Coffee Surprises

March 11, 2010 Written by JP    [Font too small?]

Information is one of the greatest assets if you want to be a good conversationalist. This is especially true of dialogues that involve health and nutrition. The more you know about such topics the more interesting the conversations will be for all involved. Let’s take today’s topic as an example – coffee. Many physicians continue to promote the idea that coffee should generally be avoided or at least used sparingly. The basis for this position varies widely, but it often involves a proposed risk to the cardiovascular system and the possibility of adverse effects on sleep quality. In recent years, some other medical authorities have adopted an alternate point of view and crowned coffee as a healthy elixir. Listening to physicians on both sides of the coffee debate can be quite interesting. But actually taking part in that kind of exchange is very different situation.

Even in the midst of a recession, coffee sales are continuing to skyrocket. A recent analysis from the UK shows a dramatic 17% growth in this segment of the economy between the years of 2005 to 2009. What’s more, an additional 25% boom is expected by 2014. But the one thing that has changed is where people are drinking their daily cup of Joe. More and more Brits are enjoying premium coffee at home. (1)

The amount of research on coffee and components of coffee beans is quite impressive. Scientific interest in the beverage is partially a numbers game. Researchers want to know how this international obsession with coffee is likely to impact the health of societies for better or worse. In the private sector, manufacturers are beginning to fund research in this field as well because of indications that coffee beans may one day yield functional supplements and/or medications. Here’s an overview of several recent studies that have been circulating in the both the research + development, and scientific communities.

Coffee Extracts Possess Antiviral Activity – A substance contained in coffee, N-methyl-pyridinium formate, may inhibit the replication of a number of viruses including herpes simplex virus type 1 (HSV-1), influenza virus type A and poliovirus. This “novel component of coffee” also appears to promote cytotoxicity (killing) of viruses. (2)

Coffee May Protect Against Gout – A review in the March 2010 edition of Current Opinion in Rheumatology states that certain dietary and lifestyle choices may influence uric acid levels and, thereby, affect the risk of developing gout. Avoiding sugar, increasing daily exercise and losing excess weight are all cited as proactive steps that can be taken to lower uric acid and gout prevalence. Eating more low-glycemic fruits, nuts and vegetables is also recommended in the review. However the closing sentence of the study abstract is what caught my eye. “Coffee and vitamin C supplementation could be considered as preventive measures as these can lower urate levels, as well as the risk of gout and some of its comorbidities”. (3)

Coffee Roasting Matters – Phytochemicals in brewed coffee are believed to contribute “more than 50% of the dietary antioxidants in many countries”. New research now indicates that the darker the roast, the greater the antioxidant protection. In addition, dark roasted coffee appears to dramatically lower the activity of an inflammatory substance known as NF-kappaB. In a mouse study, a single dose of dark roasted coffee lead to a profound decrease in NF-kappaB levels by 68%. A report in the February 2010 issue of the journal Free Radical Biology and Medicine concludes that, “dark roasted coffee dampens a crucial mechanism in inflammation and induced a pivotal mechanism in oxidative stress defense”. Excess inflammation and oxidative stress are considered key contributors to the aging process and have been implicated in the development of many chronic diseases such as arthritis, cardiovascular disease and even dementia. (4)

Coffee Protects the Brain – Two recent systemic reviews evaluated the effects of caffeine exposure with regard to Alzheimer’s Disease (AD) and Parkinson’s Disease. A few of the most intriguing points about coffee and AD are summarized by the following quotes from a new meta-analysis published in the Journal of Alzheimer’s Disease:

  • “Most studies (3 out of 5) support coffee’s favorable effects against cognitive decline, dementia or AD”.
  • “Two studies had combined coffee and tea drinking and indicated some positive effects on cognitive functioning”.
  • “For tea drinking, protective effects against cognitive decline/dementia are still less evident”.
  • “Coffee drinking of 3-5 cups per day at midlife was associated with a decreased risk of dementia/AD by about 65% in late-life”. (5)

