A BBC experiment has found that beetroot juice can significantly lower blood pressure, potentially reducing the risk of heart attack and stroke by 10%. The study, conducted for the programme 'Trust Me, I'm a Doctor', tested the effects of beetroot, garlic, and watermelon on 28 volunteers with high blood pressure.
Participants, who had an average systolic blood pressure of 133.6 mmHg, consumed each food for a week. Beetroot juice reduced readings to 128.7 mmHg, while garlic achieved 129.3 mmHg. Watermelon had a smaller effect, lowering pressure to 129.8 mmHg, likely due to its high water content diluting the active ingredient.
The active compound in beetroot is nitrate, which is converted by mouth bacteria into nitrite and then into nitric oxide, dilating blood vessels. Garlic contains allicin, which affects kidney hormones to open vessels. Watermelon provides L-citrulline, which also boosts nitric oxide levels.
Dr Andy Webb of King's College London, who led the experiment, noted that these results align with larger studies. He emphasised that other foods rich in nitrate or allicin, such as leafy greens, onions, and leeks, can also help, but preparation methods matter for effectiveness.
