Men's weight at 18 linked to cancer later in life

16^th June 2011 - Researchers in the UK and the US have identified a link between men who are overweight or obese at the age of 18 and death from cancer later in life. The study shows that the link persists even if the individuals cut their weight during middle age.

The study was carried out by the Medical Research Council in collaboration with University College London and Harvard School of Public Health in the US. Researchers examined records for 19,593 Harvard university students who had undergone medical examinations during their studies between 1914 and 1952 [Harvard Alumni Health Study cohort].

35% increased cancer risk

They found that the men in the study with the highest body mass indexes (BMIs) at 18 were 35% more likely to die from cancer than those with lower BMIs. The link between weight and cancer was particularly strong for lung, skin, oesophageal and urogenital (kidney, bladder, prostate and testicular) cancers.

For example, men whose BMI had been greater than the average (21.7) at age 18 had more than a 50% greater risk of dying from lung cancer than those with the lowest BMIs, even after accounting for whether or not they smoked, the researchers report in the latest edition of Annals of Oncology.

They say one of the most important findings is that changing weight in later years did not influence these effects.

Previous studies have suggested a possible link between early obesity and later cancer, but the authors say, unlike in the latest research, it was rare to find data in which young people had their BMI checked when they were young and then followed for several decades to see whether they developed cancer.

Also, since overweight young adults tend to remain overweight into middle age, it was harder to draw the conclusion that a high BMI at 18 was the important factor.

Importance of healthy weight

"It indicates that keeping your weight healthy as a young adult can help reduce your chances of developing cancer," Medical Research Council investigator scientist and lead author Linsay Gray tells us.  

She continues: "What the findings of this study do is give us the knowledge that there is an increased risk if your obesity is high; and what it does for GPs, and for patients themselves, is it gives them the information and it gives them the choices about managing the risks with regards to other factors."

Commenting on the findings, Jessica Harris, Cancer Research UK’s senior health information officer, says in an emailed statement: "Decades of research have shown that being overweight leads to a higher risk of several types of cancer.

“This new study has some limitations, like not being able to account for other things that affect cancer risk, but it did show that overweight people are more likely to die from certain cancers. Scientists estimate that in the UK, the current number of people who are overweight and obese could lead to around 19,000 cases of cancer a year, so keeping a healthy weight is a great way to reduce the risk."