High-tech food preservation methods using chemical preservatives occupy a dominant position in modern food industry, eclipsing traditional preservation methods such as fermentation. Fortunately, in recent years, fermented food seems to be welcomed by gourmets and health experts again, and its consumption has also increased greatly. In the cold storage area of the supermarket, we can see many fermented foods. This is by no means an outdated trend. The reappearance of fermented food marks the return of an older and healthier diet.
We can add some fermented foods to our daily diet. As people become more and more interested in fermented foods, you may want to know what benefits these foods have on our health.
On fermented food from the perspective of evolution
Fermented food is produced by controlled microbial growth and enzyme activity, which naturally change the composition of food and create different texture, flavor and fragrance. Take cheese as an example, it starts from liquid, goes through various stages of fermentation, and finally becomes solid. Its taste has become rich and its appearance has changed greatly.
Anthropological research shows that human beings began to eat fermented food very early in history. From the study of gene map, we can know that early humans have developed special cell receptors, which interact with the metabolites produced by common lactic acid bacteria in fermented foods. This evolutionary milestone enabled our ancestors to broaden their diet by eating fruits that fell to the ground and began to ferment. These findings show that our bodies have evolved to eat fermented food and benefit from it.
Almost all traditional cultures eat fermented food.
9000 years ago, the ancients in China may have made fermented drinks. The chemical analysis of ancient organic matter absorbed in the early Neolithic pottery pots in Jiahu Village, Henan Province, China shows that as early as 7000 BC, people began to produce a fermented beverage made of rice, honey and fruits (hawthorn and/or grapes). With the development of agriculture, human beings began to ferment various foods, including grains, beans, meat, fish, vegetables and fruits.
Almost every culture in the world has its own fermented food. Bulgaria is generally regarded as a country that spreads yogurt to the world. The ancient nomads in this area stored raw milk in skins for fermentation. Japan is famous for natto, and South Korea is famous for kimchi. Sufu is a traditional folk food which has been circulated in China for thousands of years. It seems that different regions have different practices. ...
Historically, fermentation was a way to preserve food. Unique compounds produced during fermentation, such as antimicrobial peptides and lactic acid, can inhibit the growth of harmful microorganisms and prevent food spoilage. However, people soon realized that the benefits of fermentation are not only to preserve food, but also to improve the taste and texture of food and enhance its nutritional value.
Food fermentation has a rich and colorful history and is an excellent healthy diet. Early food fermentation is a relatively organic process. Food is naturally fermented by microbial inoculation through human hands, raw materials, water, equipment and the environment in which food is made. Today, however, we use standardized culture methods to produce fermented food. We can use specific bacteria, yeast or fungi for fermentation purposefully, or we can use previously fermented starter for fermentation. In order to meet the needs of industrial production and people's increasingly picky taste buds, a large number of chemical additives are used, which also makes fermented food lose some authenticity and soul. So if you have the conditions, you can try to make your own fermented food, which can not only enjoy the fun of the production process, but also be healthier.
Various health functions of 13 fermented food
People's interest in fermented foods is widely known because they are related to intestinal health, and there are a lot of scientific research to support these claims. In addition, more and more studies show that fermented food can support all aspects of our health through other mechanisms.
1, supporting intestinal flora
More and more studies have reported the influence of fermented food on intestinal flora, which can increase the number of beneficial bacteria in the intestine and provide many beneficial microorganisms by itself. For example, Kefir is a fermented dairy product, which has significant benefits to intestinal flora and can increase the concentration of Lactobacillus, Lactococcus and Bifidobacterium; Short-term intake of yogurt can also improve the level of intestinal lactic acid bacteria; Tempura is a fermented soybean product in Indonesia. A small study found that tempura can increase the levels of mucin Ackerman and immunoglobulin A (a molecule involved in intestinal immune response). Fermented foods such as kimchi can provide short-chain fatty acids and dietary fiber, promote the growth of beneficial bacteria in the intestine, and are beneficial to intestinal health.
2, promote digestion and defecation method
Regular consumption of fermented food can promote healthy digestion and defecation. For patients with chronic constipation, kefir is helpful to improve stool hardness and defecation times; Yogurt can also improve constipation caused by slow intestinal transit time.
Some foods may be easier to digest after fermentation than when they are not fermented. For example, compared with unfermented bread, eating fermented bread can reduce gas production, abdominal discomfort and bloating, which may be due to the fact that fermentation reduces the levels of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) in grains.
3. They have antibacterial properties.
Fermented food not only provides beneficial microorganisms, but also produces antibacterial substances such as lactic acid and antibacterial peptides in the fermentation process, which has antibacterial effect on conditional pathogenic bacteria and pathogenic microorganisms and helps to balance the whole intestinal flora.
Kefir grains are traditional Kefir starter cultures. They are irregular in shape, curly, uneven or highly distorted in surface, mostly white or light yellow, with certain elasticity and special sour taste, and look like cauliflower. A large number of probiotics inhabit active Kefir granules, such as Lactococcus, Lactobacillus, Leuconostoc, Acetobacter, Yeast and so on. Kefir granules have antifungal and antibacterial properties, and can resist common intestinal conditional pathogens and pathogens, including Candida albicans, Salmonella, Shigella, Staphylococcus aureus and so on.
