Reacción a "Reactions: study identifies genes that may be associated with vegetarianism"

The study used data from the UK Biobank, which included dietary and genetic information from a very large sample of more than 500,000 individuals. It also used a genome-wide association study (GWAS) to identify loci [fixed position on a chromosome, which determines the position of a gene] associated with strict vegetarianism. The use of a reputable data source such as the UK Biobank and a comprehensive method such as GWAS implies a robust research design.  

The conclusions drawn - that there may be genetic factors influencing vegetarianism, especially those related to lipid metabolism and genes expressed in the brain - appear to be supported by the identification of the SNP, also called a single nucleotide SNP, on chromosome 18 and the subsequent genetic associations.  

The article mentions that previous studies have linked the identified genes to neurological disorders, cognitive performance and alcohol consumption. We have also conducted similar studies related to coffee and dairy consumption. Taken together, this and previous studies provide evidence pointing to the heritability of dietary preferences, in this specific case, vegetarianism. The uniqueness of the work appears to lie in its in-depth focus on the genetic factors underlying vegetarianism using a large dataset from the UK Biobank.  
There are limitations:  

• The study is based on self-reported dietary data. Self-reporting can often introduce bias, as participants may not recall information accurately or provide socially desirable responses.  
• There is a lack of diversity in the study population, which may affect the generalisability of the results. Without more information on this limitation, it could be assumed that the results are mainly representative of the UK population, healthy and upper class, and may not extend to other ethnic or cultural groups. 
• Another important limitation is not knowing the reasons for the adoption of vegetarianism, which may be multiple and have biological, psychological, cultural, environmental, religious, etc. roots. Such information would have been essential to differentiate genes that are more related to lipid metabolism or those that are expressed in the brain.   

Understanding the genetic factors that influence dietary choices such as vegetarianism may have practical implications:  

• Personalised dietary recommendations: knowing one's genetic predispositions could allow for better tailored dietary recommendations, which could lead to better health outcomes. 
• Clinical implications: as some of the genes are linked to neurological disorders and cognitive performance, further research could lead to a deeper understanding of how diet and metabolism influence these conditions.  
• Possible interventions: if certain genetic factors predispose people to a vegetarian diet or vice versa, interventions can be designed to help those who may face health problems due to their dietary preferences.  

In summary, this study appears to be of good quality and provides interesting information on genetic factors influencing vegetarianism, although with some limitations. The findings may be of importance in everyday life as well as in clinical practice.