What are the Health Benefits of the DASH Diet?
A cardiologist breaks down how following DASH — Dietary Approaches to Stop Hypertension — can help lower blood pressure.
Nearly half of adults in the United States have high blood pressure, also known as hypertension, according Centers for Disease Control and Prevention. High blood pressure raises the risk for heart disease and stroke, leading causes of death in the U.S. But did you know that there’s a specific diet plan that can lower blood pressure and reduce the risk of these conditions?
“I think most people know salt is a problem for blood pressure, but most people do not know about the DASH diet plan,” says Dr. Sean Mendez, a cardiologist at NewYork-Presbyterian Brooklyn Methodist Hospital.
The DASH Eating Plan is short for Dietary Approaches to Stop Hypertension. High in vegetables, fruits and whole grains, the diet also includes fat-free or low-fat dairy products, fish, poultry, beans, nuts and vegetable oils, and limits food high in saturated fat and sugar-sweetened beverages and sweets.
“Early stages of hypertension are still associated with negative outcomes, including for the heart and kidneys, and raises stroke and dementia risk,” says Dr. Mendez, who is also an assistant professor clinical medicine at Weill Cornell Medicine. “Even a little elevation in blood pressure is something that people need to be aware of and do something to address. The DASH diet plan is proven to help address hypertension.”
The Science Behind the DASH Diet
Researchers first investigated the DASH diet plan in 1997 in a clinical trial published in New England Journal of Medicine that enrolled 459 adults with high blood pressure to assess the effects of dietary patterns on blood pressure.
“By that time, we had kind of known salt is the enemy of anybody with high blood pressure,” says Dr. Mendez. “And so most diets and interventions focused on lowering salt. But these researchers said, “What if rather than counting salt or lack of salt, we focus on a diet high in fruits, vegetables and whole grains?”
For three weeks, all participants were fed a control diet low in fruit, vegetables and dairy products, with a fat content typical of the average diet in the U.S. They were then randomly assigned to two different diets: a control diet rich in fruits and vegetables, or a “combination” diet rich in fruits and vegetables with the addition of low-fat dairy products and with reduced saturated and total fat. While both diets reduced the participants’ blood pressure, the “combination” diet – the DASH diet – reduced it significantly more.
“They found that even without counting salt, people had lower blood pressure following that DASH-style diet plan,” says Dr. Mendez.
In the ensuing decades, study after study has backed up the DASH diet’s ability to lower blood pressure.
DASH Diet Plan-Friendly Foods
- Vegetables such as broccoli, collards, green peas, and sweet potatoes – all rich in potassium, fiber and magnesium.
- Fruits such as oranges, grapefruit, mangos, melon, which are full of minerals and nutrients.
- Grains, such as whole wheat bread and pasta and brown rice, and more.
- Nuts and seeds, such as almonds, peanuts, lentils, or sunflower seeds.
The Nutrients that Lower Blood Pressure in the DASH Diet
What makes the DASH Diet unique is its focus on nutrient-rich foods that naturally support healthy blood pressure. Fruits and vegetables tend to be high in potassium, an essential mineral needed by tissues in the body that helps maintain normal levels of fluid inside our cells, reduces the effects of sodium, and improves blood pressure.
“Potassium plays an important role in the regulation of vascular tone, or how tight your blood vessels are,” says Dr. Mendez. “On a cellular level, potassium seems to have positive effects in regulating blood pressure.”
Magnesium, a nutrient found in dark leafy greens, seeds, beans and nuts, and calcium, also plays a role in regulating blood pressure, as does calcium, a mineral often found in dairy products that is also responsible for building and maintaining strong bones.
“The fruits and vegetables are rich in nutrients associated with lowering blood pressure, and the calcium in dairy seems to add that extra difference,” says Dr. Mendez.
It also helps that these foods are low in salt, which can cause the body to retain fluid and has long been known to raise blood pressure. “Overall, these foods are much lower in salt than the average American diet,” says Dr. Mendez.
Though the DASH diet specifically benefits patients with high blood pressure who are looking to lower it, a lot of its principles – more fruits and vegetables, less processed foods – can be good for everyone. “But especially once you have hypertension, it’s time to make those changes for the long-term benefits,” says Dr. Mendez. Even if you need to be on blood pressure medication, following the diet may reduce how much medication you need to take, he says.
How to Adopt the DASH Diet
Make Small Changes: If you’re looking to change your diet, Dr. Mendez recommends starting small. “I find that it’s making smaller changes first rather than all of the sudden go from eating fast food every day to five servings of fruits and vegetables each day,” he says. His advice: try swapping a less nutritious snack with an apple or banana to start, and then gradually improve other areas of your diet, one thing at a time.
Write it Down: Dr. Mendez suggests keeping a food and exercise diary to help keep track of your habits. “You can see where your gaps are and it’s enlightening,” he says.
Shop the Perimeter of the Grocery Store: Stick to the outer edges of the store when food shopping, which helps encourage more whole foods, since processed foods are mostly found in the aisles. Foods that Dr. Mendez enjoys that follow the DASH diet plan include oatmeal with banana, berries, apples, and carrots. “And then low-fat Greek yogurt I find is a good way to get that dairy supplement.”
Other Ways to Manage Blood Pressure
In addition to the DASH diet plan, there is a lot you can do to keep your blood pressure under control, says Dr. Mendez, including losing weight, watching alcohol consumption, increasing physical activity and reducing salt intake. He also encourages patients to monitor their blood pressure between doctors’ appointments.
“For blood pressure especially, it’s something that patients can take control of, for example by monitoring blood pressure at home in a relaxed setting, rather than just at the doctor after you’ve sprinted from the subway,” he says. “That way you’re really knowing what’s going on rather than waiting a few months between doctors’ visits.”
It’s also important to remember that sometimes blood pressure can be hereditary, and the DASH diet will help even if a patient also needs medication to manage it. “Some people feel that it’s a failure on their part if they have to take medication,” says Dr. Mendez. “But some things are hereditary and beyond our control. Maybe you can’t get exactly to where you want to be, but you’re still giving yourself a lot of benefit by trying the DASH diet and other lifestyle modifications.”
Additional Resources
- Learn more about cardiovascular health at NewYork-Presbyterian.