Similarly impressive findings abound in the examination of trials on coffee vs. Parkinson’s Disease. A total of 26 studies were evaluated. The risk ratio for PD was about 25% lower in those with the highest caffeine intake. This protective effect appeared to be more prevalent among male coffee drinkers, but persisted in females and resulted in a 14% reduction in risk in women. All told, caffeine intake of approximately 300 mg per day appeared to provide an average decline in PD incidence of 24%. The closing remark of the meta-analysis states that “This study confirms an inverse association between caffeine intake and the risk of PD, which can hardly be explained by bias or uncontrolled confounding”. (6)

Coffee May Also Improve HDL (“Good”) Cholesterol-Mediated Atheroprotection
Source: Circulation Research. 2010;106:627-629 (link)

Two other trials of late may be surprising to some. The first investigated the impact of coffee consumption in a group of 245 patients with or without non-alcoholic fatty liver disease (NAFLD). The participants who regularly drank espresso demonstrated greater liver protection as evidenced by “ultrasound bright liver scores”. Frequent espresso consumption also expressed itself in lower rates of insulin resistance and obesity – two identifiable risk factors for NAFLD. The Italian researchers conducting the trial note that the protective effects of coffee found here tend to complement previously reported benefits demonstrated in other liver ailments such as cirrhosis and liver cancer. (7)

Perhaps the biggest shock to hit the medical world in the past few weeks was the following headline “Coffee Drinking and Caffeine Associated with Reduced Risk of Hospitalization for Heart Rhythm Disturbances”. This title is based on a study presented at the American Heart Association’s 50th Annual Conference on Cardiovascular Disease Epidemiology and Prevention. Very high dosages of caffeine are known to provoke heart rhythm disturbances in sensitive individuals. But this recent evaluation of 130,054 men and women actually discovered an 18% reduced risk of arrhythmias in those who consumed 4 or more cups of coffee a day. Even more surprising is the fact that drinking lower quantities of coffee (1 to 3 cups) provided only a 7% reduction in risk. However these findings need to be interpreted with caution. The lead author of the study, Dr. Arthur Klatsky, offered this balanced perspective in saying: “these data might be reassuring to people who drink moderate amounts of coffee that their habit is not likely to cause a major rhythm disturbance”. Dr. Klatsky went on to say that, “Coffee drinking is related to a lower risk of hospitalization for rhythm problems, but the association does not prove cause and effect”. (8)

So there you have it – the most cutting edge data on coffee currently available. Use it to dazzle your family and friends or to keep your doctors on their toes. You too can be a coffee debate master! Or better yet, consider all the research I’ve presented today to help you decide whether coffee is right for you. If you choose to include coffee in your daily routine, consider using a dark roasted variety. Not only might it help to improve your antioxidant status and lower inflammation, but some research suggests that the roasting process tends to rid coffee of any detectable pesticide residues. (9)

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

Be well!


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Posted in Bone and Joint Health, Food and Drink, Nutrition

13 Comments & Updates to “Coffee Surprises”

  1. Mark Says:

    Great article. Just wondering if flavored ground coffees remove some of the benefits from just a plain roast?

  2. JP Says:

    Thank you, Mark. 🙂

    I haven’t seen any specific research re: flavorings in coffee. My hunch is that it would depend on what flavorings are used. For instance, adding pure cocoa to coffee might very well enhance the benefits in an additive or possibly synergistic manner. On the other hand, artificial flavorings might not have the same effect.

    Be well!


  3. Tiffany Says:

    Fabulous news! I love my coffee. My grind and brew coffee maker is one of my favorite purchases, and it’s true – there’s nothing as good as fresh ground coffee. Thanks for spreading the good news.

  4. Annika Says:

    I’m a coffee junkie, but can’t stand drinking it black. Studies offer conflicting data on whether adding milk to black tea counteracts or reduces its antioxidant activity. Do you know how the addition of milk or cream to coffee affects its beneficial effects?

  5. JP Says:

    Thank you, Tiffany! 🙂

    Be well!


  6. JP Says:


    One recent study suggests that whole milk doesn’t affect the bioavailability of certain antioxidants (phenolic acids) in coffee. Non-dairy creamer and sugar may however negatively impact the antioxidant potential of coffee.

