Don't brag blindly! Here comes a self-test table for eating spicy food... How many levels can you stick to?

Among the five flavors in daily life, spicy food has always been the most popular. In the more than 400 years since it was introduced into my country, chili peppers have quickly become the main ingredient in Sichuan cuisine, one of the eight traditional cuisines, thanks to their unique and unforgettable taste. This is a rare phenomenon in the history of cuisine. Now we know that the fundamental reason why people in Sichuan and Chongqing love spicy food is that the climate here is hot and humid, and chili peppers can help the human body to expel moisture. However, some people miss chili peppers when they don't see them for a day, some people prefer light taste and don't like spicy food, and some places even do their best to ban spicy food.

Recently, the Danish Food Administration issued a letter requesting Samyang Foods to recall three of its famously spicy turkey noodles because "the pepper content is too high and may cause acute poisoning to consumers." Coincidentally, Germany also banned the sale of a type of devil pepper potato chips nationwide because a 14-year-old student died of food poisoning a few hours after eating them.

"One man's meat may be another's poison." What is the original sin behind such polarized food reviews and effects?

chili

Nobel Prize winner explains the mechanism of spicy sensation

From a scientific point of view, the feeling of spiciness is defined as "pain". This has probably become common sense today. However, if you dig deeper into why, I'm afraid few people can explain it clearly. And it is precisely with this little-known truth that American neuroscientist David Julius won the 2021 Nobel Prize in Physiology or Medicine.

In life, most people have a very consistent feeling when eating chili peppers, which is first a stinging sensation in the mouth, followed by a burning sensation, as if there is a blazing fire in the mouth. This is perfectly consistent with David Julius's research results. Through repeated experiments, he clearly told us that this real pain and illusory heat are actually a "good show directed by" the capsaicin in the chili pepper and the capsaicin-specific receptor in the human body, the vanilloid receptor type 1 (TRPV1).

Spicy food experience

As early as the late 1990s, David Julius led his team to actively analyze how capsaicin causes sensations in the human body. Through various means, he successfully identified and cloned the vanilloid receptor type 1 (TRPV1), revealing the basis of the body's perception of spiciness at the molecular level, that is, TRPV1 is an ion channel activated by pain and heat (noxious heat ≥ 42°C), and is an afferent neuron that specifically recognizes noxious stimuli. It is widely distributed in multiple tissues and organs of the body. When the mouth comes into contact with capsaicin, TRPV1 is instantly activated, generating electrical signals that are transmitted to the brain along noxious afferent neurons, and the brain then interprets these signals as "painful" stimuli.

The slight burning sensation is generally just an illusion. People become more sensitive to heat after being spicy. Because when TRPV1 is activated by capsaicin, the threshold of the human body's temperature perception is also lowered. Even when the body temperature is less than 42°C, TRPV1 will be induced to transmit harmful heat signals to the brain, causing the brain to have an abnormal perception of "heat". Therefore, under the dual stimulation of capsaicin and temperature, the excitability of sensory neurons expressing TRPV1 receptors is also enhanced. Taken together, the human body's feelings will be amplified, and the mouth will feel like it is "breathing fire".

Are humans obsessed with "paying for trouble"?

Since the feeling of spiciness is painful, why have humans become dependent on chili peppers over thousands of years as if they were collectively suffering from Stockholm syndrome?

Records show that the use of chili peppers dates back to 7000 BC in Central America. An article published in Science reveals that humans from the Bahamas to the Andes began to grow and eat domesticated chili peppers 6000 years ago. In some areas, chili pepper cultivation predates the emergence of pottery.

The more painful it is, the more people can't stop. How "good" is this "paying for pain"? I'm afraid a thousand people can give a thousand reasons, but so far, the scientific community has not yet produced a reason that convinces most scientists to love spicy food. Scientists in different fields have different perspectives, and their conclusions are naturally very different.

Enjoy the spicy feeling

Biologists have found a relationship between the average temperature of a region and the proportion of spicy food in the diet from an evolutionary perspective: the higher the average temperature of a region, the higher the proportion of spicy ingredients used in local food, because hot weather can easily breed a large number of microorganisms in food, and spicy substances have a bactericidal effect, ensuring food safety. In addition, although the explanation level of genetic factors for the preference for spicy food has always been in the range of 18% to 58%, and the rest is the role of environmental factors, this is enough to show that the preference for spicy food has some genetic tendency.

