Teenagers who are overweight and taller than average may have an increased risk of developing non-Hodgkin's lymphoma (NHL) - a type of cancer of the lymphatic system.

The lymphatic system has a key role in fighting infection in the body and lymphoma refers to cancer within this system. There are two types of lymphoma - Hodgkin's and non-Hodgkin's - and around 600 people are newly diagnosed with NHL every year in Ireland.

According to researchers in Israel, worldwide rates of NHL have been increasing in recent years and the rise in obesity is thought to have contributed to this. They set out to assess whether weight and height during adolescence could be linked with developing NHL later in life.

The study involved over 2.3 million teenagers aged 16 to 19 who were examined between 1967 and 2011. This data was then linked to the Israel National Cancer Registry, which included all cases of NHL diagnosed during the same period.

The researchers found that being overweight or obese during adolescence was associated with a 25% increased risk of NHL later in life compared with being a normal weight.

"Obesity and overweight during adolescence are risk factors for future NHL. It is important to be aware that overweight and obesity are not risk factors only for diabetes and cardiovascular disease, but also for lymphomas," commented the team from the Sheba Medical Center.

However they also found a link with increasing height. When compared with teenagers who were in the mid-range for height, those who were shorter had a 25% reduced risk of developing NHL later in life, but the tallest teenagers had a 28% increased risk.

The study noted that overall, height was found to be responsible for 6% of all NHL cases, while excess weight was found to be responsible for 3%.

The reasons for this are unclear and require further investigation, the researchers added.

Details of these findings are published in the journal, CANCER.