Coffee has been characterized as the “leading worldwide beverage” and it is estimated that 1.4 billion cups are consumed daily. About 400 million cups are consumed daily in the U.S. alone. With many of the concerns about the adverse effects of coffee having been laid to rest with past research, the picture we currently have regarding caffeinated coffee consumption and health is much clearer. Overall there is good news for coffee drinkers.
The following is a brief summary of coffee related research from 2011.
Healthy individuals who moderately consume coffee (3-4 cups /day) are:
- Less likely to have strokes
- Less likely to have type 2 diabetes
- Likely to have improved liver function
- Less likely to have neurological pathology, Alzheimer’s and Parkinson’s
- Likely to have improved fat utilization · Less likely to die from all causes
Coffee also doesn’t appear to:
- Contribute to cardiovascular disease
Adverse effects of coffee include:
- Hypertensive individuals can have an increase in blood pressure for up to 3 hours.
- In pregnancy coffee has an adverse impact “on fetal activity but not on fetal growth”.
- Individuals with intracranial aneurysms are at greater risk of rupture
- “…a daily intake of 330 mg of caffeine, equivalent to 4 cups (600 ml) of coffee, or more may be associated with a modestly increased risk of osteoporotic fractures, especially in women with a low intake of calcium.”
Note: These mini-reviews are designed as updates and direct the reader to the full text of current research. The abstracts presented here are no substitute for reading and critically reviewing the full text of the original research. Where permitted we will direct the reader to that full text.
Cuppa joe: friend or foe? Effects of chronic coffee consumption on cardiovascular and brain health. [
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Mo Med. 2011 Nov-Dec;108(6):431-8.
Patil H, Lavie CJ, O'Keefe JH.
Mid-America Heart Institute, Saint Luke's Hospital, Kansas City, USA.Caffeine is the most widely consumed psychoactive drug worldwide. Indeed the majority of adults consume caffeine on a daily basis, most commonly in the forms of coffee and tea. Coffee, in particular, is the favored caffeine source in the United States, where more than 150 million people drink coffee on a daily basis. Coffee, one of the richest sources of antioxidants in the average American's diet, contains caffeine and other antioxidants that have the potential to confer both beneficial and adverse health effects. A growing body of research shows that coffee drinkers, compared to nondrinkers, may be less likely to develop type 2 diabetes, stroke, depression, death from any cause, and neurodegenerative diseases, including Parkinson's and Alzheimer's. Coffee appears to have a neutral effect on cardiovascular health. Although more research is clearly needed, coffee, when consumed without added cream or sugar, is a calorie-free beverage that may confer health benefits, especially when used in individuals who do not have adverse subjective effects due to its stimulating effects, and when coffee is substituted for less healthy, unnatural, and/or high-calorie beverages, such as colas and other sugary and artificially sweetened sodas and soft drinks.
Coffee consumption and risk of stroke: a dose-response meta-analysis of prospective studies. [
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Am J Epidemiol. 2011 Nov 1;174(9):993-1001. Epub 2011 Sep 13.
Larsson SC, Orsini N.
Division of Nutritional Epidemiology, National Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-17177 Stockholm, Sweden. susanna.larsson@ki.seCoffee consumption has been inconsistently associated with risk of stroke. The authors conducted a meta-analysis of prospective studies to quantitatively assess the association between coffee consumption and stroke risk. Pertinent studies were identified by searching PubMed and Embase from January 1966 through May 2011 and by reviewing the reference lists of retrieved articles. Prospective studies in which investigators reported relative risks of stroke for 3 or more categories of coffee consumption were eligible. Results from individual studies were pooled using a random-effects model. Eleven prospective studies, with 10,003 cases of stroke and 479,689 participants, met the inclusion criteria. There was some evidence of a nonlinear association between coffee consumption and risk of stroke (P for nonlinearity = 0.005). Compared with no coffee consumption, the relative risks of stroke were 0.86 (95%
confidence interval (95% CI): 0.78, 0.94) for 2 cups of coffee per day, 0.83 (95% CI: 0.74, 0.92) for 3-4 cups/day, 0.87 (95% CI: 0.77, 0.97) for 6 cups/day, and 0.93 (95% CI: 0.79, 1.08) for 8 cups/day. There was marginal between-study heterogeneity among study-specific trends (I2 = 12% and I2 = 20% for the first and second spline transformations, respectively). Findings from this meta-analysis indicate that moderate coffee consumption may be weakly inversely associated with risk of stroke.
