Being tall has been linked to a greater risk of 10 common cancers by University of Oxford researchers

For every four inches above five feet a person was, the researchers said that they had a 16% increased cancer risk. The study of more than one million women suggested chemicals that control growth might also affect tumors. The study followed 1.3 million middle-aged women in Britain between 1996 and 2001. It linked 10 cancers to height - colon, rectal, malignant melanoma, breast, endometrial (uterus), ovarian, kidney, lymphoma, non-Hodgkin lymphoma and leukaemia. Those in the tallest group, over 5ft 9in, were 37% more likely to have developed a tumor than those in the shortest group, under 5ft. Although the study looked only at women, the researchers said that the height link was also present in men. They combined 10 other research studies which showed a similar link in men. Height, however, is not a universally bad thing. It is believed that people are becoming taller due to better nutrition and fewer diseases in childhood. Being tall has also been linked to reduced rates of heart disease. It is also not the biggest contributor to cancer. A height link was greatly reduced or eliminated for some cancers in smokers - researchers said that the effect of height had been swamped. Obesity is also a big factor, a 10 point increase in Body Mass Index increases the risk of breast cancer by around 40%. Height might one day help doctors screen for cancer risk and it is hoped, that by furthering the understanding of cancers, the study will help researchers discover treatments. Scientists believe that as there is a link across many cancers there may be a basic common mechanism. They think, but have not proved, that growth hormones - such as insulin-like growth factors - may be the explanation. Higher levels of growth factors could do two things. They could result in more cells - taller people are made of more stuff so there are more cells which could mutate and become tumors. Alternatively, they could increase the rate of cell division and turnover, increasing the risk of cancer. The researchers suggested that height could also have contributed to increasing cancer incidence. In Europe, average height is thought to have increased by around one centimeter every decade during the 20th Century. They argued that the height increase in that time could have resulted in a 10-15% more cancers than if heights had remained the same.