Original Communication
European Journal of Clinical Nutrition (2005) 59, 733–741. doi:10.1038/sj.ejcn.1602121 Published online 4 May 2005
Bioactive food stimulants of sympathetic activity: effect on 24-h energy expenditure and fat oxidation
Guarantor: A Belza.
Contributors: AB and ABJ codeveloped the study design. AB was involved in the subject recruitment and data collection. AB interpreted the study results. AB wrote the first draft and refined the final draft after contributions from ABJ.
1Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark
Correspondence: A Belza, Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958 Frederiksberg C. Denmark. E-mail: anbe@kvl.dk
Received 1 June 2004; Revised 18 November 2004; Accepted 21 December 2004; Published online 4 May 2005.
Abstract
Objective:
Bioactive food ingredients influence energy balance by exerting weak thermogenic effects. We studied whether the thermogenic effect of a combination of capsaicin, green tea extract (catechins and caffeine), tyrosine, and calcium was maintained after 7-day treatment and whether local effects in the gastric mucosa were involved in the efficacy.
Design:
The present study was designed as a 3-way crossover, randomised, placebo-controlled, double-blinded intervention.
Setting:
Department of Human Nutrition, RVAU, Denmark.
Subjects:
A total of 19 overweight to obese men (BMI: 28.0
2.7 kg/m2) were recruited by advertising locally.
Intervention:
The subjects took the supplements for a period of 7 days. The supplements were administrated as a simple supplement with the bioactive ingredients, a similar enterocoated version, or placebo. In all, 24-h energy expenditure (EE), substrate oxidations, spontaneous physical activity (SPA), and heart rate were measured in respiration chambers on the seventh day of each test period.
Results:
After adjustment for changes in body weight and SPA, 24-h EE was increased by 160 kJ/day (95% CI: 15–305) by the simple preparation as compared to placebo, whereas the enterocoated preparation had no such effect (53 kJ/day, -92 to 198); simple vs enterocoated versions (P=0.09). The simple preparation produced a deficit in 24-h energy balance of 193 kJ/day (49–338, P=0.03). Fat and carbohydrate oxidation were equally increased by the supplements.
Conclusion:
A supplement containing bioactive food ingredients increased daily EE by 
200 kJ or 2%, without raising the heart rate or any observed adverse effects. The lack of effect of the enterocoated preparation suggests that a local action of capsaicin in the gastric mucosa is a prerequisite for exerting the thermogenic effect.
Sponsorship:
Supported by Science, Toxicology & Technology, San Francisco, CA, USA.
Keywords:
energy expenditure, capsaicin, caffeine, green tea, tyrosine, calcium
