Association of dietary nitrate intake with the 15-year incidence of age-related macular degeneration

Background Dietary nitrate, found predominantly in green leafy vegetables and beetroot, is a precursor of nitric oxide. Under- or overproduction of nitric oxide is implicated in the etiology of several eye diseases. However, the potential influence of dietary nitrate intake on age-related macular degeneration (AMD) risk has not been assessed. Objective To investigate the temporal association between dietary nitrate intake (from both vegetable and nonvegetable sources) and the 15-year incidence of AMD, independent of potential confounders. Design A longitudinal cohort study conducted from 1992-1994 to 2007-2009. Participants/setting The Blue Mountains Eye Study is a population-based study of adults aged 49+ at baseline, from a region west of Sydney, Australia. At baseline, 2,856 participants with complete dietary data and AMD information were examined, and of these, 2,037 participants were re-examined 15 years later and thus included in incidence analysis. Main outcomes measured Incidence of AMD (main outcome) was assessed from retinal photographs. Dietary intake was assessed using a semiquantitative food-frequency questionnaire. Nitrate intake from vegetables and nonvegetable sources was calculated by use of a validated comprehensive database. Results After adjusting for age, sex, smoking, energy intake, fish consumption, and AMD risk alleles (complement factor H and age-related maculopathy susceptibility-2 single nucleotide polymorphisms), participants in the third quartile compared with those in the first quartile (reference group) of total nitrate and total vegetable nitrate intake had reduced risk of incident early AMD: odds ratio (OR) 0.61 (95% CI 0.41 to 0.90) and OR 0.65 (95% CI 0.44 to 0.96), respectively. Significant associations were not observed between the fourth vs first quartile of total nitrate and vegetable nitrate intake with incident early AMD: OR 0.74 (95% CI 0.51 to 1.08) and OR 0.69 (95% CI 0.47 to 1.00), respectively. Nonsignificant associations were also observed with 15-year incidence of late AMD and total nonvegetable nitrate intake. Conclusions These novel findings could have important implications, if the association between total nitrate intake and vegetable nitrate intake and 15-year incidence of early AMD is confirmed in other observational or intervention studies

Dietary flavonoids and the prevalence and 15-y incidence of age-related macular degeneration

Background: The majority of research performed to date has examined the effects of commonly known antioxidants such as vitamins C, E, and A and carotenoids on age-related macular degeneration (AMD) risk and progression. To date, there is limited research on promising phytochemicals with antioxidant and anti-inflammatory properties, including flavonoids. Objective: In this exploratory study, we aimed to assess the independent associations between dietary intake of total flavonoids and common flavonoid classes with the prevalence and 15-y incidence of AMD. Design: In this population-based cohort study, 2856 adults aged ≥49 y at baseline and 2037 followed up 15 y later were included in prevalence and incidence analyses, respectively. Dietary intake was assessed by using a semiquantitative food-frequency questionnaire (FFQ). Estimates of the flavonoid content of foods in the FFQ were assessed by using the USDA Flavonoid, Isoflavone, and Proanthocyanidin databases. AMD was assessed from retinal photographs. Results: In cross-sectional analysis, each 1-SD increase in total overall flavonoid intake was associated with a reduced likelihood of any AMD (multivariable-adjusted OR: 0.76; 95% CI: 0.58, 0.99). Each 1-SD increase in dietary intake of total flavonols and total flavanones was associated with reduced odds of the prevalence of any AMD [multivariable-adjusted OR (95% CI): 0.75 (0.58, 0.97) and 0.77 (0.60, 0.99), respectively]. A marginally significant trend (P = 0.05) was observed between increasing the intake of total flavanone and hesperidin (from the first to the fourth quartile) and reduced likelihood of incident late AMD, after multivariable adjustment. Participants who reported ≥1 serving of oranges/d compared with those who never consumed oranges at baseline had a reduced risk of late AMD 15 y later (multivariable-adjusted OR: 0.39; 95% CI: 0.18, 0.85). Conclusions: Our findings suggest an independent and protective association between dietary intake of flavonoids and the likelihood of having AMD. Additional prospective cohort studies are needed to validate these findings

Relationship of dietary nitrate intake from vegetables with cardiovascular disease mortality: a prospective study in a cohort of older Australians

