Q&A: Is Coffee a Health Elixir or a Hidden Risk?

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Take-Home Messages 🔑

Introduction☕

Despite its inherently bitter taste—typically an aversive flavour—coffee ranks among the most widely consumed beverages globally (1, 2). This paradox is partly explained by emotional and habitual drivers of consumption, which often outweigh purely functional motives  (3). Given coffee’s widespread popularity, it is essential to understand its potential health benefits and risks, as this knowledge should ultimately guide consumption choices.

Historically, coffee has been both praised for its stimulating effects and criticised for its potential health risks. Scientific perspectives have shifted from broad scepticism to a more nuanced appreciation of its complex health impacts (4). Far beyond a simple caffeine delivery system, coffee is a rich source of antioxidants, prebiotics and bioactive compounds—such as cafestol and chlorogenic acids—that may influence metabolism, mental performance and disease risk.

This review explores the origins, types and chemical composition of coffee, including its key bioactive components and preparation methods. It synthesises the latest research on coffee’s potential health benefits and risks, offering practical guidance on how to enjoy coffee in a way that supports overall well-being—without compromising health.

What is Coffee?☕

Coffee is a brewed beverage made from roasted seeds of berries of the Coffea genus, part of the Rubiaceae family (5). The two most widely cultivated and consumed species are Coffea arabica (Arabica or Ethiopian coffee), valued for its smooth flavour and lower caffeine content, accounting for around 60–70% of global production; and Coffea canephora (Robusta), which has a stronger, more bitter taste, higher caffeine content and greater resistance to disease. Less common species, such as Coffea liberica and Coffea excelsa, are grown in smaller quantities and appreciated for their unique flavour profiles (5).

Coffee comes in many forms and names depending on how it is brewed, the ratio of ingredients and regional preferences. From espresso-based drinks such as cappuccinos and flat whites to regional specialties such as Turkish coffee and café Cubano, each variation offers a unique flavour and cultural experience. The final taste is influenced by the coffee species, origin, roast level, grind size and preparation method. Roast level alters the chemical composition of the beans, affecting flavour notes, acidity and bitterness, while grind size impacts the extraction rate, shaping the balance between sourness, sweetness and bitterness.

Table: Coffee Types Summary

Kopi Luwak or civet coffee, is a rare and expensive coffee made from coffee beans (mostly Arabica) excreted by Asian palm civets after consuming ripe coffee cherries. While it is prized for its smooth, low-acid flavour, its production raises serious ethical concerns, especially when civets are kept in captivity. Consumers are advised to choose products sourced from wild civets and verified by reputable sources to ensure ethical practices.

Black Ivory Coffee is a rare and expensive coffee made from Thai Arabica beans that are eaten, digested and excreted by elephants. The fermentation process in the elephant’s gut reduces bitterness and results in a smooth, earthy flavour. Produced in small quantities, it supports elephant conservation and local communities, making it a more ethically conscious option than civet coffee.

Instant coffee is widely consumed for its convenience, though some purists argue it lacks the flavour complexity and freshness of traditionally brewed coffee, raising debates about whether it qualifies as "real" coffee. Both types originate from roasted beans, and studies suggest instant coffee retains many bioactive compounds—such as caffeine and antioxidants—linked to potential health benefits (6). Several brands offer 3-in-1 or 2-in-1 instant coffee sachets that combine instant coffee, sugar, and non-dairy creamer. Marketed for convenience and a sweet, café-style flavour, these products require no milk or extra ingredients. The non-dairy creamers often contain hydrogenated or partially hydrogenated vegetable oils—typically from coconut or palm kernel oil—which are high in saturated fatty acids. Their high saturated fat content raises concerns about heart health, especially with regular intake. Additionally, palm oil production contributes to deforestation, biodiversity loss and greenhouse gas emissions. Beyond palm oil, conventional coffee farming also impacts the environment through deforestation, heavy water use and pesticide application, leading to the growth of sustainable certification schemes such as Fairtrade, Rainforest Alliance and organic labels.

Decaf coffee is made from regular coffee beans with most of the caffeine removed, typically through water, solvent, or CO₂-based processes. A cup of decaf still provides much of the flavour and beneficial compounds found in regular coffee.

