HerbalEGram: Volume 14, Issue 5, May 2017
For centuries, chili peppers (Capsicum annuum, Solanaceae) have been valued for their fiery flavor as well as their medicinal and health-promoting properties. More recently, scientists are also getting steamed up about the potential of these fruit pods to fight or prevent certain diseases and even support overall longevity.
Chili peppers have long been in the spotlight, with 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 (Solanaceae) family. They also 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
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. 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 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 with cancer, heart disease, and stroke at baseline, between the ages of 30 and 79, and is the only other study to have examined chili pepper consumption and mortality. After analyzing 20,224 deaths, 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, new research also is suggesting that chili peppers have cytotoxic properties. For example, a recent study 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 Transient Receptor Potential (TRP) cation channels, specifically the subfamily V, member 1 (TRPV1, also known as capsaicin receptor cation channel), which are thought to influence cancer cell growth. Intrigued by the fact 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
The results suggest 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
Though these findings are intriguing, capsaicin may have benefits for human health where evidence can be obtained more rapidly. 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 efficacious.
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 from 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, such as waist and hip circumference. Results showed that the latter decreased by 2.4% after six weeks and 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
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 this 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.9They 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 about the effects of consuming hot chili peppers for health remain, the emerging evidence is providing new insights on the role of capsaicin on metabolism and overall health, and may lead to new dietary recommendations, as well as the potential development of new treatment therapies.