Chili peppers may do more than taste hot and bring us out in a sweat: they may also help people following a low calorie diet burn or oxidize fat more quickly, according to a new study by US researchers who tested the weight-reducing potential of a compound found in peppers belonging to the genus Capsicum.

Dr David Heber, Professor of Medicine and Public Health at UCLA Center for Human Nutrition in Los Angeles, and colleagues, presented their findings at the Experimental Biology 2010 meeting that took place from 24 to 28 April in Anaheim, California. An abstract of their study was also published in the The FASEB Journal.

For the study, Heber and colleagues tested the weight-reducing potential of dihydrocapsiate or DCT, a non-burning but structurally similar version of capsaicin, a spicy compound found in hot peppers.

DCT occurs naturally in a non-pungent pepper called CH-19 Sweet and is often used in studies instead of its spicy cousin capsaicin because it has none of the side effects.

Heber and colleagues recruited 51 male and female volunteers and asked them to follow a very low calorie diet based on a liquid meal replacement product for 28 days (800 Cal and 120 g per day).

At the end of the 4 weeks of dieting, the researchers then randomly assigned the volunteers to one of three groups: one took a a high dose pill of DCT (9 mg), another took a low dose pill of DCT (3 mg), and the third group took a placebo pill, three times a day.

The researchers took measures of body weight, body fat and how quickly the participants burned energy, at the start of the study, and at the end, after eating a single high protein test meal (400 Cal/60 g protein) of the same product they had been using in their diet.

Complete data was available for 33 of the subjects at the end of the study.

The results showed that for several hours after consuming the test meal, the group on the high dose of DCT (13 subjects) burned significantly more energy, at almost twice the rate of the placebo group (9 subjects).

They also showed that in both the DCT groups (24 subjects), fat oxidation increased significantly, which results in more fat being used for energy.

The researchers concluded that after following a low calorie diet, people may benefit from using DCT to “provide metabolic enhancement to weight management efforts”.

In other words, although this is a small study, and the results are based on one analysis after a single test meal, which may not be borne out in a larger study with repeated tests, the findings suggest DCT, like its cousin capsaicin, may cause the body to burn energy faster, which could boost metabolism.

Good news, perhaps, for people who like their chili peppers.

“Effects of dihydrocapsiate on diet-induced thermogenesis following 4 weeks of very low calorie dieting.”
T.Y. Amy Lee, Alona Zerlin, Gail Thames, Zhaoping Li, and David Heber.
The FASEB Journal, MeetingAbstracts, 24: 343.7, accessed online 29 April 2010.

Written by: Catharine Paddock, PhD