The associations between genetics, salt taste perception and salt intake in young adults

Food liking is one of the main determinants of food intake. Salt taste perception and preference, that play a role in liking of salt, may be genetically determined, although research in humans is scarce. The aim of this study was to explore the associations between genetics, salt taste perception, preference, self-reported salt habit and intake. The participants were young (18-35 years) and healthy adults (32 males and 63 females). Salt taste thresholds were determined with British Standard ISO3972:2011 methodology and salt taste preference by ratings of saltiness and pleasantness of tomato soup with salt concentrations reflecting salt content in foods. Self-reported salt habit was determined by asking participants how salty they usually eat their food and salt intake with two 24-hour 5-step multiple pass recalls. Genotyping for variants in the SCNN1B rs239345 and TRPV1 rs8065080 was performed. Participants homozygous for the minor allele of the rs8065080 had lower ratings of saltiness (p = 0.008) and higher ratings of pleasantness of soup (p = 0.027) when compared to major allele carriers. Preference for salt in soup was associated with salt habit (p = 0.003) and participants with high salt preference had higher salt intake compared to those with low salt preference (2236 ± 261 vs. 1543 ± 107 mg/1000 kcal, p = 0.017). TRPV1 rs8065080 may play a role in salt taste perception and preference, which should be confirmed in a larger sample size study. Hedonic appeal of salty food should be considered when providing personalised advice to change this behaviour

The efficacy of genotype-based dietary or physical activity advice on behaviour change to reduce the risk of CVD, T2DM or obesity: a systematic review and meta-analysis.

Context: Despite clear evidence that adherence to dietary and physical activity advice can reduce the risk of cardiometabolic disease, a significant proportion of the population do not meet recommendations. Personalised advice based on genetic variation has been proposed to motivate behaviour change, although research to date has been contradictory. Objective: To evaluate the efficacy of genotype-based dietary or physical activity advice on behaviour change in the general population and individuals that are at-risk of CVD or T2DM. Data sources: MEDLINE, Embase, PsycINFO and the Cochrane Central Register of Controlled Trials (CENTRAL) up to 7th January 2022. Randomised controlled trials of a genotype-based dietary and/or physical activity advice intervention that aimed to change dietary and/or physical activity behaviour were included. Data extraction: Abstracts of 7899 records were screened, 14 reports from 11 studies met the inclusion criteria. Data analysis: There was no effect of genotype-based dietary or physical activity advice on dietary behaviour for all studies SMD 0.00 (-0.11 – 0.11, p = 0.98) or when analysed by sub-group; ‘at risk’ SMD 0.00 (-0.16 - 0.16, p = 0.99); general population SMD 0.01 (-0.14 – 0.16, p = 0.87). Similar findings were identified for physical activity behaviour for all studies SMD - 0.01 (-0.10 – 0.08, p = 0.88) or when analysed by sub-group; ‘at risk’ SMD 0.07 (-0.18 - 0.31, p = 0.59); general population SMD -0.02 (-0.13 – 0.10, p = 0.77). The quality of evidence for the dietary behaviour outcome was low and for the physical activity behaviour outcome it was moderate. Conclusions: Genotype-based advice does not affect dietary or physical activity behaviour more than general advice or advice based on lifestyle or phenotypic measures. This was consistent in studies that recruited participants from the general population as well as studies that had recruited participants from populations at-risk of CVD or T2DM