Hypotensive Effects of Hawthorn for Patients with Diabetes Taking Prescription Drugs:
A Randomised Controlled Trial
Br J Gen Pract. 2006; 56(527):437-43 (ISSN: 0960-1643)
Walker AF; Marakis G; Simpson E; Hope JL;
Robinson PA; Hassanein M; Simpson HC
Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences,
The University of Reading, Reading. a.f.walker@reading.ac.uk
BACKGROUND: Hawthorn (Crataegus laevigata) leaves, flowers and berries are used by herbal practitioners in the UK to treat hypertension in conjunction with prescribed drugs. Small-scale human studies support this approach.
AIM: To investigate the effects of hawthorn for hypertension in patients with type 2 diabetes taking prescribed drugs.
DESIGN OF STUDY: Randomised controlled trial.
SETTING: General practices in Reading, UK. METHOD: Patients with type 2 diabetes (n = 79) were randomised to daily 1200 mg hawthorn extract (n = 39) or placebo (n = 40) for 16 weeks. At baseline and outcome a wellbeing questionnaire was completed and blood pressure and fasting blood samples taken. A food frequency questionnaire estimated nutrient intake.
RESULTS: Hypotensive drugs were used by 71% of the study population with a mean intake of 4.4 hypoglycaemic and/or hypotensive drugs. Fat intake was lower and sugar intake higher than recommendations, and low micronutrient intake was prevalent. There was a significant group difference in mean diastolic blood pressure reductions (P = 0.035): the hawthorn group showed greater reductions (baseline: 85.6 mmHg, 95% confidence interval [CI] = 83.3 to 87.8; outcome: 83.0 mmHg, 95% CI = 80.5 to 85.7) than the placebo group (baseline: 84.5 mmHg, 95% CI = 82 to 87; outcome: 85.0 mmHg, 95% CI = 82.2 to 87.8). There was no group difference in systolic blood pressure reduction from baseline (3.6 and 0.8 mmHg for hawthorn and placebo groups, respectively; P = 0.329). Although mean fat intake met current recommendations, mean sugar intake was higher and there were indications of potential
multiple micronutrient deficiencies. No herb-drug interaction was found and minor health complaints were reduced from baseline in both groups.
CONCLUSIONS: This is the first randomised controlled trial to demonstrate a hypotensive effect of hawthorn in patients with diabetes taking medication.
