Not long ago, a seemingly health-related message circulated widely on WeChat Moments, leaving many people with an "aha!" moment. The message claimed that when the body's pH level is between 7 and 7.35, it's considered "slightly acidic," making one more susceptible to minor ailments; a pH level between 6.9 and 7 increases the risk of serious diseases like cancer; and that high blood pressure and diabetes are caused by an "acidic constitution," so to prevent these diseases, one should eat more alkaline foods.
So, is it true that people's bodies are classified as acidic or alkaline? Is an "acidic constitution" really the root of all diseases? Can an acidic constitution really be adjusted to an alkaline constitution through diet? Can alkaline foods really prevent and treat cancer? To address these questions, reporters interviewed relevant medical experts in Hebei Province. All three experts interviewed stated that there is no such thing as an "acidic or alkaline constitution" in medicine. The claim that cancer patients' blood is acidic is pure nonsense. Blood pH is not easily changed by diet, and the idea that alkaline foods can treat cancer is utterly absurd.
The concept of "acid-base balance" does not exist in medicine.
The three experts stated that the concepts of "acidic constitution" and "alkaline constitution" do not exist in medicine at all and are purely fictitious.
"From the perspective of traditional Chinese medicine, there is no such thing as an acid-base constitution. Instead, according to TCM theory, constitutions are divided into balanced constitution, qi deficiency constitution, yang deficiency constitution, yin deficiency constitution, phlegm-dampness constitution, blood stasis constitution, damp-heat constitution, qi stagnation constitution, and special constitution," said He Hongtao, deputy director of the Department of Cardiovascular Medicine at the Provincial Hospital of Traditional Chinese Medicine.
"During human life activities, acidic and alkaline metabolic products are produced in the body. However, the human body has three regulatory systems that maintain the body's acid-base balance: the body's buffer system, lung regulation, and kidney regulation," said Gao Shuqing, director of the Nutrition Department at the Fourth Affiliated Hospital of Hebei Medical University. The pH value of our body fluids is always stable within a certain range. Normal human blood is slightly alkaline, with a pH of 7.35-7.45, and the environment of the duodenum is also alkaline, with a pH of 8-9. Gastric juice, cecum, urine, vaginal fluid, and skin are slightly acidic. Therefore, simply believing that the human body is acidic or alkaline is a very naive and incorrect view.
"There is no question of which is better or worse between acidic and alkaline foods. On the contrary, it reminds people to pay more attention to the balance of their daily diet, maintaining an appropriate ratio of acidic and alkaline foods to achieve a balanced diet and promote health," said Lei Min.
What are the pathogenic factors of chronic diseases?
"An 'acidic constitution' is not a cause of chronic diseases," said He Hongtao. The human body has various fluids, such as blood, tissue fluid, lymph, digestive juices, sweat, and urine. Different fluids have different pH values; for example, blood is slightly alkaline, while gastric juice is acidic. Most of us are normally in a state of acid-base balance. Only a very small number of people experience increased acidity due to certain diseases or medications, such as severe diarrhea, chronic obstructive pulmonary disease, or renal insufficiency. These diseases severely affect metabolism, leading to impaired excretion of metabolic end products and thus an imbalance in the body's acid-base balance. Therefore, an "acidic constitution" is not a cause of chronic diseases, but rather a result of "acidosis" caused by a certain disease.
"Since there's no such thing as an 'acidic constitution' in medicine, claiming that an 'acidic constitution' causes cancer is a false proposition," Gao Shuqing stated. Cancer development is a complex process involving multiple factors and steps. Currently, there are five recognized categories of carcinogenic factors: First, chemical factors such as polycyclic aromatic hydrocarbons and aromatic amines; second, physical carcinogenic factors such as ionizing radiation, heat radiation, and chronic inflammatory stimulation; third, viruses, such as Helicobacter pylori, which can induce stomach cancer, and human tumor viruses, which are a major cause of cervical cancer; fourth, genetic factors, such as breast cancer and colorectal cancer, which often have a significant family history; and fifth, immune system deficiencies. With changing lifestyles, nutritional imbalances, environmental pollution, endocrine disorders, obesity, and excessive mental stress can all become contributing factors to cancer. Therefore, the occurrence of cancer has absolutely no relation to the body's acid-base balance.
