There is growing interest in relating taste perception to diet and healthy aging. However, there is still limited information on the influence of age, sex and genetics on taste acuity as well as on the relationship between taste perception and taste preferences. We have analysed the influence of age on the intensity rating of the five basic tastes: sweet, salty, bitter, sour and umami (separately and jointly in a “total taste score”) and their modulation by sex and genetics in a relatively healthy population (men and women) aged 18–80 years (n = 1020 Caucasian European participants). Taste perception was determined by challenging subjects with solutions of the five basic tastes using standard prototypical tastants (6-n-propylthiouracil (PROP), NaCl, sucrose, monopotassium glutamate and citric acid) at 5 increasing concentrations (I to V). We also measured taste preferences and determined the polymorphisms of the genes taste 2 receptor member 38 (TAS2R38), taste 1 receptor member 2 (TAS2R38) and sodium channel epithelial 1 beta subunit (SCNN1B), as TAS2R38-rs713598, TAS1R2-rs35874116 and SCNN1B-rs239345 respectively. We found a statistically significant decrease in taste perception (“total taste score”) with increasing age for all the concentrations analysed. This association was stronger for the higher concentrations (p = 0.028; p = 0.012; p = 0.005; p = 4.20 × 10−5 and p = 1.48 × 10−7, for I to V in the multivariable-adjusted models). When we analysed taste qualities (using concentration V), the intensity rating of all the 5 tastes was diminished with age (p < 0.05 for all). This inverse association differed depending on the test quality, being higher for bitter (PROP) and sour. Women perceived taste significantly more intense than men (p = 1.4 × 10−8 for total taste score). However, there were differences depending on the taste, umami being the lowest (p = 0.069). There was a complex association between the ability to perceive a taste and the preference for the same. Significant associations were, nevertheless, found between a higher perception of sour taste and a higher preference for it in women. In contrast, the higher perception of sweet was significantly associated with a higher preference for bitter in both, men and women. The TAS2R38-rs713598 was strongly associated with bitter (PROP) taste (p = 1.38 × 10−50), having a significant interaction with sex (p = 0.030). The TAS1R2-rs35874116 was not significantly associated with sweet, whereas the SCNN1B-rs239345 was associated (p = 0.040) with salty taste. In conclusion, the inverse association between age and perceived taste intensity as well as the additional influence of sex and some genetic polymorphisms give rise to large inter-individual differences in taste perception and taste preferences that should be taken into account in future studies and for applications in precision nutrition for healthy aging.

The results suggest that the phenolic content of RW may modulate leukocyte adhesion molecules, whereas both ethanol and polyphenols of RW may modulate soluble inflammatory mediators in high-risk patients. The trial was registered in the International Standard Randomized Controlled Trial Number Register at http://www.isrctn.org/ as ISRCTN88720134.

PLIN11482A carriers were resistant to weight loss, suggesting that this polymorphism may predict outcome of BW reduction strategies based on low-energy diets.

Perilipin coats intracellular lipid droplets and modulates adipocyte lipolysis. We have evaluated the association between several polymorphisms at the perilipin (PLIN) locus (PLIN1 : 6209T > C, PLIN4 : 11482G > A, PLIN5 : 13041A > G, and PLIN6 : 14995A > T) with obesity-related phenotypes in 1589 White subjects randomly selected from a general Spanish population. In women (n = 801), the less common alleles of PLIN1 and PLIN4, in strong linkage disequilibrium (D' : 0.96), were significantly associated with lower body mass index. Carriers of the allele 2 (6209C) at the PLIN1 locus weighed significantly less (-2.2 kg; p = 0.007) than women homozygotes for the wild-type genotype. The same was true for 11482A carriers at PLIN4 (p = 0.01). Moreover, the PLIN4 variant was associated with significantly lower waist-to-hip ratio, plasma glucose, and triacylglycerol concentrations. No significant associations with these obesity-related phenotypes were found in men. In agreement with these results, statistically significant gene-gender interactions were obtained when the risk of obesity was estimated (281 subjects were obese and 1308 non-obese). Only in women, PLIN1 and PLIN4 variant alleles (6209C and 11482A) were associated with a lower obesity risk [Odds ratio (OR) = 0.58, 95% confidence interval (CI): 0.38-0.93 and OR = 0.56, 95% CI: 0.36-0.89, respectively]. In summary, our data suggest that common alleles at the PLIN locus modulate body weight and metabolic variables in humans.