Key Compounds in Coffee

Coffee contains a complex mixture of over 800 volatile compounds—substances that easily evaporate and contribute to the aroma and flavour of coffee (6). Among these, caffeine and chlorogenic acids are the most prominent bioactive components. Coffee is a major source of antioxidants, such as chlorogenic acid and quinines, which help combat oxidative stress and inflammation. Coffee contains prebiotic compounds, including soluble dietary fibres and polyphenols, that promote the growth of beneficial gut bacteria, supporting digestive health and enhancing nutrient absorption. Additionally, coffee contains small amounts of essential micronutrients including potassium, magnesium, phosphorus and several B vitamins (6).

Table: Coffee Components

LDL, low density lipoprotein

Caffeine🧬

Caffeine, the most widely consumed psychoactive substance, is a naturally occurring white, crystalline alkaloid synthesised by various plants as a chemical defence mechanism against insect predation. Caffeine, a natural stimulant from the methylxanthine class, enhances alertness and concentration by acting on the central nervous system (7). Caffeine keeps the brain alert by blocking adenosine, a chemical that normally promotes relaxation and sleep. By preventing adenosine from binding to its receptors, caffeine reduces feelings of drowsiness (7). In response, the brain releases more adrenaline—a hormone involved in the body's fight-or-flight response—and dopamine, a neurotransmitter that plays a key role in motivation, mood and feelings of pleasure (7, 8). With regular use, the brain adjusts by increasing adenosine receptors, making caffeine less effective over time and leading to a need for higher doses.

A standard cup (approximately 240 mL) of instant coffee typically contains 60–80 mg of caffeine, whereas freshly brewed coffee contains a broader range, approximately 60–120 mg, depending on preparation methods. Decaffeinated coffee offers an alternative for those sensitive to caffeine, with only about 2–5 mg per cup. A cup of tea contains roughly 40 mg of caffeine, although this amount can vary based on factors such as brewing time and tea type. Notably, some teas—such as herbal or rooibos—contain no caffeine at all.

For healthy adults (excluding pregnant women), up to 400 mg per day—roughly 4 cups of coffee or 2.5 energy drinks—is considered safe, with a single dose not exceeding 200 mg (9-11). Children should not consume caffeine (12, 13). Caffeine-related deaths, though rare, have been documented—primarily among infants, psychiatric patients and athletes—and are typically linked to high-dose exposures, highlighting the need for greater awareness of its potential toxicity and the risks associated with easy access to pure caffeine (14).

The half-life of caffeine—defined as the time required for the body to eliminate 50% of the ingested dose—ranges from approximately 2 to 12 hours, with considerable interindividual variability. This variability is primarily influenced by genetic polymorphisms. Genes affecting caffeine metabolism e.g., the cytochrome P450 1A2 CYP1A2 gene, which encodes the cytochrome P450 1A2 enzyme, the main hepatic enzyme responsible for caffeine metabolism. Individuals with the fast-metabolising CYP1A2 variant may clear caffeine more rapidly, whereas those with slow-metabolising variants experience prolonged caffeine exposure, which can affect tolerance and sensitivity to its effects (15).

The ADORA2A gene encodes the adenosine A2A receptor, which is involved in promoting sleep and regulating anxiety. Caffeine exerts many of its stimulant effects by blocking adenosine receptors, particularly A2A. Genetic variations (e.g., the rs5751876 polymorphism) in ADORA2A influence caffeine sensitivity. Individuals with certain variants (e.g. the TT genotype at rs5751876) tend to experience greater anxiety, disrupted sleep or increased alertness after caffeine intake (16).

Antioxidants🥛

Coffee is a rich source of antioxidants such as chlorogenic acids. Chlorogenic acids may reduce atherosclerosis by inhibiting artery-hardening mechanisms (17).

Adding milk can influence its antioxidant capacity. Casein, the primary protein in milk, has been shown to bind to polyphenols such as chlorogenic acids, potentially reducing their bioavailability and antioxidant activity (18). The extent of this reduction depends on the amount and type of milk added, as higher protein content may lead to greater binding (19). However, the impact may vary between individuals and is still under investigation.

