For centuries, chili peppers (Capsicum spp., Solanaceae)
have been valued for their fiery flavor as well as their medicinal and
health-promoting properties. Recent research has focused on the potential of
these fruit pods to support overall longevity, prevent diseases, and aid in
weight management.
Chili peppers have traditional uses ranging from a treatment
for colds and fevers to an agent that soothes the circulatory and digestive systems.
Rich in antioxidants, flavonoids, vitamins, and minerals, chili peppers are the
fruit of a member of the genus Capsicum, which is part of the nightshade
family. They contain a number of active chemical compounds called
capsaicinoids. Of these, capsaicin is thought to be the compound with the most
health-promoting properties.1
Chili Peppers and Longevity
It is capsaicin that is particularly intriguing, especially
to researchers at the University of Vermont who say that consumption of
capsaicin in hot red chili peppers might extend lifespan. Published in 2017,
the study, led by medical student Mustafa Chopan and professor of medicine
Benjamin Littenberg, MD, reached this conclusion by analyzing data from more
than 16,000 adults aged 18 or above, who participated in the National Health
and Nutrition Examination Survey III between 1988 and 1994. The team observed
that the primary consumers of hot red chili peppers tended to be younger, male,
white, Mexican-American, and married, as well as consumers of cigarettes,
alcohol, and various meats and vegetables.2 They also typically had lower
incomes and less overall education when compared with those who did not consume
red chili peppers.
In their analysis, the authors examined roughly 19 years of
follow-up data. During this time, there were 4,946 recorded deaths. They found
that the mortality of participants who consumed hot red chili peppers was
21.6%, as opposed to 33.6% for those who did not. Although the cause-specific
mortality analysis was limited by the relatively small number of deaths, the
researchers concluded that there was a “significant decrease in mortality
associated with hot red chili pepper consumption.” Interestingly, those with
hot red chili peppers in their diet also had generally lower high-density
lipoprotein (HDL) cholesterol levels.
The findings are significant, in part, because they support
the conclusion of a study conducted in China in August 2015. The large,
population-based cohort study looked at data from nearly 500,000 Chinese adults,
excluding patients who had a history of cancer, heart disease, or stroke at
baseline, between the ages of 30 and 79. It is the only other study to have
examined chili pepper consumption and mortality. After analyzing 20,224 deaths
that occurred during the study period, they concluded that “habitual
consumption of spicy foods was inversely associated with total and certain
cause-specific mortality, independent of other risk factors of death.”3
The authors of the 2017 study concluded that the mechanism
by which chili peppers may influence mortality is far from certain, but
hypothesized that “Transient Receptor Potential (TRP) channels, which are
primary receptors for pungent agents, such as capsaicin, may in part be
responsible for the observed relationship.”4
It is also possible, they wrote, that capsaicin, which is
known to play a role in cellular and molecular mechanisms that prevent obesity
and modulate coronary blood flow, possesses antimicrobial properties that “may
indirectly affect the host by altering the gut microbiota.”4
“Because our study adds to the generalizability of previous
findings, chili pepper — or even spicy food — consumption, may become a dietary
recommendation and or fuel further research in the form of clinical trials,”
noted Chopan.4
Capsaicin and Disease Prevention
Beyond their possible potential to increase longevity, chili
peppers may also have cytotoxic properties. For example, a study published in
2016 investigated the effect of capsaicin on cultivated cells of particularly
aggressive, difficult-to-treat forms of breast cancer known as triple negative
cancers. The study, led by Lea V. Weber, of Ruhr University Bochum in Germany,
investigated the expression and functionality of TRPV1 channels (also known as
capsaicin receptor cation channels), which are thought to influence cancer cell
growth. Intrigued that capsaicin has been shown to inhibit cancer cell growth
and even cause cell death in cancers of the colon and pancreas, the researchers
set out to understand how the compound might be used in breast cancer
treatments.5
They found that activation of TRPV1 by capsaicin caused
significant inhibition of cancer cell growth and induced apoptosis (normal,
programmed cell death) and necrosis. The authors concluded that “the current
study revealed the expression of profiles of human TRP channels in 60 different
breast cancer tissues and cell lines and furthermore validated the TRPV1
against SUM149PT breast cancers cells [a model system for the most aggressive
breast cancer subtype], indicating that activation of TRPV1 could be used as a
therapeutic target, even in the most aggressive breast cancer types.”5
Weight Management
There is an increasing body of evidence that supports the
use of capsaicinoids as an important weight management tool, and researchers
are making progress in identifying specific ingredients and innovating methods
to make them more effective.
For example, one study, authored by Stacie L. Urbina of the
Department of Exercise and Sports Science at the University of Mary Hardin-Baylor,
looked at the effects of daily supplementation with 2 mg of capsaicinoids on
appetite reduction and body composition.6 Intrigued by the potential of
capsaicin to positively affect cardiovascular health, the researchers set out
to examine the effects of different doses on healthy men and women using a
commercially available capsicum extract (Capsimax; OmniActive Health Technologies;
Morristown, New Jersey). The findings suggest that 12 weeks of supplementation
may be effective at suppressing appetite and reducing key body composition
metrics. Results showed that waist and hip circumference decreased by 2.4%
after six weeks, and there was a significant reduction in caloric intake over
12 weeks.
