King's College London

Betalains are a group of naturally occurring food bioactives found in colourful plants like beetroot, dragon fruit, prickly pear, Swiss chard and amaranth. Food bioactives are naturally found in food, and when we eat them, they are absorbed in our body and promote good health. In our previous study completed in 2022, we found that the consumption of betalain-rich dragon fruit improves vascular function and the health of the endothelium (the innermost layer of most blood vessels) in healthy young men and women. However, we were unable to discern if the effects can be attributed solely to the betalains alone and we would also like to know if these benefits can be extended to an older population.

In this study, we aim to investigate the effects of natural betalains on cardiovascular health and quality of life in the middle-aged population. This is a randomised, double-blinded, placebo-controlled crossover trial.

We are looking for healthy individuals, aged 40 - 65, with a BMI 25-29.9 kg/m², who have a normal blood pressure (<160/100 mmHg) to take part in a study investigating the effect of beetroot-derived betalains on heart health, sleep quality and quality of life.

Reimbursement: £150 for completing the study.

Can I take part?

You may be eligible if you can answer “Yes” to the following statements:

• I am aged between 40 and 65 years.
• I do not smoke or vape.
• My BMI falls between 25-29.9 kg/m².
• I am not vegetarian or vegan.

[The study intervention uses capsules made of gelatin which is of animal origins (bovine/cow). If you are happy with this, you may still participate]

• I do not have a medical history of chronic disease.
• I do not have grade II hypertension (blood pressure: >160/100 mmHg)
• I do not take medication (or stopped taking them at least 2 months ago)

[This includes antihypertensive drugs, statins, aspirin etc. However, we do accept the use of some long-term medication. Please discuss this with us]

• I do not take vitamin/dietary supplements (or stopped taking them at least a month ago)

[This includes botanicals, vitamins, minerals, amino acids except for vitamin D and iron supplements.]

• I am not under hormonal replacement therapy (contraceptives are allowed)

What does the study involve?

• 1 screening + 4 study visits to King’s College London (Waterloo Campus)
• Taking daily capsule over a total of two months
• Non-invasive cardiovascular assessments (ultrasound + tonometry)
• Providing blood samples on 4 occasions
• Wearing fitness tracker
• Recording food intake and answering questionnaires

What are the benefits of taking part?

• £150 reimbursement for your time
• Free basic health checkup

Ethical clearance

Advertisement for use for recruitment of volunteers for study ref: HR/DP-22/23-35836, approved by KCL Health Faculties Research Ethics Subcommittee