Cafestol

Cafestol exhibits both beneficial and adverse health effects. On the positive side, supplementation in individuals with increased waist circumference has been shown to reduce body weight, visceral fat volume, and gamma-glutamyl transferase levels—a marker of liver function—though it did not improve insulin sensitivity or glucose tolerance (20). These findings support cafestol’s potential role in reducing body fat and may help explain the inverse association between coffee consumption and type 2 diabetes risk.

However, cafestol is also known to raise serum LDL cholesterol levels, particularly when consumed through unfiltered or machine-brewed coffee, which contains higher concentrations of cholesterol-raising diterpenes i.e. cafestol and kahweol compared to paper-filtered brews (21). This poses a potential cardiovascular health concern with regular intake of insufficiently filtered coffee.

Cafestol and kahweol may also exert protective effects in other areas. Both compounds exhibit anticancer properties across various in vitro and in vivo models (22). Their actions include inducing apoptosis, inhibiting cell proliferation and growth and—specifically for kahweol—suppressing cell migration. Notably, these effects appear to selectively target cancer cells while sparing normal cells, highlighting their potential as natural antitumor agents.

Prebiotics and Chicory

Chicory root is often blended with coffee—particularly in products such as South Africa’s Ricoffy or traditional French-style coffee—to reduce caffeine content, add a roasted, slightly nutty flavour and enhance its nutritional profile (23). One of chicory’s key components is inulin, a type of soluble dietary fibre that functions as a prebiotic. Prebiotics are non-digestible food components that selectively stimulate the growth and activity of beneficial gut bacteria, particularly Bifidobacteria and Lactobacilli, thereby supporting a healthy microbiome (23).

Regular consumption of inulin-rich chicory has been associated with improved digestive health, enhanced mineral absorption and potential immune-modulating effects (24, 25). Additionally, by contributing to feelings of satiety, chicory may play a role in appetite regulation (26). Including chicory in coffee formulations not only broadens flavour complexity but also transforms a familiar beverage into a functional drink with potential gut-health and metabolic benefits (27).

Health Benefits and Risks

Research on coffee and health is complicated by numerous confounders, making it difficult to isolate the true effects of coffee itself. The health impact of coffee can depend on several factors, including the type and quantity consumed, preparation method. Even within the same individual, coffee consumption can vary widely—one cup may be black, another with cream or sugar; one might be instant, another brewed from a high-end machine at work or purchased at a café. Few studies distinguish between instant and brewed coffee, despite differences in caffeine and bioactive content.

Additionally, coffee drinkers often differ from non-drinkers in lifestyle behaviours—such as smoking (2), alcohol use, diet quality and physical activity—that can distort associations with health outcomes. Socio-economic status is associated with coffee intake, making it important to distinguish the effects of coffee from those of related factors such as better access to healthcare and healthier lifestyle behaviours. Further complicating matters are intake timing and individual biological differences, including genetic makeup.

Furthermore, the psychosocial context of coffee consumption—such as drinking it in a relaxed social setting versus under work-related stress—may also modulate its physiological effects, yet this nuance remains largely unexplored (28). High stress or poor sleep may increase coffee consumption, while both factors independently affect health.

Reverse causation is also a possibility—that is, instead of coffee influencing health, individuals with certain health conditions may reduce or avoid coffee consumption, thereby distorting the observed associations. Moreover, coffee might replace less healthy beverages such as sugary sodas, further complicating the interpretation of results.

Health Benefits

Cognitive Performance

Recently Li, Yu (29) found that higher coffee and caffeine intake are positively associated with better cognitive performance in older adults, potentially mediated by serum alkaline phosphatase levels, with genetic analyses suggesting protective effects and possible therapeutic targets.

Physical Performance 💪

Caffeine is widely recognised as an ergogenic aid, meaning it can enhance physical or mental performance. Moderate doses (3–6 mg/kg body weight) have been shown to provide small but significant improvements in endurance performance, including power output and time-trial results (30) and enhances volleyball-specific skills (31). Self-selected motivational music and caffeine intake independently enhanced anaerobic performance in female handball players, with the combined use showing the greatest—though not statistically significant—improvement (32). However, responses vary depending on factors such as genetics (e.g., CYP1A2 gene) (33), as well as context and population. Caffeine benefits some athletes but has shown no improvements in older adults or in certain high-intensity workouts or in basketball players (34-36).

