Source | Fan Zhihong_Original nutritional information
Editor | Wu Jia
A few days ago, the news reported that men with pro-inflammatory dietary habits, especially obese individuals, have a risk of lacking testosterone (the main type of male sex hormone) about 30% higher compared to men who eat less pro-inflammatory foods. In other words, men who are both obese and love to eat pro-inflammatory foods tend to have lower levels of male hormones.
In response to this, Professor Fan Zhihong from the College of Food Science and Nutritional Engineering at China Agricultural University introduced that the pro-inflammatory foods and components mentioned by scholars include the following categories:
− Processed meats, red meats (such as beef, lamb, pork), especially processed meat products.
− Various refined carbohydrates, including white steamed bread, white rice, white bread, white noodles, especially sweets, sugary beverages, and fried foods, are highly pro-inflammatory.
Alcohol.
Foods rich in saturated fatty acids and trans fatty acids. Foods rich in saturated fatty acids include biscuits, cookies, various pastries, instant noodles, potato chips, french fries, coconut oil, etc.
Professor Fan Zhihong believes that with the same food ingredients, as long as they are cooked to a golden, crispy, fragrant state, with added sugar, and repeatedly heated oil, it will increase the pro-inflammatory effect. It is well understood that consuming sugar promotes inflammation, but for some friends, the new knowledge that cooking to a golden crispy state increases inflammation may be met with disbelief or anxiety.
Here are answers to a few typical questions.
User A says: It’s fragrant when the food is slightly burnt! Isn’t progress in human evolution shown by cooking and eating barbecue meat rather than raw? That’s how people have been eating since ancient times.
Professor Fan Zhihong: This makes sense. Ancient people learned to eat barbecue meat after discovering the use of fire. Eating cooked meat is indeed healthier compared to eating raw meat. It can kill bacteria, parasites, and aid in digestion.
Although cooking food to a slightly burnt state during barbecue may inevitably produce many carcinogens, at that time, the average human lifespan was very short, and most people were lean, so they didn’t need to worry much about inflammation. If you only plan to live past your fifties, being a bit carefree in your diet is not a problem.
Moreover, in the daily life of ancient commoners, there were no sweets, sweet beverages, cookies, cakes, various fried foods (up until 50 years ago, common people couldn’t even afford cooking oil), white rice, or steamed bread; they mainly ate whole grains, beans, and coarsely ground rice flour.
Therefore, the variety of pro-inflammatory components in their diet was limited, with plenty of dietary fiber and antioxidants. Even if they ate slightly burnt food, it wasn’t a big issue overall.
The problem now is that we consume white rice, white flour, live a life high in fats and sugars, and want to cook all foods to a crispy state, resulting in too many pro-inflammatory components. With life expectancy reaching nearly 80, if you want to have a higher quality in the last 30 years, you have to take care of yourself.
User B says: I love to sauté spring onions and garlic slices in hot oil until they turn yellow, it gives the stir-fry a strong aroma. Is this not okay?
Professor Fan Zhihong: Of course, it’s okay. Onions, shallots, and garlic are vegetables that easily produce acrylamide when heated. After sautéing in hot oil, the Maillard reaction occurs, producing a strong aroma.
The purpose of sautéing onions and garlic is to enhance the aroma of the food. The tastier the food, the more late glycation end products it produces, promoting appetite.
For people not concerned about weight loss, it’s fine to eat some fragrant foods. After all, the amount of onions and garlic used in cooking is minimal, and healthy individuals need not worry. Maillard reaction products are not toxic substances; even if they were toxic, you would need to consume a considerable amount for them to take effect.
However, anything overly delicious, anything particularly tempting, should not be eaten or drunk in excess, or else there will be consequences. For example, sugar and sweets, salt, and MSG, alcoholic beverages, and so on. If you eat charred spring onions and garlic slices in large quantities every day, it may not be wise. Moderation is beneficial, excess is harmful.
User C asks: Foods made in an air fryer or oven have a delightful aroma that my family loves to eat. Are they slightly better in terms of inflammation compared to deep-frying or barbecuing?
Professor Fan Zhihong: Whether it’s a deep fryer, an air fryer, or an oven, after providing sufficient temperature and moisture evaporation conditions, they will all induce a high level of Maillard reaction, making the food fragrant. However, they will also produce pro-inflammatory substances like acrylamide and AGEs. The quantity produced, however, differs.
On a theoretical basis, under the same raw materials and the same surface color conditions, deep-frying produces the highest amount of pro-inflammatory substances. This is because in fried foods, not only carbohydrates and amino acids participate in the Maillard reaction, but also fat oxidation products produced at high temperatures. Moreover, the oil used in frying usually has a high content of saturated fatty acids, which enter the interior of the food during frying, and excessive saturated fatty acids themselves have a pro-inflammatory effect.
