Association between tea, coffee and caffeine consumption and risk of female infertility: a cross-sectional study.

OBJECTIVES: To explore the association between tea, coffee, and caffeine consumption and the risk of female infertility. METHODS: We analyzed data from 2099 females aged 18 to 44 years, participating in the National Health and Nutrition Examination Survey (NHANES) 2013-2018. We used generalized linear models (GLM) and generalized additive model (GAM) to investigate the dose-response relationship between the tea, coffee, and caffeine consumption and infertility, adjusting for potential confounders. RESULTS: A non-linear relationship was detected between tea consumption and infertility and the inflection point was 2 cups/day. On the right side of the inflection point, we did not detect a significant association. However, on the left side, we found a negative relationship between tea consumption and infertility (OR: 0.73; 95% CI: 0.57 to 0.93; P = 0.0122). Meanwhile, our study found no significant association between coffee (0.96, 0.81 to 1.13, P = 0.6189) or caffeine consumption (1.15, 0.93 to 1.42, P = 0.2148) and female infertility. CONCLUSIONS: Tea consumption was non-linearly associated with infertility, whereas no significant associations were found between coffee, caffeine consumption and infertility.

A systematic review and dose-response meta-analysis of prospective cohort studies on coffee consumption and risk of lung cancer.

Studies on the association between coffee consumption and risk of lung cancer have been conflicting. The aim of this study was to systematically review the current evidence on the association between coffee consumption and risk of lung cancer and to quantify this association by performing a meta-analysis. A comprehensive systematic search was performed on online databases up to July 2023 investigating the association between coffee consumption and risk of lung cancer. All prospective cohort studies reporting odds ratios (ORs), rate or risk ratios (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) in this context were included. The overall effect size was calculated using the random-effects model and statistical between-studies heterogeneity was examined using Cochrane's Q test and I2. A total of 14 prospective cohort studies were included in this systematic review and meta-analysis. We found a significant positive association between coffee consumption and risk of lung cancer (RR: 1.28; 95% CI: 1.12, 1.47). This association remained significant when we included a pooled analysis paper and excluded 5 cohort studies (RR: 1.37; 95% CI: 1.12, 1.66). We observed no proof of significant publication bias using Egger's test (P = 0.58). Moreover, dose-response analysis showed that each one cup/day increase in coffee consumption was related with a 6% higher lung cancer risk (RR: 1.06; 95% CI: 1.03, 1.09). In conclusion, we found a significant positive association between coffee consumption and risk of lung cancer.

Dietary factors and risk for amyotrophic lateral sclerosis: A two sample mendelian randomization study.

Correlations between dietary factors and amyotrophic lateral sclerosis (ALS) have been found in previous observational studies. However, no further studies have used Mendelian randomization to further explore the causal relationship between dietary factors and ALS. Clarifying these relationships is a crucial part of developing nutritional recommendations for ALS prevention. The exposure and outcome datasets employed in this study were extracted from the IEU Open GWAS project (https://gwas.mrcieu.ac.uk/). The exposure datasets involved in our Mendelian analyses consisted of meat intake (processed meat intake, poultry intake, beef intake, pork intake, non-oily fish intake, and oily fish intake), staple foods intake (bread intake and cereal intake), vegetable intake (cooked vegetable intake, salad/raw vegetable intake), fruit intake (fresh fruit intake and dried fruit intake), and beverage intake (coffee intake and tea intake). The weighted median, MR-Egger, Inverse Variance Weighted, Simple mode and Weighted mode methods were all utilized. And we applied Inverse Variance Weighted method as the main judgement criterion for Mendelian randomization analysis. Heterogeneity and pleiotropy analyses were conducted to confirm the validity of the outcomes. Genetically predicted that oily fish intake (OR: 0.7648; 95% CI: 0.5905-0.9904; P = .0420), coffee intake (OR: 0.7385; 95% CI: 0.5660-0.9637; P = .0256), and fresh fruit intake (OR: 0.6165; 95% CI: 0.4007-0.9487; P = .0278) were causally associated with a decreased risk of ALS. Negative results (P > .05) were received for all other dietary factors. This study found that oily fish intake, coffee intake and fresh fruit intake reduced the risk of developing ALS. Additionally, other factors were not associated with ALS.