Purpose Short-term trials indicate inorganic nitrate and nitrate-rich vegetables may have vascular health benefits. However, few observational studies have explored the relationship between nitrate intake and long-term cardiovascular disease (CVD) outcomes. The primary aim of this study was to investigate the association of nitrate intake from vegetables with CVD mortality in a sample of older Australians. Methods A subgroup of participants without diabetes or major CVD at baseline (1992–1994) were included from the Blue Mountains Eye Study, a population-based cohort study of men and women aged ≥ 49 years. Diets were evaluated using a validated food frequency questionnaire at baseline, 5 years and 10 years of follow-up. Vegetable nitrate intake was estimated using a comprehensive vegetable nitrate database. Cox proportional hazard regression was used to explore the association between vegetable nitrate intake and CVD mortality. Results During 14 years of follow-up, 188/2229 (8.4%) participants died from CVD. In multivariable-adjusted analysis, participants in quartile 2 [69.5–99.6 mg/day; HR 0.53 (95% CI 0.35, 0.82)], quartile 3 [99.7–137.8 mg/day; HR 0.51 (95% CI 0.32, 0.80)], and quartile 4 [\u3e 137.8 mg/day; HR 0.63 (95% CI 0.41, 0.95)] of vegetable nitrate intake had lower hazards for CVD mortality compared to participants in quartile 1 (\u3c 69.5 mg/day). Conclusions In older Australian men and women, vegetable nitrate intake was inversely associated with CVD mortality, independent of lifestyle and cardiovascular risk factors. These findings confirm a recent report that intake of vegetable nitrate lowers the risk of CVD mortality in older women and extend these findings to older men

Genome-wide analysis identifies genetic effects on reproductive success and ongoing natural selection at the FADS locus

: Identifying genetic determinants of reproductive success may highlight mechanisms underlying fertility and identify alleles under present-day selection. Using data in 785,604 individuals of European ancestry, we identified 43 genomic loci associated with either number of children ever born (NEB) or childlessness. These loci span diverse aspects of reproductive biology, including puberty timing, age at first birth, sex hormone regulation, endometriosis and age at menopause. Missense variants in ARHGAP27 were associated with higher NEB but shorter reproductive lifespan, suggesting a trade-off at this locus between reproductive ageing and intensity. Other genes implicated by coding variants include PIK3IP1, ZFP82 and LRP4, and our results suggest a new role for the melanocortin 1 receptor (MC1R) in reproductive biology. As NEB is one component of evolutionary fitness, our identified associations indicate loci under present-day natural selection. Integration with data from historical selection scans highlighted an allele in the FADS1/2 gene locus that has been under selection for thousands of years and remains so today. Collectively, our findings demonstrate that a broad range of biological mechanisms contribute to reproductive success

Genetic variants linked to myopic macular degeneration in persons with high myopia: CREAM Consortium

Purpose To evaluate the roles of known myopia-associated genetic variants for development of myopic macular degeneration (MMD) in individuals with high myopia (HM), using case-control studies from the Consortium of Refractive Error and Myopia (CREAM). Methods A candidate gene approach tested 50 myopia-associated loci for association with HM and MMD, using meta-analyses of case-control studies comprising subjects of European and Asian ancestry aged 30 to 80 years from 10 studies. Fifty loci with the strongest associations with myopia were chosen from a previous published GWAS study. Highly myopic (spherical equivalent [SE] -5.0 diopters [D]) cases with MMD (N = 348), and two sets of controls were enrolled: (1) the first set included 16,275 emmetropes (SE -0.5 D); and (2) second set included 898 highly myopic subjects (SE -5.0 D) without MMD. MMD was classified based on the International photographic classification for pathologic myopia (META-PM). Results In the first analysis, comprising highly myopic cases with MMD (N = 348) versus emmetropic controls without MMD (N = 16,275), two SNPs were significantly associated with high myopia in adults with HM and MMD: (1) rs10824518 (P = 6.20E-07) in KCNMA1, which is highly expressed in human retinal and scleral tissues; and (2) rs524952 (P = 2.32E-16) near GJD2. In the second analysis, comprising highly myopic cases with MMD (N = 348) versus highly myopic controls without MMD (N = 898), none of the SNPs studied reached Bonferroni-corrected significance. Conclusions Of the 50 myopia-associated loci, we did not find any variant specifically associated with MMD, but the KCNMA1 and GJD2 loci were significantly associated with HM in highly myopic subjects with MMD, compared to emmetropes

Genome-wide analysis identifies 12 loci influencing human reproductive behavior.

