THE DASH DIET AND RISK OF HYPERTENSION

Diet plays an important role in the management of high blood pressure (hypertension). One of the most studied dietary approaches for managing high blood pressure is the Dietary Approaches to Stop Hypertension (DASH) eating plan/diet.

The DASH diet is an eating plan that includes plenty of fruits, vegetables, whole grains, legumes, nuts and low-fat dairy products but restricts red meat, salt, added sugars and sugar-sweetened drinks. The diet is lower in saturated fat and sodium and higher in potassium, calcium, magnesium and dietary fibre than a typical Western diet, all of which can help lower blood pressure. The focus on wholegrains, legumes, fruits, vegetables and low-fat dairy foods also means that the diet is likely to have a lower glycemic index (GI) and there is some evidence that lower GI diets may help reduce blood pressure (see this month’s Perspectives and Diabetes Care).

While originally designed to help in the management of high blood pressure, several studies have also looked at whether the DASH diet can help reduce the risk of developing hypertension. In 2023, a group of researchers from Greece conducted a systematic review and meta-analysis of 12 observation studies (9 cohort and 3 cross-sectional) investigating adherence to the DASH diet and risk of hypertension. The studies included a total of more than 115,000 people with an average age of 36-61 years. Hypertension was defined as systolic blood pressure (SBP) ≥ 140mmHg and/or diastolic blood pressure (DBP) ≥ 90mmHg or the use of antihypertensive medication.

The researchers found that following a DASH-style diet may help protect against the development of high blood pressure. In a combined analysis of the cohort studies, the risk of developing hypertension was 19% lower in those with high versus low adherence to the diet. Similarly, when the findings of the cross-sectional studies were combined, the odds of hypertension was 20% lower in high versus low adherers to the DASH diet.

The authors of the review conclude that not only does the DASH diet appear to be beneficial for reducing the risk of high blood pressure, but that their findings are also in line with current hypertension guidelines, which recommend that lifestyle modifications should start early, even in people with normal blood pressure, to help to reduce the risk of developing the condition.

The findings are also consistent with recommendations for lifestyle changes recommended by the International Society of Hypertension in their recent (2023) position paper, to prevent or delay the onset of high blood pressure. Among many other lifestyle changes, they recommend following a healthy eating plan including an increased intake of fibre-rich plant foods (including vegetables, fruits, legumes, wholegrains, nuts and seeds), fish, unsaturated fats, low-fat dairy products, and a reduced intake of red meat, salt and added sugars (including sugar-sweetened drinks).

Read more:

• DASH eating plan
• Theodoridis and colleagues. Adherence to the DASH Diet and Risk of Hypertension: A Systematic Review and Meta-Analysis. Nutrients. 2023.
• Evans and colleagues. Glycemic index, glycemic load, and blood pressure: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr. 2017.
• Charchar and colleagues. Lifestyle management of hypertension: International Society of Hypertension position paper endorsed by the World Hypertension League and European Society of Hypertension. J Hypertens. 2024

Dr Kate Marsh is an is an Advanced Accredited Practising Dietitian, Credentialled Diabetes Educator and health and medical writer with a particular interest in plant-based eating and the dietary management of diabetes and polycystic ovary syndrome (PCOS).

Contact: Via her website www.drkatemarsh.com.au