Coffee consumption and risk of total and cardiovascular mortality among patients with type 2 diabetes

Epidemiologic evidence on coffee and cancer

Coffee consumption is a major and frequent dietary exposure in diverse cultures around the globe whose safety has been questioned. A substantial body of epidemiologic evidence, consisting of over 500 papers relating the consumption of coffee to cancer of various sites, has accumulated to date. Numerous individual, site-specific meta analyses have been undertaken at various times. However, there is no comprehensive, up-to-date overview of the entirety of the knowledge base. To address this need, this review summarized the findings of the meta analyses and recent papers on site-specific human cancers among coffee consumers. For hepatocellular and endometrial cancers, there appears to be a strong and consistent protective association; for colorectal cancer, the direction of association is borderline protective. There appears to be no association with breast, pancreatic, kidney, ovarian, prostate, or gastric cancer. Risk of bladder cancer appears to be associated with heavy coffee consumption in some populations and among men. The associations with childhood leukemia and mother's consumption of coffee were ambiguous-with some suggestion of risk at high levels of daily consumption.

Tea and coffee consumption and cardiovascular morbidity and mortality

OBJECTIVE

To examine the associations of coffee and tea consumption with risk of morbidity and mortality of stroke and coronary heart disease (CHD) and with all-cause mortality.

METHODS AND RESULTS

Coffee and tea consumption were assessed with a validated food-frequency questionnaire, and 37 514 participants were observed for 13 years for the occurrence of cardiovascular morbidity and mortality. A U-shaped association between coffee and CHD was found, with the lowest hazard ratio (HR [95% CI]) for 2.1 to 3.0 cups per day (0.79 [0.65 to 0.96]; P(trend)=0.01). Tea was inversely associated with CHD, with the lowest HR (95% CI) for more than 6.0 cups per day (0.64 [0.46 to 0.90]; P(trend)=0.02). No associations between tea or coffee and stroke were found (P(trend)=0.63 and P(trend)=0.32, respectively). Although not significant, coffee slightly reduced the risk for CHD mortality (HR, 0.64; 95% CI, 0.37 to 1.11; P(trend)=0.12) for 3.1 to 6.0 cups per day. A U-shaped association between tea and CHD mortality was observed, with an HR of 0.55 (95% CI, 0.31 to 0.97; P(trend)=0.03) for 3.1 to 6.0 cups per day. Neither coffee nor tea was associated with stroke (P(trend)=0.22 and P(trend)=0.74, respectively) and all-cause mortality (P(trend)=0.33 and P(trend)=0.43, respectively).

CONCLUSIONS

High tea consumption is associated with a reduced risk of CHD mortality. Our results suggest a slight risk reduction for CHD mortality with moderate coffee consumption and strengthen the evidence on the lower risk of CHD with coffee and tea consumption.

Functional foods for dyslipidaemia and cardiovascular risk prevention

A food can be regarded as ‘functional’ if it can demonstrate a beneficial efficacy on one or more target functions in the body in a convincing way. Beyond adequate nutritional qualities, functional foods should either improve the state of health and wellbeing and/or reduce the risk of disease. Functional foods that are marketed with claims of heart disease reduction focus primarily on the major risk factors, i.e. cholesterol, diabetes and hypertension. Some of the most innovative products are designed to be enriched with ‘protective’ ingredients, believed to reduce risk. They may contain, for example, soluble fibre (from oat and psyllium), useful both for lowering cholesterol and blood pressure, or fructans, effective in diabetes. Phytosterols and stanols lower LDL-cholesterol in a dose-dependent manner. Soya protein is more hypocholesterolaemic in subjects with very high initial cholesterol and recent data indicate also favourable activities in the metabolic syndrome.n-3 Fatty acids appear to exert significant hypotriacylglycerolaemic effects, possibly partly responsible for their preventive activity. Dark chocolate is gaining much attention for its multifunctional activities, useful both for the prevention of dyslipidaemia as well as hypertension. Finally, consensus opinions about tea and coffee have not emerged yet, and the benefits of vitamin E, garlic, fenugreek and policosanols in the management of dyslipidaemia and prevention of arterial disease are still controversial.

