Two decades ago, the DASH (Dietary Approaches to Stop Hypertension) study tested the effects of three different diets on almost 500 participants over eight weeks. The first diet was a typical American diet, relatively low in fruits and vegetables (3.5 servings daily) and high in junk foods and sweets. The second offered more fruits and vegetables (8.5 servings daily) as well as seeds, nuts, and beans, and not many sweets. The third was the very healthy DASH diet, rich in fruits and vegetables (9.5 servings daily), beans, nuts, seeds, and whole grains, and barely any sweets.
Participants truly stuck to each diet plan: All meals were provided by the researchers, with one meal per day eaten at the study center and the rest provided in coolers for take-home. All diets had the same amount of sodium (salt) and calories.
What did the original DASH study find?
After only two weeks, both the more-fruits-and-vegetables diet and the DASH diet significantly lowered blood pressure. This healthy blood pressure effect lasted for the whole eight-week study. Most importantly, it didn’t occur due to any differences in sodium intake or weight loss among the participants in all three diet groups.
Further, the study highlighted a remarkable effect on participants following the DASH diet. Among those with a diagnosis of high blood pressure, systolic blood pressure (the top number) dropped by 11.4 points, and diastolic blood pressure (the lower number) by 5.5 points. Basically, the DASH diet was more effective than a lot of blood pressure medications. Who wants to take a pill when you can simply eat healthier, which will provide plenty of other benefits? For example, diets higher in fruits and vegetables are associated with lower risk for all sorts of cardiovascular disease, like heart attacks and strokes.
What does the new data tell us about heart benefits?
Researchers eager to learn more about the heart benefits recently took a second look at data collected in the original study. Using blood samples from the original study participants in all three diet groups, they ran newer tests that can detect levels of heart strain, heart muscle injury, and total body inflammation. They found that both the more-fruits-and-vegetables diet and the DASH diet significantly lowered levels of heart strain and heart muscle injury, after just eight weeks. Total body inflammation levels were not significantly different, but scientists hypothesize that inflammation — which is linked to weight — would decrease with ongoing healthy eating and the inevitable weight loss that follows. This has been shown in many other studies.
The benefits of eating even slightly more fruits and vegetables can be seen in as little as two to eight weeks: significantly lower blood pressure, a measurably lower strain on the heart, and decreased heart muscle damage. Here is an important point: You can’t see these changes with your eyes. Blood pressure measurements and blood tests that find markers of heart strain and damage can show invisible changes critically important to our health, that can later lead to a heart attack, aortic aneurysm, stroke, peripheral artery disease, even dementia. A healthy cardiovascular system, the network of arteries connected to our hearts, keeps our bodies functioning well.
What it is not about: The numbers on the scale. The overall goal of a healthy diet should not be only about weight loss. If it is, then all of the other benefits are missed. A healthy diet and lifestyle will lead to healthy weight loss, which is great, but if that’s the only goal, then folks end up disappointed and disillusioned. Focus instead on eating healthy to be healthy, and take the focus off of the scale.