Coffee, Supplements / 30.03.2026

Please note: Supplements are generally not FDA tested or approved. Some supplements can interfere with medications including blood pressure meds and anticoagulants.  Do not delay seeking medical attention for medical concerns by taking supplements without medical advice. Combining supplements can increase the risk of toxicity and side effects. Statements and product contents have not been independently confirmed by MedicalResearch.com or Eminent Domains Inc. Please discuss any and all supplements you take or are considering taking with your health care provider. [caption id="attachment_72987" align="aligncenter" width="500"]paraxanthine-gummies-caffeine Pexels image[/caption] Caffeine has been the world's most consumed psychoactive substance for centuries. Found in coffee, tea, energy drinks, and countless supplements, it is so deeply embedded in daily life that questioning its supremacy as a performance enhancer seems almost contrarian. Yet a growing body of research is doing exactly that, focusing not on caffeine itself but on the compound your body actually converts it into: paraxanthine. When you drink a cup of coffee, your liver metabolizes caffeine into three primary compounds. Paraxanthine accounts for approximately 84% of that metabolic output, making it by far the dominant active byproduct. This has led researchers to ask a straightforward question: if paraxanthine is what your body is actually using, what happens when you skip the middleman and consume it directly?
Author Interviews, Coffee, Genetic Research, JAMA, Kidney Disease / 15.02.2023

MedicalResearch.com Interview with: [caption id="attachment_60028" align="alignleft" width="133"]Dr. Sara Mahdavi Dr. Mahdavi[/caption] Dr. Sara Mahdavi, PhD Clinical Scientist and Clinical Instructor Research Appointment in the Faculty of Medicine University of Toronto Toronto, ON MedicalResearch.com: What is the background for this study? Response: This was a long-term study spanning 16 years and began with a population of young adults who were medically assessed on a regular basis. It was remarkable to see just how striking the effects of coffee were in the group that had the susceptible genetic variant, what we termed “slow caffeine metabolizers” yet no effect whatsoever in those who did not were termed “fast metabolizers”.
Author Interviews, Coffee, Ophthalmology / 04.12.2021

MedicalResearch.com Interview with: [caption id="attachment_58458" align="alignleft" width="150"]Kristine Dalton PhD FAAO, FBCLA School of Optometry & Vision Science University of Waterloo Waterloo, Canada Dr. Dalton[/caption] Kristine Dalton PhD FAAO, FBCLA School of Optometry & Vision Science University of Waterloo Waterloo, Canada MedicalResearch.com: What is the background for this study? Response: Dynamic visual acuity refers to the ability to detect and perceive small details in objects that are moving relative to an observer.  Dynamic visual acuity is a complex visual function, that involves a number of different aspects of vision, including detecting the target, moving the eyes appropriately to observe the target, and processing the visual information from the target in the brain to interpret what we are seeing.   What makes dynamic visual acuity so interesting to study, is that as a visual function, it appears to play an important role in a number of real-world situations, including playing sports, driving, and piloting, and it may provide us more information about how the visual system is functioning compared to the more traditional, static vision tests alone. Previous research has demonstrated that consumption of caffeine has been shown to benefit physiological, psychomotor, and cognitive performance.  More recently there has been an increased interest in studying the impacts of caffeine on the vision system, however the impact of caffeine on dynamic visual acuity has not been studied.  This study was designed to address this limitation in the literature, particularly because dynamic visual acuity appears to be such an important visual function for real-world activities.  
Author Interviews, Coffee, Heart Disease, JAMA, OBGYNE / 09.11.2021

MedicalResearch.com Interview with: [caption id="attachment_58356" align="alignleft" width="200"]Stefanie N. Hinkle, PhD Assistant Professor Department of Biostatistics, Epidemiology and Informatics Perelman School of Medicine, University of Pennsylvania Dr. Hinkle[/caption] Stefanie N. Hinkle, PhD Assistant Professor Department of Biostatistics Epidemiology and Informatics Perelman School of Medicine University of Pennsylvania MedicalResearch.com: What is the background for this study? Response: Over 80% of U.S. women of reproductive age consume caffeine daily.While most women decrease consumption after becoming pregnant, many continue to consume caffeine throughout pregnancy. The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women limit their caffeine consumption to <200 mg/d out of an abundance of caution due to potential associations with pregnancy loss and fetal growth restriction at higher intakes. There remains limited data on associations with maternal cardiometabolic outcomes in pregnancy.  
Author Interviews, Coffee, Diabetes / 26.10.2020

