Soon after the arrival of Columbus on Caribbean shores, chili peppers spread from the Americas and conquered cuisines from Budapest (think paprika) and Benghazi to Bombay and Beijing.
Recent research seems to add another reason to savor these spicy, colorful, antioxidant-rich vegetables.
It turns out that capsaicin – the chemical that makes chilies hot – can help with weight and inflammation control.
Capsaicin creams have become common on drugstore shelves, as a topical anti-inflammatory and analgesic aid.
from bell peppers?
Two years ago, researchers at Ontario’s McMaster University reported that purified capsinoids from sweet peppers increased calorie burning substantially in people engaged in aerobic exercise (Josse AR et al. 2010).
Scientists from McMaster’s Exercise Metabolism Research Group recruited 12 healthy young men (average age 24) with average BMIs for crossover, double-blind trial.
The men were randomly assigned to receive either a placebo or purified capsinoids.
Their metabolic and thermogenesis rates were measured while they were at rest and after 90 minutes of moderately intense aerobic exercise (stationary cycling).
As the Canadians wrote, "… compared to the placebo pills, [supplemental] capsinoids increased resting energy expenditure by about 20 percent, and … capsinoid ingestion induced greater lipid oxidation [fat-burning] at rest” (Josse AR et al. 2010).
Neither of these effects was seen during the exercise period, but the McMaster team found that the men drew more heavily than usual on stored body fat (versus stored sugars) as fuel after 30 minutes of exercise.
As they put it, "The changes we observed confirm previous data on the thermogenic and metabolic effects of capsinoids at rest and further promote its potential role as an adjunct weight loss aid, in addition to diet and exercise” (Josse AR et al. 2010).
We also examined the weight and metabolic effects of capsaicin in our 2007 article, "Hot Factor in Chilies May Hinder Fat Build Up.”
It’s less well known that sweet bell peppers contain similar compounds that may also aid weight control.
Let’s examine the results of a new evidence review … which should make peppers of all kinds more appealing than ever!
Review confirms peppers’ weight and metabolic benefits
When it comes to weight control and metabolism, the capsaicin in chilies appears to do at least three desirable things:
Stimulate thermogenesis (raises the metabolic rate, thus increasing the body’s propensity to burn stored body fat and sugars).
Inhibit post-meal rises in blood sugar, thereby moderating release of insulin and curbing craving for starchy/sugary carbs.
Earlier this year, Purdue University researchers concluded that the available clinical evidence supports weight control claims made for chili powder, whether added to food or consumed in capsules (Ludy MJ et al. 2012).
In addition, the evidence affirms similar benefits from consuming the non-spicy counterparts in sweet peppers, called capsinoids (e.g., capsiate).
However, the Purdue team found that while capsaicin promotes thermogenesis in lean people, it may not do this as consistently in overweight and obese people.
(Four out of six studies found that capsaicin boosts calorie-burning in obese and overweight people, while two detected no such benefit.)
In addition to body composition affecting the efficacy of chili peppers and capsaicin supplements, dose also influenced the outcomes.
Studies that used ground red pepper tested doses ranging from 0.2mg per meal to 33mg daily for a full month.
Studies testing supplements employed doses from 0.2 mg to 7 mg of ground red pepper in capsules, providing from 130 mg to 150 mg of capsaicin.
As the Purdue scientists wrote, "Collectively, the studies reviewed provide supportive evidence for roles of capsaicin and capsiate in weight management.”
They added a note of caution: "Published studies occurred under controlled conditions and may not apply to environments with free choice of foods and dietary supplements” (Ludy MJ et al. 2012).
Josse AR, Sherriffs SS, Holwerda AM, Andrews R, Staples AW, Phillips SM. Effects of capsinoid ingestion on energy expenditure and lipid oxidation at rest and during exercise. Nutr Metab (Lond). 2010 Aug 3;7:65.
Ludy MJ, Moore GE, Mattes RD. The effects of capsaicin and capsiate on energy balance: critical review and meta-analyses of studies in humans. Chem Senses. 2012 Feb;37(2):103-21. Epub 2011 Oct 29.