Kefir may also be a useful adjuvant for the treatment of Helicobacter pylori infection. Kombucha is a fermented tea beverage made of black tea or green tea, which can inhibit the growth of Helicobacter pylori, Escherichia coli, Salmonella typhimurium and Campylobacter jejuni. Yogurt also contains lactic acid bacteria, which have extensive antibacterial properties.
4. Reduce the content of anti-nutritional substances and improve the nutritional value of food.
Fermentation has a profound influence on the nutritional composition of food. Antinutritional substances are compounds that can reduce or hinder the absorption of beneficial nutrients in plant foods. Fermentation can reduce the content of anti-nutrients and improve the bioavailability of a series of micronutrients.
Fermentation will also:
5, help to strengthen bones
Studies have shown that fermented dairy products can promote bone health. Fermented dairy products are rich in calcium, phosphorus, protein, vitamin D and vitamin K2, which are important nutrients necessary for healthy and strong bones.
Fermented dairy products also seem to help prevent bone loss related to estrogen deficiency, which indicates that eating fermented dairy products may be beneficial to the bone health of postmenopausal women.
6. Promote the metabolic health of the heart
Cardiometabolic risk factors are a series of interrelated factors, including hypertension, insulin resistance, unhealthy cholesterol and triglyceride levels, which will increase the risk of cardiovascular disease, type 2 diabetes or stroke. A large number of studies show that fermented food may help to reduce these risk factors and promote the metabolic health of the heart.
7, contribute to weight management
Fermented food can promote healthy weight. Eating kimchi will affect the production of related genes by fat cells. Epidemiological studies show that drinking yogurt is related to lowering body mass index, reducing waist circumference and reducing body fat.
8. Enhance immunity and diminish inflammation.
Fermented food has a positive effect on the immune system and may reduce inflammation. Immunoglobulin e is an immune molecule involved in allergic reactions. Probiotics found in Kefir can inhibit the production of immunoglobulin E. A polysaccharide contained in Kefir can inhibit the degranulation of mast cells, which means that Kefir can help prevent or relieve allergies. Babies born to women who eat fermented food during pregnancy have a lower risk of atopic dermatitis.
9. Regulate cell growth
Preliminary research shows that fermented food may help to regulate cell growth and proliferation, so it may play a role in preventing cancer. In vitro studies showed that Kombucha had selective toxicity to colon cancer cells while protecting the health of normal colon epithelial cells. Some probiotics in kimchi can prevent the formation of cancer cells, while fermented beet juice can prevent the formation of abnormal intestinal crypts, which is usually an early signal of intestinal cancer.
10, keep skin healthy.
Fermented food can help maintain skin health by affecting intestinal flora, systemic inflammation level and insulin signal. For example, for acne patients, fermented dairy products may be a better choice than non-fermented dairy products, because fermentation will significantly reduce the level of insulin-like growth factor 1 in dairy products, which is a molecule in dairy products, which will increase inflammation and sebum production, leading to acne. Fermented food may also be beneficial to skin health by regulating intestinal axis, which is a signal molecular network connecting gastrointestinal tract and skin.
1 1, to help maintain a healthy mood.
Intestinal flora imbalance will cause systemic chronic inflammatory reaction, which may affect our brains and lead to mental health problems such as anxiety and depression. Fermented food can support mental health by reducing the levels of inflammatory microorganisms and intestinal inflammation.
Food fermentation can also increase the bioavailability of some phenolic plant compounds that regulate nerve transmission. Finally, probiotics in fermented food may also directly act on the neural pathways of the brain through the intestinal brain axis, which is a complex neural network connecting the intestinal nervous system and the central nervous system.
12, which contributes to cognitive function.
Preliminary research shows that eating fermented food may improve our cognitive function. Lactobacillus pentosaceus is a probiotic isolated from kimchi, which can inhibit the memory impairment caused by drugs in mice. In a human experiment using functional magnetic resonance imaging technology, people found that eating fermented dairy products rich in probiotics can regulate brain activity. Finally, a randomized controlled trial found that fermented bean products significantly reduced mild cognitive impairment and increased the level of brain-derived neurotrophic factor (BDNF) in blood compared with the subjects taking placebo. BDNF can stimulate neuroplasticity, that is, our brain's ability to reorganize and create new neural pathways.
13, against toxins
Fermented food has shown its application prospect in strengthening the defense against environmental toxins and promoting detoxification. Lactic acid bacteria commonly found in fermented foods can bind heavy metals and excrete them. Some probiotics contained in fermented foods such as sauerkraut can reduce the absorption of organophosphorus pesticides in the intestine. Fermentation can also reduce the level of mycotoxins in some foods (such as grains). If you want to strengthen your physique against toxic substances and slowly excrete toxins from your body, it may be helpful to eat fermented food properly every day.
In a word, adding some fermented foods to our daily diet is of great benefit to our health, involving all aspects of our physiology and psychology. So, how do fermented foods exert these health benefits, and how can they be best integrated into our daily diet? Listen to the next decomposition.
The pictures are all from the Internet.
References:
13 the benefits of fermented foods and how they can improve your health, Chris Kresser, master/the benefits of fermented foods/