The Impact of Diet on Cardiovascular Risk

This data comes from the Diet to Stop Hypertension (DASH) trial that offered the DASH diet. The DASH diet starts with reduced salt. After all, it was designed to reduce high blood pressure. It also emphasizes eating fruits, vegetables, and grains and limiting calories to about 2000 daily.437 participants followed the DASH diet. , were randomized to receive a diet high in fruits and vegetables, or a control diet. The researchers calculated the 10-year risk of cardiovascular events using a common equation based on blood pressure and lipid profiles before and after completing eight weeks of treatment. [1]

Cardiovascular risk – pooled cohort equation (PCE)

This mathematical model was introduced a decade ago and has been used for over a decade as a tool for defining adverse cardiovascular risk. It was derived empirically from prospective studies that included age, sex, race, smoking status, blood pressure, hypertensive and diabetic status, and levels of total and HDL cholesterol. It is used as a standard guide by physicians when counseling patients. As with other algorithmic risk calculations, their performance changes as the population moves away from the original study group, causing risk to be overestimated or underestimated.

Changes in cardiovascular risk in this study were based on changes in total and HDL cholesterol and systolic blood pressure (first vs. high numbers).

result

• The DASH diet lowered systolic blood pressure, total cholesterol, and HDL cholesterol more than the control diet or the fruit and vegetable diet.
• DASH diet and fruit and vegetable diet reduced cardiovascular risk by about 10% after 8 weeks

Even between these two “good” diets, there were trade-offs. Specifically, DASH lowered systolic blood pressure more significantly (that’s how it was designed), but this was mitigated by the greater improvement in HDL from the fruit and vegetable diet.

before rushing to the grocery store

Fortunately, although the DASH trial was more diverse than the other studies, the improvement in risk factors with diet was twice as great in women and four times greater in blacks.

“This is particularly important because dietary patterns have been identified as one of the most important mediators of hypertension risk among black adults. It has become a major focus of policy impact to encourage increased intake.”

Inequalities in access to nutritious foods such as fruits and vegetables are only part of the problem. As mentioned earlier, the use of salt in cooking varies regionally in the United States as well as in China. The role of systolic blood pressure, which is partly related to salt intake, was the main factor in risk reduction in this study, so our culinary preferences, rather than access to fruits and vegetables, are comparable risk factors. or more. We don’t know.

Another consideration is the magnitude of the diet effect, which decreases by 10% over 10 years. Is this improvement clinically meaningful? In this example, it appears to be for high-risk blacks and women. Still, I’m not sure I would give up the occasional steak frites for that reduced risk, especially if I generally pursue a “plant-based” diet as much as possible and get off the couch and exercise every day. Hmm.

[1] The control diet was high in fat, saturated fat, and cholesterol, and contained approximately 25% of the average intake of potassium, magnesium, and calcium. Fruit and vegetable diets provide more of these foods and contain more potassium and magnesium. It included “fat-free or low-fat dairy products and reduced saturated and total fat, cholesterol, sweets and sugary drinks.”

Source: Effect of diet on 10-year atherosclerotic cardiovascular disease risk (from the DASH study) American Journal of Cardiology DOI: 10.1016/j.amjcard.2022.10.019