Caffeine: Benefits, Dosage, Contraindications
Other name(s)
1, 3, 7-trimethylxanthine or methyltheobromine
Scientific name(s)
1, 3, 7-trimethylxanthine
Family or group:
Phytosubstances
Indications
Rating methodology
EFSA approval.
Migraine ✪✪✪✪✪
Taking 100 to 260 mg of caffeine orally in combination with 500 to 2,000 mg of acetaminophen, 500 mg of aspirin and/or 50 to 100 mg of sumatriptan is effective for treating migraines. Some evidence shows that caffeine combined with aspirin and acetaminophen may be more effective than sumatriptan in treating a migraine attack. Oral caffeine combined with analgesics is approved by the United States Food and Drug Administration (FDA) for treating migraines and tension-type headaches.
Posologie
Oral
100 - 250 mg
Oral sumatriptan for acute migraine.
Treatment of menstruation-associated migraine with the nonprescription combination of acetaminophen, aspirin, and caffeine: results from three randomized, placebo-controlled studies.
Efficacy and safety of acetaminophen, aspirin, and caffeine in alleviating migraine headache pain: three double-blind, randomized, placebo-controlled trials.
Treatment of severe, disabling migraine attacks in an over-the-counter population of migraine sufferers: results from three randomized, placebo-controlled studies of the combination of acetaminophen, aspirin, and caffeine.
Concentration ✪✪✪✪✪
Taking 100 to 600 mg of caffeine can improve alertness after prolonged sleep deprivation but generally does not affect mental performance or accuracy. Drinking coffee containing 100 mg of caffeine before a cognitive performance test improves reaction time in individuals who have recently had poor-quality sleep and those with sufficient sleep.
Posologie
Oral
100 - 600 mg
The effects of L-theanine, caffeine and their combination on cognition and mood.
The effects of a low dose of caffeine on cognitive performance.
The effects of black tea and other beverages on aspects of cognition and psychomotor performance.
Influence of caffeine ingestion on perceived mood states, concentration, and arousal levels during a 75-min university lecture.
Type 2 Diabetes ✪✪✪✪✪
Caffeine consumption from beverages such as coffee or tea is associated with a reduced risk of developing type 2 diabetes. This effect is dose-dependent. However, it is not clear if caffeine is beneficial in diabetic adults. Some small studies show that caffeine consumption may further reduce insulin sensitivity in patients with type 2 diabetes, gestational diabetes, or in those at risk of developing diabetes.
Posologie
Oral
200 - 500 mg
Caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes: a systematic review and a dose-response meta-analysis.
The relationship between green tea and total caffeine intake and risk for self-reported type 2 diabetes among Japanese adults.
Coffee and tea consumption and risk of type 2 diabetes.
Does long-term coffee intake reduce type 2 diabetes mellitus risk?
Hypotension ✪✪✪✪✪
Preliminary clinical research shows that consuming caffeine-containing beverages increases blood pressure in older adults with postprandial hypotension.
Posologie
Oral
Memory ✪✪✪✪✪
Taking a single dose of caffeine from 65 to 200 mg per day orally seems to improve memory in some individuals, such as students and those with an extroverted personality.
Posologie
Oral
65 - 200 mg
Obesity ✪✪✪✪✪
Caffeine combined with ephedrine appears to promote fat mass loss when taken alongside a low-fat diet and physical exercise. Specifically, taking 192 mg of caffeine combined with 20 to 90 mg per day of ephedra, for 6 months, seems to cause slight weight loss (5.3 kg) in individuals with a body mass index between 25 and 40 kg/m.
Posologie
Oral
192 mg
Randomised comparison of diets for maintaining obese subjects' weight after major weight loss: ad lib, low fat, high carbohydrate diet v fixed energy intake.
The acute and chronic effects of ephedrine/caffeine mixtures on energy expenditure and glucose metabolism in humans.
