It’s no secret. Junk food is bad for our gut. Fortunately, food can also be very beneficial, an asset for maintaining good gut health.
Food is medicine. It is not a treatment in the strict meaning of the term, but it conditions the state of functioning of the intestine, from which the functioning of our organism directly follows. Food changes the state of the gut. What happens in the intestine when the diet becomes unfavourable? How long does it take for the negative influence of diet to become visible in the intestine?
Diet and disease
It is well known that the modern diet, often referred to as “junk food”, is harmful to health. All the chronic diseases known as “civilisation diseases” develop rapidly with this type of diet. We find pathologies in which the link with eating habits is the most obvious, such as diabetes, cardiovascular diseases, obesity, as well as some neurodegenerative diseases and a number of cancers. For other diseases, the link is less obvious at first sight, but it does exist. This is the case for asthma, allergies, joint pain, migraines, hyperactivity, cancers, etc.
Many of us have experienced the harmful effects of food, with the widespread problems of gas, bloating and, in more serious and disabling situations, painful bowel, mucosal irritation and intestinal porosity. Scientists have recently been able to quantify this influence over time. They have found that modern diets lead to changes in the gut very quickly.
Inflamed mucosa and unbalanced gut microbiota
To establish their conclusions, the researchers observed the evolution of the state of the intestine in people who adopted a modern Western diet compared to an African-style diet. To estimate the impact of diet, they asked Americans to adopt the African-style diet and Africans to change their diet to the Western diet.
The abundant presence of meat, especially red meat, fat, often cooked, and processed and refined products are major characteristics of the Western diet. The African diet, on the other hand, is rich in fibres (fruit, vegetables, cereals), low in fat, and contains few meat products.
The results obtained are very interesting. In just two weeks, major biological changes in the gut are already taking place. These changes concern the intestinal microbiota and the inflammatory state. The Western diet leads to the production of biological markers of cancer proliferation in the gut. And this is observed in healthy, middle-aged subjects. In addition, the evolution of the intestinal flora towards a flora of fermentation of sugar and fat, and putrefaction of meat products, is also known to increase the risk of intestinal cancer.
To ensure that there were no predispositions in the studied populations, the researchers imposed dietary exchanges. The group initially fed with Western food was switched to African food and vice versa. The dietary changes were accompanied by the same biological changes in the intestinal flora and the inflammatory state of the mucosa.
The African-style diet (high fibre, low fat and meat products) reduces the risk of bowel cancer, while the Western diet increases the risk.
Reduce inflammation of the intestine
This new study confirms the preventive results of diet, already obtained by many previous scientific studies. The importance of dietary fibre, along with the consumption of fresh fruit and vegetables, moderation of cooked fats and meat products, is again evident. These parameters are more in line with the diet for which humans are biologically adapted.
Here are some simple dietary tips to reduce or limit inflammation of the intestine:
- Fresh fruit and vegetables should form the basis of the diet, allowing for a less acidifying diet.
- You should not try to eat too much fibre at all costs, but rather fibre that is gentle on the intestine.
- Meat and fish should only be added to the diet and not be the basis of the diet. Their presence is not essential on a daily basis. It is even possible to balance your diet favourably without them. A daily and abundant intake of meat foods means that other foods such as dairy products and cereals should be limited.
- The amount of fat should be reduced for many people. Without seeking to eliminate fat, fat should not represent more than 25% of the day’s total calorie intake (compared with an average of 35 to 40% at present), except for people who have a poor, or very poor, tolerance for carbohydrate foods.
O’Keefe SJD, Li JV, Lahti L et coll. Fat, fibre and cancer risk in African Americans and rural Africans. Nature Communication. 2015. DOI :10.1038/ncomms7342