Hot, hot, hot foods are the focus of new research released this week, which suggests eating fiery ingredients such as chili peppers may do more than burn your tongue. These foods may help you live longer.
“There is accumulating evidence from mostly experimental research to show the benefit of spices or their active components on human health,” said Lu Qi, an associate professor at Harvard School of Public Health and co-author of the study which was published this week in the BMJ. But the evidence evaluating consumption of spicy foods and mortality from population studies was lacking, he said.
As a result, researchers from the Chinese Academy of Medical Sciences studied data collected from 2004-2008 as part of the China Kadoorie Biobank. Using self-reported questionnaires, they analyzed the spicy food consumption of nearly half a million people age 30-70, across 10 regions in China, excluding those with cancer, heart disease and stroke.
They then reviewed the records of 20,224 people who died over a seven-year followup period and found those who ate spicy foods six or seven times a week had a 14% lower risk of death for all causes than people who ate spicy foods less than once a week. People who frequently consumed spicy food also showed a lower risk of death from cancer, ischaemic heart and respiratory system diseases.
Fresh and dried chili peppers were the most common spicy sources, according to the study.
What is it about spicy foods? The study points to the benefits of capsaicin, a bioactive ingredient in chili peppers, which has been previously linked to health perks such as increased fat burning. Folk medicine practitioners also say capsaicin can help fight infection and stimulate the kidneys, lungs and heart.
Then, there’s the old wives’ tale which says eating spicy food will induce labor (there’s no scientific evidence supporting this claim, in case you’re wondering).
There are also a few risks associated with eating spicy foods. “There are certain foods that are triggers for people with incontinence or overactive bladders, including spicy foods, which doctors have identified as common irritants for women,” Kristen Burns, an adult urology nurse practitioner at Johns Hopkins Hospital, in Baltimore, said.
To be clear, this new research found an “association” between death and spicy food consumption. An editorial published with the study cautions that this is not definitive. As a result, experts emphasize the need for more research before a connection between these ingredients can be scientifically established.
“It’s an observational study within a single culture,” said Dr. Daphne Miller, associate clinical professor at the University of California San Francisco and author of “The Jungle Effect: The Healthiest Diets from Around the World, Why They Work and How to Make Them Work for You.”
There are many variables associated with eating spicy food that haven’t been accounted for, she said. The study itself cites limitations which include the lack of information about other dietary and lifestyle habits or how spicy food was cooked or prepared. In addition, researchers note that although chili pepper was the most commonly used spice based on self-reports, the use of different spices tends to increase as the use of chili pepper increases. Consuming these other spices may also result in health benefits, independent of chilies.
However, Miller said the findings are still plausible, given spicy foods also have high levels of something called phenolic content (which are chemicals with nutritional and anti-inflammatory value).
Bio-psychologist John E. Hayes agrees. The fact that there seems to be an overall protective effect in chili intake is especially interesting, according to Hayes, an associate professor of food science and director of Sensory Evaluation Center at Penn State University. He has previously studied spicy food and personality association.
Now scientists need to figure out why this benefit is occurring.
“As a bio-psychologist that studies food,” said Hayes, “we have to consider: Is it a biological mechanism or a behavioral mechanism?” A biological connection could mean that when you eat spicy food, thermogenesis occurs, increasing the basil metabolic rate, said Hayes, while a behavior mechanism could be that eating spicy food slows food intake, causing a person to eat fewer calories. A lower calorie consumption could indicate a more healthful diet, which would be an unaccounted variable not shown by the new study.
Qi, the author of this new study, believes the protective effect associated with spicy foods would indeed translate across cultures, but Hayes said we have to be careful.
“It’s a very big study, a very controlled study,” he said, but may not generalize to other countries. For instance, in the U.S. “spicy food is ubiquitously available but not ubiquitously consumed.”
“You have to consider that when we talk about spicy food, we can mean vastly different things, with different health implications,” said Hayes. “That spicy food could be low energy density vegetables, like kimchee. Or it could be a high energy density food like barbeque spare ribs.”
So before you make a run for the hot sauce, more research is needed to qualify what spicy entails and the various ingredients, which the current study does not break down.
“This isn’t an excuse to go out and eat 24 wings and then rationalize it by claiming they are going to make you live longer,” said Hayes. “When you’re looking at a whole food, versus the individual component, we have to be very cautious.”
This is the big caveat. “In science we try to break things down into the simplest parts, while still considering the context,” Hayes said.