Wild Blueberries for High Blood Pressure

Overseen By Brett J Wong, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Georgia State University

Must not be taking: Insulin, Antibiotics, Anti-inflammatories, others

Disqualifiers: Cancer, Cardiovascular, Neurological, others

Compensation: Varies

Number of Visits: 5

Duration: 8 weeks

80 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how eating wild blueberries might benefit people with high blood pressure. Researchers aim to determine if these berries can enhance heart health, brain function, and gut health. Participants will consume either a blueberry powder or a placebo powder daily. Individuals with high blood pressure for at least six months who do not smoke or drink heavily may be suitable for this study. As an unphased trial, this study provides a unique opportunity to contribute to groundbreaking research on natural health solutions.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are using more than one blood pressure medication, insulin, antibiotics, or anti-inflammatory drugs.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that wild blueberries are generally safe to eat. Studies have not found any major negative effects from consuming them. In one study, participants ate wild blueberries for a few months without significant adverse reactions. Another study also found no major side effects from blueberries. They can be a healthy addition to the diet. Overall, wild blueberries appear well-tolerated, making them a safe choice for most people. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Wild blueberries are unique because they're a natural option that might help manage high blood pressure. Most treatments for high blood pressure involve medications like ACE inhibitors, beta-blockers, or diuretics, which can have various side effects. Unlike these standard treatments, wild blueberries contain antioxidants like anthocyanins, which researchers believe could improve blood vessel function and reduce blood pressure naturally. This approach is exciting because it offers a dietary intervention that could complement or even reduce the need for traditional medications, making it an attractive option for those seeking more natural health solutions.

What evidence suggests that wild blueberries might be an effective treatment for high blood pressure?

Research has shown that wild blueberries might help lower blood pressure. Studies have found that consuming berries, such as wild blueberries, can significantly reduce both systolic and diastolic blood pressure. In one study with rats, blueberry supplements lowered systolic blood pressure by up to 14%. In a study with humans, daily consumption of wild blueberries improved blood vessel health and reduced systolic blood pressure by about 3.6 mmHg. In this trial, participants will receive either 22 g of freeze-dried wild blueberry powder or a placebo powder daily to evaluate the effects on blood pressure. These findings suggest that wild blueberries could benefit individuals with high blood pressure. ^{1 2 4 6 7}

Who Is on the Research Team?

Rafaela G Feresin, PhD

Principal Investigator

Georgia State University

Are You a Good Fit for This Trial?

Adults aged 45-65 with slightly high blood pressure (120-139/80-89 mmHg) for at least 6 months, a BMI of 25-30, and the ability to consent can join. Excluded are those on certain medications, with active cancer or major health issues, smokers, heavy drinkers, pregnant women, and those allergic to berries.

Inclusion Criteria

BMI 25-30 kg/m2 via anthropometric measurements

Ability to give consent

I am between 45 and 65 years old.

Exclusion Criteria

Allergies to berries

Pregnant or lactating

Smoking

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Treatment

Participants receive daily consumption of 22 g of freeze-dried wild blueberry powder or placebo for cardiovascular, gut, and cognitive health assessment

8 weeks

3 visits (in-person) at baseline, 4 weeks, and 8 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Wild Blueberries

Trial Overview The trial is testing if wild blueberries improve heart health, brain function, and gut bacteria in non-Hispanic Black and White adults with elevated blood pressure compared to a placebo.

How Is the Trial Designed?

Group I: Wild Blueberry Experimental Treatment 1 Intervention

22 g of freeze-dried wild blueberry freeze-dried powder per day

Group II: Placebo Placebo Group 1 Intervention

22 g of freeze-dried macronutrient-matched placebo powder per day

Who Is Running the Clinical Trial?

Georgia State University

Lead Sponsor

Trials

71

Recruited

33,600+

Published Research Related to This Trial

Current clinical evidence suggests that while there is no direct blood pressure lowering effect from dietary berry consumption, certain berries may help normalize blood pressure in individuals who are already hypertensive.

The review highlights the potential role of specific berry polyphenols, such as anthocyanins and ellagic acid, in influencing blood pressure regulation, although results are mixed and complicated by confounding factors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Role of Berry Consumption on Blood Pressure Regulation and Hypertension: An Overview of the Clinical Evidence. Vendrame, S., Adekeye, TE., Klimis-Zacas, D.[2022]

A meta-analysis of six randomized controlled trials involving 204 participants found no significant effect of blueberry supplementation on lowering blood pressure, with mean differences of -0.28 mmHg for systolic and -0.5 mmHg for diastolic pressure.

The study suggests that blueberry supplementation does not provide clinical benefits for blood pressure management, highlighting the need for larger and better-designed trials to explore this potential relationship.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of blueberry supplementation on blood pressure: a systematic review and meta-analysis of randomized clinical trials. Zhu, Y., Sun, J., Lu, W., et al.[2018]

In a 12-week study involving 134 healthy individuals with high normal blood pressure or stage 1-2 hypertension, consumption of polyphenol-rich berry juices significantly reduced systolic blood pressure compared to a placebo, with reductions of 6.9 mmHg at 6 weeks and 3.4 mmHg at 12 weeks.

