Blueberries have been championed for their high antioxidant potential and anti-inflammatory properties. They are recognized as a good source of flavonoids, especially anthocyanins, which have strong antioxidative activity, some of which have antioxidant activity shown in laboratory studies. Research shows they can reduce both systolic and diastolic blood pressure and potentially better than pharmaceuticals.
The blood pressure relief comes from pterostilbene, a compound found in both grapes and blueberries. This antioxidant is chemically related to reservatrol, another heart-healthy compound that is found in the skin of grapes. Various studies have shown pterostilbene to have possible anti-cancer and anti-diabetes properties.
A growing body of research is also establishing blueberries as a potential ally to protect against diseases such heart disease and Alzheimer’s — so it’s no surprise that more and more people are picking blueberries than ever before!
Blood Pressure Benefits
Eight weeks of consuming a daily dose of 22 grams of freeze-dried blueberry powder resulted in 5.1% and 6.3% reductions in systolic and diastolic blood pressure, wrote the researchers in the Journal of the Academy of Nutrition and Dietetics.
“The potential is enormous,” said Dr. Anais Archambeault commenting on the study. “Many patients on antihypertensives experience less than a 5% decrease in overall blood pressure and here we clearly have a natural product that may eventually outperform well known drugs,” she said.
Dr. Archambeault claims that with the right nutriceutical prescription, blueberry powder in combination with other antioxidants may prove very effective for patients who don’t react well or benefit from blood pressure medication.
The benefits were also linked to an increase in levels of nitric oxide (NO), which were found to increase from 9.11 to 15.35 micromoles over the course of the study. NO is a potent vasodilator, helping to relax the walls of blood vessels and lower blood pressure.
“To our knowledge, this is the first study to evaluate the effects of blueberries on arterial function as was done in this study, as well as in this study population,” said corresponding author Bahram Arjmandi, PhD. “These findings suggest that blueberries may prevent the progression to full-blown hypertension.”
“Considering the prevalence of hypertension in the US, preventive strategies such as dietary modifications (e.g. functional foods and dietary supplements) that aim to improve hypertension and its related complications are warranted.”
Growing Interest Based on Research
“Compelling” data published in the American Journal of Clinical Nutrition indicated that blueberry flavonoids could boost endothelial function and enhance heart health.
Endothelial dysfunction may play an important role in the increases in blood pressure that occur after menopause. Further, endothelial dysfunction is known to increase arterial stiffness, which is involved in the development and progression of both hypertension and cardiovascular disease.
The exact way in which flavonoids affect the brain are unknown, but they have previously been shown to cross the blood brain barrier after dietary intake.
An acute dose of blueberries (300 grams) was found to be associated with an 18% decrease in DNA damage to blood cells due to oxidative stress, according to findings published in Nutrition Research.
A study appearing in ACS’ Journal of Agricultural and Food Chemistry, found that that although there are over 600 species of blueberries and blueberry-like fruits growing in Mexico, Central and South America, two types of neotropical blueberries were extreme super fruits — they had significantly more antioxidants than a type of blueberry commonly sold in U.S. supermarkets stores. The researchers say that these neotropical blueberries “have the potential to be even more highly promising edible fruits.”
The Florida State researchers recruited 48 women to participate in their eight-week, randomized, double-blind, placebo-controlled clinical trial. Participants were randomly assigned to receive either 22 grams per day of freeze-dried blueberry powder or 22 grams of a control powder for eight weeks. This dose was equivalent to one cup of fresh blueberries.
The data showed that the blueberry powder was associated with significant reductions in systolic and diastolic blood pressure.
“The changes in blood pressure noted in this study are of clinical significance as they demonstrate that blood pressure can be favorably altered by the addition of a single dietary component (e.g. blueberries),” said lead author Sarah Johnson, PhD.
In addition, improvements in brachial-ankle pulse wave velocity were also reported. Pulse wave velocity is a non-invasive method for assessing arterial stiffness and has been shown to predict future cardiovascular events. In the current study, brachial ankle pulse wave velocity (baPWV), which is a composite measure of central (aortic) and peripheral arterial stiffness, was significantly reduced after eight weeks in the blueberry-treated group, whereas there were no changes in the control group.
On the other hand, carotid-femoral pulse wave velocity (cfPWV), the best measure of aortic stiffness, did not change in either group. This suggests that peripheral arteries may be more responsive to dietary interventions than central arteries.
“This [study] suggests that regular consumption of blueberries over the long term could potentially delay the progression of hypertension and reduce cardiovascular risk in postmenopausal women,” concluded the researchers.
The study was supported by the US Highbush Blueberry Council and the US Department of Agriculture.