Coffee is the most popular drink globally after water and the most widely traded tropical product in the world. The UN’s Food and Agriculture Organisation describes it as “goodness in a cup” and people in the UK drink 95 million cups per day.
Confusion persists about the safety of drinking coffee, especially in relation to cancer. So, let’s explore the evidence.
Our experts at World Cancer Research Fund say there is strong evidence that coffee decreases the risk of liver and womb cancers. There’s also some evidence that coffee decreases the risk of mouth, pharynx and larynx, and skin cancers.
The evidence surrounding coffee and cancer is so interesting that – in November – we announced funding for a new research project looking at whether coffee improves survival rates in people diagnosed with large bowel cancer.
How does coffee affect cancer risk?
We don’t yet fully know. Coffee is rich in a large number of compounds that may have antioxidant and anti-inflammatory effects. Chlorogenic acid, one of those compounds (also found in large quantities in kale), may play a role in both improving how our body metabolises and manages glucose levels, and in regulating insulin levels – which in turn can affect our cancer risk.
Drinking coffee may also help to regulate hormone levels. Some studies have shown that people who drink coffee have higher levels of sex hormone-binding globulin. This is a protein produced mainly in the liver which binds certain hormones (and so stops them moving around and potentially causing problems elsewhere in the body).
Can I drink as much coffee as I like?
Not quite. After many years of listing coffee as a possible carcinogen, the World Health Organisation downgraded it in 2016 saying there wasn’t enough evidence. And in 2018, a lawsuit claiming coffee should come with a cancer warning was overturned.
However, there is still concern over a chemical called acrylamide which forms when some foods, such as coffee beans, are cooked at high temperatures. And there are also other health risks associated with coffee.
When high levels of sugar and fat are added
If you add syrup, sugar or cream to coffee, you may create a drink that does more harm than good. Excess consumption of sugary drinks can increase the risk of weight gain, overweight or obesity.
Caffeine is a stimulant that affects some people more than others and can disrupt sleep. It’s not recommended for children, and pregnant women are advised to limit their caffeine intake.
Research suggests that consuming very hot drinks, such as tea in south-east Iran, and maté in parts of South America, increases the risk of oesophageal cancer. However, other factors are involved.
And even though coffee has proven benefits, we don’t have the full picture such as:
- how much or how frequently should we drink coffee to get the best effect?
- does caffeinated or decaffeinated make a difference?
- do instant and filter coffees offer the same benefits?
Until we have more evidence, why not sit back and enjoy a cup of coffee while reading a free booklet explaining the 10 things we know can cut your risk of developing cancer?