[Kim Jaeho's Life Story]<201> Healthy Foods My Body Likes

Hippocrates, known as the father of medicine, expressed the importance of food by saying, "Let food be thy medicine and medicine be thy food." Qin Shi Huang, the first emperor to unify China, is recorded to have sent thousands of people to the Korean Peninsula in search of an elixir that would prevent aging and death (the elixir of immortality). Around us, many people believe that eating well is essential for health and practice the health foods they trust.

Dictionaries define health food as "food specially made to maintain or improve health," but opinions vary on what exactly constitutes health food. This definition alone makes it difficult to determine specifically which foods are health foods. Occasionally, researchers visit longevity villages to study and report on the lifestyles and diets of their inhabitants, but this method also fails to provide a clear answer.

It is not easy to judge the correctness of the various opinions on what constitutes health food, but the conditions for a food to be considered healthy are clear. First, a health food must contain all the nutrients required by our body. Unfortunately, there are limitations in the accuracy of information regarding the types and amounts of nutrients our body needs and which foods contain these nutrients in appropriate amounts.

Moreover, it is important that when we eat such foods, our body can properly digest and absorb them, and that harmful substances in the food do not damage the body. From the perspective of digestion and absorption, the food and eating methods favored by the "my body," the consumer of the food, can be called health food. To understand health food from this perspective, it is important to accurately understand the principles of digestion and synthesis.

Plants use water, carbon dioxide, and solar energy to produce carbohydrates (photosynthesis), convert these carbohydrates into fats, and synthesize proteins by utilizing nitrogen compounds such as nitrates or ammonia to live. In contrast, animals and humans, which cannot perform photosynthesis, survive by taking nutrients from plants or other animals, a process that necessarily involves digestion and synthesis.

Most nutrients exist as large molecules that are not water-soluble, so our bodies cannot absorb or directly use them. Food must be mechanically broken down (mechanical digestion), then chemically broken down into small, water-soluble molecules (chemical digestion) to be easily absorbed?this is digestion. The absorbed nutrients are then used to produce energy needed for activities and to synthesize various substances required by the body.

Because our bodies synthesize necessary substances based on these principles of digestion and synthesis, special foods like the elixir of immortality are unlikely to exist. For proteins, whether animal or plant-based, they are broken down into 20 types of amino acids through digestion, and then various proteins needed by the body are synthesized by changing the ratios of these amino acids. This is why it is difficult to say that animal protein is especially better than plant protein.

If there were a food containing all the necessary nutrients in appropriate amounts, it would be considered health food, but since such a perfect food does not exist, the idea that a specific food is health food is incorrect. Each food contains different amounts of nutrients, so if one eats only certain foods, some nutrients may be deficient while others may be excessive. This is why it is important to maintain a broad balance by eating a variety of foods.

Eating non-healthful meals for a long time leads to various diseases. In the United States, more than half of adults suffer from chronic diseases such as hypertension, diabetes, and obesity. To address this, dietary guidelines were established in 1980 and revised every five years. In 1990, a federal law was enacted to provide a legal basis for these dietary guidelines, which include well-organized content about healthful eating.

The U.S. dietary guidelines can be summarized in three points. First, maintain healthy eating habits within an appropriate calorie range; second, consume a variety of colorful vegetables, whole fruits, at least half of grains as whole grains, fat-free or low-fat dairy products, various protein foods, and plant-based fats; third, limit foods such as saturated fats (less than 10% of daily calories), trans fats, sugars (less than 10% of daily calories), salt (less than 5g per day), and alcohol (up to one drink per day for women and two drinks per day for men).

Also, since no food is automatically digested just by eating it, how one eats is as important as the type of food. To absorb nutrients well and maintain digestive health, bad eating habits such as overeating or binge eating should be corrected to support digestion (see Life Story, episode 34).

It should be remembered that the digestive health status of Koreans is not very good. In 2019, 52,501 people died from digestive diseases, including 40,538 deaths from digestive cancers, accounting for 17.8% of all deaths. Korea has an unusually high incidence of digestive cancers, with stomach and colorectal cancers ranking first and second worldwide, liver cancer remains prevalent, and bile duct and pancreatic cancers, which were rare in the past, are rapidly increasing.

Jaeho Kim, Independent Researcher