Waking up to a hot cup of coffee is a must for many. For some, it is a stress buster, while for others the caffeine boost keeps them alert at tasks. Primarily, coffee is a stimulant that many reach out for.
Roasted coffee is a mixture of bioactive compounds, with caffeine, chlorogenic acids, diterpenes, cafestol and kahweol being the most active ones. Based on the degree of roasting, the type of beans and the brewing method, different types of coffee, such as regular filter coffee, espresso, latte, cappuccino, macchiato, mocha, and Americano, are available.
Studies have shown that coffee has potential health benefits in the cardiovascular, central nervous system, gastrointestinal tracts, and brain-gut axis. However, scientists are still exploring its effect on the brain.
Caffeine and neural pathways
Studies have found that caffeine induces relaxation, calmness, and alertness by enhancing the release of brain chemicals such as norepinephrine, dopamine, acetylcholine, serotonin, glutamate, gamma-aminobutyric acid (GABA), and neuropeptides in the brain.
Other studies have reported that caffeine helps maintain the calcium ions concentration in the neurons during synaptic transmission. Moreover, it may increase oxygen consumption and cerebrospinal fluid production in the brain. In 2023, a preliminary study published in the Journal of Agricultural and Food Chemistry found that espresso (concentrated caffeine) can inhibit tau protein clumps in the brain. Tau protein accumulation is a hallmark of the onset of Alzheimer’s.
“We analysed different concentrations of espresso on [lab-grown neurons] to check the inhibition of tau protein in the laboratory,” Dr Mariapina D’Onofrio, associate professor in the Department of Biotechnology, University of Verona, Italy, tells Happiest Health. A reduction in the tau protein aggregation was observed in those neuronal cells, indicating espresso’s potential role in Alzheimer’s treatment, she adds.
Also, previously, Chuanhai Cao and his team from the University of South Florida, USA, observed that the intake of concentrated coffee reduced the risk or delayed the onset of dementia. This could be due to caffeine’s ability to reduce enzyme activity, which is responsible for the amyloid beta protein production in the neurons.
Read more: Managing Alzheimer’s, the ayurveda way
For Gurmann Singh, 28, interface manager in a construction company, Mumbai, coffee helps to relieve work-related stress, giving him a sense of calm and relaxation. “I am not a morning coffee drinker but need a cup of coffee in the evening every day,” he says. However, Singh prefers a flat white coffee over a concentrated one.
“Drinking a cup of coffee gives me a feeling of relaxation and freshness and makes me mentally active,” he adds.
According to Dt Ifraah Kulsum Khan, a clinical nutritionist and dietitian based in Bengaluru, caffeine in coffee is a good stimulant as its effects are felt on the central nervous system and brain. “It provides the feeling of relaxation, and [improves] focus due to the increased circulation of brain chemicals such as adrenaline,” she says.
A 2021 survey report involving 1500 adult coffee drinkers in Poland, highlighted that the aroma of coffee and its aftereffects make it the most consumed drink in the country.
The downside of excess caffeine
It is estimated that over two billion people worldwide drink coffee in different varieties daily. However, observing a growing coffee consumption among youngsters, Dt Khan cautions that excess consumption leads to severe addiction and gastric problems, which could increase the risk of other health issues, she adds.
Nisha Sharma, 28, Greater Noida, used to drink 8-10 cups of concentrated coffee to be alert and awake during her research activities. “Having a cup of coffee became necessary for me to have an active and headache-free day,” she says. However, she suffered severe gastric problems, and now follows a strict diet to avoid digestion problems, she adds.
Researchers believe that excess coffee consumption leads to anxiety in habitual coffee drinkers and could impair brain functions. In 2021, researchers from the University of Minho, Portugal, observed reduced communication between different parts of the brain in habitual coffee drinkers. With the help of MRI, they observed that brain regions involved in the senses, movement and emotional functions were affected due to regular coffee consumption.
Dr D’Onofrio also explains that “The results of our study do not emphasise drinking too much coffee, as it could lead to another kind of problem. Further research is needed to be done for a better understanding of this study.”
Experts suggest that three cups of coffee per day is enough for a human body, and it should not be taken on an empty stomach. Since coffee has positive as well as negative effects on health, one should keep a check on one’s addiction to it. Moreover, one should consult a dietitian and nutritionist regarding one’s coffee consumption.