Is diet related to skin condition? A Mendelian randomization study.

Observational studies have revealed associations between various dietary factors and skin conditions. However, the causal relationship between diet and skin condition is still unknown. Data on 17 dietary factors were obtained from the UK Biobank. Data on four skin conditions were derived from the UK Biobank and another large-scale GWAS study. Genetic predictions suggested that the intake of oily fish was associated with a lower risk of skin aging (OR: 0.962, P = 0.036) and skin pigmentation (OR: 0.973, P = 0.033); Tea intake was associated with a lower risk of skin pigmentation (OR: 0.972, P = 0.024); Salad/raw vegetables intake was associated with a lower risk of keratinocyte skin cancer (OR: 0.952, P = 0.007). Coffee intake was associated with increased risk of skin aging (OR: 1.040, P = 0.028); Pork intake was associated with increased risk of skin aging (OR: 1.134, P = 0.020); Beef intake was associated with increased risk of cutaneous melanoma (OR: 1.013, P = 0.016); Champagne plus white wine intake was associated with increased risk of cutaneous melanoma (OR: 1.033, P = 0.004); Bread intake was associated with increased risk of keratinocyte skin cancer (OR: 1.026, P = 0.013). Our study results indicate causal relationships between genetically predicted intake of oily fish, tea, salad/raw vegetables, coffee, pork, beef, champagne plus white wine, and bread and skin conditions.

Association of coffee and tea consumption with osteoporosis risk: A prospective study from the UK biobank.

OBJECTIVE: The association of coffee and tea consumption with osteoporosis is highly controversial, and few studies have focused on the combined effects of the two beverages. This study aimed to investigate the independent and combined associations of coffee and tea consumption with osteoporosis risk. METHODS: A prospective cohort study involving 487,594 participants aged 38-73 years from the UK Biobank was conducted. Participants with reported coffee and tea consumption and without osteoporosis at baseline were included. Coffee and tea consumption were assessed via a touch-screen questionnaire at baseline. Newly diagnosed osteoporosis during the follow-up period, defined based on ICD-10 codes (M80-M82), was the primary outcome. Cox regression analyses were utilized to calculate hazard ratios (HRs) and 95 % confidence intervals (CIs). Dose-effect associations were assessed using restricted cubic spline analysis. RESULTS: During a median follow-up of 12.8 years, 15,211 cases of osteoporosis were identified. Compared to individuals without coffee or tea consumption, drinking coffee was associated with an HR of 0.93 (95 % CI: 0.89-0.96), and tea consumption with an HR of 0.86 (95 % CI: 0.83-0.90). Continuous trends were significant for both coffee and tea consumption, showing non-linear associations with osteoporosis incidence. Moderate consumption, such as 1-2 cups of coffee or 3-4 cups of tea per day, was associated with a lower incidence of osteoporosis, with HRs of 0.9 (95 % CI: 0.86-0.94) and 0.85 (95 % CI: 0.81-0.90), respectively. Additionally, combined coffee and tea consumption displayed a U-shaped association with osteoporosis risk, with the lowest risk observed in individuals who consumed 1-2 cups of both beverages daily, with an HR of 0.68 (95 % CI: 0.61-0.75). CONCLUSION: Our findings highlight the potential benefits of moderate coffee and tea consumption in reducing the risk of osteoporosis.

Maternal caffeine intake during pregnancy and the risk of delivering a small for gestational age baby: Kuopio Birth Cohort.

