Scientific Analysis of Raw Food Safety: Reshaping Human Evolutionary Dietary Instincts and Five Immune Barriers

Despite the numerous benefits of raw food, most Chinese people still hesitate to eat it raw-a fear of raw food exists. People worry about the safety of raw food mainly about two things: first, chemicals such as pesticides, heavy metals, and carcinogens; and second, microorganisms such as viruses, bacteria, and parasites. However, people may not have considered that heating and cooking generally cannot remove pesticides and other harmful substances, while the bacteria and microorganisms that are supposed to be removed should not actually be removed. This is because bacteria and microorganisms are not enemies of humans, but friends. The theory of bacterial disease was first established by the French biologist Louis Pasteur. However, in his later years, he said that bacteria are nothing; the environment is everything!

Let's first look at heavy metals, pesticides, and chemicals. Anyone who has studied high school chemistry should know that heating chemicals in water generally doesn't reduce their concentration; in fact, it may increase it (e.g., heavy metal content), and can even produce new, harmful compounds (for example, after boiling, chlorine in tap water may combine with hydrocarbons in the water to form chloroform). In fact, the bigger food safety issues today go far beyond these two; more importantly, there are anti-nutritional substances such as sugar, salt, hydrogenated oils (trans fats), lectins, or genetically modified ingredients. The heating and cooking process, besides reducing lectins in grains, often increases other unsafe factors, such as sugar, salt, and hydrogenated oils.

Besides the reasons mentioned above, such as pesticide use, people are also hesitant to eat raw food due to fears of parasites, bacteria, and viruses. For a period afterward, many seafood restaurants in Beijing, as well as Japanese restaurants serving raw salmon, closed down due to concerns about tuberothecia. In fact, our close relatives, monkeys and chimpanzees, love to eat ants and other insects, and some primitive tribes also enjoy eating live insects. Many vegetarians from southern India who immigrated to Britain developed severe anemia. Medical examinations revealed a severe deficiency in vitamin B12. It turned out that Indian plants contained insects that provided vitamin B12, while British pesticides and cleaning agents blocked this source. Ironically, insects saved the lives of Indian vegetarians.

Let's review the history of humankind: when were we at our physical peak? It was during the Paleolithic era, 50,000 years ago. Our ancestors were about 30% larger than us then, and their brains were about 11% larger. For 99% of our 5 million-year evolutionary history, humans consumed raw food, large quantities of raw animal products-unheated, unsalted, and unseasoned-rich in protein and linolenic acid. This led to a threefold increase in brain size and a smaller stomach. By the time we entered the Paleolithic era, 50,000 to 100,000 years ago, humans had developed strong muscles, robust bones, and large skulls. After entering the Neolithic era 10,000 years ago, agricultural technology emerged, leading to the production of grains and dairy products. Cooking techniques were also developed, allowing for heating and salting. From the perspective of overall dietary anthropology, humans have actually consumed cooked food for less than 1% of the time.

Let's look at the lifestyles of long-lived ethnic groups today. Take Japan, Bama in Guangxi, China (a region known for its longevity), and Hansh in Pakistan as examples. Their lifestyles are quite similar; they all prefer raw food or minimal cooking. 80% of the Hansh people's food is raw: Japanese cuisine is full of raw foods, including raw salads, raw eggs, various sashimi, and raw beef. Therefore, you don't need to fear raw food unless you don't want to live a long life. In fact, bacteria and viruses are the ancestors of humans and all living things. Microorganisms are friends of humans, coexisting peacefully. Viruses and bacteria appeared on Earth first, then plants and animals, and finally humans. There are thousands of bacteria per cubic centimeter of air. Each person, composed of raw flesh, carries countless bacteria, viruses, and microorganisms. For example, there are over a million tuberculosis bacilli in the lungs of every normal person, yet normal people do not get tuberculosis. Prisoners in the former Soviet Union, lacking sunlight, exercise, and fresh air in prisons, suffered from malnutrition in their diets, causing their lungs to partially rot. Once rotten, tuberculosis bacilli could multiply rapidly using this as nutrients.

Microorganisms and bacteria are not dangerous at all; on the contrary, they can be captured and utilized by the human body, and are often beneficial. For some invasive microorganisms, a healthy body has five barriers sufficient to capture, eliminate, or keep them out. Furthermore, even if aggressive bacteria, viruses, and parasites invade during the consumption of raw food, it is not actually dangerous. Our bodies have at least five protective barriers, sufficient to keep them out or capture and utilize them.

The first barrier is the mouth. Microorganisms or insects entering the mouth are broken down by chewing and salivary enzymes. The second barrier is the stomach. Any remaining microorganisms or insects entering the stomach will be devastatingly broken down by gastric juices (especially gastric acid). Gastric acid is essentially hydrochloric acid-a strong acid with a normal pH between 1 and 2. It can burn a hole in your carpet, instantly obliterating microorganisms or parasites. Therefore, the stomach forms the second powerful protective barrier, making it difficult for any microorganisms or parasites to escape. The third barrier is the intestinal mucosa. If taking antacids or drinking too much water during meals dilutes gastric juices, resulting in insufficient gastric acid, then any remaining microorganisms or parasites may escape the gastric acid's wrath and enter the intestines. The intestinal mucosa is our body's third protective barrier against foreign objects, preventing undigested food or foreign substances from entering the bloodstream. The fourth barrier is white blood cells. If there are leaks in the intestinal mucosa, then microorganisms or parasites may penetrate it and enter the surging bloodstream. Here, your immune army-white blood cells-forms the fourth line of defense, launching a massive sweep and annihilation of invaders. The fifth barrier is the blood-brain barrier. If the resistance of white blood cells is weak, microorganisms or parasites may travel throughout the body via the bloodstream. However, they have difficulty entering the body's command center-the brain-because there is a fifth line of defense there-the blood-brain barrier-which prevents harmful substances from entering the brain from the bloodstream.

You should understand that for microorganisms or parasites to actually enter the brain or other vital parts of the body, they need to overcome numerous obstacles. This is impossible when the human body has a normal immune system. By the time these things become possible, the body is already riddled with problems and on its last legs, vulnerable to any adversity. The invasion of microorganisms or parasites is merely the final straw that breaks the camel's back, leaving it already overburdened.