The blood pressure variability was also significantly lower in participants consuming the berry juices, indicating that these juices may be particularly beneficial for individuals with hypertension.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Polyphenol-rich juices reduce blood pressure measures in a randomised controlled trial in high normal and hypertensive volunteers. Tjelle, TE., Holtung, L., Bøhn, SK., et al.[2015]

In a study of 44 adults with metabolic syndrome, consuming blueberry smoothies twice daily for six weeks significantly improved endothelial function, as measured by the reactive hyperemia index, compared to a placebo group.

While blueberry consumption did not lead to changes in blood pressure or insulin sensitivity, the improvement in endothelial function suggests potential cardiovascular benefits from including blueberries in the diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blueberries improve endothelial function, but not blood pressure, in adults with metabolic syndrome: a randomized, double-blind, placebo-controlled clinical trial. Stull, AJ., Cash, KC., Champagne, CM., et al.[2022]

In a 10-week study with rats, blueberry supplementation significantly reduced systolic blood pressure by up to 14% compared to control and high-fat diets, indicating potential cardiovascular benefits.

Blueberry-fed rats also showed improved vascular reactivity, with reduced contractile responses and enhanced relaxation of blood vessels, suggesting that blueberries may help counteract endothelial dysfunction caused by high-fat diets.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blueberry intervention improves vascular reactivity and lowers blood pressure in high-fat-, high-cholesterol-fed rats. Rodriguez-Mateos, A., Ishisaka, A., Mawatari, K., et al.[2022]

Feeding flavonoid-rich blueberries to spontaneously hypertensive stroke-prone rats significantly lowered their blood pressure by inhibiting angiotensin-converting enzyme (ACE) activity, which was elevated in these rats compared to normotensive rats.

After 2 weeks on a blueberry diet, ACE activity in the hypertensive rats decreased, and this effect persisted for up to 6 weeks, suggesting that blueberries could be a beneficial dietary intervention for managing early hypertension.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Feeding blueberry diets inhibits angiotensin II-converting enzyme (ACE) activity in spontaneously hypertensive stroke-prone rats. Wiseman, W., Egan, JM., Slemmer, JE., et al.[2022]

A systematic review of 17 randomized clinical trials found that blueberry and cranberry supplementation had neutral effects on blood pressure (BP) in patients with cardiometabolic diseases, showing no significant reductions in systolic BP (SBP) or diastolic BP (DBP).

Despite some studies indicating potential benefits, the pooled results revealed only minor, statistically non-significant reductions in BP, highlighting the need for further high-quality research to confirm any clinical efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of blueberry and cranberry supplementation on blood pressure in patients with cardiovascular diseases: A systematic review and meta-analysis of randomized clinical trials. Delpino, FM., Dos Santos, FS., Flores, TR., et al.[2023]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06735599

Wild Blueberries for Gut, Brain, and Heart Health in Adults ... The purpose of the study is to determine the effectiveness of wild blueberries on cardiovascular health, cognitive function, and gut microbiota composition in ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9268395/

The Role of Berry Consumption on Blood Pressure Regulation ... A significant reduction in both SBP and DBP was found with consumption of berries, as well as red grapes/red wine.

3. withpower.com withpower.com/trial/phase-hyperemia-8-2024-bffa1

Wild Blueberries for High Blood Pressure In a 10-week study with rats, blueberry supplementation significantly reduced systolic blood pressure by up to 14% compared to control and high-fat diets, ...

4. sciencedirect.com sciencedirect.com/science/article/pii/S0002916523463009

Wild blueberry (poly)phenols can improve vascular ... We observed that 12 wk daily WBB consumption improved FMD by 0.85% and ambulatory systolic BP decreased by −3.59 mmHg with respect to the ...

5. clinicaltrials.gov clinicaltrials.gov/study/NCT07177781

Effects of Wild Blueberry Consumption on Brain Function in ... Change in outcomes at the end of a 16-week wild blueberry intervention and a 16-week control period with a matched placebo. Blood pressure ( ...

6. sciencedirect.com sciencedirect.com/science/article/pii/S0002916523234784

Favorable effects of berry consumption on platelet function, ... In this study, consumption of berries for 2 mo reduced blood pressure, increased HDL-cholesterol concentrations, and prolonged PFA-100 CTs (CADP-CT), which ...

7. webmd.com webmd.com/vitamins/ai/ingredientmono-1013/blueberry

Blueberry - Uses, Side Effects, and More Eating freeze-dried blueberries or taking blueberry powder by mouth doesn't lower blood pressure in people with high blood pressure or other heart disease risk ...