Why is DASH diet still most effective to reduce heart attack risk

According to new research presented at the American Heart Association’s Hypertension Scientific Sessions 2022, (between September 7 and 10) in San Diego, widespread adoption of lifestyle changes, such as limiting heavy alcohol consumption and exercising regularly, may prevent thousands of deaths and save more than one billion dollars in health care costs over the next 10 years. The analysis found that adoption of the DASH diet could have the greatest benefit, with an estimated 15,000 heart disease events prevented among men and 11,000 among women.

What are the stages of hypertension

According to the 2017 joint American Heart Association and American College of Cardiology High Blood Pressure Guideline, stage 1 hypertension is defined as having a systolic (top number) level of 130-139 mm Hg or having a diastolic (bottom number) measure of 80-89 mm Hg. Stage 2 hypertension is defined as systolic measures of 140 mm Hg or higher, or diastolic measures of 90 mm Hg or higher.

Why is dash effective

The DASH eating plan is specifically designed to help manage blood pressure. The diet emphasises eating more fruits, vegetables, lean meat sources, nut, seeds and grains and limiting consumption of red meat, sodium, sugars and sugar-sweetened beverages.

The research team found that 8.8 million adults in the US between the ages of 35 and 64, have untreated stage 1 hypertension and could improve with lifestyle changes, such as physical activity, sustained weight loss, moderating alcohol intake and adoption of the DASH diet.

In the absence of other health conditions, such as Type 2 diabetes or kidney disease, and a predicted >(10%) 10-year cardio-vascular disease risk, people with stage 1 hypertension are considered at low risk of heart attack or stroke compared to people with stage 2 or higher hypertension. So, they are advised to deal with it through lifestyle modification first and not immediate medication.

“Nearly nine million young and middle-aged adults with untreated stage 1 hypertension represent a significant, impending burden for health care systems. Our results provide strong evidence that large-scale, healthy behaviour modifications may prevent future heart disease, related complications and excess health care costs,” Kendra D. Sims, Ph.D., M.P.H., a postdoctoral fellow at the University of California, San Francisco and co-lead researcher of this study was quoted as saying.

Reacting to the study, Dr Sanjay Kumar, Director, Cardiology, Fortis Escorts Hospital, Faridabad, says, “Two of the most studied diet plans with proven cardio-metabolic benefits are Mediterranean and Dash diets. These diet patterns have better long-term effects than selective dietary changes like low fat diets. Newer low carbohydrate ketogenic and paleo diets have faster short-term effects on weight and glycaemic control but in the long run, Dash and Mediterranean diets are more effective.”

What do doctors say about arresting stage 1 hypertension

“We know that DASH diet is extremely important, especially in controlling hypertension — specifically in Stage 1. Why was Stage 1 created? So, before the latest guidelines in 2017, this stage — where BP is between 132/139 and 180/189 — was considered as pre-hypertension or early hypertension. We do not refer to this stage as hypertension because then a very large population would classify as hypertensive. However ultimately people realise that this (their blood pressure) is a problem they need to address. We, doctors, tend to use the term hypertension so that patients become more cautious and adopt treatment, which at this stage consists only of lifestyle modifications and no medicine,” says Dr Nagendra Singh Chauhan, Director, Interventional Cardiology, Heart Institute, Medanta Hospital, Gurugram.

“Lifestyle modifications include exercise and diet — here DASH diet is extremely important. It is considered in the top eight best diets to get hypertension and cardiovascular diseases under control. It is a very simple diet and suggests that we stick to vegetables, protein, dairy, lean meat, nuts, fruits and avoid sweets, sugar, sweetened drinks, carbohydrates, easily digestible carbohydrates, fatty meat and saturated fat. This is a general fact — any diet with sweets and saturated fat is not good and now we are giving equal importance to both components. Additionally, you need to exercise. This again is known but what one needs to understand that in addition to the DASH diet, it will help manage the symptoms of hypertension especially in stage 1 and 2. While it is important even for stage 3 patients, it can prove to be the most effective if adopted in stage 1,” adds Dr Chauhan.

Indians need a composite programme

The bigger question is if Indians can afford a DASH diet. “A DASH diet recommends about eight servings of fruits and salads a day in addition to low fat dietary products. In a family of four, it means consumption of 2 to 3 kg of fruits a day. This is not there in most houses in the country primarily because of economic reasons. So, in a country like ours we should amend dietary patterns and adopt other lifestyle changes like physical activities, meditation and yoga,” says Dr Kumar.

Dr Chauhan echoes this viewpoint. “We need a structured programme to control hypertension in India, which involves public and private stakeholders, a condition which is most common in India where people under 35 and 40 are reporting it. We should inculcate the habits of eating a healthy diet in early childhood so that they don’t have issues of hypertension later,” he adds.