Many research studies have examined how coffee affects the brain and its functions. The potential effects are mainly related to caffeine, one of the main constituents of coffee. Conclusions of studies on both caffeine and coffee are highlighted below with more detailed information.
Coffee and brain Performance
The caffeine in coffee acts as a mild stimulant to the central nervous system. Studies have shown that, depending on the level of intake, caffeine can help to improve mental performance, especially on alertness, attention, and concentration.
The European Food Safety Authority (EFSA) concluded that a cause and effect relationship between improved alertness and 75mg of caffeine (the amount in a regular cup of coffee) had been established.
Caffeine can improve wakefulness in situations of reduced alertness or lack of sleep, for example, night-time driving, working at night, suffering from cold, and during the post-lunch dip.
In a sample of people under 40, a study found that caffeine or coffee may be effective in improving performance in those suffering from jet lag or shift work sleep disorder.
Some studies have shown that caffeine may enhance memory performance, particularly when tedious, repetitive tasks are involved. However, higher intake may decrease performance, possibly due to over-stimulation.
How does coffee affect our sleep?
The stimulant effects of caffeine may affect sleep patterns and evidence suggests there is an association between daily intake of caffeine, sleep quality, and daytime sleepiness. Sensitivity, however, varies between individuals, and adapting caffeine intake during the day may improve sleep patterns. intake late in the day may help improve sleep patterns.
Effects of caffeine tend to be less pronounced in regular caffeinated coffee drinkers than in occasional/noncoffee drinkers. In addition to this, age and genetics may also play a vital role.
Research has shown that abstaining from caffeinated coffee for a whole day may help to improve sleep quality.
Reducing caffeine intake late in the day may help improve sleep patterns.
The scientific evidence shows that caffeine does not induce dependence, as also confirmed by WHO. Abrupt cessation of caffeine consumption may, however, lead to withdrawal symptoms in some regular caffeine consumers but these are generally not severe and of short duration.
For many people, drinking coffee regularly may become a habit, but a habit is not the same as addiction. The World Health Organization has stated that there is no evidence to suggest that caffeine use has comparable physical and social consequences of addiction.
Brain mapping technology shows that caffeine is not linked to the brain circuit of dependence.
In line with previous research on sudden cessation of caffeine, The American Psychiatric Association has recently defined Caffeine Withdrawal as a syndrome resulting from abrupt cessation or reduction in caffeine, following prolonged daily use.
The symptoms of Caffeine Withdrawal (headache, reduced alertness, and drowsiness) can be avoided altogether if caffeine intake is decreased progressively.
Recent studies suggest that habitual coffee consumption may help maintain cognitive function in older adults, particularly in women. Research has also shown the effects of coffee on neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease.
Regular coffee drinking throughout life may slow down age-related cognitive decline, especially in women and this protective effect increases with ages between the 20s and 30s.
The majority of studies in humans suggest that regular coffee consumption over a lifetime reduces the risk of developing Alzheimer’s disease. One meta-analysis found that coffee intake was linked to a 17-20% lower risk of Alzheimer’s disease.
Research suggests that regular coffee drinkers have a lower risk of developing Parkinson’s disease than non-coffee drinkers. The risk decreases with increasing caffeine intake.
The constituents in coffee responsible for these effects on neurological function are still under research. Caffeine may play a role but other neuroprotective, antioxidative or anti-inflammatory components of coffee are also candidates. However, for Parkinson’s disease, research suggests that the potential preventative effect may be due to caffeine.
Caffeine and Pharmacy
Caffeine is a central nervous system stimulant that occurs naturally in more than 60 plant species and is in use in a range of foods, beverages, and drugs. Caffeine is classified as both a food additive and a drug by the Food and Drug Administration of the United States.
The half-life of caffeine (time taken for the body to eliminate one-half of the caffeine) varies widely between people, depending on factors such as age, body weight, pregnancy status, medication intake, and liver health. In healthy adults, the half-life is approximately 5 to 6 hours. Heavy cigarette smoking can decrease the half-life of caffeine by up to a half and in pregnancy, the half-life may be increased by as much as 15 hours.
Caffeine is processed or metabolized in the liver by the cytochrome P450 oxidase enzyme system and broken down into three metabolic dimethylxanthines. These include:
Paraxanthine (forms 84%), which breaks down fats and increases blood levels of glycerol and fats.
Theobromine (forms 12%), which dilates blood vessels and also has a diuretic effect, increasing urination.
Theophylline (forms 4%), which dilates the airways and is used in the treatment of asthma.