Effects of caffeinated and decaffeinated coffee on biological risk factors for type 2 diabetes: a randomized controlled trial. [
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Nutr J. 2011 Sep 13;10:93.
Wedick NM, Brennan AM, Sun Q, Hu FB, Mantzoros CS, van Dam RM.
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA. nwedick@hsph.harvard.eduBACKGROUND: Coffee consumption has been associated with a lower risk of type 2 diabetes in prospective cohort studies, but the underlying mechanisms remain unclear. The aim of this study was to evaluate the effects of regular and decaffeinated coffee on biological risk factors for type 2 diabetes.
METHODS: Randomized parallel-arm intervention conducted in 45 healthy overweight volunteers who were nonsmokers and regular coffee consumers. Participants were assigned to consumption of 5 cups (177 mL each) per day of instant caffeinated coffee, decaffeinated coffee, or no coffee (i.e., water) for 8 weeks.
RESULTS: Average age was 40 years and body mass index was 29.5 kg/m2. Compared with consuming no coffee, consumption of caffeinated coffee increased adiponectin (difference in change from baseline 1.4 µg/mL; 95% CI: 0.2, 2.7) and interleukin-6 (difference: 60%; 95% CI: 8, 138) concentrations and consumption of decaffeinated coffee decreased fetuin-A concentrations (difference: -20%; 95% CI: -35, -1). For measures of glucose tolerance, insulin sensitivity, and insulin secretion, no significant differences were found between treatment groups.
CONCLUSIONS: Although no changes in glycemia and/or insulin
sensitivity were observed after 8 weeks of coffee consumption, improvements in adipocyte and liver function as indicated by changes in adiponectin and fetuin-A concentrations may contribute to beneficial metabolic effects of long-term coffee consumption.
The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis. [
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Am J Clin Nutr. Oct;94(4):1113-26. Epub 2011 Aug 31.
Mesas AE, Leon-Muñoz LM, Rodriguez-Artalejo F, Lopez-Garcia E.
Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid/IdiPAZ, Madrid, Spain.BACKGROUND: The effect of coffee and caffeine on blood pressure (BP) and cardiovascular disease (CVD) in hypertensive persons is uncertain.
OBJECTIVE: The objective was to summarize the evidence on the acute and longer-term effects of caffeine and coffee intake on BP and on the association between habitual coffee consumption and risk of CVD in hypertensive individuals.
DESIGN: A systematic review and meta-analysis of publications identified in a PubMed and EMBASE search up to 30 April 2011 was undertaken. Data were extracted from controlled trials on the effect of caffeine or coffee intake on BP change and from cohort studies on the association between habitual coffee consumption and CVD.
RESULTS: In 5 trials, the administration of 200-300 mg caffeine produced a mean increase of 8.1 mm Hg (95% CI: 5.7, 10.6 mm Hg) in systolic BP and of 5.7 mm Hg (95% CI: 4.1, 7.4 mm Hg) in diastolic BP. The increase in BP was observed in the first hour after caffeine intake and lasted =3 h. In 3 studies of the longer-term effect (2 wk) of coffee, no increase in BP was observed after coffee was compared with a caffeine-free
diet or was compared with decaffeinated coffee. Last, 7 cohort studies found no evidence of an association between habitual coffee consumption and a higher risk of CVD.
CONCLUSIONS: In hypertensive individuals, caffeine intake produces an acute increase in BP for =3 h. However, current evidence does not support an association between longer-term coffee consumption and increased BP or between habitual coffee consumption and an increased risk of CVD in hypertensive subjects.
