Nutrition and Coronary Heart Disease
Study with a BMI exceeding one standard deviation of the mean had a 44% increased
risk of ischaemic heart disease.
Larsson et al (1984) used a number of different measures of obesity, finding that the
only significant relationship with ischaemic heart disease were ‘waist to hip’
measurements. This result however was not robust after the inclusion of other
confounding variables such as cholesterol levels. Lapidus (1984) did find that ‘waist to
hip’ measurements were an independent risk factor for myocardial infarction for
females. More recent evidence also indicates that waist to hip ratios are a more
significant indicator of risk for CHD than BMI (Larsson et al, 1992 & Wingard, 1990).
In the literature, however, the most common measure for obesity is BML So, despite
the evidence that there might be better measures of obesity, this paper used BMI as an
indicator of obesity, using the definitions above.
Sedentary lifestyle
There is strong evidence that lack of exercise will increase the risk of CHD. As early as
the Framingham Study a strong association was shown. In this study an energy output
score was used and shown to be a predictor of CHD (Dawber, 1980). More recently a
meta-analysis showed an increased risk of death for sedentary lifestyles (Berlin, 1990).
Nutrition - Saturated fats
There is some strong evidence to suggest that dietary intake, especially dietary saturated
fats, will affect rates of CHD (Keys, 1970; Keys et al 1986; Kagan et al, 1974). Similar
results were found in two more recently published longitudinal studies (Slattery, 1988 &
Stephen, 1990). However, it is not clear whether it is an independent risk factor.
Nutrition - Fish oils
Fat available in fish has high concentrations of eicosapentaenoic acid. There is some
evidence that the consumption of fish can reduce the risks of CHD. Kromhout et al
(1985) found that mortality rates were 50% lower for those participants who consumed
at least 30 grams of fish a day, compared to those who did not eat fish at all. However,
it is unclear whether the consumption of fish, or lack of, is an independent risk factor
for coronary heart disease. Sanders (1987) found that experimental diets with high fish
consumption were responsible for the reduction of blood lipid levels.
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