From ham quiche for breakfast to bubble tea in the afternoon, our meals are surrounded by processed foods. Processing and manufacturing add to the appearance and flavor of food, but does the taste have an impact on health?
What is the difference between ultra-processed food and processed food?
With the development of processing technology, the global food supply continues to grow every year, and the "ultra-processed food" in the daily diet of European and American countries accounts for 50-60% of the total calories. The food we buy in our lives is more or less processed by the factory. Did you know that there are different grades of processed foods? The most widely used system to classify processed foods in the world is the "NOVA Food Classification".
The NOVA Food Classification classifies foods into 4 categories, taking into account the nature, degree and purpose of processing:
1. Unprocessed or minimally processed food: Food can be eaten without processing or simple processing, such as drying, grinding, steaming, baking, sterilization, refrigeration, freezing, etc., with the main purpose of extending the shelf life of the food, such as brown rice, white rice, oats, flour, meat, eggs, fresh milk, milk powder, tea, coffee, drinking water, etc.
2. Processed and cooked ingredients: substances obtained from Class 1 foods or natural foods by extraction, refining, etc., such as olive oil extracted from plants, cream extracted from milk, sugar or syrup extracted from sugar cane, starch extracted from corn or other plants, etc.
3. Processed foods: Usually a combination of Class 1 and Class 2 foods, the main purpose is to improve the preservation and flavor of food, such as various canned foods, freshly made breads, cheeses, etc.
4. Ultra-processed foods: In addition to sugar, salt, and oil, a variety of chemical ingredients (preservatives, sweeteners, colorings and other food additives) are added to try to make the food more attractive and richer, such as sugary drinks, corn chips, biscuits, cakes, packaged bread sold in supermarkets, sausages, French fries, microwave real-time food, etc.
What are the health effects of eating ultra-processed foods?
1. Obesity
When you're hungry, you may not feel full after eating a packet of chips, but eating a bowl of lettuce salad makes a difference, so choosing low-calorie-density foods as part of your weight-loss strategy can help boost satiety and reduce calorie intake. However, ultra-processed foods usually have high glycemic load (GL) and high calorie density, and high GL will induce an increase in insulin response, so that the nutrients eaten will be converted into fat and stored.
2. Cardiovascular disease
A prospective generational study published in the prestigious British Medical Journal in 2019 pointed out that the intake of ultra-processed foods was associated with an increased incidence of cardiovascular disease, coronary artery disease, and cerebrovascular disease. Ultra-processed foods such as sugary drinks and cakes have a lot of advanced glycation end-products (AGEs), which can easily promote inflammation and may lead to or accelerate the occurrence of cardiovascular diseases in the long run. Ultra-processed foods are usually high in sodium, saturated fat, added sugar, low in fiber, and tend to be of worse quality than unprocessed or processed foods, while excessive calorie intake is associated with overweight and obesity, and is also considered a major factor in cardiovascular disease.
3. Cancer
Studies have shown that a 10% increase in the proportion of ultra-processed foods in the diet is associated with a 12% increase in overall cancer and a 10% increase in the risk of breast cancer. If we often eat these overly processed foods, such as biscuits, carbonated drinks, potato chips, sausages, ham, etc., and consume too much oil, salt, and sugar, not only are nutrients deficient, but also contain a variety of added ingredients that will burden the body and cause cancer in the long run.
4. Dementia
A study published in Neurology in July 2022 included health data from more than 70,000 participants with no history of dementia at the beginning of the study, and after 10 years of follow-up, 518 participants were found to have dementia. The researchers then evaluated the relationship between the subject's intake of ultra-processed foods and the risk of dementia, and found that a 10% increase in ultra-processed food intake was associated with a 25% increase in the risk of developing dementia, suggesting that eating too much overly processed food can indeed make the brain stupid, affect brain health and reduce cognitive function. Interestingly, replacing an equivalent amount of ultra-processed food intake with 10% unprocessed or mildly processed foods can reduce the risk of dementia by 19%.
Dietary strategies to reduce ultra-processed food intake
From the moment you step out of the house, you can buy ultra-processed foods that are delicious, convenient, tasty, and inexpensive. Eat supermarket soufflé bread for breakfast, eat burger with fries and cola from a fast food restaurant for lunch, and take out the frozen shrimp fried rice in the freezer and wait in the microwave for a few minutes when you get home for dinner, but this kind of food usually contains a lot of sugar, salt, fat and additives, and you don't eat fresh vegetables and fruits, which can easily lead to an unbalanced diet. Although it is impossible for us to completely avoid processed foods, we can try to add a little fresh food to our daily diet, or reduce the proportion of ultra-processed foods, and eat less if we can!
For example, you can change delicate bread to steamed sweet potatoes or whole-wheat steamed buns, fast food to go to a snack bar to order a bowl of noodles with hot vegetables, and replace dried fruits with fruits when you are hungry in the afternoon.