5 mg/kg caffeine dose—within NCAA legal limits—did not improve squat or countermovement vertical jump height in trained collegiate athletes (37). Males outperformed females, but caffeine had no additional effect across sexes. While performance improved slightly between trials (likely due to warm-up effects), no ergogenic benefit from caffeine was observed. These findings align with growing evidence that caffeine's impact is highly individual and may depend on dose, habituation, and psychological factors—including the mere expectation of consuming caffeine (38).

Coffee and All-Cause Mortality and Timing of Coffee Intake🕰️🌅

For all-cause mortality, the umbrella review found that coffee consumption was associated with a 17% reduction in risk at three to four cups per day compared to none (4). Higher coffee consumption is associated with reduced all-cause mortality among U.S. adults, but these benefits are limited to black coffee or coffee with low added sugar and saturated fat (39). Drinking coffee primarily in the morning is associated with a lower risk of all-cause and cardiovascular mortality compared to drinking it throughout the day or not at all (40).

Insulin Resistance, Type 2 Diabetes and Metabolic Syndrome

Regular coffee intake is associated with a lower risk of type 2 diabetes (41). Opting for black coffee or using low-fat milk and minimal sweeteners may enhance these benefits (42). Coffee’s bioactive compounds, including chlorogenic acids and polyphenols, can improve insulin sensitivity and glucose metabolism. In Korean women, drinking two or more cups of black coffee daily was linked to a 36% reduction in insulin resistance, measured by the Homeostatic Model Assessment of Insulin Resistance, which uses fasting glucose and insulin levels (42). Although caffeine may temporarily reduce insulin sensitivity, long-term consumption—especially without added sugar or cream—appears beneficial. The same study found these effects only in women drinking black coffee, not in men or those adding sweeteners or cream (42).

A cross-sectional study using data from the National Health and Nutrition Examination Survey found a U-shaped, non-linear relationship between coffee intake and diabetic kidney disease, with moderate consumption linked to lower risk (43). Additionally, Brazilian coffee has been shown to enhance the antidiabetic and liver-protective effects of metformin through synergistic antioxidant and enzyme-inhibitory actions, suggesting potential therapeutic value in combining coffee with metformin for managing type 2 diabetes (44).

A meta-analysis of 13 studies with over 159,000 participants found that higher coffee intake is linked to lower metabolic syndrome risk, though the relationship is non-linear and causality is uncertain (45). The TOMORROW study also suggests coffee may help prevent metabolic syndrome in rheumatoid arthritis patients (46).

Fracture Risk and Osteoporosis 🦴

While earlier reviews (4), suggested increased fracture risk in women due to caffeine-related calcium loss, a more recent and comprehensive meta-analysis (47) involving over 560,000 participants found that regular coffee and tea consumption may actually reduce osteoporosis risk. These protective effects appear stronger with higher intake and may be influenced by factors such as milk addition, sex and coffee preparation method.

Coffee and Cardiovascular Health🫀

Coffee consumption appears to have varied effects on cardiovascular health.

Lipids and Blood Coagulation

Chlorogenic acids in coffee may help reduce atherosclerosis by inhibiting mechanisms that harden arteries. Coffee consumption has a dual effect on serum lipid profiles: it is associated with increased total and LDL cholesterol levels, while showing complex, gender-specific and non-linear relationships with HDL cholesterol and triglycerides (48).

Moderate coffee intake has been shown to inhibit platelet aggregation, particularly when stimulated by collagen and arachidonic acid (49). This effect is attributed to coffee’s phenolic compounds rather than caffeine. Coffee consumption does not significantly alter fibrinogen levels, with no observed association between coffee intake and fibrinolytic markers (50). The impact of coffee on endothelial function appears dose-dependent: moderate consumption may improve endothelial function due to antioxidant properties, while acute intake of caffeinated coffee may temporarily impair it (51). Epidemiological studies have also found that coffee consumption is associated with a reduced risk of venous thrombosis, potentially mediated by reductions in von Willebrand factor and factor VIII levels (50).