Maternal coffee intake and associated risk factors: effects on fetal growth and activity. [
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Acta Med Port. 2011 Mar-Apr;24(2):241-8. Epub 2011 May 20.
Conde A, Teves C, Figueiredo B.
Unidade Maternidade de Júlio Dinis, Centro Hospitalar do Porto, Portugal.Empirical studies have shown that fetal growth and activity can be affected by several risk factors, such as maternal anxiety, depression and tobacco or alcohol consumption. Caffeine intake has received less attention in the literature, as well as the analysis of the mutual interplay of the range of such risk factors. This study aimed to examine effects of mother's coffee intake and associated risk factors during early pregnancy on fetal growth and activity. The sample involved 47 fetuses (51.1% male and 48.9% female) with gestational ages between 20-22 weeks whose mothers were recruited in a Portuguese antenatal obstetric unit. Repeated measures of mother's anxiety (STAI-S) and depression (EPDS) and information about socio-demographics and substances consumption were collected during the first and second trimesters of pregnancy. Fetal activity and biometry were measured during the 2(nd) trimester ultrasound. Results showed that 1) 23.4% of the pregnant women (N = 11) had regular coffee intake; 2) no significant differences were found neither on fetal growth nor on fetal movements considering mother's coffee intake; 3) when mother's socio-demographics and substances consumption were considered, tobacco consumption and anxiety at the 2(nd) trimester appeared as significant predictors of fetal growth and mother's coffee intake and anxiety symptoms at the 2(nd) trimester emerged as significant predictors of fetal movements. An adverse impact of maternal coffee intake during pregnancy was found on fetal activity but not on fetal growth. A deeper understanding of the multiple pathways by which these risk factors affect fetal growth and activity is needed.
Coffee consumption and mortality in women with cardiovascular disease. [
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Am J Clin Nutr. 2011 Jul;94(1):218-24. Epub 2011 May 11.
Lopez-Garcia E, Rodriguez-Artalejo F, Li TY, Mukamal KJ, Hu FB, van Dam RM.
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA. esther.lopez@uam.esBACKGROUND: Coffee is commonly consumed among populations of all ages and conditions. The few studies that have examined the association between coffee consumption and mortality in patients with cardiovascular disease (CVD) have obtained conflicting results.
OBJECTIVE: The objective was to assess the association between filtered caffeinated coffee consumption and all-cause and CVD mortality during up to 24 y of follow-up in women with CVD from the Nurses' Health Study. DESIGN: The Nurses' Health Study included 11,697 women. Coffee consumption was first assessed in 1980 with a food-frequency questionnaire (FFQ) and then repeatedly every 2-4 y. Cumulative consumption was calculated with all available FFQs from the
diagnosis of CVD to the end of the follow-up in 2004 to assess long-term effects. In addition, the most recent coffee measurement was related to mortality in the subsequent 2 y to assess shorter-term effects. Analyses were performed by using Cox regression models.
RESULTS: We documented 1159 deaths, of which 579 were due to CVD. The relative risks [RRs (95% CI)] of all-cause mortality across categories of cumulative coffee consumption [<1 cup (240 mL or 8 oz)/mo, 1 cup/mo to 4 cups/wk, 5-7 cups/wk, 2-3 cups/d, and =4 cups/d] were 1, 1.04 (0.86, 1.27), 1.13 (0.95, 1.36), 1.01 (0.86, 1.18), and 1.18 (0.89, 1.56), respectively (P for trend = 0.91). The RRs of CVD mortality across the same categories of coffee intake were 1, 0.99 (0.75, 1.31), 1.03 (0.80, 1.35), 0.97 (0.78, 1.21), and 1.25 (0.85, 1.84), respectively (P for trend = 0.76). Similarly, caffeine intake was not associated with total or CVD mortality. Finally, we observed no association of the most recent coffee and caffeine intakes with total and CVD mortality in the subsequent 2 y.