The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits

Adherence to dietary guidelines and successful aging over 10 years

Background. We aimed to prospectively examine the relationship between overall diet quality (reflecting adherence to dietary guidelines) and successful aging in a population-based cohort of older adults. Methods. In this population-based cohort study, we analyzed 10-year follow-up data from 1,609 adults aged 49 years and older, who were free of cancer, coronary artery disease, and stroke at the baseline and who had complete dietary data. Dietary data were collected using a semiquantitative food frequency questionnaire. Total diet scores (TDS) were allocated for intake of selected food groups and nutrients for each participant as described in the national dietary guidelines. Higher scores indicated closer adherence to dietary guidelines. Successful aging was defined as the absence of disability, depressive symptoms, cognitive impairment, respiratory symptoms, and chronic diseases (cancer, coronary artery disease, and stroke). Results. At 10-year follow-up, 610 (37.9%) participants had died and 249 (15.5%) participants aged successfully. After multivariable adjustment, each 1-unit increase in TDS at baseline was associated with a 8% increased odds of successful aging 10 years later, odds ratio 1.08 (95% confidence interval 1.00-1.15). Participants in the highest (high adherence to dietary guidelines) versus lowest quartile (poor adherence to guidelines) of TDS at baseline had 58% higher odds of successful aging after 10 years, odds ratio 1.58 (95% confidence interval 1.02-2.46). Conclusions. Greater compliance with recommended national dietary guidelines (higher diet quality) was associated with an increased likelihood of successful aging, as determined through a multidomain approach

Adherence to dietary guidelines and successful aging

Abstract presented at the Experimental Biology 2015 conference, 28 March-1 April 2015, Boston, United States

Wholegrain and legume consumption and the 5-year incidence of age-related cataract in the Blue Mountains Eye Study

The Authors 2020. The present study aims to investigate the effect of wholegrain and legume consumption on the incidence of age-related cataract in an older Australian population-based cohort. The Blue Mountains Eye Study (BMES) is a population-based cohort study of eye diseases among older adults aged 49 years or older (1992-1994, n=3654). Of 2334 participants of the second examination of the BMES (BMES 2, 1997-2000), 1541 (78.3% of survivors) were examined 5 years later (BMES 3) who had wholegrain and legume consumption estimated from the food frequency questionnaire (FFQ) at BMES 2. Cataract was assessed using photos taken during examinations following the Wisconsin Cataract Grading System. Multivariable-Adjusted logistic regression models were used to assess associations with the 5-year incidence of cataract from BMES 2 (baseline) to BMES 3. The 5-year incidence of cortical, nuclear and posterior subcapsular (PSC) cataract were 18.2%, 16.5% and 5.9%, respectively. After adjustment for age, sex and other factors, total wholegrain consumption at baseline was not associated with incidence of any type of cataract. High consumption of legume showed a protective association for incident PSC cataract (5th quintile: Adjusted odds ratio 0.37, 95% confidence interval 0.15-0.92). There was no significant trend of this association across quintiles (P=0.08). In this older Australian population, we found no associations between wholegrain intake at baseline and the 5-year incidence of three cataract types. However, intake of legumes in the highest quintile, compared to the lowest quintile, may protect against PSC formation, a finding needing replication in other studies

Olfactory impairment is associated with functional disability and reduced independence among older adults

Objectives: Despite its relatively high prevalence, population-based data are lacking on whether olfactory impairment influences the functional status and independence of older adults. We assessed associations between olfactory impairment with activities of daily living (ADL) measures and the likelihood of using community support services and/or reliance on non-spouse family/friend support among older adults. Study design: Olfaction was measured using the San Diego Odor Identification Test (SDOIT) among 1636 participants of the Blue Mountains Eye Study (2002–4). Functional status was determined by the Older Americans Resources and Services ADL scale. Use of services and non-spouse family/friend support was self-reported. Results: Use of community support services was reported by 15.2% and 5.2% of persons with and without olfactory impairment, respectively. After multivariable adjustment including for cognitive function, participants with compared to those without olfactory impairment were more likely to use community support services and non-spouse family/friend support, odds ratio, OR, 1.82 (95% confidence intervals, CI 1.16–2.86) and OR 1.62 (95% CI 1.14–2.32), respectively. ADL difficulty was reported by 16.9% (n = 57) and 4.4% (n = 45) of participants with and without olfactory loss, respectively. Olfactory impairment was associated with increased likelihood of experiencing ADL difficulty, multivariable-adjusted OR 1.98 (95% CI 1.10–3.57). Olfactory loss was significantly associated with impaired basic ADL, OR 1.57 (95% CI 1.12–2.20). Conclusions: The functional ability and independence of older adults is significantly impaired in the presence of olfactory impairment. Early diagnosis of olfactory loss by primary physicians and geriatricians could facilitate timely interventions assisting the maintenance of functional independence in later life