Heart Rate

A meta-analysis of six randomised control trials found that consuming 3–6 cups of coffee daily for 2–24 weeks had no effect on resting heart rate, suggesting no impact in healthy or mildly at-risk individuals (52). However, a randomised crossover trial showed that Turkish coffee reduced heart rate in healthy young women, indicating possible acute effects (53).

Hypertention

A systematic review of 25 observational studies found that higher coffee intake is linked to reduced hypertension risk, though results varied by region, sex and sample size (54).

Cardiovascular Disease  and Mortality

Moderate coffee consumption is associated with lower risks of heart disease and stroke.

•             One systematic review with meta-analysis found reduced cardiovascular disease (CVD)-related mortality in males (HR: 0.63), but not in females (HR: 0.78) (55).

•             An umbrella review of 11 meta-analyses (12 million individuals) showed up to 4 cups daily reduced stroke risk by 12% and modestly lowered dementia risk. However, heavy intake may increase CVD risk (56).

•             Among diabetics, daily coffee and tea intake was linked to reduced CVD and mortality risk, though evidence certainty was moderate-to-low (57).

•             National Health and Nutrition Examination Survey data revealed that various coffee types—including caffeinated, sugar-free, full-fat, and fat-free—were associated with reduced all-cause and cardiovascular mortality in adults with prediabetes. Caffeinated coffee lowered CVD mortality, while full-fat coffee was linked to lower CVD prevalence (58).

Inflammation

A systematic review and meta-analysis of 11 cross-sectional studies involving 66,691 adults found a linear inverse association between coffee consumption and C-reactive protein levels, with higher intake linked to progressively lower CRP, and suggested that factors such as gender and smoking adjustment may modify this relationship (59).

Neurodegenerative Diseases 🧠

Emerging evidence suggests that coffee consumption, particularly caffeinated and unsweetened varieties, may play a role in reducing the risk and progression of neurodegenerative diseases. A large UK Biobank study (60) involving 204,847 participants over nine years found that consuming ≥3 cups/day of unsweetened, caffeinated coffee was linked to reduced risks of Alzheimer’s and related dementias (HR: 0.75), Parkinson’s disease (HR: 0.71) and neurodegenerative mortality (HR: 0.67). No protective associations were observed for decaffeinated or sweetened coffee, suggesting neuroprotective effects may be specific to caffeinated, unsweetened varieties. A systematic review and meta-analysis (61) reported potential cognitive benefits from long-term chlorogenic acid intake, though current randomised controlled trials show no significant effects, underscoring the need for more rigorous studies. Another systematic review found that moderate caffeine intake may slow Alzheimer’s progression in individuals with mild cognitive impairment, with effects influenced by dose, genetics and timing of exposure (62).

Gout🔬

Higher coffee intake is linked to reduced gout risk, particularly in men (63) but also in women (64), with a dose-dependent effect—≥4 cups/day offering the greatest protection. A Mendelian randomisation study supports this inverse association (65), but the interpretation is limited by methodological concerns. The genetic variants used explain only a small proportion of coffee intake variability, which may undermine causal inference (66).

Coffee, particularly caffeinated, may lower serum uric acid—a key gout risk factor—via effects on xanthine oxidase and uric acid clearance. In a within-participant trial (67), decaffeinated coffee reduced serum uric acid in hyperuricaemic men, while caffeinated coffee increased uric acid and xanthine oxidase activity in normouricaemic individuals, with no change in clearance. These effects likely stem from polyphenols and chlorogenic acids, which may enhance insulin sensitivity and uric acid excretion (68, 69). Caffeine, structurally similar to allopurinol, may inhibit xanthine oxidase, though high acute doses can transiently raise uric acid.

Tea does not show the same protective association (70). Sugary drinks (71) and fructose-sweetened (high fructose corn syrup) beverages(72), in contrast, are strongly associated with increased gout risk.

