Bell peppers – also called sweet peppers and red peppers or Capsicum annuum – have a unique ability to boost our metabolism and help reduce fat. They also help suppress appetite and decrease inflammation according to the research.
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| Sweet peppers reduce fat. |
What are bell peppers?
Bell peppers are technically called Capsicum annuum. This species includes both mild and hot red, green and yellow peppers. It includes hot jalapenos. It includes cayenne peppers. It also includes bell peppers.
In other words, some of the most relevant benefits of Capsicum annuum doesn’t mean you have to take the heat. Bell peppers are also called sweet peppers. These sweet peppers can be green, yellow or red in color.
Red bell peppers are simply mature ripened green bell peppers. But there still is the Permagreen variety that will stay green. Yellow and orange bell peppers can also turn red when they ripen. But they may also mature as yellow and orange depending upon the variety.
Bell peppers tested for activity and fat
In a 2020 study, researchers from Japan’s Kyoto University of Advanced Science investigated sweet bell peppers for their ability to boost metabolism and help reduce fat.
The research tested 69 adults who were middle-aged and older. They were divided into a placebo group and a bell pepper group. The bell pepper group was given 9 milligrams a day of bell pepper extract. The other group was given a placebo. The study was double-blind so neither the doctors nor the test subjects knew who received the bell pepper extract.
The study was administered for 12 weeks. Before and after the three-month period, the researchers tested the subjects’ activity levels, energy expenditure, metabolic equivalents, weight, BMI, body fat percentage, visceral fat, and waist circumference.
After the three-month period, the researchers found that the bell pepper group had significantly more energy expenditures. Those in the less active group also showed more physical activity. Their physical activity went up from an average of 84.5 points to 99.2 points.
These charts show how physical activity was significantly boosted in the bell pepper (“Capsinoids”) group. (Courtesy Nutrients Journal)
And during the physical activity, their metabolism increased over what it was before during physical activity. This means their metabolism levels increased as soon as they were active. Energy expenditure during physical activity went from an average of 481 to 562 after the three months, using metabolic equivalents or METs,
The researchers also found those in the bell pepper group had significantly reduced waist circumference, percent body fat and reduced visceral fat volumes.
This chart shows how the bell peppers (“Capsinoids”) reduced body fat levels among the subjects. (Courtesy Nutrients Journal)
Peppers also reduce inflammation
The researchers also tested mice with the bell peppers. They also saw increased physical activity among those given the bell peppers. But they also found their levels of inflammation decreased.
Peppers reduce appetite
One of the other benefits of red and sweet peppers is that they help the body reduce appetite. In a 1999 study, researchers from Canada’s Laval University tested people with four different breakfast combinations. The combinations included different levels of fat, and some also included peppers in the foot.
The researchers found that the women who ate the peppers had a reduction of appetite.
In a 2009 study, researchers from the University of Copenhagen tested 27 people. They were given either a placebo or a combination of sweet bell pepper and green tea. Again the researchers found that the bell pepper and green tea reduced eating (energy intake). The researchers concluded:
“Bioactive ingredients may therefore be helpful in reducing energy intake and might support weight loss periods by relatively sustaining satiety and suppressing hunger.”
Why do peppers increase metabolism and reduce fat?
Capsicum annuum peppers contain compounds called capsinoids. These include capsiate, dihydrocapsiate, and nordihydrocapsiate. These are similar to capsacin, which is found in cayenne pepper.
The essential thing is that these capsinoids stimulate heat in the body. This comes hand-in-hand with stimulating the metabolic rate. As a result, other research has found that pepper extract can help mitigate the sensation of feeling cold.
Is there a gut bacteria link?
This might also be related to the reality that peppers apparently boost certain types of bacteria in the gut. A 2020 study from West Virginia State University tested diets in a community and found that peppers seemed to increase lactobacteria and acetobacteria levels in certain microbiomes.
They linked these improvements to peppers’ content of compounds such as apigenin, beta-carotene, beta-cryptoxanthin, myricetin and quercetin. According to other research, organic bell peppers have more of these antioxidants.
Scientific References
Yokoyama K, Yamada Y, Akamatsu Y, Yoshinaka Y, Yamamoto A, Koizumi T, Ohyama K, Suzuki K, Hashimoto M, Sato H, Kimura M. Effects of Capsinoids on Daily Physical Activity, Body Composition and Cold Hypersensitivity in Middle-Aged and Older Adults: A Randomized Study. Nutrients. 2020 Jan 14;12(1). pii: E212. doi: 10.3390/nu12010212.
Garcia-Lozano M, Haynes J, Lopez-Ortiz C, Natarajan P, Peña-Garcia Y, Nimmakayala P, Stommel J, Alaparthi SB, Sirbu C, Balagurusamy N, Reddy UK. Effect of Pepper-Containing Diets on the Diversity and Composition of Gut Microbiome of Drosophila melanogaster. Int J Mol Sci. 2020 Jan 31;21(3). pii: E945. doi:10.3390/ijms21030945.
Unno, T.; Nagano, M.; Yamaguchi, Y.; Oohira, T. Effects of capsinoids-containing dietary supplements on sensation of cold constitution and measure of unidentified complaints in young women. Jpn. Pharmacol. Ther. 2011, 39, 525–531.
Reinbach HC, Smeets A, Martinussen T, Møller P, Westerterp-Plantenga MS. Effects of capsaicin, green tea and CH-19 sweet pepper on appetite and energy intake in humans in negative and positive energy balance. Clin Nutr. 2009 Jun;28(3):260-5. doi: 10.1016/j.clnu.2009.01.010.
Yoshioka M, St-Pierre S, Drapeau V, Dionne I, Doucet E, Suzuki M, Tremblay A. Effects of red pepper on appetite and energy intake. Br J Nutr. 1999 Aug;82(2):115-23.