DASH plan linked to reduced CHD risk

7 September 2010

MedWire News: Prehypertensive and hypertensive patients who follow the Dietary Approaches to Stop Hypertension (DASH) dietary plan may have a reduced 10-year risk for coronary heart disease (CHD), study findings show.

This finding was particularly marked among patients of African-American ethnicity, say Lawrence Appel (The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA) and colleagues.

As previously reported by MedWire News, other studies have shown that following the DASH diet may improve blood pressure (BP). Indeed, Appel and colleagues observed a similar occurrence in the present study, and they suggest that this antihypertensive benefit is a likely contributor to the noted improvement in CHD risk seen among the patients consuming a DASH diet.

The researchers also emphasize that the 10-year risk reduction suggested by their findings is merely an estimation based on Framingham Risk equations, although they say that “evidence from cohort studies suggest that as long as adherence is maintained, benefits should persist.”

Appel and team recruited 436 untreated prehypertensive (120–139/80–89 mmHg) or stage-one hypertensive (140–159/90–99 mmHg) patients.

All patients were randomly assigned to consume a control diet (typical American high-fat, low-mineral diet n=154), a high fruit and vegetable diet (F/V, n=154), or the DASH diet (high fruits, vegetable, low-fat dairy, and low total fat consumption, n=151).

After an 8-week follow-up period, the researchers calculated CHD risk factors, such as BP and cholesterol, for each patient, and used formulae from the ongoing Framingham Heart Study to determine 10-year CHD risks.

Of note, the patients’ weights remained stable throughout the intervention period.

The findings, published in the journal Circulation: Cardiovascular Quality and Outcomes, revealed that the patients’ median 10-year risk for CHD was 0.98% at baseline, and decreased after 8 weeks in all groups.

The relative risk ratio comparing 8-week with baseline 10-year CHD risk was 0.93 and 0.82 among patients on the F/V and DASH diets, respectively (p=0.12 and p<0.001, respectively), compared with control patients. The team also found that, compared with patients consuming an F/V diet, those on a DASH diet had an 11% reduction in 10-year CHD risk (p=0.012).

Interestingly, on sub-analysis, a greater CHD risk reduction was observed among the 260 patients of African-American origin compared with the 152 Caucasian patients. Compared with all patients on a control diet, Caucasian and African-American patients consuming a DASH diet had 8% and 22% reductions in 10-year CHD risk, respectively (p=0.296 and p<0.001, respectively).

Appel et al conclude: “Further research should focus on public health and clinical strategies to promote adoption of the DASH dietary pattern, which is currently recommended by the 2005 US dietary Guidelines for Americans.”

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Circ Cardiovasc Qual Outcomes 2010; Advance online publication