MedicalResearch.com Interview with: Yuji Komorita, MD, PhD Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University Maidashi 3-1-1, Higashi-ku, Fukuoka MedicalResearch.com: What is the background for this study?   Response: Both green tea and coffee have been reported to confer health benefits, and reduce all-cause mortality in general population, respectively. However, no study has investigated the combined impact of them on health or mortality. We followed 4,923 Japanese patients with type 2 diabetes registered at the Fukuoka Diabetes Registry (median, 5.3 years; follow-up rate, 99.5%).  MedicalResearch.com: What are the main findings?  Response: Drinking 4 or more daily cups of green tea was associated with 40% lower risk of death, and 2 or more cups of coffee was associated with 41% lower risk. Furthermore, the combination of 4 or more cups of green tea and 2 or more cups of coffee every day was associated with 63% lower risk of death. We have shown that higher consumption of green tea and coffee was associated with reduced all-cause mortality, and their combined effect appeared to be additive in people with type 2 diabetes.
Author Interviews, Coffee, OBGYNE / 25.08.2020

MedicalResearch.com Interview with: [caption id="attachment_55208" align="alignleft" width="128"]Professor Jack E. James, PhD Reykjavík University Reykjavík Iceland Prof. James[/caption] Professor Jack E. James, PhD Reykjavík University Reykjavík Iceland  MedicalResearch.com: What prompted this study?  Response: Chronic exposure to any chemical during pregnancy is cause for concern. There should be no exception simply because that chemical, caffeine, happens to be widely consumed. Caffeine is a habit-forming substance of no nutritional value. If anything, its widespread consumption suggests that it should be given special attention. Concern is heightened by what is known about the effects of caffeine on the human body, where it affects neural processes in the brain, including networks that control respiration and heart function. When consumed during pregnancy, caffeine readily crosses the placenta, exposing the fetus to the drug. Notably, the fetus is largely physically incapable of metabolising caffeine – that ability develops during the first year of life. Pregnancy studies have shown that caffeine can interfere with fetal heart function and oxygenation. 
Author Interviews, Coffee, Hepatitis - Liver Disease, JAMA, OBGYNE, Pediatrics / 30.07.2019

MedicalResearch.com Interview with: [caption id="attachment_50491" align="alignleft" width="128"]Dr-Hui Wang Dr. Hui Wang[/caption] Prof Hui Wang PhD Wuhan University China MedicalResearch.com: What is the background for this study? What are the main findings? Response: We started our work in the adverse outcome of maternal caffeine intake during pregnancy about 15 years ago. Then, we found that prenatal caffeine intake could result in nonalcoholic fatty liver disease in the offspring. However, the underlying mechanism was unclear. So, we start the current work, and found that hat maternal caffeine intake disrupts liver development before and after birth, which might be the trigger of the adult non-alcoholic fatty liver disease in the offspring rats. Moreover, we further found that the fetal programming of liver glucocorticoid – insulin like growth factor 1 axis, a new endocrine axis first reported by our team, might participate in such process. 
Author Interviews, Cancer Research, Coffee / 21.07.2019

MedicalResearch.com Interview with: coffee-smell caffeineMr Jue Sheng Ong,  PhD Student  QIMR Berghofer’s Statistical Genetics Group MedicalResearch.com: What is the background for this study? Response: Previous findings have shown conflicting results on whether coffee is associated with cancer risk. To evaluate whether there’s any evidence for a causal relationship between coffee and cancer outcomes, we performed two types of association analyses using data from the half a million participants in the UK.
  • We first studied whether an individual’s self-reported coffee consumption is related to their overall risk of developing or dying from any cancers.
  • Then, we repeated the analyses using genetically predicted coffee intake (using about 35 genetic markers related with coffee intake) instead of their self-reported consumption: a technique known as mendelian randomization which is commonly used in modern epidemiology to remove bias from environmental confounders.
Using both techniques, we found no evidence to support a relationship between coffee consumption and the risk of developing or dying from cancers.
Addiction, Author Interviews, Coffee / 16.05.2019

MedicalResearch.com Interview with: [caption id="attachment_49187" align="alignleft" width="128"]Dr Lorenzo Stafford, PhD, CPsycholSenior Lecturer, Department of PsychologyUniversity of PortsmouthPortsmouth Stafford[/caption] Dr Lorenzo Stafford, PhD, CPsychol Senior Lecturer, Department of Psychology University of Portsmouth Portsmouth  MedicalResearch.com: What is the background for this study?   Response: The background to this work was that I had been thinking for sometime on the role of our sense of smell in drug consumption and addiction.  Most of the research in this area is dominated by visual processes, in particular showing how cues associated to drugs (e.g. packet of cigarettes, bottle of beer) become conditioned in such drug users. That work has been useful in explaining how in recovering addicts, long after the withdrawal symptoms have subsided, when exposed to such cues, they can nevertheless relapse to craving and consuming the drug; hence though a powerful driver, addiction is not just about reversing withdrawal symptoms. However, most of our richer experiences are multisensory, so it seems likely that other senses must also play a role in the addictive process. Years ago, I completed a PhD on the topic of caffeine and with the general importance placed on the sensory (especially smell) aspects of coffee, all planted the seed for a possible study. We completed two experiments that examined the lowest concentration at which participants (high, moderate and non-coffee consumers) could detect (Threshold test) a coffee associated chemical (exp 1) and in a separate task, how fast they were at identifying (Recognition test) the odour of real coffee. In experiment 2, participants (coffee consumers and non-consumers) completed the same Threshold test for the coffee odour but also completed a Threshold test for a control odour.
Author Interviews, Coffee, Heart Disease, Nutrition / 13.05.2019

