The findings are based on 183 men and women with the bowel disease, from two district hospitals in the north east of England.

At the time of the study, symptoms of frequency, urgency, and bloody stools had subsided, and the patients were well. On average, patients had had their disease for six years.

Dietary intake was assessed using a food frequency questionnaire, listing 107 types of food commonly eaten in the UK, and a food atlas, showing portion size. A food table was used to indicate the sulphur content of the foods consumed.

During the year of monitoring, just over half the patients relapsed (52%). Those who ate the most meat (100g or more a day) were three times as likely to relapse as those who ate the least (50g a day) If this was red and/or processed meat the risk was even greater: these patients were five times as likely to relapse. A high intake of animal protein in general - meat, fish, eggs tripled the risk.

Those who drank the most alcohol (more than 2 units a day) were also almost three times as likely to relapse compared with those who drank the least (less than 1 unit a day).

Risk of relapse was not associated with high intake of milk and dairy products, and high levels of dietary fibre did not seem to ward off the risk of relapse either.

When the food constituents were assessed, high intakes of sulphur and sulphate were associated with relapse, which could explain the link with red meat and alcohol, say the authors.

The main sources of dietary sulphur are the sulphur amino acids, found in high protein foods, such as red meat, cheese, milk, nuts and eggs, and sulphate. Sulphate is found in brassica vegetables, such as broccoli, and is used as a preservative in processed foods, especially bread, beer, sausages, and dried fruit. Many alcoholic drinks also contain sulphate.

A high sulphur diet produces hydrogen sulphide, which damages the inner lining of the bowel, making it more 'leaky' and increasing cell turnover, say the authors.

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'We intend to continue doing this into the future in an effort to make a positive contribution to the diet and health of the nation.'

Approximately 75% of salt consumed is from processed foods, 10-15% is added by consumers and 10-15% is naturally present in food.

Nickie Roberts, Executive Director of the Blood Pressure Association said: 'We strongly support the Food Standards Agency's campaign and are delighted that it has launched during our national blood pressure testing week.

'Reducing salt intake will lower blood pressure and will save thousands of people dying or suffering from strokes, heart attacks and heart failure.

'The Blood Pressure Association is tackling this through its "Know Your Numbers!" campaign to drive home the importance of every adult taking action on blood pressure in order to prevent needless suffering.

'Anyone who wants to know more about how cutting salt intake will lower blood pressure should get in touch with the BPA.'

Sid the Slug, the FSA's health awareness campaign tool

Sid the slug is a sympathetic character created by ad agency HHCL/Red Cell and developed by the internationally acclaimed Jim Henson's Creature Shop to front the multimedia health campaign.

He will appear in all TV, national poster and print advertising and on the dedicated campaign website. Salt kills slugs, and Sid the slug will highlight the link between eating too much salt and the increased risk of high blood pressure, heart disease and stroke.

For more information about the campaign go to www.salt

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