However, open-headed lettuce varieties - such as butterhead lettuce - as well as raspberries, are also common carriers of bugs such as norovirus, a severe stomach bug.
A scientific review by the FSA has estimated that around 2.4 million cases of foodborne illness occur every year in the UK - up from the 2009 estimate of approximately one million. Of that, an estimated 380,000 cases of norovirus linked to food occur in the UK per year.
Food Standards Scotland said these new figures do not indicate an increase in total illness, or any new risk to public health, but rather provide a better estimation of the proportion of infectious intestinal disease that is due to food.
While oysters are the most high risk food, the largest proportion of food poisoning cases come from open-headed lettuce, which accounts for 30 per cent of all foodborne norovirus cases.
eating out accounts for an estimated 37 per cent of all foodborne norovirus cases, while takeaways cause 26 per cent. Raspberries sold in shops and super markets are also a likely carrier, accounting for four per cent of all cases.
Dr Jacqui McElhiney, head of food protection science and surveillance at Food Standards Scotland, said: “The Food Standards Agency’s (FSA’s) comprehensive study on the latest estimates of foodborne illness in the UK highlights that food is a more important source for certain bugs, such as norovirus, than we had previously thought.
“However, it is important to highlight that the increase in the FSA’s overall estimated number of cases does not indicate that more people are becoming ill, but rather these figures, through the latest scientific research methods, provide a more reliable indication of the role of food in human illness in the UK.”
The research said that, on average, an individual would only end up with norovirus once in every 15,000 portions of open-headed lettuce – which would take around 40 years. Oysters pose the highest risk per serving, with illness likely on average once in around 160 servings.
Dr McElhiney added: “Food Standards Scotland will continue working with others to ensure food is safe and reduce cases of food poisoning.
“This research emphasises the ongoing importance of practising good food hygiene, both when preparing and cooking meals at home and for catering businesses. To avoid cross-contamination and to reduce the risk of food poisoning, various safety steps should be taken such as washing hands and using separate chopping boards for raw foods and ready to eat foods, for example don’t use the same chopping board for both raw meat and vegetables.”