There are no good genetic markers for incorporating the study of genetic susceptibility to obesity in epidemiological studies. In animal models, the leptin (LEP) and the leptin receptor (LEPR) genes have been shown to be very important in obesity because leptin functions as a negative feedback signal in regulating body-weight through reducing food intake and stimulating energy expenditure. In humans, several polymorphisms in these genes have been described. However, their association with obesity is still very controversial because there are no good case-control studies designed to specifically test this association. Our objective has been to conduct a population-based case-control study to estimate the risk of obesity arising from the -2548G > A and Q223R polymorphisms in the LEP and LEPR genes, respectively. 303 obese cases (101 men and 202 women) and 606 controls (202 men and 404 women) were selected from a Spanish Mediterranean population. Genetic, clinical and life-style characteristics were analyzed. No association was found between the -2548G > A polymorphism and obesity. However, the Q223R variant was significantly associated with obesity in a recessive model, the RR genotype being more prevalent in controls than in obese subjects. The inverse association between the Q223R polymorphism and obesity (OR = 0.62; 95% CI: 0.39-0.99) remained significant even after additional adjustment for education, tobacco smoking, alcohol, physical activity, origin of the obese patient, and the -2548G > A polymorphism in the LEP gene (OR = 0.54; 95% CI: 0.32-0.89). In conclusion, the -2548G > A polymorphism is not a relevant obesity marker in this Mediterranean population, although Q223R does seen to be so.

The associations between dietary fat and cardiovascular disease have been evaluated in several studies, but less is known about their influence on the risk of diabetes. We examined the associations between total fat, subtypes of dietary fat, and food sources rich in saturated fatty acids and the incidence of type 2 diabetes (T2D). A prospective cohort analysis of 3349 individuals who were free of diabetes at baseline but were at high cardiovascular risk from the PREvención con DIeta MEDiterránea (PREDIMED) study was conducted. Detailed dietary information was assessed at baseline and yearly during the follow-up using a food frequency questionnaire. Multivariable Cox proportional hazards models were used to estimate T2D HRs and 95% CIs according to baseline and yearly updated fat intake. We documented 266 incident cases during 4.3 y of follow-up. Baseline saturated and animal fat intake was not associated with the risk of T2D. After multivariable adjustment, participants in the highest quartile of updated intake of saturated and animal fat had a higher risk of diabetes than the lowest quartile (HR: 2.19; 95% CI: 1.28, 3.73; and trend = 0.01 compared with HR: 2.00; 95% CI: 1.29, 3.09; andtrend < 0.01, respectively). In both the Mediterranean diet and control groups, participants in the highest quartile of updated animal fat intake had an ∼2-fold higher risk of T2D than their counterparts in the lowest quartile. The consumption of 1 serving of butter and cheese was associated with a higher risk of diabetes, whereas whole-fat yogurt intake was associated with a lower risk. In a Mediterranean trial focused on dietary fat interventions, baseline intake of saturated and animal fat was not associated with T2D incidence, but the yearly updated intake of saturated and animal fat was associated with a higher risk of T2D. Cheese and butter intake was associated with a higher risk of T2D, whereas whole-fat yogurt intake was associated with a lower risk of T2D. This trial was registered at www.isrctn.com as ISRCTN35739639.

Our results support that higher baseline BCAAs and their increases at 1 year were associated with higher type 2 diabetes risk. A Mediterranean diet rich in extra-virgin olive oil significantly reduced the levels of BCAA and attenuated the positive association between plasma BCAA levels and type 2 diabetes incidence. Clinical trial number: SRCTN35739639 ( www.controlled-trials.com ).

The −13910C>T polymorphism (rs4988235) upstream from the lactase (LCT) gene, strongly associated with lactase persistence (LP) in Europeans, is emerging as a new candidate for obesity. We aimed to analyze the association of this polymorphism with obesity-related variables and its modulation by dairy product intake in an elderly population. We studied 940 high-cardiovascular risk Spanish subjects (aged 67 ± 7 years). Dairy product consumption was assessed by a validated questionnaire. Anthropometric variables were directly measured, and metabolic syndrome-related variables were obtained. Prevalence of genotypes was: 38.0% CC (lactase nonpersistent (LNP)), 45.7% CT, and 16.3% TT. The CC genotype was not associated with lower milk or dairy product consumption in the whole population. Only in women was dairy intake significantly lower in CC subjects. The most important association was obtained with anthropometric measurements. CC individuals had lower weight (P = 0.032), lower BMI (29.7 ± 4.2 vs. 30.6 ± 4.2 kg/m2; P = 0.003) and lower waist circumference (101.1 ± 11.8 vs. 103.5 ± 11.5 cm; P = 0.005) than T-allele carriers. Obesity risk was also significantly higher in T-allele carriers than in CC individuals (odds ratio (OR): 1.38; 95% confidence interval (CI): 1.05–1.81; P = 0.01), and remained significant even after adjustment for sex, age, diabetes, physical activity, and energy intake. However, in subgroup analysis, these associations were found to be significant only among those consuming moderate or high lactose intakes (>8 g/day). No significant associations with lipids, glucose, or blood pressure were obtained after adjustment for BMI. In conclusion, despite not finding marked differences in dairy product consumption, this polymorphism was strongly associated with BMI and obesity and modulated by lactose intake in this Mediterranean population.