PURPOSE: High caffeine intake during pregnancy is associated with restricted fetal growth. We aimed to evaluate the association between maternal caffeine intake during early and late pregnancy and the risk of delivering a small for gestational age (SGA) baby. METHODS: Kuopio Birth Cohort (KuBiCo) is a prospective cohort study including women whose pregnancies and deliveries were treated at the prenatal clinics in outpatient healthcare centers and in Kuopio University Hospital, Finland. Maternal diet and caffeine intake during the first (n = 2007) and third (n = 4362) trimester of pregnancy were assessed using a 160-item food frequency questionnaire (2013-2022). SGA was defined as birth weight corrected for gestational age below - 2 standard deviations from the mean, according to the sex-specific Finnish fetal growth curves. RESULTS: Altogether in 32 and 38% (1st and 3rd trimester) of all women and in 44 and 52% of coffee drinkers, caffeine intake exceeded the recommendation for caffeine intake ( ≤ 200 mg/day) during pregnancy. The women with moderate (51-200 mg/day) (aOR 1.87; 95% CI: 1.16-3.02) and high (> 200 mg/day) (aOR 1.51; 95% CI: 1.08-2.10) caffeine intake during the first trimester were in the highest risk of having an SGA newborn. Caffeine intake in the third trimester of pregnancy was not associated with SGA. CONCLUSIONS: Moderate and high caffeine intake during early pregnancy is associated with SGA. As the results suggest that even moderate caffeine intake during the first trimester may increase the risk of SGA, the intake within recommendation limits does not necessarily appear to be safe for pregnant women and their newborns.

Mendelian randomization reveals the impact of diet on infertility in men and women.

Background: Although studies on the effects of diet on fertility has progressed, some cumulative evidence has piled against popular hypotheses. The aim of our study was to investigate the effects of 31 diets including 23 individual dietary intakes and 8 dietary habits on infertility in men and women. Methods: The datas of diets and infertility were collected from genome-wide association studies (GWAS). Mendelian randomization (MR) methods were used to analyze causal relationships. Multivariate MR (MVMR) adjusted for the effects of other exposures on causality. And MR-Egger, Cochran's Q, radial MR, and MR-PRESSO tests were employed to assess heterogeneity and horizontal pleiotropy. Results: Our study found that coffee intake (OR, 3.6967; 95% CI, 1.0348 - 13.2065; P = 0.0442) and cooked vegetable intakes (OR, 54.7865; 95% CI, 2.9011 - 1030.5500; P = 0.0076) increased the risk of male infertility. For women, beer was a risk factor for infertility (OR, 4.0932; 95% CI, 1.8728 - 8.9461; P = 0.0004); but processed meat was negatively associated with infertility (OR, 0.5148; 95% CI, 0.2730 - 0.9705; P = 0.0401). MVMR demonstrated selenium as a protective factor against female infertility (OR, 7.4474e-12; 95% CI, 5.4780e-22 - 1.0125e-01; P = 0.0314). Conclusion: We found the causal relationships between four diets and infertility. We look forward to more high-quality epidemiologic studies to prove our conclusions.

Association between coffee and caffeine intake and risk of COPD: Findings based on NHANES 2007-2012.

BACKGROUND: The association between coffee and caffeine intake and the risk of COPD and lung function has not been thoroughly discussed in Americans, with subgroup and threshold effects remaining unclear. OBJECTIVES: This study investigated the association between coffee and caffeine consumption and the risk of chronic obstructive pulmonary disease (COPD) as well as lung function utilizing data from the NHANES 2007-2012. METHODS: We assessed the associations of coffee and caffeine consumption with the risk of COPD and lung function parameters, including FEV1 and FVC, adjusting for common demographic and disease characteristics in a cross-sectional analysis of NHANES data. RESULTS: A total of 9763 participants were included in the study, and 592 were diagnosed with COPD. Multivariate regression models revealed positive associations between coffee and caffeine consumption and the risk of COPD and lung function. Subgroup analyses stratified by sex, DM, hypertension status, and smoking habits identified potential effect modifiers as well as inflection points from threshold effect examinations. CONCLUSIONS: The results of this cross-sectional study indicated significant positive correlations between coffee and caffeine consumption and the risk of COPD. Additionally, positive correlations between exposure variables and FEV1 and FVC were detected. Among the stratification factors, smoking status exhibited the most potential for modifying effects. Future practices and research are needed to validate the results and explore the underlying mechanisms.

Coffee, Alcohol, and Artificial Sweeteners Have Temporal Associations with Gastrointestinal Symptoms.

