New research shows that eating a handful of walnuts a day can lower blood pressure, reduce weight gain, and thus reduce the risk of diabetes and heart disease.
Researchers at the University of Minnesota discovered the miraculous potential benefits of nuts after monitoring the diets of 3,300 people for over 25 years and conducting several follow-up studies.
Walnuts are the only nuts that contain omega-3 alpha-linolenic acid (ALA) that scientists believe may explain the benefits. Fatty acid has previously been linked to improved heart health. However, they say more research is needed to confirm the results.
Earlier research has linked walnuts to lower blood pressure and suggested it prevented diabetes and heart disease. However, these results have not yet been supported by rigorous clinical research.
Researchers at the University of Minnesota suggested that walnuts lower blood pressure because they contain omega-3 fatty acids (stock photo)
In the study – published Wednesday in the journal Nutrition, Metabolism and Cardiovascular Diseases – researchers analyzed data from 3,341 Americans around the age of 45.
Participants took part in the Coronary Artery Risk Development in Young Adults (CARDIA) study conducted by the University of Alabama in 1985-2015.
They were initially interviewed about their diet and continued in the seventh, twentieth, and twenty-fifth years of the study.
What is high blood pressure? What are the risks?
High blood pressure or hypertension is rarely noticeable. But if left untreated, it increases the risk of serious problems like heart attacks and strokes.
The only way to find out if you have high blood pressure is to have your blood pressure checked.
Blood pressure is recorded with two numbers. Systolic pressure (the higher number) is the force with which your heart pumps blood throughout your body.
Diastolic pressure (lower number) is the resistance to blood flow in the blood vessels. Both are measured in millimeters of mercury (mmHg).
Too high blood pressure puts additional strain on the blood vessels, heart and other organs such as the brain, kidneys and eyes.
Persistent high blood pressure can increase the risk of a range of serious and potentially life-threatening conditions, such as:
- heart disease
- heart attacks
- heart failure
- peripheral arterial disease
- aortic aneurysms
- kidney disease
- vascular dementia
Of the 340 people involved, who ate walnuts, on average consumed about 0.6 ounces (19 grams) a day – the equivalent of seven walnuts.
These people were more often women, white and well-educated.
At the age of 20, they were invited back for a health check where their BMI, activity levels and blood pressure were measured.
The results showed that those in the group who ate walnuts had lower blood pressure than those who did not eat them.
Blood pressure measurements are shown as two numbers, either the systolic pressure – or the pressure on the artery walls when the heart beats – and the diastolic pressure – or the pressure on the artery walls between beats.
Among those who did not eat walnuts, their blood pressure was 117.2 / 73.6 millimeters of mercury (mmHg).
But for those who ate nuts, it was 116/71 mmHg.
The researchers found that diastolic blood pressure, the second digit, was significantly lower in people who ate walnuts.
But none of the numbers fell within the unhealthy range, which is higher than 120/80 mmHg, according to the Centers for Disease Control and Prevention (CDC).
About 20 percent of the people who ate walnuts in the study had high blood pressure, compared to 22 percent of those who didn’t.
The researchers also suggested that walnuts lead to less weight gain and a better-quality diet.
They found that those who did not eat nuts had a BMI of 29.7, which puts them at the upper limit of overweight, with 39 percent obese.
But among those who had walnuts, the BMI was barely lower at 29, while 35 percent were obese.
Those who ate nuts also had a higher newspaper activity score than those who did not.
The researchers also said that walnut eaters had significantly lower fasting glucose levels, a better heart disease risk profile, and a higher-quality diet.
So-Yun Yi, a PhD student in public health at the university who was involved in the research, said the study supports claims that walnuts are “part of a healthy diet.”
“Interestingly, walnut consumers had a better profile of risk factors for cardiovascular disease, such as a lower body mass index … compared to other nut consumers,” they said.
Scientists have concluded that walnuts can help the heart because they are the only nuts that contain Omega-3 fatty acids, which has been linked to heart benefits.
They also contain many other nutrients, including protein, fiber, and magnesium, which can also support heart health.
But the researchers added that their results were observational and that clinical trials should be conducted to confirm the results.
It was unclear if other nuts had an effect on this, as nut eaters generally consumed more nuts compared to those who did not.