⚠️ Important Considerations

People who already have gout may still need to monitor coffee intake, especially if they are sensitive to caffeine or have comorbid conditions (e.g., heart issues). The benefits are generally observed with long-term consumption rather than short-term effects.

Cancer 🧬

Growing evidence suggests that coffee consumption may influence cancer risk, with protective effects observed for several cancer types

·        A meta-analysis found that while case-control studies suggest a lower risk of colorectal cancer with higher coffee consumption, cohort studies did not support this association, making the overall evidence inconclusive due to study design differences and potential confounding factors (73).

·        A meta-analysis of nine epidemiologic studies found that drinking two additional cups of coffee per day is associated with a 43% lower risk of liver cancer, supporting an inverse relationship regardless of liver disease history (74).

·        A meta-analysis of 59 studies found that higher coffee consumption is associated with a modest reduction in overall cancer risk, with stronger inverse associations observed for specific cancers such as liver, endometrial, colorectal and breast cancer (75).

·        A meta-analysis of eleven studies involving over 340,000 participants found a strong inverse association between coffee consumption and the risk of hepatocellular carcinoma, with higher intake linked to significantly lower odds, especially among Asian populations (76).

Liver Diseases

A meta-analysis of nine studies found that drinking two additional cups of coffee per day is associated with a lower risk of cirrhosis and cirrhosis-related death, suggesting a dose-dependent protective effect of coffee (77).

Multiple Sclerosis (MS)

Two recent reviews explored the link between caffeine and multiple sclerosis (MS), yielding distinct insights. One systematic review of eight studies found no clear connection between caffeine intake and MS-related disability, though it hinted at possible cognitive benefits for patients (78). In contrast, a meta-analysis of 10 observational studies involving over 19,000 participants reported that coffee consumption may lower the risk of developing MS, even after adjusting for confounding factors (79). Both studies emphasise the need for more rigorous, prospective research to clarify caffeine’s role in MS prevention and management.

Other

Caffeine consumption, particularly from tea, may help slow the progression of age-related macular degeneration, though its role in preventing disease onset remains uncertain (80).

Health Risks⚠️

Appetite and Weight 🍽️ 🤤 ⚖️

Coffee’s influence on appetite and body weight is complex, involving both behavioural and metabolic pathways. Recent studies have explored its effects on food preferences, hormonal responses and adipose tissue remodelling.

A pilot crossover randomised trial investigated the effects of coffee intake on appetite parameters in women with overweight or obesity (81). Results indicated that coffee consumption increased the desire for sweet foods, fructose intake and triglyceride levels, but showed no changes in ghrelin or cholecystokinin levels, suggesting coffee may influence appetite and dietary behaviour through sensory-specific desire (81). A systematic review and meta-analysis of cross-sectional studies found no overall association between coffee consumption and general or abdominal obesity, but a positive link was observed between coffee intake and general obesity in women (82). A recent study showed that coffee consumption in rats fed a high-fat diet modulated adipose tissue remodelling by influencing thermogenic, lipogenic and angiogenic gene expression across brown, inguinal and epididymal fat depots (83). These findings suggest that coffee may counteract diet-induced obesity through enhanced energy metabolism and reduced lipid accumulation in adipose tissue.

Sleep🌙

High caffeine intake, especially late in the day, can disrupt sleep patterns and contribute to insomnia. A randomised clinical crossover trial investigated the effects of caffeine dose and timing on sleep (84). A 100 mg dose had no impact on sleep, while a 400 mg dose disrupted sleep initiation, architecture, and quality, particularly when consumed within 12 hours of bedtime (84). Sleep fragmentation increased with 400 mg taken eight hours prior and perceived sleep quality worsened when consumed four hours before bedtime, highlighting the potential disconnect between subjective and objective sleep assessments (84).

Coffee and Digestive Health

Coffee is widely consumed and often scrutinised for its impact on gastrointestinal (GI) health (85). While popular belief and anecdotal reports suggest it may aggravate certain digestive conditions, scientific evidence paints a more nuanced picture (85).