BACKGROUND: Various dietary strategies for managing irritable bowel syndrome (IBS) target mechanisms such as brain-gut interactions, osmotic actions, microbial gas production, and local immune activity. These pathophysiological mechanisms are diverse, making it unclear which foods trigger IBS symptoms for a substantial proportion of patients. AIM: To identify associations between foods and gastrointestinal symptoms. METHODS: From the mySymptoms smartphone app, we collected anonymized diaries of food intake and symptoms (abdominal pain, diarrhea, bloating, and gas). We selected diaries that were at least 3 weeks long. The diaries were analyzed for food-symptom associations using a proprietary algorithm. As the participants were anonymous, we conducted an app-wide user survey to identify IBS diagnoses according to Rome IV criteria. RESULTS: A total of 9,710 food symptom diaries that met the quality criteria were collected. Of the survey respondents, 70% had IBS according to Rome IV criteria. Generally, strong associations existed for caffeinated coffee (diarrhea, 1-2 h postprandial), alcoholic beverages (multiple symptoms, 4-72 h postprandial), and artificial sweeteners (multiple symptoms, 24-72 h postprandial). Histamine-rich food intake was associated with abdominal pain and diarrhea. Some associations are in line with existing literature, whilst the absence of an enriched FODMAP-symptom association contrasts with current knowledge. CONCLUSIONS: Coffee, alcohol, and artificial sweeteners were associated with GI symptoms in this large IBS-predominant sample. Symptom onset is often within 2 h postprandial, but some foods were associated with a delayed response, possibly an important consideration in implementing dietary recommendations. Clinical trials must test the causality of the demonstrated food-symptom associations.

The association between wet overactive bladder and consumption of tea, coffee, and caffeine: Results from 2005-2018 National Health and Nutrition Examination Survey.

BACKGROUND & AIMS: Previous studies have reported an inconsistent relationship between overactive bladder (OAB) and the consumption of tea, coffee, and caffeine. Our study aims to determine these associations in a large and nationally representative adult sample. METHODS: This cross-sectional study included 15,379 participants from the 2005-2018 US National Health and Nutrition Examination Survey (NHANES) database. The outcome was the risk of wet OAB that was diagnosed when the OAB symptom score was ≥3 with urgent urinary incontinence and excluded other diseases affecting diagnosis. The exposures were the consumption of tea, coffee, and caffeine. Weighted logistic regression models were established to explore these associations by calculating odds ratios (OR) and 95% confidence intervals (CI), as did restricted cubic splines (RCS) used to analyze the nonlinear associations. RESULT: Of all the participants (n = 15,379), 2207 had wet OAB. Mean [SE] consumption of tea, total coffee, caffeinated coffee, decaffeinated coffee, and caffeine was 233.6 [15.7] g/day, 364.3 [15.5] g/day, 301.6 [14.9] g/day, 62.7 [7.9] g/day, 175.5 [6.6] mg/day in participants with wet OAB, respectively. In the fully adjusted model, compared to those without tea consumption, the high consumption of tea (>481 g/day) was associated with an increased risk of wet OAB (OR: 1.29; 95%CI: 1.01-1.64). Low decaffeinated coffee (0.001-177.6 g/day) had a negative association with the risk (OR: 0.66; 95%CI: 0.49-0.90). In the RCS analysis, tea consumption showed a positive linear association with the risk of wet OAB, and decaffeinated coffee showed a nonlinear relationship with the risk and had a turning point of 78 g/day in the U-shaped curve between 0 and 285 g/day. Besides, total coffee, caffeinated coffee, and caffeine consumption had no significant association with the risk. Interestingly, in the high tea consumption, participants with high total coffee consumption [>527.35 g/day, OR and 95%CI: 2.14(1.16-3.94)] and low caffeine consumption [0.1-74.0 mg/day, OR and 95%CI: 1.50(1.03-2.17)] were positively associated with the risk of wet OAB. CONCLUSION: High tea consumption was associated with the increased risk of wet OAB, especially intake together with high total coffee and low caffeine consumption, but no significant association with the single consumption of total coffee and caffeine. Low decaffeinated coffee was associated with a decreased risk of wet OAB. It is necessary to control tea intake when managing the liquid intake of wet OAB patients.

Maternal caffeine, coffee and cola drink intake and the risk of gestational diabetes - Kuopio Birth Cohort.