MedicalResearch.com Interview with: Professor Elina Hypponen Professor in Nutritional and Genetic Epidemiology Director: Australian Centre for Precision Health  Australian Centre for Precision Health| University of South Australia Cancer Research Institute | South Australian Health & Medical Research Institute  MedicalResearch.com: What is the background for this study? Response: In Randomised controlled trials caffeine, which is a key constituent of coffee, has been shown to increase blood pressure. There is also some past evidence to suggest that higher coffee consumption may increase the risk of cardiovascular disease, but only in individuals who are slow caffeine metabolisers. We used information from about 350,000 individuals from the UK, to look at the association between patterns of  habitual of coffee consumption and the subsequent risk of cardiovascular disease. As we also know that people are genetically different with respect to their ability to metabolise caffeine, a further aim for our study was to look at whether those people who are able to metabolise caffeine effectively, may also be more resistant to possible cardiovascular effects of coffee, compared to those who metabolise caffeine more slowly. 
Author Interviews, Coffee / 19.04.2019

MedicalResearch.com Interview with: Eugene Chan, PhD Senior Lecturer in Marketing Monash Business School Monash University Australia and  Sam Maglio PhD Associate Professor of Marketing Department of Management University of Toronto  MedicalResearch.com: What is the background for this study? What are the main findings?  Response: The physiological effects of coffee and caffeine consumption have been well-studied, but we were interested in the psychological effects. Especially in Western societies, there is a mental association between coffee and arousal – that coffee is an arousing beverage. This led us to ask, might this association itself produce the psychological “lift” without actually drinking beverages? We found that it does. Merely seeing pictures of coffee or thinking about coffee can increase arousal, heart rates, and make people more focused. The effects are not as strong as actually drinking coffee of course, but they are still noticeable.
Alzheimer's - Dementia, Author Interviews, Coffee, Parkinson's / 14.11.2018

MedicalResearch.com Interview with: Donald Weaver, PhD, MD, FRCPC, FCAHS Senior Scientist and Director, Research Institute Krembil Research Institute University Health Network Toronto, Canada MedicalResearch.com: What is the background for this study? What are the main findings? Response: First, we are seeking novel molecules that might have usefulness in the treatment of Alzheimer’s disease (AD). Since Mother Nature is a superb chemist, natural products are an ideal place to start looking for possible therapeutics. There is a long history (penicillin, digitalis …) of drugs identified from natural product sources. Moreover, in earlier work by us, we have shown that other natural products extracted from maple syrup have possible therapeutic efficacy against AD. Therefore, it was logical for us to look at extracts of coffee. We see similarities between maple syrup and coffee. In both of these natural products, the plant derived material (i.e. the coffee bean, or sap from maple syrup) is initially boiled or roasted prior to its use; thus, it is not a direct simple plant product, but one that has been heated (boiled or roasted). We suspect that the heating process “does more chemistry” enabling the generation of new molecules from the plant derived materials. In our study we show that a class of compounds (phenylindanes) from roasted coffee has the ability to inhibit the misfolding of two proteins (beta-amyloid, tau) whose misfolding and aggregation (“clumping”) is implicated in the disease process of AD. Second, as described below, there is already epidemiological evidence that coffee consumption may offer some protective effects against Alzheimer’s disease and Parkinson’s disease (PD), so by looking at the constituents of coffee for chemicals that might block the clumping of beta-amyloid and/or tau, was an attempt to seek a molecular link explaining the epidemiology.
Author Interviews, Coffee, Kidney Disease / 14.09.2018

MedicalResearch.com Interview with: [caption id="attachment_37320" align="alignleft" width="200"]Coffee Wikipedia image Coffee
Wikipedia image[/caption] Miguel Bigotte Vieira  MD Nephrology and Renal Transplantation Department Centro Hospitalar Lisboa Norte Lisbon, Portugal MedicalResearch.com: What is the background for this study? What are the main findings? Response: An inverse relationship between coffee consumption and mortality has been reported in the general population. However, the association between caffeine consumption and mortality in patients with chronic kidney disease (CKD) remains unclear. We examined the association between varying levels of caffeine consumption and mortality among 4863 patients with CKD in a prospective nationwide cohort, using the continuous National Health and Nutrition Examination Survey (NHANES) 1999-2010. Our study showed a protective effect of caffeine consumption among patients with chronic kidney disease. The reduction in mortality was present even after considering other important factors such as age, gender, race, smoking, other diseases, and diet. 
Author Interviews, Coffee, Weight Research / 23.07.2018