Sport Performance ✪✪✪✪✪
Caffeine boosts muscle power, adrenaline, blood flow, and heart rate, thereby enhancing sports performance. Caffeine is one of the most commonly used stimulants by athletes. Caffeine consumption is permitted by the National Collegiate Athletic Association (NCAA) within certain limits. Urine concentrations above 15 mcg/mL are banned in competition. It takes 500 mg of caffeine, approximately 6 to 8 cups of coffee consumed 2 to 3 hours before competition, to reach this urine concentration for most individuals.
Posologie
Oral
3 - 6 mg/kg
Effect Of Ambient Temperature On Caffeine Ergogenicity During Endurance Exercise
Metabolic Effects Of Caffeine Ingestion And Physical Work In 75-year Old Citizens. A Randomized, Double-blind, Placebo-controlled, Cross-over Study
The Influence Of A CYP1A2 Polymorphism On The Ergogenic Effects Of Caffeine
Asthma ✪✪✪✪✪
Caffeine supplementation seems to improve respiratory function in mild to moderate asthma for a duration of 4 hours.
Posologie
Oral administration
9 mg/kg
Parkinson's Disease ✪✪✪✪✪
It is unclear whether caffeine improves certain symptoms of Parkinson’s disease, as clinical research results are conflicting. A large retrospective study revealed that caffeine consumption above 300 mg per day for 18 months alongside dopaminergic treatment did not slow the progression of Parkinson’s disease. Moreover, caffeine does not appear to be helpful in reducing the risk of tardive dyskinesia. Additionally, large-scale epidemiological studies have shown that people who consume caffeinated beverages, such as coffee, tea, and cola, have a lower risk of developing Parkinson's disease. Indeed, men consuming 3 to 4 cups of caffeinated coffee per day, or 421 to 2,716 mg of total caffeine, seem to have the lowest risk of developing this disease.
Posologie
Oral administration
124 - 2716 mg
Fatigue ✪✪✪✪✪
During physical exercise, athletes experienced less physical fatigue with caffeine supplementation. Furthermore, clinical research has shown that consuming 500 ml of an energy drink providing 1 gram of taurine and other ingredients, including caffeine and B vitamins, reduces fatigue related to exertion. It is possible that this effect is due to the combination of ingredients rather than taurine alone.
Posologie
Oral administration
240 - 300 mg
Synergies
Properties
Cardiovascular
Caffeine can influence cardiovascular reactivity to stress, either by enhancing the stress response itself or by increasing the response during stress. Caffeine can cause a slight decrease in heart rate after consumption and seems to increase blood pressure. This effect is likely due to caffeine's vasoconstrictive effect and the inhibition of adenosine receptors and adenosine-induced vasodilation. Additionally, large amounts of caffeine, over 10 mg/kg/day, may cause tachycardia and premature ventricular contractions. However, clinical research shows that long-term caffeine consumption leads to reduced effects on blood pressure over time.
Usages associés
Neurological
Caffeine stimulates the central nervous system (CNS), the heart, muscles, and potentially the pressor centers controlling blood pressure. Possible mechanisms include adenosine receptor blockade and phosphodiesterase inhibition. Caffeine reduces cerebral blood flow through vasoconstriction due to adenosine receptor blockade. By blocking adenosine receptors (A1 and A2), caffeine can induce dopamine release and exert stimulating effects on the CNS. The stimulating effects of caffeine on the CNS are believed to improve alertness and psychomotor performance. Moreover, caffeine may protect brain dopaminergic neurons from degeneration and prevent Parkinson's disease. This effect seems to be related to adenosine receptor modulation.
Usages associés
Digestive Effect
Caffeine increases gastric acid secretion, facilitating digestion.
Metabolic
Some clinical evidence shows that acute caffeine consumption causes a dose-dependent increase in plasma levels of free fatty acids and ketones, 4 hours after ingestion.
Usages associés
Respiratory Effect
Caffeine has been used to counter respiratory diseases such as asthma and neonatal apnea. It decreases airway resistance and stimulates breathing via adenosine receptor blockade and phosphodiesterase inhibition. In addition, it stimulates the brain's respiratory center, increases peripheral chemoreceptor reactivity to carbon dioxide, and enhances diaphragmatic activity. Caffeine also reduces respiratory muscle fatigue.
