British Journal of Nutrition

Research Article

Maximum tolerable dose of red pepper decreases fat intake independently of spicy sensation in the mouth

Mayumi Yoshiokaa1a2 c1, Makoto Imanagaa2, Hiromi Ueyamaa2, Miya Yamanea2, Yoshiko Kuboa2, André Boivina1, Jonny St-Amanda1, Hiroaki Tanakaa2 and Akira Kiyonagaa2

a1 Molecular Endocrinology and Oncology Research Center, Laval University Medical Center (CHUL) and Department of Anatomy and Physiology, Laval University, 2705 Boulevard Laurier, Ste-Foy, Quebec G1V 4G2, Canada

a2 Faculty of Sport and Health Science, Fukuoka University, Fukuoka 814-0184, Japan


Dietary red pepper suppresses energy intake and modifies macronutrient intake. We have investigated whether a stimulus in the mouth and the sensation of spiciness are necessary for red pepper-induced changes in energy and macronutrient intake in human volunteers. In a preliminary test, sixteen Japanese male volunteers tasted samples of a soup with graded doses of red pepper in order to define a moderate and a maximum tolerable (strong) dose of red pepper. On the day of the experiment, a standardised breakfast was given to the volunteers. At lunchtime, the subjects ingested one of four experimental soups containing either a placebo, a moderate or a strong dose of red pepper plus placebo capsules, or a placebo soup plus capsules delivering a strong dose of red pepper. The rest of the meal was given ad libitum to all subjects. The amount of food, protein and carbohydrate ingested was similar for all conditions. Energy and fat intake were similar after the ingestion of the moderate soup compared with placebo. However, the strong soup significantly lowered fat intake compared with placebo (P=0·043), and ingestion of strong capsules also tended to suppress it (P=0·080). Moreover, energy intake after strong soup and capsules tended to be lower than placebo (P=0·089 and 0·076, respectively). The present results indicate that the maximum tolerable dose is necessary to have a suppressive effect of red pepper on fat intake. The main site of the action of red pepper is not in the mouth.

(Received August 18 2003)

(Revised February 16 2004)

(Accepted February 29 2004)


c1 *Corresponding author: Dr Mayumi Yoshioka, fax +1 418 654 2761, email