Kao Shu-ching stated that the following unhealthy eating habits and foods can easily lead to cancer and should be avoided:
Pickled fish, meat, and salted vegetables contain nitrites and nitrosamines, with nitrosamines being highly carcinogenic.
Barbecued foods, such as roast beef, roast duck, roast lamb, roast goose, and roast lamb skewers, contain heterocyclic amines, which are potent carcinogens. The content is even higher in charred meat and fish.
Smoked foods, such as smoked meat and smoked fish, contain the carcinogen benzo[a]pyrene.
Fried foods. When fried until burnt, they produce carcinogenic polycyclic aromatic hydrocarbons.
Moldy food. Foods such as rice, wheat, beans, corn, and peanuts are prone to mold growth when damp. Once contaminated with mold, they can produce aflatoxin, a potent carcinogen.
Alcohol. Alcohol has been classified as a human carcinogen by the World Cancer Research Fund. Furthermore, alcohol is a co-carcinogen of tobacco because harmful carcinogens in tobacco are soluble in alcohol and adhere to the surface of the digestive tract mucosa, causing even stronger damage.
In addition, people who like to eat very hot food have a higher incidence of esophageal cancer, while people who are accustomed to high-salt foods have a significantly higher incidence of stomach cancer.
"The onset of hypertension is mainly related to genetic factors, environmental factors (diet, mental stress), overweight or obesity, and sleep apnea syndrome," said He Hongtao. Dietary factors include high-salt diets, low-calcium diets, low-potassium diets, high-fat diets, and alcohol consumption. The onset of diabetes is mainly related to genetic and environmental factors. Environmental factors include advanced age, lifestyle, overnutrition, and lack of exercise, which can lead to obesity, especially central obesity, and consequently diabetes. High-protein and high-calorie diets easily lead to obesity.
A diet that is too acidic or too alkaline will only lead to an imbalance in nutrient intake.
"The acidity or alkalinity of food is mainly classified based on the ash produced after the food is metabolized in the body," said Lei Min. Foods containing higher levels of chlorine, sulfur, and phosphorus, which produce acidic ash after metabolism, are considered acidic foods. These include meats, poultry, fish, shrimp, eggs, grains, and nuts such as peanuts, walnuts, and hazelnuts. Foods containing higher levels of calcium, potassium, and magnesium, which produce alkaline ash after metabolism, are considered alkaline foods. These include various vegetables, fruits, beans, dairy products, and nuts such as almonds and chestnuts.
"Under normal circumstances, whether it is acidic or alkaline food, it will be acidic in the stomach and slightly alkaline in the intestines," said He Hongtao. He added that no matter what kind of food we eat, our bodies have the ability to maintain the pH value of the body fluids at a normal and constant level, thus keeping our bodies in a healthy state of acid-base balance.
"A diet that is too acidic or too alkaline will only lead to an imbalance in nutrient intake, which is harmful to human health," said Lei Min. Alkaline foods are mainly found in plant-based foods and dairy products, providing the body with abundant glucose, fructose, lactose, vitamin C, potassium, magnesium, calcium, dietary fiber, and phytochemicals. However, current research has found that the human body needs 60-70 kinds of nutrients daily, and these alkaline foods also have their shortcomings, lacking essential fatty acids, polysaccharides, high-quality protein, iron, and phosphorus. If we only eat "alkaline foods" and not "acidic foods" for a long time, the incidence of diseases such as colon cancer, high blood lipids, gout, and cardiovascular diseases may decrease, but it will lead to an increase in the incidence of "malnutrition," such as iron-deficiency anemia, zinc deficiency, and hypoproteinemia. Therefore, there are no bad foods, only bad combinations. Only a reasonable combination of alkaline and acidic foods, allowing them to complement each other, can better maximize the nutritional value of food.
