Meaty way to health?
Carnivore diet is a dietary trend based exclusively or mainly on animal products - especially meat (often red), fish, eggs and sometimes dairy products. Quite the opposite excludes all vegetable foods, i.e. cereals, legumes, fruits, vegetables and nuts. It is an extremely low-carb, high-content regimen proteins a fats, which has gained attention especially on social networks, where it is presented as a way to lose weight, solve various chronic problems and overall improving health. In a sense, it represents the opposite of veganism – while vegans avoid animal products, the carnivore diet completely excludes the plant component.
This eating style is close to other low-carb diets, but at the same time it is more radical in many ways. Its concept is an extreme form of low-carb or ketogenic diet, which is particularly reflected in the blood fat profile. Like other low-carb diets, it usually leads to reduction levels triglycerides a increase "worthy" HDL cholesterol, but at the same time often increases level LDL cholesterol.
Higher LDL is associated with the risk of atherosclerosis and heart disease, while high HDL and low triglycerides, on the other hand, contribute to a reduced risk of cardiovascular disease.
The overall impact on cardiometabolic risk is therefore mixed and depends on other factors such as baseline health or length of diet.
At blood pressure or inflammatory quality data is lacking for markers, but it is assumed that it is possible weight loss (if it occurs) can lead to improved values, similar to other reduction diets.
In terms of body weight, the elimination of carbohydrates often leads to reduction in caloric intake a rapid weight loss, especially in the initial stages. Research suggests that low-carb diets can be slightly more effective at reducing weight than high-carb diets, with a difference of around 1-2 kg. At the same time, metabolic indicators improve (e.g. blood sugar level in diabetics, in whom glycated hemoglobin is also reduced, which makes it possible to reduce drug doses). The historical context is also interesting: before the discovery of insulin a very strict meat diet was used to treat type 1 diabetes because the elimination of carbohydrates led to lower urine glucose levels and longer patients' lives. Today, the low-carbohydrate and ketogenic diet is recognized as one of the possible therapeutic paths for obesity and type 2 diabetes, but the carnivore diet is still insufficiently researched in this regard.
Even though supporters of the carnivore diet often mention benefits such as better concentration, stable energy or the disappearance of the feeling of mental dullness, these effects can mostly be attributed to ketosis and a stable blood sugar level - i.e. physiological changes that occur when carbohydrates are excluded in general, not exclusively as a result of a meat diet. Whether these benefits persist over the long term and without nutritional compromise remains unclear.
In terms of inflammation a immunity there is no conclusive evidence yet. Some proponents of the diet report remission of autoimmune problems in rheumatoid arthritis or Crohn's disease. But in theory, a high income can saturated fats and the absence of protective phytonutrients lead to higher inflammatory stress in the body.
One short-term study found that in women on low carb on a diet increased inflammatory marker CRP by 25%, while for women on high carbohydrate CRP diet down 43%. This shows that diet composition affects inflammation independently of weight, as a diet high in fiber and carbohydrates appears to suppress inflammation more than a diet high in fat. On the other hand, it is known that weight loss itself - regardless of the composition of the diet - brings reduction of inflammatory markers including CRP.
In other words, it follows that even a diet without fiber can lead to an improvement in inflammatory parameters, if it also helps to reduce weight.
In practice, therefore, for an overweight person, the positive effect of reduced pounds may outweigh the negative effect of the absence of plant foods. For a definite evaluation long term influence carnivore diet on inflammatory processes lack quality studies. So far, it is true that both positive immunological effects (e.g. alleged "anti-inflammatory" effect due to the disappearance of plant antigens) and a possible increase in inflammation remain hypothetical and are perhaps further research.
The influence on the intestinal tract is also an important area microbiome. Since fiber serves as the main source of nutrition for beneficial gut bacteria, its complete absence significantly alters the microbial composition in the gut. An experiment published in the journal Nature showed that within just a few days on a purely animal diet, dramatic shifts in composition of gut microbes with increased activity of pro-inflammatory species. This confirms that the composition of the diet can have a rapid and fundamental effect on the bacterial balance in the gut.
An interesting fact that will undoubtedly "break" the black-and-white view of the functioning of natural laws is the recently published pilot case study, which analyzed the microbiome of one healthy man who had been eating carnivores for a long time and compared it with the microbiomes of normal omnivorous individuals. Surprisingly, it turned out that the composition of his gut bacteria was not drastically different - the strains dominated Firmicutes with representatives known more for fiber fermentation. Total diversity microbiome (alpha and beta diversity) and the functional potential of the intestinal ecosystem did not differ significantly from control subjects. It even turned out that the microbiome of this "carnivore" was not even very close to the microbiomes of people who eat meat daily (in the context of a mixed diet), suggesting that differences between individuals can be significant and that simple categorizations (carnivore vs. omnivore) may not always correspond to expected patterns.
However, general conclusions for the majority of the population cannot be drawn from these observations.
However, this unique case report may not be representative, it cannot be concluded that a carnivorous diet in general does not have an effect on the intestinal microbiota. It is possible that the individual in question consumed fermented dairy products or bone broths, or that their body and microbiome adapted by producing alternative nutrients (e.g. mucus in the gut can partially replace fiber as a source of nutrients for some bacteria). Generally applies, that a diet without fiber leads to a decrease in the production of protective short-chain fatty acids (butyrate) in the intestine and can impair the integrity of the intestinal barrier and local immunity. Long-term consequences for gut health (e.g. risk of colon cancer or inflammatory diseases) are therefore a potential problem - high intake is known to red meat along with low fiber intake, it is associated with a higher incidence of colorectal cancer and diverticular bowel disease in epidemiological studies.
Current findings therefore warn of possible risks for intestinal health, although individual exceptions cannot be overlooked.
