Coffee and Tea May Lower Head and Neck Cancer Risk

For years, coffee was viewed as a rather unhealthy habit. Now, however, a large analysis suggests that the favourite drink of many people could slow certain types of cancer.

People who drink several cups of coffee a day, or tea now and then, may be doing more than following a stimulating daily ritual. An international research group analysed data from tens of thousands of people and reached an intriguing conclusion: particular amounts of coffee appear to reduce the risk of head and neck cancer, while the findings for tea are more mixed.

What the researchers actually found about coffee and head and neck cancer

The analysis, published in the journal Cancer, brings together 14 observational studies from Europe, North America and Latin America. In total, it included data from 9,548 patients with head and neck cancer and 15,783 people without this diagnosis.

The researchers collected information on, among other factors:

• how often and how much coffee and tea people consumed
• whether they drank decaffeinated coffee
• smoking and alcohol consumption
• dietary habits, including fruit and vegetable intake
• participants’ age and sex

Using this information, the team calculated how different levels of consumption were associated with the risk of tumours affecting the mouth, throat and larynx.

“Those who drank more than four cups of caffeinated coffee a day had an approximately 17 per cent lower risk of head and neck cancer in this analysis.”

The association was particularly noticeable for cancers of the oral cavity and the back of the throat. For other tumour types in this region, the link was less pronounced.

Decaffeinated coffee and tea: not a free pass

What decaffeinated coffee may offer - and what it may not

Decaffeinated coffee was also examined in more detail. Its possible benefit appeared limited: the data suggest a lower risk of oral cavity cancer, but showed no clear advantage for other head and neck tumours.

This indicates that caffeine is unlikely to be the only factor involved. Even without the stimulant, coffee seems to contain substances that may help protect cells.

Tea: a small amount may help, but more could be harmful

The picture for tea is considerably more complex:

• Drinking up to one cup of tea a day was associated with a nine per cent lower risk of head and neck cancer.
• People who drank more than one cup daily, by contrast, had a 38 per cent higher risk of laryngeal cancer.

Experts cite reflux symptoms as one possible explanation. Tea consumed very hot or in large quantities can irritate the oesophagus, make it easier for stomach acid to move upwards and therefore expose the larynx to acid more often. Reflux is regarded as a factor that can contribute to laryngeal cancer.

“Tea is not automatically a case of ‘the more, the better’ - the amount, and probably also the temperature and type, appear to be crucial.”

Which compounds in coffee and tea could be protective

The lead researcher points out that bioactive compounds in these drinks are likely to play a key role. These include:

• Polyphenols: plant compounds that can reduce inflammation and neutralise free radicals.
• Flavonoids: a subgroup of polyphenols, often found in high amounts in dark coffee and tea.
• Antioxidants: these protect cell components from oxidative stress, which can cause DNA damage.

Such compounds may act in several ways. They can curb inflammatory processes, make it more difficult for damaged cells to divide and help the body break down toxins more quickly. In theory, this reduces the likelihood that previously damaged cells will permanently develop into malignant tumour cells.

Why the head and neck area may benefit in particular

The mucous membranes of the mouth, throat and larynx come into direct contact with the liquid. Protective and irritating substances can therefore have an especially strong effect in these areas. Smoking or heavy alcohol consumption places further strain on these regions, and coffee may be able to lessen some of that damage without fully offsetting it.

“Coffee cannot make cells ‘invulnerable’, but it could make them somewhat more resilient to harmful influences.”

Where the study has limitations

The analysis identifies notable associations, but it does not prove a cause-and-effect relationship. These were observational studies rather than controlled experiments.

Several factors limit the strength of the findings:

• Self-reporting: participants had to recall their drinking habits, which can easily lead to inaccuracies.
• Unclear tea varieties: many studies did not distinguish precisely between black tea, green tea and herbal tea.
• Coffee preparation: filter coffee, espresso, moka coffee and French press coffee contain different quantities of compounds.
• Confounding factors: people who drink a lot of coffee may also smoke more often or eat differently, and statistical models can never completely account for this.

A British nutrition expert therefore stresses that smoking and alcohol, as powerful risk factors, can never be fully “calculated out” of the results. People with healthier lifestyles may be more likely to choose particular drinks and may already have a lower cancer risk for that reason.

How much coffee is still healthy?

Four cups a day may sound like an ordinary office routine to many working people. From a cardiology perspective, professional bodies generally consider up to 400 milligrams of caffeine a day unproblematic for healthy adults. Depending on its strength, that is roughly equivalent to three to five cups of filter coffee.

Despite the effects described here, experts advise taking individual circumstances into account:

• People with heart rhythm disorders should discuss their intake with a doctor.
• Anyone who sleeps poorly should have their final cup earlier in the day.
• Significantly lower caffeine limits apply during pregnancy and breastfeeding.

“The study offers one possible additional reason to drink coffee - but it does not replace medical advice or fundamental lifestyle changes.”

Lifestyle matters more than a latte macchiato

The researchers emphasise that no drink can replace the established protective factors. The most important influences on the risk of head and neck tumours are:

• consistently avoiding tobacco
• keeping alcohol consumption as low as possible
• eating plenty of fruit, vegetables and fibre
• maintaining a healthy body weight and being active in everyday life
• vaccination against human papillomaviruses (HPV), where appropriate

At most, coffee can be one piece of the puzzle. Anyone who continues to smoke heavily and drink a lot will not seriously lower their risk with cappuccino.

What coffee fans can take from the study

For many readers, the main message is likely to be this: based on the current evidence, a morning coffee seems more like a modest ally than a risk - provided the heart is healthy and the cup is not sweetened with litres of sugar.

The fine dividing line for tea is also noteworthy. A moderate amount appears to offer benefits, whereas larger quantities, especially when drunk very hot, could place additional strain on the larynx. Tea lovers may therefore want to consider temperature and portion size, and choose gentler options such as mild herbal blends or green tea that has not been brewed too strongly.

Further studies are intended to establish which varieties, roast levels and preparation methods provide the greatest amount of protective compounds, and for whom this could lead to specific recommendations. Until then, people who enjoy coffee and have no medical reason to avoid it can drink their cup with a little more peace of mind - as part of an overall health-conscious lifestyle.