Areca nut use following migration and its consequences.

Areca nut use is widespread in the Oriental countries, affecting approximately 20% of the world's population. The combined use of areca nut and smokeless tobacco (ST) is practiced particularly in the Indo-Chinese continents. While there is considerable global variation in the use of these products, migrant studies relevant to areca nut use is of considerable interest to epidemiologists in suggesting the extent to which these environment exposures are important in the aetiology of different cancers and other health-related consequences. Studies on Indian migrants to the Malay peninsula, South and east Africa and various Asian ethnic groups resident in several parts of the United Kingdom have shown that the consumption of areca nut (often mixed with ST) is highly prevalent in these communities. Available data on the prevalence of areca chewing among these migrant populations are reviewed here. The carriage of these risk factors from South Asia to other countries has resulted in excess risk of oral cancer in these new settlements. There is also a high incidence of cardiovascular disease, hypertension and late onset diabetes among Indians living in the United Kingdom and there is new evidence to suggest that the combined roles of areca and ST may be contributory. Because of their enhanced financial situation, substance abuse may increase in their new country of domicile. The two products are psychologically addictive and a dependency syndrome related to their use among Asian immigrants to the United Kingdom has been described recently.