Monday, August 10, 1998 Published at 16:45 GMT 17:45 UK
UK study raises 'fake fat' concern
The US FDA recently approved research supportive of the SPE Olestra
A fat substitute which could soon be used in processed foods in the UK has been shown to have worrying side effects, according to a Cambridge study.
Sucrose polyester (SPE) passes straight through the body without being digested. Some scientists and nutritionists believe it may play a useful role in combating the growing problem of obesity.
Already in the United States, an SPE called Olestra has proved popular in potato crisps.
However, many of the volunteers who took part in a study for Addenbrooke's Hospital in Cambridge reported problems including increased bowel movements, anal leakage and some increased abdominal pain.
The researchers from the hospital's Department of Gastroenterology say the volunteers also showed significantly lower levels of vitamin E and six carotenoids.
Carotenoids are plant pigments found in yellow and red vegetables, which are converted into vitamin A in the liver. There is some evidence that they protect against cancer.
Seventy-six volunteers were used in the three month, double-blind, controlled study, reported in the British Journal of Nutrition.
The subjects consumed between 20 and 40 grams of SPE daily which was incorporated into foods such as chips, meat pies, milk and biscuits.
At the end of the trial period, blood, stool, urine and other tests were taken - together with questionnaires - to build up a picture of how the SPE affected each person.
Dietary analysis showed that the total fat consumption was significantly reduced following three months on SPE.
The researchers recognised that the amount of SPE being consumed by the volunteers was greater than the amount being eaten currently by Americans in potato crisps. Nevertheless, they conclude further research should be undertaken before the fat substitute is used more widely.
"This study has demonstrated important deleterious effects of SPE which need to be carefully examined before this product is made available for widespread long-term consumption in a broad range of foods," they write.
Proctor and Gamble, the makers of Olestra, have applied to the Food Advisory Committee for permission to sell the product in the UK.
The US Food and Drug Administration recently gave its backing to research by the manufacturers which sought to rebuff claims that eating the fat substitute could lead to cancer, heart disease and blindness.