Cancer on the curriculum: should children be taught that obesity is a cause of cancer?

28 May 2019 | Healthy living

Isabella Renehan, a BBC Bitesize researcher, shares her findings on how little is being taught in UK schools about the link between cancer and obesity. She's pictured here with her father, Professor Andrew Renehan, who is one of our Research Grant Panellists.

Eight years ago (then aged 16), I sat in a classroom going through a GCSE Biology past-exam paper. "Who can name two conditions that are caused by obesity?" asked the biology teacher. My hand shot straight up. "Diabetes and cancer!" I chimed. "Close," my teacher replied, "but the answer is actually diabetes and heart disease." I frowned, and before the teacher could move on, my hand was up in the air again. "I think you'll find that obesity is one of the biggest causes of cancer." My teacher said with a laugh that the answer 'cancer' was not in the mark scheme and so was incorrect.

This story might leave you asking, 'Surely children are taught about the link between cancer and obesity?' Well, unfortunately, they are not.

What are children being taught?

It's clear that I didn’t learn that obesity is a cause of cancer in Biology GCSE. So where did I learn this? My father, Andrew Renehan, is Professor of Cancer Studies and Surgery at the University of Manchester. He's someone who has dedicated a lot of research to the link between obesity and cancer and I've always looked up to him. I've told him this story time and time again. As a result, we decided to investigate in more detail what is taught in schools, publishing our findings in a research letter to the Lancet. We found that not only is the association rarely on the syllabus, but that where it is mentioned it suggests obesity might be linked to cancer, rather than it is a cause. And students are not taught that obesity is not just about excess fat but also it invariably means unhealthy fat.

Why is this important?

Firstly, there is a widespread lack of awareness among adults of the link between cancer and obesity - only 25 per cent of people are aware of this link according to a study in the Journal of Public Health. But more than 60 per cent of adults in the UK are overweight or obese. If cancer can be prevented through weight control, it would certainly seem sensible that more adults should know about this. It's universally accepted that smoking causes cancer, a fact drilled into us as children. Smoking rates have fallen from peaks of over 70 per cent among men just after World War II to now less than 20 per cent, and one could argue that early education on the link between smoking and cancer has contributed to this. If obesity is to be reduced, awareness of its link with cancer among school leavers is an obvious first step.

Secondly, other attempts to raise awareness on the link between obesity and cancer have faced backlash. In 2018, one cancer charity launched a campaign explicitly linking obesity to cancer. We're so used to anti-smoking advertising, yet this campaign was heavily criticised on social media as fat-shaming propaganda and there were calls for it to be banned. There is something provocative about obesity, but not smoking, which shrouds it from debate.

It's clear that although the statement ‘obesity is a cause of cancer’ is a fact, for many it's controversial, inappropriate and offensive. If we're to raise awareness of the truth of this statement and at the same time handle the subject delicately, a good place to start would be through school education, since a person’s youth is filled with moments that can affect them for the rest of their lives – let's make sure it's a positive impact.

Isabella Renehan | 28 May 2019