AIMS: Coffee intake is associated with a decreased risk of type 2 diabetes among non-pregnant people. We aimed to investigate the association between caffeine, coffee and cola drink intake in early pregnancy and the risk of gestational diabetes (GDM). METHODS: Kuopio Birth Cohort (KuBiCo) is a prospective cohort study including pregnant women who were followed at the prenatal clinics in outpatient healthcare centers and gave birth in Kuopio University Hospital, Finland (n=2214). Maternal diet during the first trimester of pregnancy was assessed using a 160-item food frequency questionnaire. GDM was diagnosed by oral glucose tolerance test according to the Finnish national guidelines mainly between 24 and 28 gestational weeks. RESULTS: Women with moderate coffee intake in the first trimester were less likely diagnosed with GDM than women without coffee intake in an age-adjusted model (OR 0.87; 95% CI 0.76-0.99; p = 0.03), but the association was attenuated in multi-adjusted models (p = 0.11). No association was found between caffeine intake and GDM. One third (32.4%) of pregnant women consumed caffeine over the recommendation (> 200 mg/d). Women who consumed cola drinks more than the median (33.3 mL/d) had an increased risk of GDM (OR 1.29; 95% CI 1.02-1.63, p = 0.037) in multi-adjusted model compared to those who consumed less. CONCLUSIONS: Caffeine intake during the first trimester of pregnancy was not associated with the risk of GDM but a minor non-significant decrease was seen with moderate coffee intake. Although the average consumption of cola drinks was low in the KuBiCo cohort, higher consumption was associated with an increased risk of GDM. Further studies are needed to evaluate the safe amount of coffee during pregnancy, since the recommended caffeine intake was exceeded in almost half of the coffee drinkers.

Caffeinated beverages intake and risk of deep vein thrombosis: A Mendelian randomization study.

This study aimed to explore the potential link between coffee and tea consumption and the risk of deep vein thrombosis (DVT) through Mendelian randomization (MR) analysis. Employing the MR, we identified 33 single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for coffee intake and 38 SNPs for tea intake. The investigation employed the inverse-variance weighted (IVW) method to evaluate the causal impact of beverage consumption on DVT risk. Additionally, MR-Egger and MR-PRESSO tests were conducted to assess pleiotropy, while Cochran's Q test gauged heterogeneity. Robustness analysis was performed through a leave-one-out approach. The MR analysis uncovered a significant association between coffee intake and an increased risk of DVT (odds ratio [OR] 1.008, 95% confidence interval [CI] = 1.001-1.015, P = 0.025). Conversely, no substantial causal effect of tea consumption on DVT was observed (OR 1.001, 95% CI = 0.995-1.007, P = 0.735). Importantly, no significant levels of heterogeneity, pleiotropy, or bias were detected in the instrumental variables used. In summary, our findings suggest a modestly heightened risk of DVT associated with coffee intake, while tea consumption did not exhibit a significant impact on DVT risk.

Coffee Drinking and the Odds of Osteopenia and Osteoporosis in Middle-Aged and Older Americans: A Cross-Sectional Study in NHANES 2005-2014.

The study investigates the association of coffee consumption and odds of osteoporosis/osteopenia among individuals older than 50 years in the United States. In NHANES 2005-2014, drinking ≤ 2 cups(16 oz) of coffee per day can reduce the risk of osteoporosis/osteopenia at the femoral neck and lumbar spine in US adults. Previous epidemiological studies revealed that daily coffee intake reduced the incidence of a cluster of metabolic diseases, however, the link between coffee consumption and prevalence of osteoporosis/osteopenia still remain inconclusive and awaits further confirmation. Based on data collection from 2005 to 2014 survey cycles, National Health and Nutrition Examination Survey (NHANES), a sample size of 8789 participants aged 50 and above completing two nonconsecutive 24-h dietary recalls were eventually enrolled for analysis. Associations between coffee intake and BMD were assessed. A lower odds of having femoral neck osteopenia/osteoporosis (FOO) was observed in participants with moderate intake of coffee (≤ 2 cups per day), rather than other beverages (OR 0.83; 95% CI, 0.72-0.95; p = 0.01). Moreover, significant associations existed between daily caffeine intake and both FOO and lumbar-spine osteopenia/osteoporosis (LOO). Even after adjusting for decaffeinated coffee, tea, sugar-sweetened beverages (SSBs), and coffee consumption, osteopenia and osteoporosis the odds remained lower at both femoral and neck levels. Our data suggest moderate habitual coffee intake (≤ 2 cups coffee/day) would have protective effects against osteoporosis/osteopenia of femoral neck and spine, among US adults over the age of 50.

