular disease in the Framingham population are important to guide the development and implementation of population-based strategies for promoting cardiovascular health, including nutrition interventions.