According to a study conducted in Japan, researchers said this effect was more pronounced in participants with sedentary lifestyles.
The study was published in the journal, Nutrients.
The double-blind human study involved 69 participants who were 50 years or older living in the Kyoto Prefecture, Japan. They were randomly allocated to the study or placebo group.
Participants in the study group were administered an oral dose of soft vegetable film capsule containing 200mg of rapeseed oil which includes 1.5mg of capsinoids (ratio of capsiate, dihydrocapsiate, nordihydrocapsiate is 7:2:1) extracted from the pepper fruit variety CH-19 Sweet (Capsicum annuum L.).
The placebo group were administered 200mg of rapeseed oil in the same capsule.
Subjects ingested the experimental food or placebo twice daily (once between waking and breakfast and again between dinner and bedtime). Each dose was comprised of three capsules, so the study group ingested 9mg of capsinoids daily. The dosing period was set at 12 weeks.
Capsule intake diaries were provided to each subject, and they were instructed to record before going to sleep each day whether they had taken the experimental food.
The primary outcome was physical activity level in daily life, and the secondary outcomes were body composition and fatness.
PA was measured using a waist-mounted activity meter with a triaxial accelerometer. The number of steps and the physical activity intensity were collected every minute throughout the wearing period. PA intensity was measured in metabolic equivalents (METs) which is defined as the amount of oxygen consumed while sitting at rest and is equal to 3.5 ml O2 per kg body weight x min.
Body composition and fatness was measured with a bioelectrical impedance analysis. It collected data on body weight, lean body mass (LBM), percent body fat (% fat), and visceral fat. Waist circumference was measured using a tape measure.
Effect on physical activity
Capsinoids intake was found to significantly increase PA intensity from 84.5 ± 17.2 at week zero, to 99.2 ± 24.9 at 12 weeks in the sedentary subjects.
Energy expenditure also improved in the inactive subjects from 481.2 ± 96.3 kcal/day at baseline to 562.5 ± 145.5 kcal/day at 12 weeks.
The results indicated that the total amount of physical activity per day increased in the subjects consuming capsinoids who exhibited an inactive tendency.
Effect on body composition
At week six, subjects in the study group exhibited a significant decrease in waist circumference (p=0.003) and visceral fat (p=0.016).
The same subjects also showed significantly lower body fat percentage at week 12 (p=0.022).
Capsinoids such as capsiate, dihydrocapsiate, nordihydrocapsiate have been reported in mice and human studies for its energy-metabolism-promoting effect, body-heat-production-promoting effect and body-fat-mass-reducing effect.
In this study, the continuous ingestion of capsinoids is believed to increase the amount of daily physical activity in people with sedentary lifestyles and potentially help reduce waist circumference, visceral fat, and body fat percentage in older adults.
The researchers acknowledged the small sample size of the study, and recommended that “further investigations with subjects of sufficient number and similar properties would be needed.”
“Effects of Capsinoids on Daily Physical Activity, Body Composition and Cold Hypersensitivity in Middle-Aged and Older Adults: A Randomized Study”
Authors: Keiichi Yokoyama, et al.