There's probably no food quite as baffling as the chili pepper.
A bite of a habanero, jalapeño or cayenne can pack such an ouch that all logic says they should repel those who attempt to consume them. Yet for centuries humans have not only eaten such spicy foods -- but enjoyed them. In recent years, worldwide consumption of hot spices has grown dramatically, fueled by the popularity of Mexican salsas, Thai and Indian curries and the like.
Scientists seeking to better understand the alluring properties of hot foods have found evidence that we may be so drawn to them because they are good for us. While the research is still preliminary, it suggests spicy food may have all kinds of health benefits ranging from boosting metabolism and preventing gastric damage to reducing the risk of heart disease and cancer.
The newest study, published this week in The BMJ, finds a link between regular consumption of spicy foods and a lower risk of death.
As far as these types of epidemiological studies go, this one is huge. It's based on dietary data of nearly 500,000 people from China, the birthplace of all manner of spicy foods from chicken stir-fried in mounds of red peppers to mouth-numbing dumplings bathed in a red oil.
The participants, who were enrolled in 2004-2008 and followed for a mean of 7.2 years, were asked to fill out a questionnaire that included general questions about their health and diet including how often they ate spicy foods. Out of 487,375 participants, 20,224 died during the study period.
After controlling for age, gender, level of education, marital status, alcohol consumption, smoking, health history, and other variables, the researchers found an inverse relationship between eating spicy foods and risk of death. Those who ate spicy foods 1-2 times a week had a 10 percent lower risk of death than those who rarely or never ate them, and those who ate them 3-7 times a week had a 14 percent lower risk of death.
The link was similar for both men and women. Frequent consumption of spicy foods was also linked to a lower risk of death from specific conditions: cancer, ischaemic heart and respiratory system diseases.
Jun Lv, a professor in the department of epidemiology and biostatistics at Peking University; Lu Qi, an associate professor at Harvard's School of Public Health; and their co-authors also wrote that their data shows that the associations they found for those diseases seem to be stronger for those who consumed fresh chili pepper than those who consumed dried chili, sauce or oil.
The researchers said that while it isn't possible to draw any conclusions about whether eating spicy foods causes you live longer from their work that more studies are needed to look at this link in more depth. If their findings are confirmed, they said, it could lead to updated dietary recommendations and development of herbal supplements.
"Spices have been an integral part of culinary cultures around the world and have a long history of use for flavoring, coloring, and preserving food, as well as for medicinal purposes ... however, the evidence relating daily consumption of spicy foods and total and disease specific mortality from population studies is lacking," they wrote.
Lv, Qi and the other researchers suggested that capsaicin, the molecule responsible for the hot sensation in spicy foods by binding to the pain receptors in the tongue and making them feel like they are burning, may be the reason behind the link between chili peppers and longevity.
"The beneficial roles of capsaicin have been extensively reported in relation to anti-obesity, antioxidant, anti-inflammatory, anti-cancer, and anti-hypertensive effects," they wrote. They also noted that spices have been shown to have an anti-microbial function that may impact the bacteria that live in your gut in such a way that it helps increase longevity.
In an editorial accompanying the study, Nita Forouhi, a researcher at the epidemiology unit of the University of Cambridge, said that the Chinese study has a number of strengths but that the dietary survey contained only "crudely measured" categories (red meat, fresh vegetables, fresh fruits) so it was unable to take into account other dietary habits that might have impacted the results, and that the quantity and strength of the chili consumed was also unknown.
Forouhi said that as a result the research should be "considered hypothesis generating, not definitive."
"Should people eat spicy food?" Forouhi said. "It's too early to say, but the debate and the research interest are certainly hotting up."