Vegetarians think they decided to forgo eating meat, fish, and poultry because they oppose killing animals, religious, environmental or health reasons, or simply because grains, fruits, vegetables and are most tasty.
A substantial body of evidence points to the heritability of dietary preferences. While vegetarianism has been practiced for millennia in various societies, its practitioners remain a small minority of people worldwide.
Eastern religious traditions that discourage meat consumption include Hinduism and Buddhism. In ancient Greece, vegetarianism was practiced as early as the 6th century BCE by the followers of Pythagoras and Orphism, and during the Renaissance and Enlightenment periods, several prominent personalities in Europe practiced vegetarianism. Vegetarian societies began to be established in Europe and America in the 19th century.
To a large extent still are, major motivations behind adopting a vegetarian diet include its ability to lower the risk of metabolic syndrome, obesity, dyslipidemias, diabetes, cardiovascular disease, and some cancers.
On the other hand, there is evidence that avoiding animal protein can lead to nutritional deficiencies and may be associated with negative effects such as anemia, dental erosion, osteopenia, and psychological disorders.
Reasons for vegetarianism
But scientists at Northwestern University in Chicago, the UK and Washington University in St. Louis have now discovered another reason that is beyond the control of those who choose to be vegetarian.
Certain variations in genes involved in lipid metabolism and brain function may be associated with choosing a vegetarian diet, according to a new study led by emeritus pathology Prof. Nabeel Yaseen who has just published his study entitled “Genetics of vegetarianism: A genome-wide association study” in the open-access journal PLOS ONE.A person’s dietary choices may also involve a combination of personal taste, their metabolism, and the effects of different foods on the body. All of these factors are strongly influenced by genetics, but the role of a person’s genes in choosing a vegetarian diet is not well understood.
In the new study, researchers performed a genome-wide association study where they screened thousands of genomes to identify genetic variations linked to being vegetarian. They used the UK Biobank – a population-based health research resource consisting of 500,000 people, aged between 40 and 69 at recruitment.Phenotypic information on each participant was gathered from physical and cognitive measurements; blood, urine, and saliva samples; and questionnaires querying socio-demographic, lifestyle, and health-related factors.
The researchers compared genomes from 5,324 strict vegetarians to almost 330,000 non-vegetarians who are participants om the database. They identified variants associated with 34 genes that may contribute to choosing a vegetarian diet.
Several of these genes have important functions in lipid metabolism and brain function, which raises the possibility that differences in how the body processes lipids and the resulting effects on the brain may underlie the ability and choice to subsist on a vegetarian diet.
These results add to existing research pointing to a role for genetics in dietary choices, but the researchers note that more research is needed into potential differences between lipid synthesis and metabolism in vegetarians and non-vegetarians, as well as other physiologic pathways which might underlie vegetarianism.A better understanding of these pathways could help nutritionists design more effective dietary recommendations based on a person’s individual genetics.
