It's rarely the single glass that matters. It's the weekly total, and the pattern behind it.
We ask about alcohol at your check-up, and we ask in units, because units are how the risk is measured. A glass of wine with dinner is one thing. A weekly total well over the guideline is another. Here's where the line sits.
What 14 Units Looks Like
UK guidance is that it's safest not to drink more than 14 units a week, spread evenly over three or more days. One unit is 10ml of pure alcohol. A pint of regular beer or cider is 2 units, and a single measure of spirits is 1 unit, so 14 units is about seven pints or fourteen single spirits. A standard 175ml glass of wine is roughly 2 units, so around six or seven glasses. Larger glasses and stronger wines add up faster than most people expect.
What Heavier Drinking Does to the Mouth
The biggest concern is cancer. Public health guidance states that there is a significantly increased risk of oral cancer among drinkers, and the risk rises with the amount. Drinkaware's guidance goes further: risk starts to increase even at low levels. Combining alcohol with smoking raises it by more than the two added together, which is why we ask about both. We've written about how we check for oral cancer separately.
Gum health comes into it too. Guidance for dental teams notes that patients with gum disease may benefit from cutting back. And what's in the glass matters for your enamel: wine is acidic, and sugary mixers are exactly the sort of frequent sugar hit your teeth don't enjoy.
So Is One Glass at Dinner a Problem?
For your teeth, one glass with a meal is unlikely to be what decides anything. Having it with food, finishing it in reasonable time rather than sipping for hours, and drinking some water alongside all help. We'd also say honestly that no level of drinking is completely risk-free for cancer, so the answer for your overall health is "less is better", not "this amount is safe".
A Few Simple Habits
Spread what you drink over the week rather than saving it up. Keep a few alcohol-free days. Go easy on sugary mixers. Drink water between drinks. And wait a while, around an hour, before brushing after an acidic drink, so you're not scrubbing softened enamel.
We're not asking to judge. We're asking because the number changes how closely we look. If you'd like to talk it through, we're glad to.
Sources: GOV.UK (Office for Health Improvement and Disparities), Delivering better oral health, chapter 12: alcohol. Drinkaware, Alcohol and mouth, throat and voice box cancers.