Spicy food flavoured with hot chilli peppers contains a natural chemical ingredient that may lower blood pressure, according to a study of rats with hypertension.
Scientists have discovered that the long-term ingestion of capsaicin, the ingredient in chillies that makes them taste hot, can reduce blood pressure -- at least in rats.
Previous studies have produced mixed results when it comes to finding a link between hot chillis and blood pressure, but this may be because they were carried out over relatively short time periods, the scientists said.
The findings are the first to establish a link between the ingestion of capsaicin over a longer period of time and a lowering of blood pressure in animals genetically predisposed to having hypertension.
"We found that long-term dietary consumption of capsaicin, one of the most abundant components in chilli peppers, could reduce blood pressure in genetically hypertensive rats," said Dr Zhiming Zhu, of Chongqing, in China.
The study suggests that capsaicin works by activating a special "channel" in the lining of the blood vessels called the transient receptor potential vanilloid 1. When the channel is activated, it increases the production of nitric oxide in blood vessels that is believed to protect against inflammation.
Dr Zhu said one clue came from China, where the prevalence of hypertension is greater than 20pc in the north-eastern regions of the country, but between 10 and 14pc in souther-western regions such as Sichuan where spicy food is favoured.
"People in these regions like to eat hot and spicy foods with a lot of chilli peppers.
For example, a very famous local food in my hometown, Chongqing, is the spicy hot pot," Dr Zhu said.