    I’ll dig around some more and see if there’s enough data to warrant a column on this topic. Thank you for posing this thoughtful question.

    Be well!


  7. Annika Says:

    Thanks, JP! Luckily, I prefer my coffee unsweetened, and would never consider using non-dairy creamer. Raw whole milk is my additive of choice; I’m happy to see that at least one study showed that milk didn’t diminish coffee’s health benefits.

  8. JP Says:

    Update: More support for the role that coffee in fatty liver protection …

    Eur J Clin Nutr. 2015 Mar 25.

    Coffee but not green tea consumption is associated with prevalence and severity of hepatic steatosis: the impact on leptin level.

    BACKGROUND/OBJECTIVES: Most of the studies that have investigated the association between coffee consumption and hepatic steatosis have been experimental and small-scale clinical studies. As a result, epidemiological studies are scarce. To clear the association, we conducted a cross-sectional study and investigated the effects of coffee consumption with those of green tea consumption.

    SUBJECTS/METHODS: We analyzed 1024 Japanese male workers. The diagnosis of hepatic steatosis was based on ultrasonography. We divided coffee and green tea consumption into the following three categories: non-drinker; 1-2 cups/day and ⩾3 cups/day. To investigate the association between hepatic steatosis and coffee or green tea consumption, we calculated the odds ratio (OR) and adjusted the means of leptin levels on each severity of hepatic steatosis.

    RESULTS: A total of 265 of our subjects (25.9%) were diagnosed with hepatic steatosis. The ORs of the group of subjects who drank >3 cups of coffee/day was significantly lower compared with that of the noncoffee drinker group (OR 0.59, 95% confidence intervals 0.38-0.90, P=0.03). Although there was a significant difference between coffee consumption and leptin level only in the asymptomatic group, we found a decreasing trend in the asymptomatic and moderate-severe hepatic steatosis group. We did not find the same relationships in green tea consumption.

    CONCLUSIONS: Although we did not find an association between hepatic steatosis and green tea consumption, coffee may have beneficial effects on hepatic steatosis. In addition, we produced one possible hypothesis that coffee consumption negatively associates with leptin levels in hepatic steatosis.

    Be well!


  9. JP Says:

    Update 05/19/15:

    PLoS One. 2015 May 15;10(5):e0126469.

    Coffee Consumption, Newly Diagnosed Diabetes, and Other Alterations in Glucose Homeostasis: A Cross-Sectional Analysis of the Longitudinal Study of Adult Health (ELSA-Brasil).

    INTRODUCTION: Observational studies have reported fairly consistent inverse associations between coffee consumption and risk of type 2 diabetes, but this association has been little investigated with regard to lesser degrees of hyperglycemia and other alterations in glucose homeostasis. Additionally, the association between coffee consumption and diabetes has been rarely investigated in South American populations. We examined the cross-sectional relationships of coffee intake with newly diagnosed diabetes and measures of glucose homeostasis, insulin sensitivity, and insulin secretion, in a large Brazilian cohort of middle-aged and elderly individuals.

    METHODS: We used baseline data from 12,586 participants of the Longitudinal Study of Adult Health (ELSA-Brasil). Logistic regression analyses were performed to examine associations between coffee consumption and newly diagnosed diabetes. Analysis of covariance was used to assess coffee intake in relation to two-hour glucose from an oral glucose tolerance test, fasting glucose, glycated hemoglobin, fasting and -2-hour postload insulin and measures of insulin sensitivity.

    RESULTS: We found an inverse association between coffee consumption and newly diagnosed diabetes, after adjusting for multiple covariates [23% and 26% lower odds of diabetes for those consuming coffee 2-3 and >3 times per day, respectively, compared to those reporting never or almost never consuming coffee, (p = .02)]. An inverse association was also found for 2-hour postload glucose [Never/almost never: 7.57 mmol/L, ≤1 time/day: 7.48 mmol/L, 2-3 times/day: 7.22 mmol/L, >3 times/day: 7.12 mol/L, p<0.0001] but not with fasting glucose concentrations (p = 0.07). Coffee was additionally associated with 2-hour postload insulin [Never/almost never: 287.2 pmol/L, ≤1 time/day: 280.1 pmol/L, 2-3 times/day: 275.3 pmol/L, >3 times/day: 262.2 pmol/L, p = 0.0005) but not with fasting insulin concentrations (p = .58).

