Eating a handful of walnuts a day may lower your blood pressure, reduce weight gain and in turn reduce the risk of diabetes and heart disease, a new study finds.
Scientists at the University of Minnesota have uncovered the nuts’ miraculous potential benefits after tracking the diets of 3,300 people for more than 25 years and undergoing various health checks.
Walnuts are the only nuts that contain Omega-3 alpha-linolenic acid (ALA), which may explain the benefits, according to the scientists. The fatty acid has previously been linked to improved heart health. However, they say more studies are needed to confirm the findings.
Previous research has linked walnuts to lowering blood pressure and suggested they prevent diabetes and heart disease. However, these results have yet to be supported by a rigorous clinical trial.
University of Minnesota scientists suggested that walnuts lower blood pressure because they contain Omega-3 (stock image)
In the study — published Wednesday in the journal Nutrition, Metabolism and Cardiovascular Diseases — the scientists analyzed data from 3,341 Americans who were about 45 years old.
Participants had participated in the Coronary Artery Risk Development in Young Adults (CARDIA) study at the University of Alabama between 1985 and 2015.
They were initially interviewed about their diet and followed the study in Years 7, 20, and 25.
What is high blood pressure? What are the risks?
High blood pressure or hypertension rarely has noticeable symptoms. But if left untreated, it increases your risk of serious problems such as heart attacks and strokes.
The only way to find out if your blood pressure is high is to have your blood pressure checked.
Blood pressure is recorded with two numbers. The systolic pressure (higher number) is the force with which your heart pumps blood around your body.
The diastolic pressure (lower number) is the resistance to blood flow in the arteries. They are both measured in millimeters of mercury (mmHg).
If your blood pressure is too high, it puts extra strain on your blood vessels, heart and other organs, such as the brain, kidneys and eyes.
Persistent high blood pressure can increase your risk for a number of serious and potentially life-threatening conditions, such as:
- heart disease
- heart attacks
- to succeed
- heart failure
- peripheral arterial disease
- aortic aneurysms
- kidney disease
- vascular dementia
Of those involved, the 340 people who ate walnuts ate an average of about 19 grams per day — the equivalent of seven walnut kernels.
These people were more often female, white and highly educated.
At the age of 20, they were invited for a health check that measured their BMI, their activity level and blood pressure.
The results showed that those in the walnut-eating group had lower blood pressure than those who did not eat nuts.
Blood pressure readings are shown as two numbers, as the systolic pressure — or pressure on artery walls when the heart beats — and diastolic pressure — or pressure on artery walls between beats.
Among those who did not eat walnuts, their blood pressure score was 117.2/73.6 millimeters of mercury (mmHg).
But for those who did eat the nuts, it was 116/71 mmHg.
The scientists said that diastolic blood pressure, or second digit, was significantly lower in people who ate walnuts.
But neither figure fell into the unhealthy range, which is anything above 120/80 mmHg, according to the Centers for Disease Control and Prevention (CDC).
About 20 percent of the walnut eaters in the study had high blood pressure, compared with 22 percent of those who didn’t eat them.
The scientists also suggested that walnuts led to lower weight gain and a better quality diet.
They found that those who didn’t eat nuts had a BMI of 29.7, putting them at the top of the overweight range, and 39 percent were obese.
But among those who had walnuts, BMI was barely lower at 29, while 35 percent were obese.
Those who ate the nuts also had higher newspaper activity scores than those who didn’t.
Scientists also claimed that walnut eaters had significantly lower fasting glucose levels, a better risk profile for cardiovascular disease and a better quality diet.
So-Yun Yi, a public health doctoral student at the university who was involved in the study, said the study supported claims that walnuts are “part of a healthy diet.”
“Interestingly, walnut consumers had a better cardiovascular disease risk factor profile, such as a lower body mass index … compared to other nut consumers,” they said.
The scientists said that walnuts may help the heart because they are the only nut that has Omega-3, which has been linked to heart benefits.
They also contain a variety of other nutrients, including protein, fiber, and magnesium, which may also support heart health.
But researchers added that their results were observational and clinical trials needed to be conducted to confirm the results.
It was not clear whether other nuts had an impact, as walnut eaters generally ate more nuts than those who did not consume them.