CONCLUSION: Consumption of filtered caffeinated coffee was not associated with CVD or all-cause mortality in women with CVD.
Trigger factors and their attributable risk for rupture of intracranial aneurysms: a case-crossover study. [
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Stroke. 2011 Jul;42(7):1878-82. Epub 2011 May 5.
Vlak MH, Rinkel GJ, Greebe P, van der Bom JG, Algra A.
Department of Neurology and Julius Center, University Medical Center Utrecht, Room STR 7.140, Mailbox STR 6.131, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.BACKGROUND AND PURPOSE: Little is known about activities that trigger rupture of an intracranial aneurysm. Knowledge on what triggers aneurysmal rupture increases insight into the pathophysiology and facilitates development of prevention strategies. We therefore aimed to identify and quantify trigger factors for aneurysmal rupture and to gain insight into the pathophysiology.
METHODS: During a 3-year period, 250 patients with aneurysmal subarachnoid hemorrhage completed a structured questionnaire regarding exposure to 30 potential trigger factors in the period soon before subarachnoid hemorrhage (hazard period) and for usual frequency and intensity of exposure. We assessed relative risks (RR) of rupture after exposure to triggers with the case-crossover design comparing exposure in the hazard period with the usual frequency of exposure. Additionally, we calculated population-attributable risks.
RESULTS: Eight triggers increased the risk for subarachnoid hemorrhage: coffee consumption (RR, 1.7; 95% CI, 1.2-2.4), cola consumption (RR, 3.4; 95% CI,1.5-7.9), anger (RR, 6.3; 95% CI, 4.6-25), startling (RR, 23.3; 95% CI, 4.2-128), straining for defecation (RR, 7.3; 95% CI, 2.9-19), sexual intercourse (RR, 11.2; 95% CI, 5.3-24), nose blowing (RR, 2.4; 95% CI, 1.3-4.5), and vigorous physical
exercise (RR, 2.4; 95% CI, 1.2-4.2). The highest population-attributable risks were found for coffee consumption (10.6%) and vigorous physical exercise (7.9%).
CONCLUSIONS: We identified and quantified 8 trigger factors for aneurysmal rupture. All triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture. Some triggers are modifiable, and further studies should assess whether reduction of exposure to these factors or measures preventing sudden increase in blood pressure decrease the risk of rupture in patients known to have an intracranial aneurysm.
Habitual coffee consumption and risk of hypertension: a systematic review and meta-analysis of prospective observational studies. [
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Am J Clin Nutr. 2011 Jun;93(6):1212-9. Epub 2011 Mar 30.
Zhang Z, Hu G, Caballero B, Appel L, Chen L.
Department of Epidemiology, Michigan State University, East Lansing, MI, USA.BACKGROUND: In 2 meta-analyses of randomized controlled trials, increased coffee intake was associated with slightly higher blood pressure. However, these trials were short in duration (<85 d).
OBJECTIVE: We conducted a systematic review and meta-analyses of long-term prospective studies that examined the association of habitual coffee consumption with risk of hypertension.
DESIGN: We searched electronic databases (MEDLINE, EMBASE, Agricola, and Cochrane Library) through August 2009 with the use of a standardized protocol. Eligible studies were prospective cohort trials that examined the association of coffee consumption with incident hypertension or blood pressure.
RESULTS: From 6 prospective cohort studies, a total of 172,567 participants and 37,135 incident hypertension cases were included. Mean follow-up ranged from 6.4 to 33.0 y. Compared with the lowest consumption [<1 cup (˜237 mL)/d], the pooled relative risks (RRs) for hypertension were 1.09 (95% CI: 1.01, 1.18) for the next higher category (1-3 cups/d), 1.07 (95% CI: 0.96, 1.20) for the second highest category (3-5 cups/d), and 1.08 (95% CI: 0.96, 1.21) for the highest category (>5 cups/d). A dose-response meta-analysis showed an inverse "J-shaped" curve (P for quadratic term < 0.001) with hypertension risk increasing up to 3 cups/d (RR for comparison of 3 with 0 cups/d: 1.07; 95% CI: 0.97, 1.20) and decreasing with higher intakes (RR for comparison of 6 with 0 cups/d: 0.99; 95% CI: 0.89, 1.10).
