Wild Blueberries for High Blood Pressure

Overseen by Rafaela G Feresin, PhD

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Recruiting

Sponsor: Georgia State University

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

Disqualifiers: Cancer, Cardiovascular, Neurological, others

Trial Summary

What is the purpose of this trial?

The purpose of the study is to determine the effectiveness of wild blueberries on cardiovascular health, cognitive function, and gut microbiota composition in non-Hispanic Black and White adults with elevated blood pressure.

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.

What data supports the effectiveness of the treatment Wild Blueberries, Deerberry, Bilberry, Wortleberry, Huckleberry for high blood pressure?

Research shows that while blueberries and similar berries may not directly lower blood pressure, they can improve blood vessel function, which might help manage high blood pressure indirectly. ^{1 2 3 4 5}

Is it safe to consume wild blueberries for high blood pressure?

Research on blueberries, including wild varieties, suggests they are generally safe for human consumption. Studies have not shown significant adverse effects, but more high-quality research is needed to confirm their safety and effectiveness for blood pressure management. ^{1 2 3 5 6}

How do wild blueberries help with high blood pressure?

Wild blueberries may help lower high blood pressure by inhibiting the activity of an enzyme called ACE, which is involved in blood pressure regulation. This is different from many standard treatments that directly target blood pressure levels with medication. ^{1 2 3 5 7}

Research Team

Rafaela G Feresin, PhD

Principal Investigator

Georgia State University

Eligibility Criteria

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

Trial Timeline

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)

Treatment Details

Interventions

• Wild Blueberries (Cancer Vaccine)

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.

Participant Groups

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+

Dr. Jian-Dong Li

Georgia State University

Chief Executive Officer since 2011

PhD in Biomedical Sciences from University of California, San Francisco; MD from Qingdao University School of Medicine

Dr. Steve Simonson

Georgia State University

Chief Medical Officer since 2014

MD from Medical College of Wisconsin; Master's in Health Sciences from Duke University School of Medicine

Findings from Research

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]

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 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 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]

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]

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]

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]

References

1. Switzerland pubmed.ncbi.nlm.nih.gov

The Role of Berry Consumption on Blood Pressure Regulation and Hypertension: An Overview of the Clinical Evidence. [2022]

2. Canada pubmed.ncbi.nlm.nih.gov

Feeding blueberry diets inhibits angiotensin II-converting enzyme (ACE) activity in spontaneously hypertensive stroke-prone rats. [2022]

3. England pubmed.ncbi.nlm.nih.gov

Effects of blueberry supplementation on blood pressure: a systematic review and meta-analysis of randomized clinical trials. [2018]

4. Switzerland 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. [2022]

5. England 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. [2023]

6. England pubmed.ncbi.nlm.nih.gov

Blueberry intervention improves vascular reactivity and lowers blood pressure in high-fat-, high-cholesterol-fed rats. [2022]

7. England pubmed.ncbi.nlm.nih.gov

Polyphenol-rich juices reduce blood pressure measures in a randomised controlled trial in high normal and hypertensive volunteers. [2015]