Coffee has distinct effects on GI function—most notably, it promotes gastroesophageal reflux and stimulates colonic and gallbladder activity (85). However, it is not a proven cause of dyspepsia, and its physiological effects extend beyond caffeine alone (85). While coffee is frequently suspected to trigger gastroesophageal reflux disease (GERD) symptoms, a meta-analysis found no consistent association between coffee intake and GERD overall—except in cases diagnosed via endoscopy, where a modest increase in risk was observed (86). Additionally, in a cross-sectional study of 1,669 patients, coffee consumption (including total intake and specific subtypes) was not associated with an increased risk of colonic diverticulosis (87).

During Pregnancy

Caffeine and coffee consumption during pregnancy increased the risk of pregnancy loss, with a dose–response relationship showing higher risk with greater intake (88, 89). Additionally, individuals harbouring the MTHFR 677 gene variants who have an inherited risk of miscarriage/spontaneous abortion (90) may metabolise caffeine less efficiently, potentially heightening susceptibility to adverse pregnancy outcomes when combined with high caffeine intake. However, studies investigating both MTHFR and coffee intake during pregnancy are needed to confirm. Furthermore, high maternal caffeine intake, especially from coffee, has been associated with adverse effects on foetal development, including low birth weight and preterm birth (91). While continuous maternal tea consumption during the second and third trimesters was positively linked to children's cognitive and motor development, no significant benefit was observed with coffee intake. Maternal coffee intake is also associated with an increased risk of childhood acute leukemia, particularly acute lymphoid leukemia (ALL) (92).

Hearing Loss🦻🛑

A study examined the link between dietary caffeine intake and hearing loss (HL) using data from 6,082 participants in the National Health and Nutrition Examination Survey. It focuses on two types of HL: speech-frequency hearing loss (SFHL) and high-frequency hearing loss (HFHL). Results show that individuals with higher caffeine intake had higher rates of both SFHL and HFHL. After adjusting for confounders, high caffeine intake remained associated with SFHL but not HFHL. The study also found that the association was stronger in participants under 65 years, with no link in older adults. This suggests that high caffeine consumption may increase the risk of SFHL, particularly in younger adults (93).

Osteoarthritis 🦴🦵⚡

Data from the National Health and Nutrition Examination Survey and Mendelian randomisation was used by researchers to investigate the link between coffee consumption and osteoarthritis (OA) (94). Findings showed that higher coffee intake, particularly over 4 cups per day, is associated with an increased risk of OA, especially knee and hip OA, suggesting a potential causal relationship (94).

Cancer ☕🔥⚠️🎗️

While coffee has shown protective effects against certain cancers, some studies suggest potential risks depending on consumption patterns and temperature. A systematic review and meta-analysis of 14 prospective cohort studies found a positive association between coffee consumption and lung cancer risk, with each additional cup per day linked to a 6% increase in risk, suggesting a potential dose–response relationship (95). This large UK Biobank cohort study found that drinking hot or very hot beverages, particularly in higher daily amounts, is associated with an increased risk of oesophageal squamous cell carcinoma, but not oesophageal adenocarcinoma (96).

Anaemia 🩸

Coffee (including decaf versions) contains polyphenols (tannins and chlorogenic acids) that can inhibit the absorption of non-haeme iron, especially when consumed close to meals (97). This effect may increase the risk of iron deficiency anaemia, particularly in individuals already vulnerable to low iron levels. Iron absorption can be reduced by up to 60% when coffee is consumed within an hour of a meal (98). Improper coffee habits may raise anaemia risk by 2.91 times (99).

Caffeine Use Disorder ☕⚡😵

Caffeine use disorder is characterised by a problematic pattern of caffeine consumption that causes significant distress or impairment (100, 101). According to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (Caffeine Use Disorder DSM-5 - Therapedia), it is defined by the presence of three or more of the following within a 12-month period:

·        A persistent desire or repeated failed attempts to control caffeine use.

·        Continued intake despite physical or mental health issues due to use (disrupts sleep or contributes to anxiety).

·        Withdrawal effects—such as headaches, tiredness, low mood and irritability—when reducing or stopping caffeine.

Up to 30% of caffeine users may meet the criteria for the disorder (101). Caffeine use disorder can lead to caffeine toxicity (around 1 to 1.5 grams per day), known as caffeinism, characterised by restlessness, anxiety, sleep disturbances and digestive issues (102). Tapering off caffeine gradually is advised to manage withdrawal.