CONCLUSION: The results suggest that habitual coffee consumption of >3 cups/d was not associated with an increased risk of hypertension compared with <1 cup/d; however, a slightly elevated risk appeared to be associated with light-to-moderate consumption of 1 to 3 cups/d.
Coffee and its consumption: benefits and risks. [
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Crit Rev Food Sci Nutr. 2011 Apr;51(4):363-73.
Butt MS, Sultan MT.
National Institute of Food Science and Technology, University of Agriculture, Faisalabad, Pakistan. drmsbutt@yahoo.comCoffee is the leading worldwide beverage after water and its trade exceeds US $10 billion worldwide. Controversies regarding its benefits and risks still exist as reliable evidence is becoming available supporting its health promoting potential; however, some researchers have argued about the association of coffee consumption with cardiovascular complications and cancer insurgence. The health-promoting properties of coffee are often attributed to its rich phytochemistry, including caffeine, chlorogenic acid, caffeic acid, hydroxyhydroquinone (HHQ), etc. Many research investigations, epidemiological studies, and meta-analyses regarding coffee consumption revealed its inverse correlation with that of diabetes mellitus, various cancer lines, Parkinsonism, and Alzheimer's disease. Moreover, it ameliorates oxidative stress because of its ability to induce mRNA and protein expression, and mediates Nrf2-ARE pathway stimulation. Furthermore, caffeine and its metabolites help in proper cognitive functionality. Coffee lipid fraction containing cafestol and kahweol act as a safeguard against some malignant cells by modulating the detoxifying enzymes. On the other hand, their higher levels raise serum cholesterol, posing a possible threat to coronary health, for example, myocardial and cerebral infarction, insomnia, and cardiovascular complications. Caffeine also affects adenosine receptors and its withdrawal is accompanied with muscle fatigue and allied problems in those addicted to coffee. An array of evidence showed that pregnant women or those with postmenopausal problems should avoid excessive consumption of coffee because of its interference with oral contraceptives or postmenopausal hormones. This review article is an attempt to disseminate general information, health claims, and obviously the risk factors associated with coffee consumption to scientists, allied stakeholders, and certainly readers.
Bone quality associated with daily intake of coffee: a biochemical, radiographic and histometric study. [
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Braz Dent J. 2010;21(3):199-204.
Lacerda SA, Matuoka RI, Macedo RM, Petenusci SO, Campos AA, Brentegani LG.
Department of Morphology, Stomatology and Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil. suzie@forp.usp.brCaffeine induces loss of calcium and influences the normal development of bone. This study investigated the effects of coffee on bone metabolism in rats by biochemical measurement of calcium, bone densitometry and histometry. Male rats, born of female treated daily with coffee and with coffee intake since born, were anesthetized, subjected to extraction of the upper right incisor, and sacrificed 7, 21 and 42 days after surgery. Blood and urine samples were taken, and their maxilla radiographed and processed to obtain 5-µm-thick semi-serial sections stained with hematoxylin and eosin. The volume and bone quality were estimated using an image-analysis software. The results showed significantly greater amount of calcium in the plasma (9.40 ± 1.73 versus 9.80 ± 2.05 mg%) and urine (1.00 ± 0.50 versus 1.25 ± 0.70 mg/24 h) and significantly less amount in bone (90.0 ± 1.94 versus 86.0 ± 2.12 mg/mg bone), reduced bone mineral density (1.05 ± 0.11 versus 0.65 ± 0.15 mmAL), and lower amount of bone (76.19 ± 1.6 versus 53.41 ± 2.1 %) (ANOVA; p=0.01) in animals treated with coffee sacrificed after 42 days. It may be concluded that coffee/caffeine intake caused serious adverse effects on calcium metabolism in rats, including increased levels of calcium in the urine and plasma, decreased bone mineral density and lower volume of bone, thus delaying the bone repair process.
