Coffee is a brewed drink prepared using roasted coffee beans which are taken from the berries of the Coffea plant. There are two main species of coffee beans which are the Arabica and Robusta, and depending on where they are grown, both the country and the altitude determines the flavour of the coffee. For example, Brazilian coffee usually has more chocolate and spice flavour compared to Ethiopian coffee which has a stronger, sweet berry flavour.
There are two main factors that could be considered benefits to drinking coffee. The first is associated with its high antioxidant status. Antioxidants are important for health as they prevent our cells from being oxidised by toxins, chemicals and inflammation. The second is the stimulant caffeine, although this also presents potential risk factors if consumed in excessive amounts and for certain people who may be vulnerable to its effects (see below). Coffee, in addition, does contain some B vitamins, magnesium and potassium.
Recent research published in the Annals of Internal Medicine suggests that having three cups of coffee per day could lengthen lifespan by lowering the risk of death from several key conditions including heart disease. The study followed over 500,000 people from 10 European countries for over 16 years. However, critics say that the study could not take into account every circumstance, such as economic, social and other lifestyle factors, that could have contributed to their findings. They also excluded participants with some pre-existing conditions such as diabetes, heart disease, or stroke before beginning the study.
Coffee can help some people to feel less tired and increase energy levels thanks to its caffeine content. When coffee is consumed, it is absorbed into the bloodstream and travels to the brain where it ‘fires up’ certain neurons that can lead to improved memory, mood, energy and cognitive function if consumed in moderation.
The caffeine benefits can then reach even further when it comes to athletic performance as it may help to increase the amount of oxygen consumption during exercise, as well as stimulating the nervous system, which may aid the breakdown of body fat for energy. Some reports state that drinking coffee before exercise can improve athletic performance as much as 11-12%.
Initial research suggests that caffeine may moderately boost your metabolic rate and that it may help the body to burn fat, both during activity and when resting. Researchers have speculated, therefore, that caffeine could show promise in the treatment of obesity. However, more research is required before this could be made as a valid health claim.
There have been several studies into whether drinking coffee can help guard against neurodegenerative diseases such as dementia and Alzheimer’s, including papers published in 2010, 2011 and 2015. However, the findings of these studies have so far been inconsistent and larger studies with longer follow-up periods are required before a clear link can be established between coffee and these neurological conditions.
There is some evidence to suggest that coffee may lower the risk of developing type 2 diabetes, although more research in this area is required. In response to a separate study on coffee and diabetes, the NHS points out that proven methods of reducing your risk include maintaining a healthy weight, eating a varied and balanced diet, and exercising regularly.
The NHS currently do not set limits for coffee consumption for most people, but they do advise pregnant women to limit their caffeine intake to 200mg per day. This is the equivalent to two mugs of instant coffee but less than two mugs of filter coffee.
Caffeine is a stimulant and everyone reacts differently to it. Caffeine can act as a diuretic which can cause the body to produce urine more quickly. People who are more sensitive to caffeine or who drink a lot of caffeinated drinks sometimes report dizziness, tremors and insomnia as side effects. If you are concerned about your caffeine intake you should speak to your doctor or GP.
It is also worth bearing in mind that many coffee-based drinks contain added milk, sugar, artificial sweeteners or flavoured syrups, and these extras can add a significant chunk of calories, fat and sugar to your diet.
Coffee comes in different forms: whole beans, ground coffee and freeze-dried. Whole beans and ground coffee are best kept dry and in an airtight container away from light, heat and moisture to maintain freshness and they usually last up to 6 months. Freeze-dried (instant) coffee on the other hand can be kept a lot longer and you should look at the individual jars or containers for their use-by date.
Nutritionally speaking organic black, fresh (beans or ground) coffee is best as it is higher in antioxidants. Some research suggests that dark roast blends have higher antioxidant levels than light or medium roast blends.