Acute Effects of Coffee Consumption on Blood Pressure and Endothelial Function in Individuals with Hypertension on Antihypertensive Drug Treatment: A Randomized Crossover Trial.

INTRODUCTION: Coffee is a complex brew that contains several bioactive compounds and some of them can influence blood pressure (BP) and endothelial function (EF), such as caffeine and chlorogenic acids (CGAs). AIM: This study aimed to evaluate the acute effects of coffee on BP and EF in individuals with hypertension on drug treatment who were habitual coffee consumers. METHODS: This randomized crossover trial assigned 16 adults with hypertension to receive three test beverages one week apart: caffeinated coffee (CC; 135 mg caffeine, 61 mg CGAs), decaffeinated coffee (DC; 5 mg caffeine, 68 mg CGAs), and water. BP was continuously evaluated from 15 min before to 90 min after test beverages by digital photoplethysmography. Reactive hyperemia index (RHI) assessed by peripheral arterial tonometry evaluated EF before and at 90 min after test beverages. At the same time points, microvascular reactivity was assessed by laser speckle contrast imaging. Repeated-measures-ANOVA evaluated the effect of time, the effect of beverage, and the interaction between time and beverage (treatment effect). RESULTS: Although the intake of CC produced a significant increase in BP and a significant decrease in RHI, these changes were also observed after the intake of DC and were not significantly different from the modifications observed after the consumption of DC and water. Microvascular reactivity did not present significant changes after the 3 beverages. CONCLUSION: CC in comparison with DC and water neither promoted an acute increase in BP nor produced an improvement or deleterious effect on EF in individuals with hypertension on drug treatment who were coffee consumers.

Association Between Instant Coffee Consumption and the Development of Chronic Obstructive Pulmonary Disease: Results From a Community-Based Prospective Cohort.

BACKGROUND: A poor diet is a risk factor for chronic obstructive pulmonary disease (COPD). The interaction between dietary factors and cigarette smoking in the development of COPD is unclear. We investigated the interactions between dietary patterns and smoking status on COPD-related outcomes. METHODS: We used data from the Anseong-Ansan cohort that has been followed for 20 years. A total of 6,221 individuals without COPD in the baseline survey were analyzed. Five dietary patterns were identified using a semi-quantitative food frequency questionnaire. Associations of dietary patterns with COPD and forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio in different strata of smoking status were evaluated using Cox regression and linear mixed models, respectively. RESULTS: The highest quartile of the "coffee" pattern (high coffee consumption) was associated with COPD (hazard ratio, 1.46; 95% confidence interval [CI], 1.03-2.08) and lower FEV1/FVC ratio (ß = -1.2%; 95% CI, -1.9% to -0.6%) using the lowest quartile as a reference for heavy smokers, but not light or never smokers (P value for interaction = 0.035 for COPD). Regarding the associations between various consumption levels of black coffee, combined coffee, and instant coffee and COPD, an association with COPD was only observed for instant coffee in heavy smokers. CONCLUSION: High instant coffee consumption is associated with COPD development in heavy smokers, but not in light or never smokers. This may be attributed to sugar and cream in instant coffee mixes.

A Mendelian randomization study on the causal relationship between smoking, alcohol consumption, and the development of myopia and astigmatism.