MedicalResearch.com Interview with: Coffee being poured Coffee pot pouring cup of coffee. copyright American Heart Association Leah Panek-Shirley, PhD Assistant Professor Buffalo State College Health, Nutrition, and Dietetics Houston Texas MedicalResearch.com: What is the background for this study? What are the main findings? Response: The findings of existing previous research evaluating the effects of caffeine on appetite and eating are equivocal. This study evaluated the effects of no (0 mg/kg body weight, e.g. placebo), low (1 mg/kg body weight), and moderate (3 mg/kg body weight) doses of caffeine in juice on appetite and eating in the laboratory and under free-living conditions. While this study identified a small decrease (about 70 calories) in caloric intake after consuming the low (1 mg/kg) dose of caffeine in the laboratory at breakfast, this difference did not persist throughout the entire day.  In addition, there were no differences in hunger, fullness, thirst, or desire to eat as a result of caffeine.
Author Interviews, Coffee, Sleep Disorders / 01.03.2018

MedicalResearch.com Interview with: Coffee being poured Coffee pot pouring cup of coffee. copyright American Heart AssociationJulia F. van den Berg, PhD Leiden University, Department of Clinical Psychology Leiden, The Netherlands  MedicalResearch.com: What is the background for this study? What are the main findings? Response: Caffeine is the most used psychoactive substance worldwide, mostly consumed via coffee, energy drinks, tea and chocolate. Experimental studies have shown that caffeine can negatively affect sleep quality. The timing of caffeine consumption may play a role; the closer to bedtime, the more caffeine consumption is  likely to have a negative effect on sleep. We also wondered if chronotype, being a morning or evening person, would make a difference in the effect of caffeine on sleep. We sent out questionnaires on sleep quality, chronotype, and a detailed questionnaire on type and timing of caffeine use to 880 secondary education students (mean age 21.3 years). We found that for the entire group, the amount of caffeine per week was not associated with sleep quality, regardless of chronotype. However, when we divided the group into subgroups of students who did, and students who did not usually consume caffeine in the evening (after 6PM), we found something interesting. Only for students who did not consume caffeine in the evening (20% of the total sample), a higher total caffeine consumption per week was associated with poorer sleep, in spite of the fact that these students consumed a lot less  caffeine per week than the group who did consume caffeine in the evening. This suggests a self-regulatory mechanism: students who know they are sensitive to caffeine do not drink it in the evening, nevertheless, the caffeinated beverages they drink during the day do affect their sleep.
Author Interviews, Coffee, Heart Disease, Red Meat, Stroke / 15.11.2017

MedicalResearch.com Interview with: Coffee being poured Coffee pot pouring cup of coffee. copyright American Heart AssociationLaura Stevens University of Colorado Aurora, CO MedicalResearch.com: What is the background for this study? What are the main findings? Response: We started with asking ourselves how we could better predict cardiovascular and stroke outcomes.  In an ideal world, we would be able to predict cardiovascular disease (CVD) and stroke with 100% accuracy long before the occurrence of the event.  The challenge here is there are so many potential risk factors, and testing each one using traditional methods would be extremely time consuming, and possibly infeasible. Therefore, we used artificial intelligence to find potential risk factors that could be important for risk of CVD and stroke.  The results of this analysis pointed to consumption of coffee cups per day and the number of times red meat was consumed per week as being potentially important predictors of CVD. We then looked into these findings further using traditional statistical analyses to determine that increased coffee consumption and red meat consumption appeared to be associated with decreased risk of CVD.  The study initially used data from the Framingham Heart Study (FHS) original cohort. The findings from this data were then tested using data from 2 independent studies, the Cardiovascular Heart Study (CHS) and the Atherosclerosis Risk in Communities Study (ARIC), which both supported the association of increased coffee consumption with decreased CVD risk.
Author Interviews, Coffee, Kidney Disease / 04.11.2017

