It’s well-known that some food and drink stains your teeth. Coffee, tea and red wine all contain tannins and sugar that can cause discolouration, so it’s best to drink them in moderation. Smoking can also make your teeth more yellow. Some foods can actually help to whiten your teeth. Try strawberries, celery, apples, carrots and other crunchy foods, as well as cheese and nuts. They all help the mouth to produce more saliva, which washes teeth clean naturally.