High-Flavanol Diet Linked To Lower Blood Pressure
Eating lots of foods with flavanols - antioxidants found in certain fruits, veggies, tea, and cocoa - may be good for your blood pressure, according to a study published in October 2020 in Scientific Reports.
The researchers examined blood pressure data and results from urine tests in order to identify biomarkers (a substance that determines how much flavanol is present in the diet ) for over 25,000 people in the U.K.
Systolic Blood Pressure - which is the number that indicates how much blood pressure exerts upon artery walls during heartbeats - was approximately 1.9 millimeters lower for men than it was for women who consume the most flavanol. It was 2.5 mmHG higher in women who had the highest intake of flavanol, and about 2.5 mmHG less in men.
The study found that blood pressure differences associated with high-flavanol eating were greater in elderly people and with those diagnosed with hypertension, than they are in younger adults or in individuals with normal blood pressure.
"Our study shows for the first time that flavanols consumed as part of the normal diet are associated with lower blood pressure," says senior study author Gunter Kuhnle of the department of food and nutritional sciences at the University of Reading in the U.K.
The Pros and Con of the Study Design These cases often lead to people reporting healthier eating habits than what they actually have.
Biomarkers are a better option than self-reported diet information because the flavanols content in food and drink may vary. The researchers note that tea can have anywhere from 10 to 325 mgs (mg), flavanols per 100 grams (g).
Kuhnle states that using nutritional biomarkers for estimating the intake of bioactive foods compounds is long considered the best method to conduct research because it permits objective measurement.
One of the biggest limitations of this study is that the results of the U.K. study - which is where tea is the primary source of dietary fluvanols- might not be representative of what could happen in other countries where people prefer different food and beverages.
Another limitation of the research is that they only looked at urine testing for flavanol intake in one point in time. This means that it could be possible for eating habits to change over time that may impact blood pressure or risk for cardiovascular disease, researchers note.
The study was also funded by Mars Inc. candymaker, where the two authors are employed.
According to a June 2018 review in Molecular Aspects of Medicine, other studies that have looked at flavanols and blood pressure also found they may reduce stiffness and cholesterol in the arteries. Particularly, the review found that flavanols from cocoa and tea had these benefits for heart health.
Kuhnle claims that blood pressure drops with flavanols are comparable to those seen in earlier studies with diets such as the Mediterranean and Dietary Approaches to Stop Hypertension.
The Mayo Clinic states that a Mediterranean diet includes consuming fruits, vegetables and whole grains as well nuts and olive oil. The Mayo Clinic recommends that dairy should be consumed in moderation and red meats and processed meats limited. DASH is a diet that limits sodium intake. It recommends different food servings each week and limits the amount of salt consumed.
A 2013 study published in BMC Medicine found that a Mediterranean diet decreased diastolic (or bottom number) blood pressure by 1.5mmHg. This is the pressure the blood exerts when it rests between beats. However, this trial did not find any connection between Mediterranean diet and systolic pressure.
A study from the New England Journal of Medicine found that people who tried to reduce their sodium intake to the lowest possible level, followed a DASH diet, had a lower systolic pressure than those who ate in any other way. This was 11.5 mmHg higher for hypertension patients and 7.1 mmHg for non-hypertensive people. People tried to decrease sodium intake by decreasing it from extreme levels to moderate levels. The DASH diet resulted in a 2.1 mmHg reduction in systolic body pressure.
Deepak Bhatt MD, MPH is the executive director for interventional cardiovascular programs at Brigham and Women's Hospital Heart & Vascular Center and a Harvard Medical School professor. "A sustained 2 mmHg decrease in blood pressure would have a significant benefit to a population-level benefit – so from a health perspective, this number is meaningful."
"However for an individual that would not be the same as what many people experience with salt restriction, specifically the Mediterranean and DASH diets," Dr. Bhatt says. He wasn't part of the Flavanol Study.
How Flavanol rich foods can lower blood pressure. Flavanols make up a part of a vast array of compounds in plant foods, including fruits, vegetables and beans.
Heller stated that foods contain these compounds, which have been proven to offer many health benefits. These include lowering the risk of some diseases, such as heart disease and metabolic syndrome. They act as strong antioxidants and anti-inflammatory agent."
Heller suggests that unprocessed teas and coffees without added sugar or cream are the best options to get flavanols. This holds true especially for chocolate and cocoa.
Heller suggests that people who wish to lower blood pressure through diet should consider increasing their intake of flavonols.
Heller says that we all eat food, but not only single nutrients. Therefore, it's crucial to understand how our eating habits impact our ability to absorb flavanols as well as other plant compounds. Adopting the DASH/Mediterranean dietary plan is an excellent way to boost one's intakes of flavanols, fiber, vitamins and minerals. This can also help lower blood pressure and reduce the chance of developing other chronic diseases.