Coffee consumption and risk of cardiovascular diseases and all-cause mortality among men with type 2 diabetes

OBJECTIVE

Coffee consumption has been linked to detrimental acute metabolic and hemodynamic effects. We investigated coffee consumption in relation to risk of CVDs and mortality in diabetic men.

RESEARCH DESIGN AND METHODS

We conducted a prospective cohort study including 3,497 diabetic men without CVD at baseline.

RESULTS

After adjustment for age, smoking, and other cardiovascular risk factors, relative risks (RRs) were 0.88 (95% CI 0.50-1.57) for CVDs (P for trend = 0.29) and 0.80 (0.41-1.54) for all-cause mortality (P for trend = 0.45) for the consumption of >or=4 cups/day of caffeinated coffee compared with those for non-coffee drinkers. Stratification by smoking and duration of diabetes yielded similar results. RRs for caffeine intake for the highest compared with the lowest quintile were 1.02 (0.70-1.47; P for trend = 0.96) for CVDs and 0.96 (0.64-1.44; P for trend = 0.69) for mortality.

CONCLUSIONS

These data indicate that regular coffee consumption is not associated with increased risk for CVDs or mortality in diabetic men.

Coffee consumption and risk of cardiovascular events and all-cause mortality among women with type 2 diabetes

AIMS/HYPOTHESIS

Coffee has been linked to both beneficial and harmful health effects, but data on its relationship with cardiovascular disease and mortality in patients with type 2 diabetes are sparse.

METHODS

This was a prospective cohort study including 7,170 women with diagnosed type 2 diabetes but free of cardiovascular disease or cancer at baseline. Coffee consumption was assessed in 1980 and then every 2-4 years using validated questionnaires. A total of 658 incident cardiovascular events (434 coronary heart disease and 224 stroke) and 734 deaths from all causes were documented between 1980 and 2004.

RESULTS

After adjustment for age, smoking and other cardiovascular risk factors, the relative risks were 0.76 (95% CI 0.50-1.14) for cardiovascular diseases (p trend = 0.09) and 0.80 (95% CI 0.55-1.14) for all-cause mortality (p trend = 0.05) for the consumption of >or=4 cups/day of caffeinated coffee compared with non-drinkers. Similarly, multivariable RRs were 0.96 (95% CI 0.66-1.38) for cardiovascular diseases (p trend = 0.84) and 0.76 (95% CI 0.54-1.07) for all-cause mortality (p trend = 0.08) for the consumption of >or=2 cups/day of decaffeinated coffee compared with non-drinkers. Higher decaffeinated coffee consumption was associated with lower concentrations of HbA(1c) (6.2% for >or=2 cups/day versus 6.7% for <1 cup/month; p trend = 0.02).

CONCLUSIONS

These data provide evidence that habitual coffee consumption is not associated with increased risk of cardiovascular diseases or premature mortality among diabetic women.

Coffee consumption and mortality after acute myocardial infarction: the Stockholm Heart Epidemiology Program

BACKGROUND

Cohort studies have suggested little effect of coffee consumption on risk of acute myocardial infarction. The effect of coffee consumption on prognosis after myocardial infarction is uncertain.

METHODS

In a population-based inception cohort study, we followed 1,369 patients hospitalized with a confirmed first acute myocardial infarction between 1992 and 1994 in Stockholm County, Sweden, as part of the Stockholm Heart Epidemiology Program. Participants reported usual coffee consumption over the preceding year with a standardized questionnaire distributed during hospitalization and underwent a health examination 3 months after discharge. Participants were followed for hospitalizations and mortality with national registers through November 2001.

RESULTS

A total of 289 patients died during follow-up. Compared with intake of <1 cup per day, coffee consumption was inversely associated with mortality, with multivariable-adjusted hazard ratios of 0.68 (95% confidence interval [CI] 0.45-1.02) for 1 to <3 cups, 0.56 (95% CI 0.37-0.85) for 3 to <5 cups, 0.52 (95% CI 0.34-0.83) for 5 to <7 cups, and 0.58 (95% CI 0.34-0.98) for > or =7 cups per day (P trend .06). Coffee intake was not associated with hospitalization for congestive heart failure or stroke. Candidate lipid and inflammatory biomarkers did not appear to account for the observed inverse association with mortality.

