Sugar consumption and human cancer in sites other than the digestive tract

In order to assess the relationship between dietary intake of sugar and cancer a comprehensive search of the scientific literature was undertaken. An earlier publication details an analysis of studies relating to cancers of the digestive tract (Burley, 1997). Here, a total of 69 publications were reviewed which reported the results of ecological, case-control or cohort studies which had assessed the relationship between dietary sugar intake or sucrose-containing foods and risk of cancer at other sites. Cancer sites reviewed included the breast, pancreas, prostate, testis, female reproductive system, lung and upper aerodigestive tract and bladder. For most of these cancer sites the number of studies was insufficient to reach a conclusion. For breast cancer, the data on international per capita sugar intakes suggest a consistent positive correlation with breast cancer mortality rates. However, this relationship is not consistent in within-country ecological studies or in case-control studies, in which sugar intakes have been assessed as mono- and disaccharides or as sucrose. There is some suggestion of a weak increase in risk of breast cancer with high consumption of sucrose-containing foods, such as cakes and biscuits. However, these foods provide a range of other nutrients, particularly fat, which may also be implicated in the development of breast cancer, and further studies specifically designed to address this area are required. It is apparent that there is insufficient evidence to conclude whether sugar has a role in cancer at any site.