MedicalResearch.com Interview with: Coffee Wikipedia imageMedicalResearch.com Interview with: Miguel Bigotte Vieira, MD Centro Hospitalar Lisboa Norte Lisboa, Portugal Response: An inverse relationship between coffee consumption and mortality has been reported in the general population. However, the association between caffeine consumption and mortality in patients with chronic kidney disease (CKD) remains unclear. We examined the association between varying levels of caffeine consumption and mortality among 2328 patients with CKD in a prospective nationwide cohort, using the continuous National Health and Nutrition Examination Survey (NHANES) 1999-2010. A dose-dependent inverse association between caffeine and all-cause mortality was observed in patients with CKD. This association was independent of influential factors including age, gender, race, annual family income, education level, estimated GFR, albumin/creatinine ratio, hypertension, smoking status, dyslipidemia, body mass index, previous cardiovascular events and diet: consumption of alcohol, carbohydrates, polyunsaturated fatty acids and fibers. Comparing with 1st quartile of caffeine consumption, adjusted HR for death was 0.88 (95% CI, 0.68-1.44) for 2nd quartile, 0.78 (95% CI, 0.60-1.01) for 3rd quartile and 0.76 (95% CI, 0.59-0.97) for 4th quartile (p=0.027 for trend across quartiles)
Author Interviews, Coffee, Kidney Disease / 01.11.2017

MedicalResearch.com Interview with: [caption id="attachment_37801" align="alignleft" width="150"]Miguel Bigotte Vieira MD Centro Hospitalar Lisboa Norte Lisbon, Portugal Dr. Bigotte Vieira[/caption] Miguel Bigotte Vieira MD Centro Hospitalar Lisboa Norte Lisbon, Portugal  MedicalResearch.com: What is the background for this study? What are the main findings? Response:  An inverse relationship between coffee consumption and mortality has been reported in the general population. However, the association between caffeine consumption and mortality in patients with chronic kidney disease (CKD) remains unclear. We examined the association between varying levels of caffeine consumption and mortality among 2328 patients with CKD in a prospective nationwide cohort, using the continuous National Health and Nutrition Examination Survey (NHANES) 1999-2010. A dose-dependent inverse association between caffeine and all-cause mortality was observed in patients with CKD. This association was independent of influential factors including age, gender, race, annual family income, education level, estimated GFR, albumin/creatinine ratio, hypertension, smoking status, dyslipidemia, body mass index, previous cardiovascular events and diet: consumption of alcohol, carbohydrates, polyunsaturated fatty acids and fibers. Comparing with 1st quartile of caffeine consumption, adjusted HR for death was 0.88 (95% CI, 0.68-1.44) for 2nd quartile, 0.78 (95% CI, 0.60-1.01) for 3rd quartile and 0.76 (95% CI, 0.59-0.97) for 4th quartile (p=0.027 for trend across quartiles)
Author Interviews, Coffee, Gastrointestinal Disease, Hepatitis - Liver Disease / 03.10.2017

MedicalResearch.com Interview with: [caption id="attachment_37320" align="alignleft" width="200"]Coffee Wikipedia image Coffee
Wikipedia image[/caption] Patrizia Carrieri PhD INSERM U912 - ORS PACA IHU - Faculté de Médecine Marseille, France MedicalResearch.com: What is the background for this study? What are the main findings? Response: This study is based on the longitudinal data of the French  ANRS HEPAVIH cohort of patients with HIV and Hepatitis C co-infection. This cohort was set up thanks to a collaboration between INSERM (National Institute of health and medical research) UMR912 in Marseille, the ISPED (public health and epidemiology institute) in Bordeaux and several hospital/university sites. Our INSERM team in Marseille is specialized in the study of the impact of behaviors on HIV and HCV outcomes, including mortality. We could think that HCV cure was enough to reduce mortality in HIV-HCV patients as the mortality risk was 80% lower in those who were cured of (i.e. who “cleared”) Hepatitis C thanks to treatment. However, our study showed that, even after HCV cure, sociobehavioral factors still matter: drinking at least 3 cups of coffee a day was associated with a 50% reduction in mortality risk as well as not smoking which was also associated with a reduced mortality risk. This association between elevated coffee intake and reduced mortality risk is probably due to the properties of polyphenols contained in coffee which can protect the liver and also reduce inflammation.
Author Interviews, Coffee, Weight Research / 28.08.2017