    CONCLUSION: Our present study provides further evidence of a protective effect of coffee on risk of adult-onset diabetes. This effect appears to act primarily, if not exclusively, through postprandial, as opposed to fasting, glucose homeostasis.

    Be well!


  10. JP Says:

    Update 05/23/15:

    Cancer Epidemiol Biomarkers Prev. 2015 May 21.

    Associations of coffee drinking with systemic immune and inflammatory markers.

    BACKGROUND: Coffee drinking has been inversely associated with mortality as well as cancers of the endometrium, colon, skin, prostate, and liver. Improved insulin sensitivity and reduced inflammation are among the hypothesized mechanisms by which coffee drinking may affect cancer risk; however, associations between coffee drinking and systemic levels of immune and inflammatory markers have not been well characterized.

    METHODS: We used Luminex bead-based assays to measure serum levels of 77 immune and inflammatory markers in 1,728 older non-Hispanic Whites. Usual coffee intake was self-reported using a food frequency questionnaire. We used weighted multivariable logistic regression models to examine associations between coffee and dichotomized marker levels. We conducted statistical trend tests by modeling the median value of each coffee category and applied a 20% false discovery rate criterion to P-values.

    RESULTS: Ten of the 77 markers were nominally associated (P-value for trend<0.05) with coffee drinking. Five markers withstood correction for multiple comparisons and included aspects of the host response namely chemotaxis of monocytes/macrophages (IFNγ, CX3CL1/fractalkine, CCL4/MIP-1β), pro-inflammatory cytokines (sTNFRII) and regulators of cell growth (FGF-2). Heavy coffee drinkers had lower circulating levels of IFNγ (OR=0.35; 95% CI 0.16-0.75), CX3CL1/fractalkine (OR=0.25; 95% CI 0.10-0.64), CCL4/MIP-1β (OR=0.48; 95% CI 0.24-0.99), FGF-2 (OR=0.62; 95% CI 0.28-1.38), and sTNFRII (OR=0.34; 95% CI 0.15-0.79) than non-coffee drinkers.

    CONCLUSIONS: Lower circulating levels of inflammatory markers among coffee drinkers may partially mediate previously observed associations of coffee with cancer and other chronic diseases.

    IMPACT: Validation studies, ideally controlled feeding trials, are needed to confirm these associations.

    Be well!


  11. JP Says:

    Update 06/25/15:

    Nutr Neurosci. 2015 Jun 22. [Epub ahead of print]
    The coffee paradox in stroke: Increased consumption linked with fewer strokes.
    Liebeskind DS, Sanossian N, Fu KA, Wang HJ, Arab L.

    Objective: To determine the association in amount of daily coffee consumption with incidence of stroke in a broad cohort, considering other vascular risk factors.

    Methods: We utilized the Third National Health and Nutrition Examination Survey (1988-1994; NHANES III) data on participants aged ≥17 years old to examine coffee consumption and stroke. Multivariate logistic regression models related the amount of coffee use reported in a food frequency questionnaire with stroke, controlling for other vascular risk factors.

    Results: Of 33 994 NHANES III subjects, coffee consumption and stroke data in adults ≥17 years old were available in 19 994. Daily coffee consumption ranged from 0 to 20 (median 1) cups and 644 (3.2%) participants had a stroke diagnosed by a physician. Coffee intake varied with age, gender, and ethnicity (P < 0.001). Interestingly, heart failure, diabetes, and hypertension were less frequent, and high cholesterol more frequent in those consuming ≥3 cups per day (P < 0.001). Smoking was more frequent in all coffee drinkers (P < 0.0001). Multivariate analyses revealed an independent effect of heavier coffee consumption (≥3 cups/day) on reduced stroke (OR 0.44, 95% CI 0.22-0.87, P < 0.02) in healthy subjects that was attenuated by vascular risk factors (OR 0.78, 95% CI 0.58-1.07, P ≈ 0.12). Conclusion: Heavier daily coffee consumption is associated with decreased stroke prevalence, despite smoking tendency in heavy coffee drinkers. Be well! JP

  12. JP Says:

    Updated 06/11/16:

    J Nutr. 2016 Jun 8.

