In a recent study published in the journal BMC Nutrition, researchers evaluated the relationship between genetic variations and food choices.
Study: Genetic determinants of food preferences: a systematic review of observational studies. Image Credit: Nedim Bajramovic / Shutterstock
Background
Food selection is a multifaceted process impacted by taste, intrapersonal, interpersonal, social, cultural, environmental, nutritional, genetic, and economic considerations. Taste is the primary factor, yet preferences and perceptions differ considerably across individuals. Genetic polymorphisms might explain these variances.
Sweet, fatty, salty, spicy, and high-protein food items are among the most popular food preferences, varying by age and sex. Genetics has altered our understanding of variances at an individual level in human behavior, allowing researchers to undertake large-scale genetic association studies. Recent genetic developments have offered a more comprehensive understanding of the influence of genetics on dietary choices.
About the study
In the present systematic review, researchers evaluated the genetic influence on dietary preferences among adults.
In August 2022, the team searched the Cochrane Library, Scopus, PubMed, Web of Science, Embase, OpenGrey, and ClinicalTrials.gov databases for relevant studies evaluating the impact of genotypes on food choices, preferences, and intake among healthy adults, published between January 1994 and October 2022, without language restrictions. They also searched reviews, conference papers, editorials, and references to the studies to identify additional records.
The researchers analyzed human studies of adults, incorporating food choices and genotypes. They excluded studies solely assessing taste preferences using salt solutions, glucose, or alcoholic beverages instead of food and those evaluating food consumption without referencing dietary preferences. They also excluded studies evaluating the association between heredity factors and food choices without assessing specific genes.
Two researchers independently screened the data, resolving disagreements through re-evaluation and consulting a third researcher. Data extracted included study-associated variables (first author, publication year, study design, sample size, comparator group, and general study description), genes evaluated, the approach used to assess food choices, and primary findings. They used the Newcastle-Ottawa Scale (NOS) to assess study quality and bias risks in observational studies, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
Results
From 8,510 initially identified studies, the team removed 2,634 duplicates, performed title-abstract screening for 5,876, full-text screening for 203, and considered 50 studies eligible for the systematic review. The studies include geographically diverse populations of healthy adult males and females aged 18 to 70. Among the included studies, nine were of poor quality, and the remaining were of good quality. Most studies examined the relationship between genetic variants and preferences for macronutrients, fatty, sweet, and bitter foods.
Most studies used food frequency questionnaires (FFQs) or 24-hour dietary recalls to assess food preferences. The team found a significant association between taste receptor 2 member 38 (TAS2R38) variations (rs1726866, rs713598, and rs10246939) and sweet and bitter taste preferences. They also found significant correlations between the 5-hydroxytryptamine receptor 2A (5-HT2A) gene T102C polymorphism and protein consumption and between rs1761667 (CD36 protein) and fat preferences.
Individuals with TT genotypes of the serotonin receptor 5-HT2A gene T102C polymorphism were more likely to consume beef. The rs7498665 (SH2B1) allele was associated with higher total fat consumption, saturated fat, and monounsaturated fatty acids. Carriers of the potassium channel tetramerization domain containing 15 (KCTD15) and neuronal growth regulator 1 (NEGR1) risk alleles had lower saturated fat consumption.
Genes in the TAS2R38 locus were associated with an increased preference for sucrose and sweet-tasting foods and beverages, especially cereals. Leptin gene A19G and R109K polymorphisms were associated with a preference for sweet meals, resulting in a 1.3-fold increase in genetic risk scores. Researchers found significant relationships between taste and nutritional preferences and polymorphisms in Hungarian general and Roma populations. Carbonic anhydrase 6 (CA6) rs2274333 was associated with raw kohlrabi and salt choice, CD36 rs1527483 for fat preference, TAS2R19 rs10772420 for grapefruit preference, and TAS2R38 rs713598 for sugar addition.
A-allele carriers of the fat mass and obesity-associated gene (FTO) reported eating more energy-dense foods but drinking fewer soft drinks. Individuals with the dopamine-related catechol-O-methyltransferase (COMT) gene’s Val/Val and Val/Met genotypes demonstrated a greater craving for “unhealthy” foods. Some SNPs were associated with a preference for artichokes, broccoli, and chicory.
The systematic review showed a significant association between specific genetic variations and adult dietary preferences. Some genetic variations boost or reduce the appetite for sugary and fatty meals, while others influence food category preferences. However, given the significant variability of the studied variations, further research is required to explore these genetic variants more closely and determine the mechanisms behind the reported effects.