The blood group diet is based on an alleged relationship between the intake of certain foods and one's blood group .
The blood group diet has no scientific evidence and for this reason has been much criticized over the years: let's see how it works and the sample menus for the various blood groups.
Blood group diet, how it works
The blood group diet was developed by the naturopathic physician Peter D'Adamo in the 1990s based on the work of his father, James D'Adamo, also a naturopath, who linked food and the immune system. In Italy, the blood group diet has become popular thanks to a doctor from Piacenza, Dr. Mozzi.
The concept underlying the blood group diet is based on a hypothetical correlation between the negative effects given by the intake of lectins present in some foods and blood groups.
Lectins are proteins that can bind to carbohydrates present on cells; lectins are produced by our body and are found in various foods including cereals, seeds, tubers and legumes and are normally inactivated during cooking.
Many lectins are toxic and inflammatory and resist both to cooking and to the action of digestive enzymes; some of these lectins can bind to the surface of red blood cells and cause nausea and vomiting, in addition to agglutination, ie aggregation of red blood cells highlighted in vitro .
According to the diet of blood groups the presumed incompatibility between lectins and blood group involves repeated events of agglutination of blood groups with consequent damage to organs and development of diseases.
The blood group diet has been much criticized because it has no scientific evidence; In fact, D'Adamo did not bring any evidence to support his thesis and did not cite scientific references from other authors that proved his theories.
Example menu for different blood groups
Based on the theories just seen, D'Adamo has developed 4 different types of diets based on blood type :
The group 0
It would be the oldest and most primitive blood type . Those belonging to this blood group would, according to D'Adamo, a particularly reactive immune system and should consume mainly protein foods, as well as vegetables and legumes, excluding lentils.
People belonging to the zero group should not consume dairy products and should especially avoid products containing gluten.
An example menu for group 0 could be
> Breakfast: crepe with jam
> Snack: fresh or dried fruit, tea
> Lunch: salad of rice, chickpeas and vegetables
> Dinner: grilled chicken breast and raw or cooked seasonal vegetables, a fruit.
2. Group A
Group A is instead associated with the development of agriculture, so those who belong to this blood group should follow a diet rich in fruit, vegetables, legumes, fresh foods, fish and eggs. Group A does not recommend dairy products and red meats, which would cause weight gain.
An example menu for group A could be
> Breakfast: soy milk and breakfast cereals
> Snack: fresh seasonal fruit
> Lunch: pasta seasoned with seasonal vegetables, a mixed salad and a fruit.
> Dinner: grilled fish or omelettes and raw or cooked seasonal vegetables, a fruit.
3. Group B
For the group B D'Adamo recommends a varied and balanced diet that completely excludes gluten and that limits certain foods including corn, buckwheat, lentils, peanuts and sesame. The diet for group B includes all other foods including dairy products, to be consumed in moderation.
Here is an example menu for group B:
> Breakfast: a yogurt and a fruit
> Snack: fresh seasonal fruit
> Lunch: quinoa salad with legumes and seasonal vegetables
> Dinner: fresh cheese, seasonal vegetables and a fruit
4. The AB group
Finally, the AB group should pay attention to gluten, but also to maize, buckwheat, sesame, beans from Spain and Lima that would decrease the efficiency of insulin.
An example minus for the AB group could be:
> Breakfast: a yogurt and a seasonal fruit
> Snack: fresh seasonal fruit
> Lunch: rice with lentils, mixed salad and a fruit.
> Dinner: grilled chicken breast, raw or cooked seasonal vegetables, a fruit.
As we have seen from the example menus, these diets are not harmful in general, so many people can actually feel better by following one of the dietary regimes proposed by D'Adamo, especially if they consumed many processed or packaged foods before eating the fat and sugars, or took little fruit and vegetables.
However, the fact that there are allowed or prohibited foods in relation to one's blood type has no scientific evidence.
To stay healthy, stay in shape and age in the best way, the advice is to follow a healthy and balanced diet that does not exclude any food (except in the case of food intolerances or ethical choices) and that indeed ensures variety of foods, so as to ensure the correct supply of nutrients to the body.