The influence of environmental factors like smoking and alcohol on myopia and astigmatism is controversial. However, due to ethical concerns, alternative study designs are urgently needed to assess causal inference, as mandatory exposure to cigarettes and alcohol is unethical. Following comprehensive screenings, 326 single nucleotide polymorphisms (SNPs) related to myopia and astigmatism were included in the dataset. To validate the causal association between exposures such as cigarette smoking, alcohol consumption, and coffee intake, and outcomes namely astigmatism and myopia, five regression models were employed. These models encompassed MR-Egger regression, random-effects inverse-variance weighted (IVW), weighted median estimator (WME), weighted model, and simple model. The instrumental variables utilized in these analyses were the aforementioned SNPs. Apply Cochran's Q test to determine heterogeneity of SNPs; if heterogeneity exists, focus on IVW model results. The IVW model showed a 1.379-fold increase in the risk of astigmatism (OR = 1.379, 95%CI 0.822~2.313, P = 0.224) and a 0.963-fold increase in the risk of myopia (OR = 0.963, 95%CI 0.666~1.393, P = 0.841) for each unit increase in smoking. For each unit increase in coffee intake, the risk of astigmatism increased 1.610-fold (OR = 1.610, 95%CI 0.444~5.835, P = 0.469) and the risk of myopia increased 0.788-fold (OR = 0.788, 95%CI 0.340~1.824, P = 0.578). For each additional unit of alcohol consumption, the risk of astigmatism increased by 0.763-fold (OR = 0.763, 95%CI 0.380~1.530, P = 0.446), and none of the differences were statistically significant. However, for each unit of alcohol consumption, the risk of myopia increased by 1.597 times, and the difference was statistically significant (OR = 1.597, 95%CI 1.023~2.493, P = 0.039). The findings indicate that alcohol consumption is a risk factor for myopia but smoking and coffee intake do not affect its development. Additionally, there is no association between smoking, alcohol consumption, coffee intake, and the risk of astigmatism.

Beverage consumption and facial skin aging: Evidence from Mendelian randomization analysis.

BACKGROUND: Observational studies have linked coffee, alcohol, tea, and sugar-sweetened beverage (SSB) consumption to facial skin aging. However, confounding factors may influence these studies. The present two-sample Mendelian randomization (MR) investigated the potential causal association between beverage consumption and facial skin aging. METHODS: The single-nucleotide polymorphisms (SNPs) associated with coffee, alcohol, and tea intake were derived from the IEU project. The SSB-associated SNPs were selected from a genome-wide association study (GWAS). Data on facial skin aging were derived from the largest GWAS involving 16 677 European individuals. The inverse variance-weighted (IVW) was the main MR analysis method, supplemented by other methods (MR-Egger, weighted median, simple mode, and weighted mode). The MR-Egger intercept analysis was used for sensitivity analysis. Moreover, we conducted a replication analysis using data from another GWAS dataset on coffee consumption to validate our findings. RESULTS: Four instrumental variables (IVs) sets were used to examine the causal association between beverage consumption (coffee, alcohol, tea, SSB) and facial skin aging. Our results revealed that genetically predicted higher coffee consumption reduced the risk of facial skin aging (OR: 0.852; 95% CI: 0.753-0.964; p = 0.011, IVW method). The sensitivity analysis confirmed the robustness of the findings, with no evidence of pleiotropy or heterogeneity. The results of replicated MR analysis on coffee consumption were consistent with the initial analysis (OR = 0.997; 95% CI = 0.996-0.999; p = 0.003, IVW method). CONCLUSIONS: This study manifests that higher coffee consumption is significantly associated with a reduced risk of facial skin aging. These findings can offer novel strategies for identifying the underlying etiology of facial skin aging.

Causal relationship between coffee intake and neurological diseases: a Mendelian randomization study.

BACKGROUND: Previous observational studies focused on the association of coffee consumption and neurological disease. However, it is not known whether these associations are causal. METHODS: We used Mendelian randomization (MR) study to assess the causal relationship of coffee intake with the risk of neurological diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, epilepsy, stroke, and migraine. Single-nucleotide polymorphisms (SNPs) which had genetic statistical significance with coffee intake were used as instrumental variable (IV). Genetic instruments were stretched from the MRC-IEU (MRC Integrative Epidemiology Unit) analysis on the UK Biobank. We performed MR analyses using the inverse variance weighted (IVW) method as the main approach. Sensitivity analyses were further performed using MR-Egger and MR-PRESSO to assess the robustness. RESULTS: In the MR analysis, 40 SNPs were selected as IV, the F statistics for all SNPs ranged from 16 to 359. In IVW approach, our results provide genetic evidence supporting a potential causal association between coffee intake and a lower risk of migraine (OR = 0.528, 95% CI = 0.342-0.817, P = 0.004) and migraine with aura (OR = 0.374, 95% CI = 0.208-0.672, P = 0.001). However, we found no significant association between coffee intake and other neurological diseases along with their subtypes in this MR study. CONCLUSION: Using genetic data, our MR study found significant evidence supporting a causal association between coffee intake and migraine. This suggests that coffee consumption is likely a trigger or a prevention strategy for migraine.

