Do you believe that “ for every extra 10cm (4in) of height, when fully grown, the risk of developing cancer increased by 18% in women and 11% in men”? It sounds unbelievable, but according to a large sample and long-term experiment in Sweden, it is true.
At the 54th Annual European Society for Paediatric Endocrinology Meeting, researchers from the Karolinska Institutet (one of the largest and most prestigious medical universities in the world )and University of Stockholm showed that cancer risk has been found to increase with height in both Swedish men and women. They examined 5.5 million men and women in Sweden, born between 1938 and 1991 and with adult heights ranging between 3.3 feet and 7.4 feet, and followed the group of individuals from 1958 or from the age of 20 until the end of 2011. Then the scientists got the conclusion which I show above. What’s more, they demonstrated that taller women had a 20% greater risk of breast cancer development, while both men and women have the increased risk of developing melanoma by approximately 30% per 10 cm of height. Study lead author Dr. Emelie Benyi of Karolinska Institutet said that their study is the largest study performed on linkage between height an cancer including both male and female.
Does this mean that great height is the direct cause of development of cancer? Certainly, not! First, the cause of cancer is multifactorial. Although height might be a reason, but is very difficult to predict what is the impact on cancer risk at the individual level. Second, the study only included the sample of men and women in Sweden. To be specific, the data on adult heights was collected from the Swedish Medical Birth, the Swedish Conscription, and the Swedish Passport Registers, whereas the cancer data was retrieved from the Swedish Cancer Register. That “ taller people are more likely to develop cancer” cannot represent the whole population of human. Third, it is possible that the confounding variable exists. It is unclear so far if they also have a higher risk of dying from cancer or have an increased mortality overall, as Dr. Emelie Benyi said. Fourth, it could be a file drawer problem.
Although it seems that height and cancer risk are fairly clearly linked, tall people don’t have to be too worried about these results. “Height itself is not a risk factor, but it really appears to be a marker for one or more exposures that influence cancer risk.” said Geoffrey C. Kabat, a senior epidemiologist in the department of epidemiology and population health at the Albert Einstein College of Medicine of Yeshiva University in New York.
Many factors can influence our heights.( For example, the nutrition we intake in childhood, the amount of foods we consumed in childhood can influence heights.) Therefore we have several possible explanation for the correlation between heights and cancer risks. Growth factor is a circulating level of protein which is influenced by exercises, stress, body mass index and nutrition. It is associated with both increased height and cancer risk. So taller people (while young) are exposed to higher levels of growth factors, which could possibly promote cancer development. Also, taller people simply have a larger number of cells in their bodies that then could potentially transform into cancer. Because cancer means that some of the body’s cells begin to divide without stopping and spread into surrounding tissues. (much information about cancer in cancer.gov)So it is easy to understand that the more cells you have, the much number of cells might be abnormal. A third possible explanation is that taller individuals have a higher caloric intake, which has also previously been linked to cancer. These explain why heights and cancer risks relate each other.
Additionally, the impact of height that increases the risk of cancer is actually smaller than we think. Cancer Research UK scientists have studied in this relative risk. “The researchers found that every extra 10cm (or 4 inches) of height was associated with a 17 per cent higher risk of the disease. Drinking alcohol increases breast cancer risk: every extra unit per day increases the risk by 12 per cent (and a large glass of wine is about three units). Comparing that to the effect of weight, the risk for women with the highest BMIs is 40 per cent higher than for the slimmest women. Having children also has an effect. Women with no children have a 43 per cent higher risk of this disease than those who have had children.” So in comparison with these risks, the influence of high is not large. (If you want to learn more about it, click the following link Height and cancer risk – the long and short of it)
Now we have no clear conclusion about cancer risk and height. Please do not worry about your height. To reduce risk of cancer, there are many important thing to do, such as giving up smoking, cutting down on alcohol, and adopting a healthy diet and lifestyle.