    Coffee Consumption Is Positively Associated with Longer Leukocyte Telomere Length in the Nurses’ Health Study

    Background: Coffee is an important source of antioxidants, and consumption of this beverage is associated with many health conditions and a lower mortality risk. However, no study, to our knowledge, has examined whether varying coffee or caffeine consumption levels are associated with telomere length, a biomarker of aging whose shortening can be accelerated by oxidative stress.

    Objective: We performed a large comprehensive study on how coffee consumption is associated with telomere length.

    Methods: We used data from the Nurses’ Health Study (NHS), a prospective cohort study of female nurses that began in 1976. We examined the cross-sectional association between coffee consumption and telomere length in 4780 women from the NHS. Coffee consumption information was obtained from validated food-frequency questionnaires (FFQs), and relative telomere length was measured in peripheral blood leukocytes by the quantitative real-time polymerase chain reaction. Unconditional logistic regression was used to obtain ORs when the telomere length outcome was dichotomized at the median. Linear regression was used for tests of trend with coffee consumption and telomere length as continuous variables.

    Results: Higher total coffee consumption was significantly associated with longer telomeres after potential confounding adjustment. Compared with non-coffee drinkers, multivariable ORs for those drinking 2 to <3 and ≥3 cups of coffee/d were, respectively, 1.29 (95% CI: 0.99, 1.68) and 1.36 (95% CI: 1.04, 1.78) (P-trend = 0.02). We found a significant linear association between caffeine consumption from all dietary sources and telomere length (P-trend = 0.02) after adjusting for potential confounders, but not after additionally adjusting for total coffee consumption (P-trend = 0.37).

    Conclusions: We found that higher coffee consumption is associated with longer telomeres among female nurses. Future studies are needed to better understand the influence of coffee consumption on telomeres, which may uncover new knowledge of how coffee consumption affects health and longevity.

    Be well!


  13. JP Says:

    Updated 06/13/16:

    Clin Nutr. 2016 May 30.

    Coffee intake and the incident risk of cognitive disorders: A dose-response meta-analysis of nine prospective cohort studies.

    BACKGROUND & AIMS: Previous epidemiological studies have provided inconsistent conclusions on the impact of coffee consumption in the developing of cognitive disorders. However, no previous meta-analysis has pooled the evidence from the prospective cohort studies to assess the influence of coffee drinking and its potential dose-response patterns on the risk of developing cognitive disorders specifically.

    METHODS: Two databases (PubMed and Embase) were searched for evidence of cohort studies from inception to February 2016. We used a generic inverse-variance method with a random-effects model to pool the fully adjusted relative risks (RRs) and the corresponding 95% confidence intervals (CIs). In the dose-response analyses, a generalized least-squares trend estimation model was applied to computing the study-specific slopes.

    RESULTS: Nine prospective cohort studies involving 34,282 participants were included in our study. The duration of follow-up years ranged from 1.3 to 28. Compared with <1 cup, daily drinking of 1-2 cups of coffee was inversely linked with the occurrence of cognitive disorders (i.e., Alzheimer's disease, dementia, cognitive decline, and cognitive impairment), and the pooled RR (95% CI) was 0.82 (0.71, 0.94) with evidence of non-significant heterogeneity (I2 = 25%). Non-significant differences were presented for the association between coffee consumption (>3 vs. <1 cup/d) and incident cognitive disorders. The dose-response analysis showed a "J-shaped" curve relationship of the risk of developing cognitive disorders with coffee consumption.

    CONCLUSIONS: A "J-shaped" association was presented between coffee intake and incident cognitive disorders, with the lowest risk of incident cognitive disorders at a daily consumption level of 1-2 cups of coffee.

    Be well!


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