MedicalResearch.com Interview with: [caption id="attachment_36667" align="alignleft" width="112"]MedicalResearch.com Interview with: Robin Dando, PhD Assistant Professor Director, Cornell Sensory Evaluation Facility Department of Food Science Cornell University Ithaca, NY 14853 MedicalResearch.com: What is the background for this study? What are the main findings? Response: The study arose from a previous paper I authored in the Journal of Neuroscience, where we found Adenosine receptors in taste. We managed to prove that they were there to amplify sweet signals. This led us to wonder, what about the foods we consume, that would come into contact with these receptors in taste buds. It just happens that a lot of us habitually consume a powerful blocker of adenosine receptors every morning. Caffeine. So is our coffee impairing sweet signals? It turns out when we gave people sweetened coffee containing caffeine, they judged it as less sweet than the same coffee without the caffeine, sampled on a different day. Interestingly, this persisted, and sweet solutions they tested afterwards were still a little less sweet. Finally, just for kicks, we asked them to rate how much caffeine they thought was in either coffee, and how much more alert it made them feel. Turns out, there was no difference. They couldn’t tell which was deacf, and either coffee gave them just as much of an alertness boost. MedicalResearch.com: What should clinicians and patients take away from your report? Response: Readers should consider that they may be altering how their food tastes when consuming coffee. And perhaps also, they could be drinking decaf, and getting just as good a jolt from it (as long as someone else was preparing it for them, so they didn’t know). MedicalResearch.com: What recommendations do you have for future research as a result of this study? Response: We’re interested in how many factors we encounter in our every day lives change our perception, from the foods we’re consuming themselves, to our own bodies. We’re currently looking into how obesity, pregnancy and sleep can change our sense of taste, and the foods we crave. If you’d like to hear more about what we do, you can follow our work on twitter @DandoLab. MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community. 1.Citation: Ezen Choo, Benjamin Picket, Robin Dando. Caffeine May Reduce Perceived Sweet Taste in Humans, Supporting Evidence That Adenosine Receptors Modulate Taste. Journal of Food Science, 2017; DOI: 10.1111/1750-3841.13836 Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions. [wysija_form id="5"] Dr. Dando[/caption]Robin Dando, PhD Assistant Professor Director, Cornell Sensory Evaluation Facility Department of Food Science Cornell University Ithaca, NY 14853  MedicalResearch.com: What is the background for this study? What are the main findings? Response: The study arose from a previous paper I authored in the Journal of Neuroscience, where we found Adenosine receptors in taste.  We managed to prove that they were there to amplify sweet signals.  This led us to wonder, what about the foods we consume, that would come into contact with these receptors in taste buds. It just happens that a lot of us habitually consume a powerful blocker of adenosine receptors every morning.  Caffeine.  So is our coffee impairing sweet signals?  It turns out when we gave people sweetened coffee containing caffeine, they judged it as less sweet than the same coffee without the caffeine, sampled on a different day.  Interestingly, this persisted, and sweet solutions they tested afterwards were still a little less sweet. Finally, just for kicks, we asked them to rate how much caffeine they thought was in either coffee, and how much more alert it made them feel.  Turns out, there was no difference.  They couldn’t tell which was deacf, and either coffee gave them just as much of an alertness boost.
Annals Internal Medicine, Author Interviews, Coffee / 11.07.2017

MedicalResearch.com Interview with: Marc J. Gunter, PhD  From International Agency for Research on Cancer Lyon, France MedicalResearch.com: What is the background for this study? Response: U.S. and Japanese studies have previously found that drinking more coffee was related with a lower risk of death. However, in European populations, where coffee consumption and preparation methods are more varied, the relationship was less certain as relatively small studies had previously been conducted. Our analysis was undertaken in ~500,000 men and women from 10 European countries, the largest study to date investigating the coffee and mortality relationship.
Author Interviews, Coffee, Nutrition, Weight Research / 31.01.2017

MedicalResearch.com Interview with: [caption id="attachment_31650" align="alignleft" width="165"]Ruopeng An, PhD Assistant Professor Department of Kinesiology and Community Health College of Applied Health Sciences University of Illinois at Urbana-Champaign Champaign, IL 61820 Dr. Ruopeng An[/caption] Ruopeng An, PhD Assistant Professor Department of Kinesiology and Community Health College of Applied Health Sciences University of Illinois at Urbana-Champaign Champaign, IL 61820 MedicalResearch.com: What is the background for this study? What are the main findings? Response: Coffee and tea are among the most widely consumed beverages in U.S. adults.1,2 Unlike other popular beverages including alcohol and sugar-sweetened beverages that are typically consumed in isolation, many people prefer drinking coffee and tea with add-ins like sugar or cream. These add-in items are often dense in energy and fat but low in nutritional value. Drinking coffee and tea with add-ins on a regular basis might impact an individual’s daily energy/nutrient intake and diet quality.3 The 2015-2020 Dietary Guidelines for Americans suggests that “coffee, tea, and flavored waters also can be selected, but calories from cream, added sugars, and other additions should be accounted for within the eating pattern.”4 To our knowledge, no study has been conducted to assess consumption of coffee and tea with add-ins in relation to daily energy and nutrient intake at the population level. Bouchard et al. examined the association between coffee and tea consumption with add-ins and body weight status rather than energy/nutrient intake, and consumption was measured by a few frequency-related questions instead of a 24-hour dietary recall.5 The purpose of this study was to examine consumption of coffee and tea with add-ins (e.g., sugar, cream) in relation to energy, sugar, and fat intake among U.S. adults 18 years of age and above. Data came from 2001-2012 National Health and Nutrition Examination Survey (NHANES), comprising a nationally-representative (biennially) repeated cross-sectional sample of 13,185 and 6,215 adults who reported coffee and tea consumption in in-person 24-hour dietary recalls, respectively.
Author Interviews, Coffee, Heart Disease, JAMA / 17.10.2016