Analgesic
Caffeine blocks pain mediators, such as adenosine receptors, and the activity of certain enzymes, notably cyclooxygenase 2.
Usages associés
Anti-inflammatory
The effects of caffeine on the inflammatory response are inconsistent. In healthy adults, a single dose of caffeine has reduced plasma markers of inflammation. Theoretically, caffeine may exhibit anti-inflammatory effects by inhibiting phosphodiesterases. However, clinical research in premature infants suggests that serum caffeine levels ≥20 mcg/mL are associated with a pro-inflammatory state with increased cytokines.
Fertility Effect
Caffeine slows the breakdown of cyclic AMP in cells and increases the motility and longevity of sperm.
Safety dosage
Adult from 18 years: 400 mg
Daily consumption of caffeine up to 400 mg is not associated with significant adverse cardiovascular, bone, behavioral, or reproductive effects in healthy adults or with an increased risk of major chronic diseases, such as cardiovascular diseases. This amount of caffeine is similar to the caffeine content in about 4 cups of coffee. Acute consumption of high doses, generally over 400 mg per day, has been associated with significant adverse effects such as tachyarrhythmias and sleep disturbances. Chronic consumption, especially in large amounts, may lead to tolerance, habituation, psychological dependence, and other adverse effects.
Interactions
Médicaments
Adenosine: moderate interaction
Caffeine is a competitive inhibitor of adenosine and can reduce its vasodilator effect in humans.
Antiplatelet/Anticoagulant: moderate interaction
Caffeine appears to have antiplatelet properties. Its concomitant use with such medications may increase the risk of bleeding.
Antidiabetic: minor interaction
Caffeine might have glucose-modulating properties and interfere with the effects of antidiabetic medications.
Carbamazepine: moderate interaction
Taking caffeine may reduce the anticonvulsant effect of carbamazepine and increase the risk of seizures.
Cimetidine: moderate interaction
Cimetidine reduces the elimination of caffeine and could promote its accumulation in the blood.
Oral contraceptives: minor interaction
Oral contraceptives slow the elimination of caffeine and increase its adverse effects.
Cytochrome P450 substrates: minor interaction
Caffeine is metabolized by CYP1A2. Theoretically, medications that inhibit CYP1A2 may decrease caffeine clearance and increase caffeine levels.
Diuretics: moderate interaction
The diuretic effects of caffeine could add up to those of substances already having this property.
Ephedrine: strong interaction
The combination of caffeine and ephedrine induces serious risks of hypertension, seizures, and cardiac arrest.
Plantes ou autres actifs
Caffeine: moderate interaction
The co-administration of caffeine and melatonin can increase melatonin levels by about 142%; this effect is more pronounced in non-smokers.
Caffeine: moderate interaction
Caffeine has diuretic activity. In the event of abrupt cessation, this could alter lithium clearance and increase its adverse effects.
Precautions
Pregnant woman from 18 years: use with caution
Caffeine intake should be monitored during pregnancy, as caffeine crosses the human placenta but is not considered teratogenic, and fetal blood and tissue levels are similar to maternal concentrations. Moderate consumption has not been associated with clinically significant fetal adverse effects. Caffeine intake should be maintained below 300 mg per day during pregnancy. This is similar to the quantity of caffeine contained in about 3 cups of coffee or tea.
Child: use with caution
Daily caffeine consumption at doses lower than 2.5 mg/kg per day is not associated with significant adverse effects in children and adolescents.
Breastfeeding woman: use with caution
When used orally in large amounts, it can have negative effects on the breastfed baby. Caffeine is excreted slowly in infants and can accumulate. Caffeine may cause sleep disturbances, irritability, and increased intestinal activity in breastfed infants exposed to caffeine.
Contraindications
Allergies: prohibited
Do not use in individuals allergic to caffeine.