When grilling meat over charcoal, it’s difficult to control the temperature evenly, leading to local overheating, resulting in the production of carcinogenic compounds such as heterocyclic amines, polycyclic aromatic hydrocarbons, and plenty of pro-inflammatory components. The smoke generated during grilling contains various carcinogens, which enter the lungs in the form of PM2.5 particles, posing a significant hazard.
An air fryer requires very little oil or can cook using the food’s natural oils. Its main principle is to generate hot air through electric heating, quickly removing food moisture while heating the food. Roasting involves high-temperature static heating, where a large amount of hot air comes into contact with the food surface for an extended period, causing moisture to evaporate from the food surface and forming a fragrant and crispy crust.
Under conditions of low moisture and high temperature, both air frying and oven baking will trigger the Maillard reaction, resulting in AGEs and acrylamide, among other pro-inflammatory substances. The specific quantity produced depends on the heated surface area of the food and the level of heating.
However, because these two cooking methods can accurately control the heating time and temperature, and do not introduce more saturated fats, they produce slightly fewer pro-inflammatory substances compared to direct deep-frying, while maintaining the same texture.
Pairing aromatic roasted foods and air-fried foods with some fresh raw vegetables, and adding some natural aromatic spices and seasonings without frying, contribute to balancing inflammatory responses. Ingredients like mint leaves, perilla leaves, lettuce leaves, garlic paste, tomato sauce, lemon juice, all contain antioxidant components that help reduce inflammation.
User D asks: Whenever my family eats roasted peanuts, fried peanuts, or sunflower seeds, they tend to get “heatiness.” Could it be due to excessive pro-inflammatory components in these foods?
Professor Fan Zhihong: Yes, unless there are food allergy issues, it is highly likely that these “roasted goods” and deep-fried nuts contain excessive pro-inflammatory components. The heating during roasting, frying, or deep-frying makes the nut oils aromatic, but simultaneously generates acrylamide, polycyclic aromatic hydrocarbons, and AGEs. Small workshops and home cooking have difficulty controlling heating temperatures, and may even produce carcinogenic compounds like benzo[a]pyrene.
On the other hand, traditional varieties of peanuts and sunflower seeds are already rich in omega-6 fatty acids, with very low omega-3 fatty acid content. In other words, these foods have a severely imbalanced ratio of omega-6 to omega-3 fatty acids. An excess of omega-6 fatty acids exerts a pro-inflammatory effect. Therefore, friends who often get acne should be cautious not to overeat these fried goods, as they could worsen the condition.
User E says: Isn’t it said that toasted steamed bread can help treat stomach ailments? Traditional Chinese medicine believes that yellow foods nourish the spleen, and to truly nourish it, the steamed bread should be toasted until fragrant and brown.
Professor Fan Zhihong: First, toasted steamed bread is dry-baked, not deep-fried. Second, toasted steamed bread does not need to be charred black or even brown, a light golden color is sufficient. This way, the alarming pro-inflammatory components are not in excessive amounts.
Toasting bread slices to a yellow hue is suitable for people with excessive stomach acid and indigestion; cooking until aromatic is suitable for those with poor appetite and lean bodies. Traditional Chinese medicine emphasizes “treating the individual according to the symptom,” and not everyone needs to “nourish the spleen and stomach” in this manner. If someone already has excessive appetite or is gaining weight, there is no need to continue this type of diet.
As for the carcinogens and toxic fumes produced during grilling or frying, which are harmful to gastrointestinal patients, the same is true for individuals with gastrointestinal diseases.
User F asks: Is inflammation really that harmful? Are these aromatic dishes created after cooking really beneficial to people, besides their good taste?
Professor Fan Zhihong: In fact, promoting appetite itself is considered an advantage. Too poor an appetite is not beneficial, too low an inflammatory response isn’t ideal, and an excess of antioxidant substances can affect the absorption and utilization of various micronutrients.
The reason why many studies emphasize an anti-inflammatory diet now is that many people consume excessive pro-inflammatory foods, are obese with little exercise, consume excessive red and processed meats, sweets, and sugary beverages, and have high postprandial blood sugar response, resulting in high levels of daily inflammation in the body.
As mentioned in the scientific news earlier, the harm of pro-inflammatory foods is especially evident in obese individuals.
There is no absolute good or bad in food. If you have overindulged in fragrant foods in the past, you should reduce your intake for a while. On the contrary, if you have been eating too blandly, causing a loss of appetite, then you should consume more aromatic, fried, and roasted foods with various spices for a period.
The key to a balanced diet lies in balance. Balanced eating and exercise are essential. The proportions of various nutrients need to be balanced. The ratio of food types and body condition needs to be balanced. The ratio of pro-inflammatory and anti-inflammatory components also needs to be balanced.
