While there are some studies which suggested that capsaicin present in chilli peppers may have some benefits in pain relief (capsaicin creams) and in certain cancer types such as lung, breast and colorectal cancers, other studies suggested that excess intake of spicy foods made of hot chilli peppers rich in capsaicin may not be good, especially for the stomach and gallbladder. A recent meta-analysis also highlighted that intake of capsaicin rich chilli may increase the risk of gastric/stomach cancer. More well defined clinical studies are needed to establish these findings. However, it is better to avoid long term excessive intake of chilli peppers rich in capsaicin and use them in low to moderate quantities to stay away from the possible danger of stomach cancer.
Chilli and Capsaicin
Hot chilli peppers are one of the most common ingredients that we use in our cuisines to spice them up. Chilli peppers have been used for millions of years and are grown and consumed worldwide. There are different varieties of chilli peppers available such as bell peppers, cayenne, jalapeños, Thai peppers, naga, habanero, malagueta, tabasco, piri piri, rocoto peppers and aji peppers.
The key active compounds present in chilli peppers are :
- Linolenic acid
- Oleic acid
- p-coumaric acid
- Vitamin C
Capsaicin is the pungent component present in chilli peppers that makes it hot. The amount of capsaicin present in the chilli peppers differs based on their variety and growing conditions.
Unlike other natural irritants, capsaicin which usually irritates or creates a burning sensation, may have certain benefits associated with pain relief and are hence used in creams and patches. This is because the initial neuronal excitation induced by Capsaicin is followed by a long-lasting refractory period during which the previously excited neurons are no longer responsive to a broad range of stimuli. (Wytske Fokkens et al, Curr Allergy Asthma Rep., 2016)
Hence, capsaicin works as a pain reliever by affecting the neurotransmitter which communicates the pain signals to the brain. Capsaicin-containing creams have been in use for many years. Different studies also suggested the benefits of application of topical capsaicin cream in decreasing post-surgical neuropathic pain in cancer patients. (N Ellison et al, J Clin Oncol., 1997)
However, chilli and capsaicin have been in controversies for many years due to conflicting results on their effects on cancer risk. While there are some studies which suggest that chilli peppers may have some benefits in certain cancer types such as lung, breast and colorectal cancers, other studies suggest that excess intake of spicy foods made of hot chilli peppers rich in capsaicin may not be good, especially for the stomach and gallbladder.
Recently, in 2020, a meta-analysis was published which again evaluated the association between chilli consumption and gastric/stomach cancer risk. Hence, in this blog, we will quickly look at some of these studies to understand whether chilli pepper can be suggested as part of the cancer patients’ diet and its intake is good or bad for stomach cancer risk.
Association between Chilli Pepper and Gastric/Stomach Cancer
Meta-analysis by Researchers from Hunan Normal University in China
In a recent meta-analysis published in 2020, the researchers from the Hunan Normal University in China evaluated the association between hot chilli pepper (rich in capsaicin) consumption and gastric/stomach cancer. For the analysis, data from 13 studies involving 3,095 cases and 4,761 controls was obtained through literature search in Medline, PubMed, Web of science, Embase, Cochrane Library databases until May 2019. (Yanbin Du et al, Nutr Cancer., 2020)
Following are the key findings of this study:
- A moderate-high intake of hot chilli pepper was associated with a 1.96-fold increased risk of stomach/gastric cancers.
- Dose-response analysis found a significant nonlinear association between capsaicin intake and increased gastric cancer risk and suggested a significant high risk of gastric/stomach cancer for those with high chilli consumption but not for moderate chilli consumption.
Findings from this meta-analysis suggested that a higher intake of hot chilli peppers containing capsaicin may be associated with an increased incidence of stomach or gastric cancer. However, more well-defined studies are required to confirm these findings.
Population-based study in Mexico City (1989-1990)
In another previous study done by the researchers from the Yale University School of Medicine, Connecticut in 1994, they analyzed the data from 220 gastric cancer cases and 752 controls from a population-based case-control study conducted in Mexico City during 1989-1990 to evaluate the association between hot chilli pepper consumption and gastric/stomach cancer risk. (L López-Carrillo et al, Am J Epidemiol., 1994)
The study found that compared to those who did not consume chilli peppers, those who consumed very high amounts of hot chilli peppers were associated with a 17.11 % increased risk of gastric cancers. However, when chilli intake was measured on the basis of amount consumed per day, a significant trend among consumers was not observed.
The researchers concluded that a high consumption of hot chili peppers may be a strong risk factor for gastric/stomach cancer. However, more studies are needed to establish these findings.
Association between Capsaicin and Gastric Cancer
A study done by the National Institute of Public Health in Mexico evaluated the potential interactions between various factors such as intake of capsaicin rich hot chilli peppers, infectious factors such as Helicobacter pylori and genetic factors such as IL1B-31 genotypes on stomach/gastric cancer risk. The study found that a moderate to high intake of Capsaicin synergistically increased the risk of gastric/stomach cancer in genetically susceptible individuals who were IL1B-31C allele carriers and were infected with the more virulent Helicobacter pylori strains. (Lizbeth López-Carrillo et al, Food Chem Toxicol., 2012)
Association between Spicy Foods and Gastric/Stomach Cancer
A meta-analysis done by the researchers from China evaluated the association between spicy food intake and cancer risk. They analyzed 39 studies from 28 articles obtained through literature search in online databases such as PubMed, EMBASE, and the Cochrane Library, involving 7884 patients with cancer and 10,142 controls. The study found that eating large amounts of spicy food was associated with an increased risk for gastric cancer suggesting that spicy foods made of hot chilli peppers containing high amounts of capsaicin may not be good for your stomach. However, more research needs to be conducted to confirm whether spicy foods are a definitive risk factor for gastric/stomach cancer. (Yu-Heng Chen et al, Chin Med J (Engl)., 2017)
The above studies suggest that excess intake of hot chilli peppers and spicy foods rich in capsaicin may not be good for the stomach and may increase the risk of stomach/gastric cancers, though capsaicin may have benefits in other cancer types and in pain relief (used in creams). More well defined larger clinical trials are needed to establish these findings. However, to be safe, it is better to avoid long term excess intake of hot chillies rich in capsaicin and use them in low to moderate amounts to spice up our dishes.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer. Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.