Eating foods rich in flavanols, such as tea and cocoa, can help lower blood pressure, even in people with hypertension.
Eat plenty of foods containing flavanols, antioxidants found in some fruits, vegetables, tea and cocoa, may benefit your blood pressure, according to a study published in October 2020 in Scientific Reports.
Researchers reviewed blood pressure and cardiovascular disease data along with urine test results, looking for biomarkers of flavan-3-ol, a substance that indicates the amount of flavanol in the diet, for more than 24 000 adults in the UK.
Systolic blood pressure, the “highest number”, which indicates the pressure exerted by the blood on the walls of the arteries when the heart beats, was lower by about 1.9 mi llimeter of mercury (mmHG) in men and around 2.5 mmHG in women with the highest flavan-3-ol intake compared to their counterparts with the lowest flavan-3-ol intake. The study also found that blood pressure differences associated with a high-flavanol diet were more pronounced in older adults and people diagnosed with hypertension than in younger individuals and those with normal blood pressure. .
This study shows for the first time that flavanols consumed as part of a normal diet are associated with lower blood pressure.
Advantages and disadvantages of this study design
One of the advantages of this study is that it used urine tests to estimate the amount of flavonal that people had in their diet. Many other studies looking at the health benefits of various eating habits instead rely on food diaries or surveys that don’t always give an accurate picture of how people actually eat. In these cases, people often report healthier eating habits than they actually have.
Another advantage of using biomarkers instead of self-reported dietary information is that the amount of flavanols in a particular food or drink can vary. For example, there can be between 10 and 330 milligrams (mg) of flavanols in 100 grams (g) of tea.
The main limitation of the study is that the results of this study conducted in the United Kingdom – where tea is the main source of dietary flavanols – may not reflect what would happen in other populations where people tend to favor different foods and beverages.
Another limitation is that the researchers only looked at urine tests for flavanol consumption at one time point in time, and it’s possible that eating habits have changed over time in ways that could impact blood pressure or cardiovascular disease risk, the researchers point out.
What other studies say about flavanols, diet and blood pressure
Previous studies found that flavanols may help reduce artery stiffness, cholesterol, blood pressure, and the risk of developing or dying from cardiovascular disease, according to a review published in June 2018 in Molecular Aspects of Medicine. This review notably established a link between the flavanols present in cocoa and tea and these benefits for heart health. The reduction in blood pressure seen with flavanols in the current study is comparable to what some previous research has found with two heart-healthy diets, the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet.
The Mediterranean diet emphasizes the consumption of fruits, vegetables, whole grains, fish, nuts, olive oil and other healthy fats. He also advises consuming dairy products in moderation and limiting red and processed meats. The DASH diet takes these ideas further, recommending the number of servings per week for different foods and limiting sodium intake.
A study, published in 2013 in BMC Medicine, found that following a Mediterranean diet reduced diastolic blood pressure, the “bottom number,” which indicates the pressure the blood puts on the artery walls when the heart rests between beats, 1.5 mmHg. This study, however, did not find a link between the Mediterranean diet and systolic blood pressure.
An older study, published in the New England Journal of Medicine, found that when people tried to reduce their sodium intake to the lowest possible level, the DASH diet reduced systolic blood pressure more than other types of diet, from 11,5 mmHg more for people with hypertension and 7.1 mmHg more for people without hypertension. When people tried to reduce their sodium intake from a high to an intermediate level, the DASH diet reduced systolic blood pressure by 2.1 mmHg.
A sustained reduction of 2 mmHg of blood pressure would have a great benefit at the population level. So, from a public health perspective, that’s a significant number.
Which flavanol-rich foods are best for lowering blood pressure?
Flavanols are part of a large family of compounds found in plants such as fruits, vegetables, beans, grains and nuts. In food, these compounds confer many health benefits, including reducing the risk of certain diseases such as cardiovascular disease, metabolic syndrome and certain cancers. They act as powerful antioxidants and anti-inflammatory agents.
To reap the benefits of flavanols from sources such as cocoa and tea, it is best to consume unprocessed forms, without much added sugar, cream and other additives, advises Heller. This is especially true for cocoa and chocolate. People who want to use diet to lower blood pressure should consider increasing flavanol intake as part of a healthy diet.
Biomarker-estimated flavan-3-ol intake is associated with lower blood pressure in cross-sectional analysis in EPIC Norfolk
Recommending flavanols and procyanidins for cardiovascular health: Revisited
Effect of the Mediterranean diet on blood pressure in the PREDIMED trial: results from a randomized controlled trial
Effects on Blood Pressure of Reduced Dietary Sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet
Presse Santé strives to transmit health knowledge in a language accessible to all. In NO CASE, the information given can not replace the advice of a health professional.
Do you like our content?
Receive our latest publications every day for free and directly in your mailbox