Psychologists tell us that the tendency of "benign self-abuse" is a normal phenomenon that is prevalent in human society and an important psychological support for the love of spicy food. Individuals usually enjoy negative experiences that are misunderstood by the body or brain as threats, because once the individual realizes that the real danger does not exist, the difference between cognition and physiological reactions will produce a double sense of excitement. Therefore, humans' love of spicy food is a behavior of actively seeking negative experiences. And some scientists have proposed through research and investigation that the most pleasant spicy experience will be produced when the spiciness of the food consumed by an individual is just slightly lower than his or her tolerance.

Spiciness self-test table

People who love spicy food are often quite confident in their ability to withstand the spiciness. But don't brag, let's take a look at the detailed reference scale provided by the Scoville Scale.

In 1912, American pharmacist Wilbur Scoville designed a subjective evaluation method called the "Scoville Organoleptic Test" to measure the capsaicin content in different pepper varieties. He used his last name as the unit of capsaicin content, called the "Scoville Heat Unit", abbreviated as SHU. However, his experimental method mainly relied on the personal subjective feelings of the subjects. Later generations developed a more objective "high performance liquid chromatography" to measure, but the capsaicin content unit SHU was retained and is still used today.

Take the following table as an example. Bell peppers do not contain capsaicin at all, so their Scoville index is 0; Mexican peppers are between 2,500 SHU and 10,000 SHU, and the highest Scoville index is also the hottest pepper in the world today - Pepper X, with a spiciness of more than 2.69 million SHU. However, this pepper is a man-made variety, cultivated by Ed Currie, the creator of the Carolina Reaper, the world's hottest pepper, and an American pepper breeder, who spent 10 years cultivating it. Another intuitive reference value is that the Korean instant noodles that were recalled in this news have a spiciness of about 4,400 SHU.

Ranking of the hottest peppers in the world measured by Scoville heat units (Image source: wikipedia.com)

If you are not familiar with the SHU unit for measuring spiciness, then my country, as a country that loves spicy food and produces chili peppers, also has a spiciness rating that is "more suitable for Chinese babies' physiques." In 2014, the Department of Food Science of Sichuan Tourism College and the Key Laboratory of Culinary Science of Sichuan Higher Education Institutions combined the Scoville Index, the content of capsaicinoids in food, and the traditional spiciness rating concept to classify 123 Sichuan dishes into four levels: slightly spicy, medium spicy, spicy, and very spicy. You can do what you can in your future life.

The top 20 spiciest Sichuan dishes in the study (Image source: https://www.spkx.net.cn/)

Scientists teach you how to relieve spiciness scientifically

However, in order to prevent someone from lying about their ability to eat spicy food at the dinner table, here are some scientific tips for dealing with spicy food:

Destroy the binding of capsaicin to TRPV1 receptors. Since capsaicin is only soluble in oil and alcohol, but not in water, drinking water cannot relieve the spiciness. Instead, it will spread the capsaicin throughout the mouth and even the throat, making it even spicier. Therefore, compared to drinking water, a mouthful of milk or other dairy products is more helpful in relieving the spiciness. Dairy products not only contain oil, but also casein, which is a non-polar molecule that can bind to capsaicin, which is also a non-polar molecule, to dissolve it and eliminate the burning sensation. Therefore, foods such as whole-fat ice milk, whole-fat yogurt or ice cream are all "experts" in relieving spiciness. In addition, starchy foods can also play a certain role in alleviating spiciness, such as rice, bread, potatoes, etc. Although starch cannot dissolve capsaicin, it can absorb capsaicin like a sponge, shorten the duration of the spicy taste, and eliminate the spicy feeling. So if there is no milk, you might as well take a few more bites of rice when you accidentally get spicy.

Interfere with the brain's perception of spiciness, such as sucrose. On the one hand, the stimulation of spicy and sweet tastes acts on different receptor cells in the mouth. After activation, these cells interact with each other and interfere with the brain's perception of spiciness alone. On the other hand, the brain releases analgesic substances after receiving sweet stimulation to relieve the stinging sensation caused by spiciness.

Using acidic substances to neutralize alkaline capsaicin, such as lemon, sour plum, sweet orange, etc., can relieve the spicy feeling.

An article published in the journal Physiology and Behavior in 2018 proposed a more interesting finding: Completely blocking nasal airflow can reduce the perception of capsaicin by 50%, because after the nostrils are closed, the surface temperature of the tongue will decrease, thereby reducing the possibility of activating TRPV1. In other words, maybe next time you are spicy, you can try pinching your nostrils and use physical methods to relieve the spiciness.