With all due respect to the apple, the fruit most likely to keep the doctor away appears to be the blueberry—at least, when it comes to brain health and blood pressure.

A new randomized, double-blind, placebo-controlled study published in the American Journal of Clinical Nutrition found that people eating the equivalent of about two handfuls of wild blueberries daily (or about 75 to 80 blueberries, depending on the size) were better at word recall and also had healthier blood pressure readings than those who did not partake in a blueberry binge.

The study out of King's College London in the United Kingdom showed blueberries—and particularly the antioxidant-rich flavonoids (called anthocyanins) they contain—can help boost brain power and encourage better heart health through artery and blood vessel support.

The boost of blueberries

The King's College London study was a double-blind, parallel randomized controlled trial on 61 healthy older adults. Participants were given 26 grams of freeze-dried wild blueberry powder (containing 302 mg anthocyanins) or a matched placebo powder with no anthocyanins every day for 12 weeks.

The researchers measured endothelial function, cognition, arterial stiffness, blood pressure and other factors at baseline when the study began and again after 12 weeks. They found daily intake of wild blueberry powder (equivalent to 178 grams fresh blueberries) improved performance on cognitive tasks and improved endothelial function and blood pressure compared with the placebo powder without anthocyanins.

Specifically, the study found:

• A significant increase in flow-mediated dilation (FMD) and reduction in 24-hour ambulatory systolic blood pressure
• Enhanced immediate recall on verbal learning tasks
• Better accuracy on a task-switching task

Can blueberries lower your blood pressure?

Most experts agree anthocyanins can help improve cardiovascular disease risk factors, such as hypertension, by supporting artery and blood vessel function. The King's College study suggests that when taken in sufficient amounts (and for a sufficient amount of time), the anthocyanins in blueberries can lower blood pressure.

A few caveats: the decrease was small, meaning someone with clinically high blood pressure (hypertension) cannot rely on blueberries to manage their blood pressure. And, some previous reviews found that blueberries' effects on blood pressure were modest, inconsistent or nonexistent, but it's possible the participants weren't getting enough anthocyanins in those studies. Either way, blueberries are definitely a good addition to your daily diet if your goal is prevention.

How many blueberries should you eat a day to lower blood pressure?

It would be great if we could rely on a blueberry smoothie every day to alleviate high blood pressure or hypertension. But the science shows you should not try to manage clinically high blood pressure with blueberries alone—although adding more of these fruits to your diet certainly can't hurt!

What about those of us who have blood pressure within normal bounds…and want to keep it that way, or nudge it down a bit more? The King's College London study used freeze-dried blueberry powder equivalent to 178 g of fresh blueberries on a daily basis to get its blood pressure results.

Considering the serving size for blueberries is a half-cup to 1 cup of fruit (or 75-150 g), this is about two servings each day—which is a lot of fruit and could get expensive. Other fruits and plants have anthocyanins as well, so you can get blood pressure benefits from elderberries, aronia berries, plums, blood oranges, cherries, pomegranates, red cabbage, purple corn and the like. Generally speaking, if it is a purplish-blueish-reddish fruit or plant, it probably has anthocyanins and may benefit your blood vessel health.

How to incorporate blueberries into your diet

Blueberries are a delicious and versatile fruit—and not just in a blueberry drink like a smoothie. They are great in pancakes, muffins, bagels and other pastries. These berries are also great on top of oatmeal, cereal or yogurt, added to a green salad or eaten raw (after a good washing, of course). Combining this fruit with other heart-healthy foods, such as leafy greens and yogurt, is also a good way to magnify its blood pressure-lowering benefits.

Other health benefits of blueberries

Studies associate daily blueberry consumption with a wealth of health benefits, such as reduced risk of type 2 diabetes and cardiovascular disease. Human trials also show the antioxidant anthocyanins in berries offer protection against free radicals, and those phytochemicals may also have anti-inflammatory effects.

In addition to being a tasty way to help people better manage their weight, blueberries help support blood vessel function and healthy blood sugar management. They help the beneficial microflora in your gut to flourish—which contributes to overall well-being—and may help protect against aging and degenerative diseases like Alzheimer's.

As more studies are done, we're sure to find even more blueberry benefits. So dig in and enjoy the sweet taste of this health booster.

References

• Curtis, P.J. et al. "Blueberries Improve Biomarkers of Cardiometabolic Function in Participants with Metabolic Syndrome: Results from a 6-Month, Double-Blind, Randomized Controlled Trial." Am J Clin Nutr. June 2019.https://pubmed.ncbi.nlm.nih.gov/31136659/
• de Oliveira, M.S. et al. "Blueberry Consumption and Changes in Obesity and Diabetes Mellitus Outcomes: A Systematic Review." Metabolites. December 2022. https://pubmed.ncbi.nlm.nih.gov/36676944/
• Kalt, W. et al. "Recent Research on the Health Benefits of Blueberries and Their Anthocyanins." Adv Nutr. March 2020. https://pubmed.ncbi.nlm.nih.gov/31329250/
• Khoo, H.E. et al. "Anthocyanidins and Anthocyanins: Colored Pigments as Food, Pharmaceutical Ingredients, and the Potential Health Benefits." Food Nutr Res. August 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613902/
• Miller, K. et al. "Bioactive Compounds of Strawberry and Blueberry and Their Potential Health Effects Based on Human Intervention Studies: A Brief Overview." Nutrients. July 2019. https://pubmed.ncbi.nlm.nih.gov/31269727/
• Vendrame, S. et al. "The Role of Berry Consumption on Blood Pressure Regulation and Hypertension: An Overview of the Clinical Evidence." Nutrients. June 2022. https://pubmed.ncbi.nlm.nih.gov/35807881/
• Wood, E. et al. "Blueberries and Cardiovascular Disease Prevention." Food Funct. December 2019. https://pubmed.ncbi.nlm.nih.gov/31776541/
• Wood, E. et al. "Wild Blueberry (Poly)phenols Can Improve Vascular Function and Cognitive Performance in Healthy Older Individuals: A Double-Blind Randomized Controlled Trial." The American Journal of Clinical Nutrition. March 2023. https://ajcn.nutrition.org/article/S0002-9165(23)46300-9/fulltext
• Zhu, Y. et al. "Effects of Blueberry Supplementation on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Clinical Trials." J Hum Hypertens. March 2017. https://pubmed.ncbi.nlm.nih.gov/27654329/
• "A Daily Dose of Blueberries Could Improve Brain and Heart Health." Medical News Today. https://www.medicalnewstoday.com/articles/a-daily-dose-of-blueberries-could-improve-cognitive-and-cardiovascular-health 
• "5 Health Benefits of Anthocyanins." Cleveland Clinic. June 2022. https://health.clevelandclinic.org/anthocyanins/

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