Effects of Capsaicin Concentration in Peppers on Metabolic Rate
Hussein Aldahan, Jared Brown & Haley Scott
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92672
Abstract
A number of health problems such as diabetes, hypertension and other chronic diseases
are significantly associated with being overweight and obese. For the purpose of this study,
metabolism, defined as the breakdown of molecules to obtain energy, has a strong correlation
with weight management. In addition to physical activities, many foods have an effect on
increasing metabolism, thereby burning more calories and increasing weight loss. Recent studies
have discussed the long term effects of spices in the diet on metabolic rate. This study examined
the short term impact of capsaicin consumption on metabolic rate. Analysis of carbon dioxide
consumption via the use of a spirometer, determined that only the peppers with a Scoville rating
above 2,500 (jalapeno and chipotle) had a significant impact on metabolic rate in the short term.
This, in conjunction with previous studies, suggests that not only will long term spice
consumption promote an increased metabolic rate, but that there is a nearly immediate boost in
metabolic rate following consumption of concentrated capsaicin. These results along with
previous conclusions could have significant, economically favorable impacts on public health
and weight management.
Introduction
In a country where two thirds of the population is overweight or obese, there is a constant
demand for new, better and more efficient ways to manage weight loss and encourage a healthier
lifestyle. Researchers have been examining the benefits of naturally occurring substances and
their impact on overall health and diet. There have been thorough and comprehensive animal
studies documenting the beneficial influence of turmeric/curcumin, red pepper/capsaicin and
garlic on lipid metabolism, especially the anti-hypercholesterolemic effect of the three spices
(Srinivasan, et al., 2005). This evidence could be highly beneficial to the health of the general
public, but could also serve as an alternative treatment option or treatment supplement to an
individual suffering from hypercholesterolemia. The implementation of an additional ingredient
into the diet is a relatively low-cost, simple adjustment that could produce considerable and
lasting benefits due to chili-containing meals increasing energy expenditure and fat oxidation
(Ahuja, et al., 2006).
One possible factor for the effectiveness of spices on metabolism can be boiled down to
capsaicin. Pepper plants belonging to the Capsicum genus contain several chemically related
capsaicinoid groups, which produce the alkaloid compound (C18H27NO3) from the placenta of
the fruit. Capsaicin is the compound responsible for creating the intensity of flavor in peppers
ranging from bell peppers to the carolina reaper (Kawada, et al., 1986). The research yields
conclusive evidence to suggest that the consumption of spices can have significant and varying
health impacts. Capsaicin, black pepper, mixed spices, and more have the potential to produce
satiety, thermogenesis, and fat oxidation (Westerterp-Plantega, et al., 2006).
The simple addition of a capsaicin carrying ingredient or two into the diet could have
significant health effects without requiring significant financial obligations (Yoshioka, et al.,
1995). Knowing this information, the focus of this study is to look at the way in which the
consumption of these ingredients impacts an individual’s metabolism in a short term period.
Much of the previous research examines the addition of these foods to a diet, but this study will
examine the short term impacts of consuming these spices.
Materials & Methods
Metabolism levels were examined by using a spirometer to assess the duration of
breathing, and Explorer GLX Pasco to measure the levels of CO₂ exhaled. Fourteen participants
between the age of twenty and fifty years old were selected to participate in the study. The
spirometer was assembled and the Explorer GLX Pasco was set to measure CO₂ as a function of
temperature. Participants were each given a disposable mouthpiece to write their name on and
connect to the spirometer to collect their CO₂ concentration. A control metabolism was recorded
by the participants consuming the base salsa of only chunky Pace® salsa and five minutes later
inhaling with their nostrils and exhaling by mouth into the spirometer. Time was recorded for the
participants to exhale eight liters into the spirometer. Once the eight liter mark was reached, the
one-way valve was replaced by the Pasco CO₂ probe, which collected the concentration of CO₂.
Participants then ate 15 Tostitos Scoops® chips, each with one tablespoon of control salsa
consisting of 1 cup of chunky Pace® salsa. The first sample consisted of 34th a cup of mild thick
and chunky Pace® salsa and 14th a cup of a seeded diced bell pepper. A five minute digestion
period was reserved between the last chip eaten and the metabolism taken. This process repeated
for the following metabolic tests on the jalapeño and chipotle pepper salsas. The jalapeño salsa
consisted of 34th a cup of mild thick and chunky Pace® salsa and 14th a cup of seeded diced
jalapeño pepper, likewise the chipotle salsa consisted of 34th a cup of mild thick and chunky
Pace® salsa and 14th a cup of seeded diced chipotle pepper. Participants were allowed to keep
their disposable mouthpieces.
Results
In this study, the mean metabolic rate tested five minutes after consumption produced
control salsa (886.3563±58.06 mg/LCO₂/sec), bell pepper (1042.077±58.06 mg/LCO₂/sec),
jalapeno (1061.791317±58.06 mg/LCO₂/sec) and chipotle pepper (1073.467256±58.06
mg/LCO₂/sec). Compared with the control salsa, only jalapeno and chipotle had significantly
increased mean metabolic rate (unpaired T-test, p < 0.05)
Figure 1. Type of Pepper 5 minutes after consumption and mean metabolic rate. Mean
metabolic rate was statistically different between Salsa and Jalapeno (unpaired T-test,
p=0.03611 ). Salsa and Chipotle were statistically different (unpaired T-test, p=0.03074),
but there was no statistical difference between Salsa and Bell pepper (unpaired T-test,
p=0.1043). Error bars are mean ± SEM.
The mean metabolic rate tested ten minutes after consumption produced control salsa
(887.93521±34.2 mg/LCO₂/sec), bell pepper (979.7865±34.2 mg/LCO₂/sec), jalapeno
(1033.741±34.2 mg/LCO₂/sec) and chipotle pepper (1064.946±34.2 mg/LCO₂/sec). Once again
jalapeno and chipotle still had significantly increased mean metabolic rate when compared to the
control salsa (unpaired T-test, p < 0.05).
Figure 2. Type of Pepper 10 minutes after consumption and mean metabolic rate. Mean
metabolic rate was statistically different between Salsa and Jalapeno (p=0.0387). Salsa and
Chipotle were statistically different (p=0.0484), but there was no statistical difference
between Salsa and Bell pepper (p=0.1516). Error bars are mean ± SEM.
Discussion
The experiment resulted in a significant difference between the concentration of capsaicin in
some peppers and the effect on metabolic rate. Capsaicin values are measured using Scoville
units which measure the intensity or “spicyness” of the pepper which is created by the
capsaicinoid group (Kawada, et al., 1986). Scoville units increase in order from bell pepper (0
SHU), jalapeno (2,500-8,000 SHU) and chipotle pepper (3,500-10,000 SHU). The jalapeno and
chipotle peppers showed statistically significant increase in mean metabolic rate in both five and
ten minutes after consumption. Between the five and ten minutes after consumption, the
metabolic rate began to decline insinuating the increase in metabolic rate is short lived. The short
boost of metabolic rate limits the possibility of capsaicin becoming a solution to fighting health
issues such as obesity, but changes the role to more of a supporting role, used to supplement a
daily diet. Capsaicin is easily accessible and low budget depending on the concentration of
capsaicin in the pepper (Yoshioka, et al., 1995). Future experiments could be attempted with
peppers with much higher scoville units, such as ghost peppers or the carolina reaper pepper.
Their higher Scoville ratings may result in longer lasting effects on metabolic rate. Additionally,
further analysis and future experiments could determine precisely what Scoville rating begins to
have an impact on both short and long term metabolic rates which could have further
implications for long term health and weight management recommendations.
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