Coffee Intake Recommendations ☕📏✅

Coffee intake should be carefully tailored to age and individual health needs. For children and adolescents, caffeine should be avoided or strictly limited due to its potential impact on sleep, growth, mood and cognitive development. Health authorities recommend a maximum of 2.5 mg of caffeine per kilogram of body weight per day for children—a limit often reached through soft drinks and chocolate alone, making coffee unsuitable for this age group. Adults, however, may benefit from moderate coffee consumption, with 3–4 cups per day linked to reduced risk of certain chronic diseases as discussed above. Genetic differences in caffeine metabolism can make some individuals more sensitive to coffee, requiring less than the typical 3–4 cup daily recommendation. Drinking coffee earlier in the day is preferable to avoid sleep disruption and choosing paper-filtered brews can help reduce cholesterol-raising compounds.

To maximise health benefits, coffee should be consumed mindfully. Excessive additives such as sugar and artificial creamers can undermine its positive effects, and individuals with specific health concerns—such as pregnancy, anxiety, acute gout or hypertension—should moderate their intake. Adding milk may support bone health but aggravate anaemia risk and reduces antioxidant activity. While coffee contributes to hydration, it should not replace water as the primary fluid source. Overall, coffee can be a healthful beverage when consumed with awareness of timing, preparation and personal health factors.

Exploring Coffee Alternatives: Caffeine-Free and Functional Options 🌿☕🚫🍵🥛

Not everyone tolerates or chooses to consume coffee, whether due to caffeine sensitivity, personal preference, religious reasons or health perceptions. Fortunately, a variety of plant-based, herbal and grain-derived beverages offer similar warmth, comfort and ritual—without the caffeine. While these drinks are not made from coffee beans and differ in chemical composition, they often mimic coffee's roasted flavour or provide additional functional benefits. From chicory and dandelion roots to functional mushrooms and grain-based blends, these alternatives are gaining popularity for their unique taste profiles and perceived health-promoting properties. The table below highlights key coffee substitutes, their main ingredients and what to expect in terms of flavour and function.

Table: Coffee alternatives (not coffee)

Conclusion☕

Coffee consumption, like any dietary habit, presents both benefits and considerations. For most healthy adults, moderate intake—particularly in the morning and without excessive additives—is generally associated with positive or neutral health outcomes. Current evidence indicates potential protective effects against liver dissease, neurodegenerative diseases, type 2 diabetes and cardiovascular conditions. However, factors such as preparation method, timing of consumption and overall quantity can influence its impact on sleep quality and health.

The evolving body of research underscores a shift in nutritional science toward personalised, context-sensitive recommendations. Coffee is neither a panacea nor a universal risk; rather, it is a culturally embedded practice that, when consumed thoughtfully, may support overall well-being. As such, individuals are encouraged to reflect not only on what they consume, but also on how, when and why—recognising that informed choices can enhance the health benefits of this widely enjoyed beverage.

Reflections on Coffee Intake ☕🔄💭

🔍 Am I drinking coffee out of habit or necessity? Do I reach for a cup automatically, or am I using it to mask fatigue, stress, or poor sleep hygiene?

📊 Do I know my total daily caffeine intake? Have I considered how much caffeine I consume from coffee, tea, chocolate and other sources—and whether it exceeds recommended limits?

⚖️ Is my coffee consumption affecting my health? Have I noticed symptoms such as anxiety, insomnia, acid reflux, or increased heart rate that might be linked to caffeine?

🧘 Could I benefit from mindful coffee habits? Would spacing out my cups, choosing smaller servings, or switching to decaf in the afternoon help me feel more balanced?

🌿 Are there nourishing alternatives I enjoy? Could caffeine-free coffee alternatives, herbal teas, warm lemon water, or short movement breaks offer similar comfort or alertness without the caffeine?

⏳ Have I considered the long-term impact? Is my coffee intake sustainable for my body, especially as I age or if I develop health conditions that require moderation?

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References 📚

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In developing this work, the author utilised ChatGPT-4 to assist with language editing.