Coffee intake in midlife and risk of dementia and its neuropathologic correlates. [
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J Alzheimers Dis. 2011;23(4):607-15.
Gelber RP, Petrovitch H, Masaki KH, Ross GW, White LR.
Honolulu-Asia Aging Study at Kuakini Medical Center, VA Pacific Islands Healthcare System, Honolulu, HI, USA. rpgelber@gmail.comWhile animal data suggest a protective effect of caffeine on cognition, studies in humans remain inconsistent. We examined associations of coffee and caffeine intake in midlife with risk of dementia, its neuropathologic correlates, and cognitive impairment among 3494 men in the Honolulu-Asia Aging Study (mean age 52 at cohort entry, 1965-1968) examined for dementia in 1991-1993, including 418 decedents (1992-2004) who underwent brain autopsy. Caffeine intake was determined according to self-reported coffee, tea, and cola consumption at baseline. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for overall dementia, Alzheimer's disease (AD), vascular dementia (VaD), cognitive impairment (Cognitive Abilities Screening Instrument score <74), and neuropathologic lesions at death (Alzheimer lesions, microvascular ischemic lesions, cortical Lewy bodies, hippocampal sclerosis, generalized atrophy), according to coffee and caffeine intake. Dementia was diagnosed in 226 men (including 118 AD, 80 VaD), and cognitive impairment in 347. There were no significant associations between coffee or caffeine intake and risk of cognitive impairment, overall dementia, AD, VaD, or moderate/high levels of the individual neuropathologic lesion types. However, men in the highest quartile of caffeine intake (>277.5 mg/d) were less likely than men in the lowest quartile (=115.5 mg) to have any of the lesion types (adjusted-OR, 0.45; 95% CI, 0.23-0.89; p, trend = 0.04). Coffee and caffeine intake in midlife were not associated with cognitive impairment, dementia, or individual neuropathologic lesions, although higher caffeine intake was associated with a lower odds of having any of the lesion types at autopsy.
Maternal caffeine intake from coffee and tea, fetal growth, and the risks of adverse birth outcomes: the Generation R Study. [
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Am J Clin Nutr. 2010 Jun;91(6):1691-8. Epub 2010 Apr 28.
Bakker R, Steegers EA, Obradov A, Raat H, Hofman A, Jaddoe VW.
Departments of Epidemiology, Erasmus Medical Center, Rotterdam, Netherlands.BACKGROUND: Caffeine is a widely used and accepted pharmacologically active substance. The effect of caffeine intake during pregnancy on fetal growth and development is still unclear.
OBJECTIVE: We examined the associations of maternal caffeine intake, on the basis of coffee and tea consumption, with fetal growth characteristics measured in each trimester of pregnancy and the risks of adverse birth outcomes.
DESIGN: Associations were studied in 7346 pregnant women participating in a population-based prospective
cohort study from early pregnancy onward in the Netherlands (2001-2005). Caffeine intake in the first, second, and third trimesters was on the basis of coffee and tea consumption and was assessed by questionnaires. Fetal growth characteristics were repeatedly measured by ultrasound. Information about birth outcomes was obtained from hospital records.
RESULTS: We observed no consistent associations of caffeine intake with fetal head circumference or estimated fetal weight in any trimester. Higher caffeine intake was associated with smaller first-trimester crown-rump length, second- and third-trimester femur length, and birth length (P for trend <0.05). Offspring of mothers who consumed > or =6 caffeine units/d tended to have increased risks of small-for-gestational-age infants at birth.
CONCLUSIONS: Our results suggest that caffeine intake of > or =6 units/d during pregnancy is associated with impaired fetal length growth. Caffeine exposure might preferentially adversely affect fetal skeletal growth. Further studies are needed to assess these associations in non-European populations and to assess the postnatal consequences.