Causal relationships between coffee intake, apolipoprotein B and gastric, colorectal, and esophageal cancers: univariable and multivariable Mendelian randomization.

PURPOSE: Coffee intake and apolipoprotein B levels have been linked to gastric, colorectal, and esophageal cancers in numerous recent studies. However, whether these associations are all causal remains unestablished. This study aimed to assess the potential causal associations of apolipoprotein B and coffee intake with the risk of gastric, colorectal, and esophageal cancers using Mendelian randomization analysis. METHODS: In this study, we utilized a two-sample Mendelian randomization analysis to access the causal effects of coffee intake and apolipoprotein B on gastric, colorectal, and esophageal cancers. The summary statistics of coffee intake (n = 428,860) and apolipoprotein B (n = 439,214) were obtained from the UK Biobank. In addition, the summary statistics of gastric cancer, colorectal cancer, and esophageal cancer were obtained from the FinnGen biobank (n = 218,792). Inverse variance weighted, MR-Egger, weighted median, and weighted mode were applied to examine the causal relationship between coffee intake, apolipoprotein B and gastric, colorectal, and esophageal cancers. MR-Egger intercept test, Cochran's Q test, and leave-one-out analysis were performed to evaluate possible heterogeneity and pleiotropy. Steiger filtering and bidirectional mendelian randomization analysis were performed to evaluate the possible reverse causality. RESULTS: The result of the inverse variance weighted method indicated that apolipoprotein B levels were significantly associated with a higher risk of gastric cancer (OR = 1.392, 95% CI 1.027-1.889, P = 0.0333) and colorectal cancer (OR = 1.188, 95% CI 1.001-1.411, P = 0.0491). Furthermore, multivariable Mendelian randomization analysis also revealed a positive association between apolipoprotein B levels and colorectal cancer risk, but the effect of apolipoprotein B on gastric cancer risk disappeared after adjustment of coffee intake, body mass index or lipid-related traits. However, we did not discover any conclusive evidence linking coffee intake to gastric, colorectal, or esophageal cancers. CONCLUSIONS: This study suggested a causal association between genetically increased apolipoprotein B levels and higher risk of colorectal cancer. No causal relationship was observed between coffee intake and gastric, colorectal, or esophageal cancers.

Caffeine intake during pregnancy and adverse outcomes: An integrative review.

Caffeine intake during pregnancy is common. Caffeine crosses the placenta, raising concerns about its possible deleterious effects on the developing embryo/fetus. Studies on this subject show conflicting results, and still there is no consensus on the recommended dose of caffeine during pregnancy. We performed an integrative review with studies from six databases, using broad MESH terms to allow the identification of publications that addressed the outcomes of caffeine use during pregnancy, with no date limit for publications, in English and Portuguese language. The research returned 16,192 articles. After removing duplicates, screening by title, abstract and full-text, we evaluated 257 and included 59 articles. We found association between caffeine intake and pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. The effects were often dose dependent. No association with prematurity has been demonstrated, but one study showed a small reduction in gestational age with increasing doses of caffeine intake. Defining a safe dose for caffeine intake during pregnancy is a challenging task due to the heterogeneity in study designs and results, as well as the difficulty of reliably assessing the amount of caffeine consumed. In some studies, exposures below the recommended level of caffeine intake during pregnancy (200 mg/day), as suggested by the guidelines, were associated with pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. Well-designed studies with reliable quantification of caffeine intake are needed to assess the safety of low doses during pregnancy.