Proponents of the blood type diet claim that people with blood type A benefit more from a vegan diet. However, a new study found no link between diet and blood type. Instead, researchers suggest that plant-based diets are beneficial for people of all blood types.

Staying healthy generally involves regular exercise and following a nutritious diet. WHEREAS Centers for Disease Control and Prevention (CDC) recommend a balanced diet of fruits, vegetables, lean meats and poultry, the blood type diet suggests that nutritional needs depend mainly on a person’s blood type.

Blood type diet adapts an individual’s eating patterns to specific food items to maximize health benefits. However, a summary of 2013 in American Journal of Clinical Nutrition found that these claims lacked scientific evidence.

When looking at cardiometabolic factors, or a person’s chance of having a stroke, diabetes, and heart disease, the findings of a Study 2014 did not support the adaptation of diets according to blood groups.

Although the results showed that people on the type A diet – which includes eating high amounts of whole grains, fruits and vegetables – had a lower body mass index (BMI) and waist circumference, as well as lower blood pressure. , cholesterol and fat, these improvements in risk factors do not depend on blood type.

Despite insufficient evidence to support blood type diets, some people believe that eating a blood type diet can reduce the risk of disease.

The appeal of blood type diets can come from the health benefits associated with a plant-based diet. Researchers have linked these diets to a lower BMI and a reduced risk of obesity, diabetes and heart disease.

A recent study in JAMA network open found that low-fat vegan diets helped lower insulin resistance and increase metabolism, which helped with weight management. Based on these results, researchers affiliated with the Physicians Committee for Responsible Medicine reanalyzed the study data to determine if blood type plays a role.

The current study was a subset of JAMA network open study, and he focused exclusively on participants belonging to the 16-week trial intervention group.

The findings are displayed in Journal of the Academy of Nutrition and Dieteticswith

The trial recruited a total of 244 adult men and women from Washington, DC, with a BMI between 28 and 40. None of the participants had a history of diabetes, drug abuse, pregnancy or lactation, and no one was currently on a vegan diet. with

The researchers assigned half of the participants to follow a strict, low-fat vegan diet, while the other half did not make any changes to their diet. Participants self-reported what they ate during the 16-week trial.

The vegan group also attended weekly classes on dietary information, led by health professionals. The researchers advised all participants to continue their regular exercise habits.

The measurement of cardiometabolic risk factors was performed at the beginning and end of the test, after a 10 to 12-hour overnight fast with water only.

After that, the researchers repeated the method, but it involves blood typing. The secondary analysis included a total of 68 participants.

At the start of the trial, body weight cholesterol and low-density lipoprotein (LDL) cholesterol levels were higher in people with blood type A than in those with other blood groups. In contrast, body weight and LDL cholesterol levels were lower in people with blood type O than in those with other blood groups.

There were no significant differences between blood type and changes resulting from the vegan diet.

After 16 weeks on the low-fat vegan diet, there were no statistically significant differences in the mean body weight difference between blood group groups. People with blood type A lost an average of 5.7 kilograms (kg) compared to 7.0 kg for people with other blood types. The average weight loss for people with blood type O and those with other blood types was 7.1 kg and 6.2 kg, respectively.

The researchers also found no significant evidence of a difference in lowering average cholesterol between groups. They reported a decrease of 17.2 milligrams per deciliter (mg / dl) in group A versus 18.3 mg / dl in the other participants, and a decrease of 17.4 mg / dl for group O versus 18.4 mg / dl.

“Although the intervention diet was similar to that recommended by D’Adamo [a proponent of the blood type diet] “for individuals with blood type A and specifically recommended against those with group O, there was no link between these blood groups and the results of the dietary intervention,” the authors concluded.

There were many strengths in the study, starting with the exclusion of potential confounders that could affect the results.

For example, to exclude physical activity as a factor, participants maintained their regular exercise routine during the 16-week trial. Also, all participants started the trial simultaneously, which ruled out seasonal changes in diet.

According to the researchers, 16 weeks was a good time for participants to adjust and stick to the study. There was also a low dropout rate.

Participants did not have access to ready meals, but could prepare food at home or choose food. This method made the findings more applicable to real life conditions.

However, there were major limitations regarding representation.

Not so many participants with blood groups AB and B were involved in the trial. As a result, the team had to combine blood types. Also, study participants were health-conscious and may have been more motivated to stick to a low-fat vegan diet. As a result, participants may not be representative of the general population.

Overall, the researchers say, their data add to the actual work, consistently finding a lack of strong evidence for the blood type diet.

“These studies, like the current one, suggest that changes in diet, especially increased intake of fruits, vegetables and whole grains, are beneficial not only for individuals with blood type A, but also for all individuals, regardless of group blood, and that there is no apparent value in limiting these healthy dietary changes to a specific group of individuals based on the ABO blood group. “