Coffee, one of the world’s most popular beverages, has recently received extensive media attention over its health benefits and potential detriments, with some studies focussing on the connection between drinking coffee and dementia. This has caused some confusion – but what do the facts say?
It is estimated that dementia affects around 47 million people worldwide, while over two billion cups of coffee are consumed every day, according to the International Coffee Organisation. While research is ongoing, there is still no concrete answer to the question of whether drinking coffee increases the likelihood of developing dementia.
A well-respected French study published in the European Journal of Neurology in 2009 indicated that participants aged 65 and above who drank 3 – 5 cups of coffee a day had a much lower risk of dementia than those who drank none. It concluded that an association between coffee drinking and a diminishing risk of dementia was found.
In contrast, researchers in Finland concluded in 2011 that drinking more than 3 to 4 cups of coffee daily was linked to a higher risk of dementia and Alzheimer’s disease. However, this was refuted by a team of scientists in the USA in 2013, who found no link between increased coffee consumption and dementia.
Experts remain divided on the issue, with some citing potential benefits of drinking coffee and others citing potential harms. For example, some suggest that coffee can help fight inflammation, which is implicated in dementias such as Alzheimer’s disease. On the other hand, too many cups of coffee could increase oxidative stress, which is another factor implicated in dementias.
These findings may be useful to individuals trying to assess their risk of dementia according to their coffee habits. However, the present research does not conclusively answer the question as to whether drinking coffee causes dementia – and more research is needed.
Genese Environmental Factors
While the research on whether drinking coffee causes dementia is still inconclusive, researchers have identified certain environmental factors which have been linked to an increased risk of dementia. Such factors include air pollution, cannabis use, smoking, heavy drinking and head injuries – although none of these are definitively causative.
A study conducted at the University of Southern California, USA, suggested that chronic exposure to high levels of air pollution, such as that found in many cities, can have a detrimental effect on the brain and lead to an increased risk of dementia. It found that chronic exposure to PM2.5 and NO2 particulate pollution is associated with increased cognitive decline. Evidence also suggests that, in addition to causing cognitive decline, air pollution may be linked to structural damage to the brain that is associated with Alzheimer’s.
Additionally, people who use cannabis heavily or smoke heavily are thought to be at an increased risk of developing the condition. A study in New Zealand conducted in 2011 implicated heavy cannabis use in early-onset dementia; however, the link between cannabis and dementia remains controversial. Similarly, heavy drinkers are also thought to be at a much higher risk of dementia. Heavy drinking can cause long-term damage to brain cells which may lead to dementia in later life.
Those who have suffered a head injury, especially a severe injury such as a traumatic brain injury, are also believed to be at an increased risk of developing dementia. Studies conducted in Canada, Norway and Denmark have shown a connection – in 2011, a large-scale Northern European study identified a three-fold increased risk.
Effects of Diet and Nutrition
In addition to environmental factors, the diet of an individual has been linked to an increased risk of dementia. This can include changes to diet, such as consuming more saturated fats and less omega 3, as well as micronutrient deficiencies including vitamins B6 and 12, folate, magnesium and vitamin D.
Saturated fats are found in red meat, fast food, eggs and full-fat dairy products; research suggests excessive consumption of these is linked to an increased risk of dementia in later life. Conversely, diets high in omega 3, found in foods such as salmon, mackerel and nuts, and low in saturated fat, are thought to be beneficial for cognitive health.
In terms of micronutrient deficiencies, a number of studies have linked folate and vitamin B6 to an increased risk of Alzheimer’s disease. Low levels of vitamin B12 have also been linked to dementia, as have low levels of magnesium and vitamin D. These deficiencies can often be put right by eating a balanced and healthy diet, although supplementation may be necessary if levels remain low.
Inflammation and Stress
Another potentially contributory factor when it comes to the development of dementia is inflammation. Studies have shown that chronic inflammation can have a detrimental effect on brain health and lead to damage of neurons. This neuronal damage can lead to an increased risk of dementia.
Chronic stress can also be problematic, as it too can be linked to an increased risk of developing dementia. Chronically high cortisol levels can impair cognitive function, decrease the size of neurons, reduce plasticity and inhibit the formation of neurons. All of this can lead to an increased risk of developing Alzheimer’s in later life.
Physical Exercise
One of the best ways of maintaining good cognitive health is to stay physically active, as regular physical activity has been linked to reduced risks of developing dementia. Indeed, in a study published by the American Heart Association in 2015, adults who had engaged in physical activity of any intensity at least three times a week had a lower risk of cognitive decline.
In addition, a study conducted in 2014 found that more vigorous exercise, such as running and cycling, was associated with a reduced risk of dementia. It follows that those who want to keep their cognitive health in check should take up regular physical exercise.
Sleep Quality
Sleep is essential for proving the body with rest and allowing it to restore itself; however, it may also have a role to play when it comes to the prevention of dementia. A number of studies have suggested that poorer quality sleep, including bouts of insomnia and sleep apnoea, may increase the risk of developing the condition.
One 2014 study suggested that those who experienced more than five episodes of breathing stops (apnoeas) or arousals per hour had a much higher risk of developing Alzheimer’s in later life. Similarly, those with frequent bouts of insomnia were also more likely to develop the condition.
In contrast, some studies suggest that it is better to sleep for longer than for shorter periods of time. A study in Japan in 2011 suggested that those who slept for more than 8 hours a day were at an increased risk of developing dementia, although this was disputed by a study in the USA in 2016 which suggested the opposite.
Lifestyle Changes
To reduce the risk of developing dementia, it is important to adopt a balanced lifestyle. This should include a balanced diet, regular and varied physical exercise, a good quality 8-hour sleep and reducing stress and alcohol consumption. Additionally, keeping mentally active, by reading, playing word and number games, or learning a new language, is also suggested to be beneficial.
These activities will help to ensure the prevention of dementia, whether or not drinking coffee has a role to play. Ultimately, further research is needed to determine the effects of coffee on the risk of developing the condition.