CONCLUSIONS

Self-reported coffee consumption at the time of hospitalization for myocardial infarction was inversely associated with subsequent postinfarction mortality in this population with broad coffee intake. If confirmed in other settings, identification of relevant mechanisms could lead to an improved prognosis for survivors of acute myocardial infarction.

Coffee consumption and risk of stroke in women

BACKGROUND

Data on the association between coffee consumption and risk of stroke are sparse. We assessed the association between coffee consumption and the risk of stroke over 24 years of follow-up in women.

METHODS AND RESULTS

We analyzed data from a prospective cohort of 83,076 women in the Nurses' Health Study without history of stroke, coronary heart disease, diabetes, or cancer at baseline. Coffee consumption was assessed first in 1980 and then repeatedly every 2 to 4 years, with follow-up through 2004. We documented 2280 strokes, of which 426 were hemorrhagic, 1224 were ischemic, and 630 were undetermined. In multivariable Cox regression models with adjustment for age, smoking status, body mass index, physical activity, alcohol intake, menopausal status, hormone replacement therapy, aspirin use, and dietary factors, the relative risks (RRs) of stroke across categories of coffee consumption (<1 cup per month, 1 per month to 4 per week, 5 to 7 per week, 2 to 3 per day, and >or=4 per day) were 1, 0.98 (95% CI, 0.84 to 1.15), 0.88 (95% CI, 0.77 to 1.02), 0.81 (95% CI, 0.70 to 0.95), and 0.80 (95% CI, 0.64 to 0.98) (P for trend=0.003). After further adjustment for high blood pressure, hypercholesterolemia, and type 2 diabetes, the inverse association remained significant. The association was stronger among never and past smokers (RR for >or=4 cups a day versus <1 cup a month, 0.57; 95% CI, 0.39 to 0.84) than among current smokers (RR for >or=4 cups a day versus <1 cup a month, 0.97; 95% CI, 0.63 to 1.48). Other drinks containing caffeine such as tea and caffeinated soft drinks were not associated with stroke. Decaffeinated coffee was associated with a trend toward lower risk of stroke after adjustment for caffeinated coffee consumption (RR for >or=2 cups a day versus <1 cup a month, 0.89; 95% CI, 0.73 to 1.08; P for trend=0.05).

CONCLUSIONS

Long-term coffee consumption was not associated with an increased risk of stroke in women. In contrast, our data suggest that coffee consumption may modestly reduce risk of stroke.

[Stroke prevention outside the pharmacy : risk factors and lifestyle]

Advice on modifiable risk and lifestyle factors for stroke prevention should be an established component of medical consultation. It is most important to explain that alterations to the lifestyle can be highly efficient with respect to the individual risk profile. The following review describes the importance of lifestyle factors such as nutrition, smoking, alcohol consumption, psychiatric condition, sport, dental hygiene and sleep disturbances for the risk of stroke using current data. It provides evidence that lifestyle modifications are highly effective with respect to stroke prevention. Corresponding recommendations and preventive strategies are presented.

Coffee consumption and risk of coronary heart diseases: a meta-analysis of 21 prospective cohort studies

BACKGROUND

A large amount of cohort studies addressed coffee consumption and risk of coronary heart disease (CHD) and yielded inconsistent results. We conducted a meta-analysis to estimate the pooling effects.

METHODS

We searched for all published English articles indexed in MEDLINE or PubMed from January 1966 to January 2008. Twenty-one independent prospective cohort studies, which tested CHD risk by coffee consumption, were identified. A general variance-based method was used to pool the relative risks (RR). 15,599 cases from 407,806 participants were included in pooling the overall effects.

RESULTS

As compared to the light coffee consumption (<1 cup/d in US or <or=2 cups/d in Europe), under the random-effects model, the pooled CHD RRs (95% CI) for all studies combined were 0.96 (0.87-1.06), 1.04 (0.92-1.17) and 1.07 (0.87-1.32) for the moderate (1-3 or 3-4 cups/d), heavy (4-5 or 5-6 cups/d) and very heavy (>or=6 or >or=7 cups/d) categories of coffee consumption (all p>0.05); Moderate coffee consumption showed significantly lower CHD RR (95% CI) of 0.82 (0.73-0.92) (p<0.001) in women, and of 0.87 (0.80-0.86) (p=0.001) in men and women followed <or=10 years.