Another aspect of the study is that the ingredient delivers
effective levels of capsaicinoids without the side effects of oral and gastric
burning common with raw hot red peppers. Capsimax is made using a proprietary
OmniBead Beadlet Technology that encapsulates the highly active, natural
capsicum extract in a controlled-release coating.7 In a 2017 study at Arizona
State University led by Yue Deng of OmniActive Health Technologies, the product
was also found to support healthy weight management by increasing healthy
resting energy expenditure (the number of calories burned while at rest) by an
average of 6% after a single dose.8
Synergistic Partner
The news about chili peppers and capsaicin is not all
positive. Some studies have suggested that capsaicin may have a carcinogenic
effect. However, a new study led by Shengnan Geng of the Pharmacy College of
Henan University in China suggests that ginger (Zingiber officinale,
Zingiberaceae) and capsaicin may work synergistically, with ginger compound
6-gingerol counteracting capsaicin’s potentially harmful effects. Ginger has
been shown to have health-promoting potential in its own right, but these
researchers noted that capsaicin and 6-gingerol both bind to the same cellular
receptor — one that is related to tumor growth — and decided to investigate
further.
Over a period of several weeks, the researchers fed mice
either capsaicin in olive oil, 6-gingerol in olive oil, a combination of the
two in olive oil, or olive oil alone. Each subject received 50 mg/kg of body
weight.9 They found that 100% of the mice that received capsaicin developed
lung carcinomas, while only half of those that received the 6-gingerol
developed the carcinomas. The development of carcinomas was even lower for mice
that received both compounds at 20%.10 The study is notable for providing a new
avenue to counteract the possibility of specific capsaicin-related adverse
events.9
While many questions remain about the health effects of
consuming hot chili peppers, emerging evidence is providing new insights on the
role of capsaicin in metabolism and overall health, and may lead to new dietary
recommendations, as well as the potential development of new treatment options.
—Karen Raterman
References
- Chili Peppers Nutrition Facts. Nutrition and You website.
Available at: www.nutrition-and-you.com/chili-peppers.html. Accessed April 22,
2017.
- Chopan M, Littenberg B. The association of hot red chili
pepper consumption and mortality: A large population-based cohort study. PLoS
One. 2017;12(1):e0169876. Available at: www.ncbi.nlm.nih.gov/pmc/articles/PMC5222470/.
Accessed April 22, 2017.
- Lu J, Qi L, Yu C, et al. Consumption of spicy foods and
total and cause specific mortality: population based cohort study. BMJ.
2015;351:h3942. Available at: www.bmj.com/content/351/bmj.h3942. Accessed April
25, 2017.
- Study finds association between eating hot peppers and
decreased mortality [press release]. Burlington, VT: University of Vermont.
January 13, 2017. Available at: www.eurekalert.org/pub_releases/2017-01/uov-sfa011317.php.
Accessed April 22, 2017.
- Weber LV, Al-Refae K, Wölk G, et al. Expression and
functionality of TRPV1 in breast cancer cells. Breast Cancer. 2016;8:243-252.
Available at: www.ncbi.nlm.nih.gov/pmc/articles/PMC5167528/. Accessed August
15, 2017.
- Urbina SL, Villa KB, Santos E, et al. Capsaicinoids
supplementation reduces appetite and body circumferences in healthy men and
women, a placebo controlled randomized double blind study. The FASEB Journal.
2016;30(1):Supplement ib356. Available at: www.fasebj.org/content/30/1_Supplement/lb356.short.
Accessed August 15, 2017.
- Award winning Capsimax Capsicum Extract provides the
benefits of red hot peppers without the burn. OmniActive Health Technologies.
Available at: http://omniactives.com/capsimax. Accessed August 15, 2017.
- Deng Y, et al. Capsaicinoids advance metabolic rate using a
novel metabolic tracker breezing device: an open-label study. Advances in
Nutrition. January 2017;8(1):5. Available at: http://advances.nutrition.org/content/8/1/5.short.
Accessed August 15, 2017.
- Beer E. Mice study shows chilli and ginger cancer battling
properties. Nutraingredients.com. September 15, 2016. Available at:
www.nutraingredients.com/Research/Mice-study-shows-chilli-ginger-cancer-battling-properties.
Accessed August 15, 2017.
- Geng S, Zheng Y, Meng M, et al. Gingerol reverses the
cancer-promoting effect of capsacin by increased TRPV1 level in a
urethane-induced lung carginogenic model. J Agric Food Chem.
2016;64(31):6203-6211. Available at: http://pubs.acs.org/doi/abs/10.1021/acs.jafc.6b02480.