MedicalResearch.com Interview with: [caption id="attachment_28941" align="alignleft" width="200"]Luis E. Rohde, MD, ScD Postgraduate Program in Health Science: Cardiology and Cardiovascular Sciences, Medical School, Federal University of Rio Grande do Sul, Cardiovascular Division, Hospital de Clínicas de Porto Alegre Dr. Luis E. Rohde[/caption] Luis E. Rohde, MD, ScD Postgraduate Program in Health Science: Cardiology and Cardiovascular Sciences, Medical School, Federal University of Rio Grande do Sul, Cardiovascular Division, Hospital de Clínicas de Porto Alegre MedicalResearch.com: What is the background for this study? Response: Caffeine-rich beverages have been implicated as a common cause of several cardiac-related symptoms, such as palpitations, tachycardia, or irregular heartbeats. Because of this “intuitive” assumption, counseling to reduce or avoid caffeine consumption is still widely recommended in clinical practice by most physicians for patients with any heart disease.
Author Interviews, Coffee, Hepatitis - Liver Disease / 24.05.2016

MedicalResearch.com Interview with: [caption id="attachment_24648" align="alignleft" width="200"]Sikarin Upala MD, MS, LLB Internal Medicine, Bassett Medical Center and Columbia University College of Physicians and Surgeons, Cooperstown, New York Preventive and Social Medicine Mahidol University, Bangkok, Thailand Dr. Sikarin Upala[/caption] Sikarin Upala MD, MS, LLB Internal Medicine, Bassett Medical Center and Columbia University College of Physicians and Surgeons, Cooperstown, New York Preventive and Social Medicine Mahidol University, Bangkok, Thailand MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Upala: Chronic hepatitis C virus infection is the most common cause of chronic liver disease and cirrhosis as well as the most common cause of liver transplantation in the United States. As caffeine has been found to be related to decreased liver enzymes, chronic liver disease,cirrhosis, and risk of hepatocellular carcinoma in several liver disease pathologies. There is inconclusive findings on the effect of caffeine on hepatitis C infected patients. Thus, we conducted a systematic review and meta-analysis to summarize the effect of caffeine consumption in patients with chronic hepatitis C. We found that caffeine consumers have a 61% reduced risk of developing advanced hepatic fibrosis, which is one of the consequence of chronic hepatitis C. Our meta-analysis result is in the same way with other studies who found that coffee consumption could prevent the development of hepatic fibrosis in patients with liver disease. However, we cannot conclude about the effect of caffeine on HCV viral load as there is not enough information.
Author Interviews, Coffee, Fertility, Lifestyle & Health, NIH, OBGYNE / 24.03.2016

MedicalResearch.com Interview with: [caption id="attachment_22845" align="alignleft" width="133"]Germaine M. Buck Louis, Ph.D., M.S. Office of the Director, Division of Intramural Population Health Research Eunice Kennedy Shriver National Institute of Child Health and Human Development Rockville, Maryland 20852. Dr-Germaine M. Buck-Louis[/caption] Germaine M. Buck Louis, Ph.D., M.S. Office of the Director Division of Intramural Population Health Research Eunice Kennedy Shriver National Institute of Child Health and Human Development Rockville, Maryland 20852. MedicalResearch.com: What is the background for this study? What are the main findings? Response: To understand the association between couples’ lifestyles and risk of pregnancy loss.  Couples were recruited upon discontinuing contraception to try for pregnancy and followed daily for up to one year of trying or until pregnancy.  Pregnant women were followed daily for 7 weeks following conception then monthly.
Author Interviews, BMJ, Coffee, Karolinski Institute, Multiple Sclerosis / 04.03.2016

MedicalResearch.com Interview with: [caption id="attachment_22362" align="alignleft" width="200"]Anna Hedström PhD student Anna Hedström PhD student[/caption] Anna Hedström PhD student Karolinski Institute MedicalResearch.com: What is the background for this study? What are the main findings? Response: Previous studies on the influence of coffee consumption on multiple sclerosis (MS) risk have yielded inconclusive results, perhaps largely due to statistical power problems since these studies comprised few cases. Caffeine consumption has a protective effect on neuroinflammation and demyelination in animal models of MS. We therefore aimed to investigate whether coffee consumption is associated with MS risk, using two large population-based case-control studies (a Swedish study comprising 1620 cases and 2788 controls, and a United States study comprising 1159 cases and 1172 controls). The risk of multiple sclerosis was reduced by approximately 30% among those who reported a high coffee consumption, around six cups daily, compared to those who reported no coffee consumption. The risk of multiple sclerosis decreased with increasing coffee consumption. Potentially important influential factors were taken into consideration, such as smoking and adolescent obesity.
Author Interviews, Blood Pressure - Hypertension, Coffee / 03.12.2015