CONCLUSION

Our findings do not support the hypothesis that coffee consumption increases the long-term risk of coronary heart disease. Habitual moderate coffee drinking was associated with a lower risk of CHD in women.

Coffee and Tea Consumption and Risk of Stroke Subtypes in Male Smokers

Background and Purpose— Coffee and tea consumption could potentially reduce the risk of stroke because these beverages have antioxidant properties, and coffee may improve insulin sensitivity. We examined the associations of coffee and tea consumption with risk of stroke subtypes.

Methods— We used prospective data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, a cohort study of 26 556 male Finnish smokers aged 50 to 69 years without a history of stroke at baseline. Coffee and tea consumption was assessed at baseline using a validated food-frequency questionnaire. During a mean follow-up of 13.6 years, from 1985 through December 2004, 2702 cerebral infarctions, 383 intracerebral hemorrhages, and 196 subarachnoid hemorrhages were ascertained from national registries.

Results— After adjustment for age and cardiovascular risk factors, both consumption of coffee and tea was statistically significantly inversely associated with the risk of cerebral infarction but not intracerebral or subarachnoid hemorrhage. The multivariate relative risk of cerebral infarction for men in the highest category of coffee consumption (≥8 cups/d) was 0.77 (95% CI, 0.66 to 0.90; P for trend <0.001) compared with those in the lowest category (<2 cups/d). The corresponding relative risk comparing men in the highest category of tea consumption (≥2 cups/d) with those in the lowest category (nondrinkers) was 0.79 (95% CI, 0.68 to 0.92; P for trend=0.002).

Conclusions— These results suggest that high consumption of coffee and tea may reduce the risk of cerebral infarction among men, independent of known cardiovascular risk factors.

Coffee consumption and type 2 diabetes — An extensive review

Coffee is a complex mixture of potentially active chemicals. It contains significant amounts of phenolic polymers, chlorogenic acid and also caffeine. Agricultural factors, roasting, blending, and brewing determine coffee’s chemical composition. Recent epidemiological studies suggest that habitual coffee consumption may help to prevent some chronic diseases including type 2 diabetes. Despite reports from the clinical trials of the effect of caffeine on decreasing insulin sensitivity, long-term prospective studies revealed that coffee may improve fasting glucose, glucose tolerance and insulin sensitivity as well. In the most recent publication habitual coffee drinkers have a lower total and cardiovascular mortality rate among diabetic subjects.

Coffee consumption and mortality in a 14-year follow-up of an elderly northern Finnish population

The present study assessed the relationship between coffee consumption and mortality in a home-dwelling elderly population. A population-based cohort of 817 men and women born in 1920 or earlier and living in northern Finland provided complete data on daily coffee consumption and other variables at the baseline examination in 1991-1992. Deaths were monitored through to the end of 2005 by national death certificates, resulting in 6960 person-years of follow-up. Hazard rate ratios for mortality by daily coffee intake were estimated by Poisson regression models adjusted for some known predictors of mortality. During 14.5 years of follow-up, 623 deaths occurred. The total mortality rate was inversely related to the number of cups (average volume, 125 ml) of coffee consumed daily. After adjustment for age, sub-period of follow-up, sex, marital status, basic educational level, previous occupational group, current smoking, BMI, history of myocardial infarction, self-rated health and presence of diabetes, cognitive impairment or physical disability, the estimated relative risk reduction of total mortality per an increment of one more cup of coffee per d reported at baseline was 4 (95% CI 0, 8) %. The observed associations between coffee consumption and mortality from CVD, cancer, and other or unknown causes, respectively, were qualitatively similar to that of total mortality but the estimates were less precise. The effect of coffee consumption at baseline appeared to attenuate after 10 years since the start of follow-up. The present study provides evidence for daily (caffeine-containing) coffee intake being inversely associated with mortality in the elderly.

Coffee consumption and risk of cardiovascular events after acute myocardial infarction: results from the GISSI (Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico)-Prevenzione trial

BACKGROUND

The relation between coffee consumption and cardiovascular disease has been studied extensively, but results are still debated. In addition, little evidence is available on patients with established coronary heart disease.

