Capsaicin, the main pungent compound in hot peppers, and capsiates, non-pungent compounds in sweet peppers, show ‘modest’ weight management potential, says a new meta-analysis from Purdue University.
Evidence from a number of clinical studies showed that both capsaicin and capsiates increased energy expenditure and suppressed appetite, although the overall evidence showed that the effects were ‘modest’.
“On a population scale, modest sustained weight loss can be predicted to generate substantial health and economic benefits by increasing disease-free years, reducing disease incidence, increasing life expectancy, and decreasing medical costs,” explained the researchers in Chemical Senses .
“Nevertheless, the long-term acceptability and effectiveness of capsaicin and capsiate are unclear.”
With the World Health Organization estimating that by 2015, there will be more than 1.5 billion overweight consumers, the opportunities for a scientifically-substantiated weight management product are impressive.
The market for food, beverage and supplement weight management products is already valued at $3.64bn (2009 figures) in the US, according to Euromonitor. In Western Europe, the market was worth $1.3bn in 2009.
The slimming ingredients market can be divided into five groups based on the mechanisms of action – boosting fat burning/ thermogenesis, inhibiting protein breakdown, suppressing appetite/boosting satiety (feeling of fullness), blocking fat absorption, and regulating mood (linked to food consumption).
Like capsaicin, the potential weight management actions of capsiates are also linked to thermogenic effects. However, capsiates are not said to produce the gastrointestinal side effects of its more pungent relative.
The evidence from trials conducted around the world appears to support weight management claims, report Mary-Jon Ludy, George Moore and Richard Mattes from Purdue University.
According to their findings, the scientific evidence agrees that capsaicin promotes thermogeneis in lean individuals, but the data in overweight and obese individuals is currently “inconsistent”.
Four studies with capsiates have found benefits for energy expenditure in obese and overweight people, added the researchers, but two other studies reported no effects.
In addition to body composition having an effect on the efficacy of the ingredients, the doses used also play an important role. Studies that used capsaicin in food form (ground red pepper) used doses ranging from 0.2 mg in a single meal to 33 mg/day for 4 weeks, while studies using supplements have used doses ranging from 0.2 to 7 mg of ground red pepper in capsules, to 130 to 150 mg of pure capsaicin. A similar broad range of doses were tested for capsiate.
“Collectively, the studies reviewed provide supportive evidence for roles of capsaicin and capsiate in weight management,” wrote the Purdue scientists.
“Published studies occurred under controlled conditions and may not apply to environments with free choice of foods and dietary supplements.”
Despite the positive results to date, a number of questions remain to be answered, said Ludy, Moore and Mattes. These include:
- How sustainable the effects of the pepper compounds are on energy balance
- How altering dose, form and/or composition may influence long term efficacy
- How could capsaicin and capsiate with other weight be combined with other weight management strategies, and
- How to incorporate the ingredients successfully into the diet.
Source: Chemical Senses
February 2012, Volume 37, Issue 2, Pages 103-121, doi: 10.1093/chemse/bjr100
“The Effects of Capsaicin and Capsiate on Energy Balance: Critical Review and Meta-analyses of Studies in Humans”
Authors: M.-J. Ludy, G.E. Moore, R.D. Mattes