[caption id="attachment_19771" align="alignleft" width="177"]Wenji Li, MMed, PhD Postdoc Associate Department of Pharmaceutics Ernest Mario School of Pharmacy Rutgers, The State University of New Jersey Dr. Wenji Li[/caption] MedicalResearch.com Interview with: Wenji Li, MMed, PhD Postdoc Associate Department of Pharmaceutics Ernest Mario School of Pharmacy Rutgers, The State University of New Jersey Medical Research: What is the background for this study? What are the main findings? Dr. Li: Hypertension is a vital risk factor for many serious disorders. Male and age ≥40 years were found to be highly associated with more severe hypertension. In Singapore, the prevalence of hypertension increased markedly from age 40 years onwards. Tea, a popular beverage in Chinese people, has been approved to possess many beneficial pharmacological effects including antihypertension. However, no clinical studies on the correlation between tea drinking and its effect on lowering blood pressure among Singaporeans have been conducted. To find out the potential link, we are the first to investigate the correlation of hypertension and consumption of tea, health supplements, living habits and socio-demographic factors among Singaporean Chinese residents. By the large scale cross-sectional epidemiology study (N = 1184), we found the prevalence of hypertension among the whole investigated population was 49.73% and the prevalence increased to 66.47% in the sub-population aged ⩾60 years. High risk of hypertension was associated with age ⩾60 years, obesity, family history of hypertension, diabetes history, hyperlipidemia history, male and coffee intake. In contrast, drinking green tea at least 150 ml per week was associated with lower hypertension risk. Drinking combination of green tea and British tea was associated with higher reduction in the risk of hypertension. This study suggests that consumption of tea, especially green tea and British tea, is beneficial for lowering the risk of hypertension while the consumption of coffee may have the opposite effect. 
Author Interviews, Coffee, OBGYNE, Pediatrics / 20.11.2015

[caption id="attachment_19533" align="alignleft" width="145"]Mark A. Klebanoff, MD Center for Perinatal Research The Research Institute Nationwide Children's Hospital Dr. Klebanoff[/caption] MedicalResearch.com Interview with: Mark A. Klebanoff, MD Center for Perinatal Research The Research Institute Nationwide Children's Hospital Medical Research: What is the background for this study? What are the main findings? Dr. Klebanoff: Caffeine is among the substances most commonly consumed by pregnant women.  There are numerous sources of caffeine in the diet—regular (non-decaf) coffee, regular tea, many soft drinks, energy drinks, and some power bars. Even chocolate contains some caffeine.  It’s also included in some over the counter pain relievers, and in over the counter ‘keep awake’ pills such as No-Doz.  As a result of its wide availability, most pregnant women consume at least some caffeine.  In spite of over 30 years of research, whether moderate amounts of caffeine (up to 200 milligrams, the amount contained in about 2 normal-sized cups of coffee, per day) during pregnancy are harmful is uncertain.  However almost all previous research has been about events related to pregnancy, such as difficulty becoming pregnant, miscarriage, birth defects, and the size of the newborn.  Whether maternal caffeine use during pregnancy has an impact on things later in childhood, such as obesity and neurologic development, has hardly been studied. We used a biomarker, measured in the mother’s blood during pregnancy, for caffeine use, and found that more caffeine use was not associated with the child’s body mass index at either 4 or 7 years of age, and that at blood levels of the marker that we saw in the vast majority, caffeine was not associated with the child’s IQ, nor with behavioral abnormalities at those ages.
Author Interviews, Coffee, Erectile Dysfunction, PLoS, University Texas / 26.05.2015

David S. Lopez, Dr.P.H., M.P.H. Assistant professor University of Texas Health School of Public HealthMedicalResearch.com Interview with: David S. Lopez, Dr.P.H., M.P.H. Assistant professor University of Texas Health School of Public Health Medical Research: What is the background for this study? What are the main findings? Dr. Lopez: Coffee, and its most studied component, caffeine, have been implicated in potential health benefits due to the rich sources of antioxidants and anti-inflammatory compounds contained in this beverage. Caffeine intake reduced the odds of prevalent erectile dysfunction, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive men, but not among diabetic men. These associations are warranted to be investigated in prospective studies. Medical Research: What are the main findings? Dr. Lopez: Caffeine intake reduced the odds of prevalent erectile dysfunction, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive men, but not among diabetic men. These associations are warranted to be investigated in prospective studies.