METHODS AND RESULTS

Prospectively ascertained information among 11,231 Italian patients (9584 males and 1647 females) with recent (< or = 3 months) myocardial infarction enrolled in the GISSI (Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico)-Prevenzione trial was used. Usual dietary habits were assessed at baseline and updated at 0.5 and 1.5 years. Coffee consumption was categorized as never/almost never, < 2 cups per day, 2 to 4 cups per day, and > 4 cups per day. Medication use and fasting glucose were assessed at 0.5, 1, 1.5, 2.5, and 3.5 years. Risk was evaluated with Cox proportional hazards with time-varying covariates. The main outcome measure was the cumulative incidence of cardiovascular events (cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke). A total of 1167 cardiovascular events occurred during 36,961 person-years of follow-up. After multivariable adjustment for potential confounders in the time-dependent analysis, the relative risk of cardiovascular events across categories of coffee consumption was 1.02 (95% CI 0.87 to 1.20) for < 2 cups per day, 0.91 (95% CI 0.75 to 1.09) for 2 to 4 cups per day, and 0.88 (95% CI 0.64 to 1.20) for > 4 cups per day compared with abstainers (P for trend=0.18). Ultimately, coffee consumption did not change the risk of coronary heart disease events, stroke, and sudden death.

CONCLUSIONS

No association between moderate coffee intake and cardiovascular events was observed in post-myocardial infarction patients.

Coffee consumption and the incidence of antihypertensive drug treatment in Finnish men and women

BACKGROUND

Only 2 prospective studies have previously investigated the association between coffee consumption and incident hypertension, and the findings are equivocal.

OBJECTIVE

The objective was to determine the relation between coffee consumption and the incidence of antihypertensive drug treatment.

DESIGN

We prospectively followed 24 710 Finnish subjects aged 25-64 y without a history of antihypertensive drug treatment, coronary heart disease, or stroke at baseline. Daily coffee consumption was assessed by questionnaires.

RESULTS

During a mean follow-up period of 13.2 y, 2505 participants started antihypertensive drug treatment. The multivariate-adjusted (age, sex, study year, education, leisure-time physical activity, smoking, body mass index, high total cholesterol, history of diabetes, and alcohol, tea, fruit, vegetable, sausage, and bread consumption) hazard ratios for antihypertensive drug treatment associated with the amount of coffee consumed daily (0-1, 2-3, 4-5, 6-7, or >or=8 cups) were 1.00, 1.29 (95% CI: 1.09, 1.54), 1.26 (95% CI: 1.06, 1.49), 1.24 (95% CI: 1.04, 1.48), and 1.14 (95% CI: 0.94, 1.37) (P for trend = 0.024), respectively. This trend became marginally significant after additional adjustment for baseline systolic blood pressure (P for trend = 0.077).

CONCLUSIONS

The results indicate that coffee drinking seems to increase the risk of antihypertensive drug treatment, and this risk was higher in subjects with low-to-moderate coffee intakes; however, there was no significantly increased trend in drinkers of approximately 1 cup (100 mL)/d or >or=8 cups/d.

Coffee and tea consumption and the risk of Parkinson's disease

Several prospective studies have assessed the association between coffee consumption and Parkinson's disease (PD) risk, but the results are inconsistent. We examined the association of coffee and tea consumption with the risk of incident PD among 29,335 Finnish subjects aged 25 to 74 years without a history of PD at baseline. During a mean follow-up of 12.9 years, 102 men and 98 women developed an incident PD. The multivariate-adjusted (age, body mass index, systolic blood pressure, total cholesterol, education, leisure-time physical activity, smoking, alcohol and tea consumption, and history of diabetes) hazard ratios (HRs) of PD associated with the amount of coffee consumed daily (0, 1-4, and > or = 5 cups) were 1.00, 0.55, and 0.41 (P for trend = 0.063) in men, 1.00, 0.50, and 0.39 (P for trend = 0.073) in women, and 1.00, 0.53, and 0.40 (P for trend = 0.005) in men and women combined (adjusted also for sex), respectively. In both sexes combined, the multivariate-adjusted HRs of PD for subjects drinking > or = 3 cups of tea daily compared with tea nondrinkers was 0.41 (95% CI 0.20-0.83). These results suggest that coffee drinking is associated with a lower risk of PD. More tea drinking is associated with a lower risk of PD.