Along with the immediate sharpening many experience after drinking coffee, caffeine consumption has been found in multiple studies to enhance brain function, particularly short-term or βworking memoryβ.
According to an analysis published in Neuroscience & Biobehavioural Reviews, βthe scientific consensus regarding basic cognitive functions is that caffeine in doses from 32 to 300 mg enhances fundamental aspects of cognitive performance, such as attention, vigilance, and reaction timeβ. This is thought to be due to caffeine blocking the adenosine receptors in the brain, which temporarily heightens memory and alertness.
Coffee is also rich in polyphenols, βa group of antioxidants and particularly chlorogenic acids (naturally occurring compounds that appear in plants such as coffee and tea) that are linked to many brain health benefits,β says Dr Emily Leeming, a nutritionist and author of Genius Gut: The Life-Changing Science of Eating for Your Second Brain.
Loading
These polyphenols are believed to be protective against Alzheimerβs, the most common form of dementia. A 2023 meta-analysis published by scientists at Inje University in South Korea highlighted that for those who drank fewer than four cups a day, polyphenols βmay contribute to the prevention of neurodegeneration and cognitive declineβ. Caffeine has also been shown to reduce amyloid-beta production and tau phosphorylation β key pathological hallmarks of Alzheimerβs.
Dr Gill Livingston, professor in psychiatry of older people at University College London, says that of the studies undertaken to date, βthe jury is still out but [caffeine] does not seem to harm youβ.
2. It contains good bacteria that boost your gut health
The polyphenols in coffee also act as βpotential prebiotics for your gut microbes,β Leeming says, boosting their growth and motility, and creating favourable conditions for other good bacteria to flourish.
Research from ZOE, the nutrition app, found that coffee had the strongest food-microbiome association of 150 consumables they surveyed. Coffee drinkers had six to eight times more L. asaccharolyticus in their microbiome β a bacteria which also led to increased levels of hippurate, a key marker of metabolic and gut health.
Drinking coffee can have a positive effect on the gut biome in women, new research has found.Credit: Shutterstock
Leeming also points out that while much has been made of the potential upsides of coffee drinking, caffeine can be deleterious for our health if consumed too late in the day. She advises drinking it no later than noon, βas caffeine floats around in our bloodstream long after the buzz has worn off, and can lead to a lower quality of sleep, even for those who have no problem getting to sleep after an evening espressoβ. Poor sleep has repeatedly been found to increase mortality risk.
There are concerns too that, as a high-caffeine diet increases the amount of calcium lost via urine, bone density could diminish if enough replacement calcium is not consumed. The Royal Osteoporosis Society advises that, βif your calcium intake is low, or you have other risk factors for osteoporosis, aim to have no more than four cups of coffee a dayβ.
3. Coffee drinkers have improved heart health, studies show
A study by Queen Mary University of London and the Budapest Semmelweis University in 2022 found that up to three cups of coffee a day had a protective effect on heart health, and led to a reduction in overall mortality rate and risk of stroke. Research published in the European Heart Journal in January, meanwhile, showed that morning coffee consumption was associated with improved heart health. Compared to non-coffee drinkers, those who consumed theirs in the morning were 16 per cent less likely to die of any cause, and 31 per cent less likely to die of cardiovascular disease.
According to Tracy Parker, a senior dietitian at the British Heart Foundation, βresearch shows that drinking moderate amounts of caffeine β up to four or five cups of coffee a day β doesnβt seem to have a negative impact on the heart and should be fine for most people.β But she warns that excessive consumption (above the recommended 400mg daily), βcan lead to temporary increases in blood pressure and heart rate, as well as side effects like palpitations, anxiety, nausea and headaches.β Leeming also adds that βnot everyone reacts well to coffee. It can cause jitters, or digestive issues in some people.β
Make the most of your health, relationships, fitness and nutrition with our Live Well newsletter. Get it in your inbox every Monday.