Podcast "Let's Talk Cancer": Obesity, nutrition and cancer

In this podcast episode of Let's Talk Cancer, Dr Elisabete Weiderpass, Director of the International Agency for Research on Cancer (IARC) talks with Cary Adams, CEO of UICC, about obesity, nutrition and cancer.

Obesity is a growing health concern worldwide.

The global obesity rate has almost tripled since 1975. The World Health Organization reckons that worldwide 39% of adults are overweight, and 13% are obese.
 
Too much body fat increases a person’s chances of developing illnesses such as cancer. More than a dozen types of cancer are linked to excess body weight.
 
Usually, obesity results from inherited, physiological and environmental factors, combined with diet and physical activity choices.

Fortunately, even modest weight loss can improve or prevent the health problems associated with obesity. Public health actions to support healthier lifestyles include education, advertising bans, and higher taxes on sugar and food labels.

Dr Elisabete Weiderpass, Director of the International Agency for Research on Cancer (IARC) joins us for this episode of Let’s Talk Cancer.

Podcast transcript 

Cary Adams: Hello. Welcome to Let's Talk Cancer by the Union for International Cancer Control, an organization that unites and supports the cancer community to reduce the global cancer burden. I'm Cary Adams and I am the CEO of UICC, based here in sunny Geneva. At least 40% of all cancers can be prevented, according to W.H.O., by acting on modifiable risk factors such as tobacco consumption and nutrition. Last time we looked at tobacco control, But today we will be looking at nutrition, obesity and metabolic disorders and their link with cancer. With us to discuss all of this is Dr. Elizabeth Weiderpass, past director of the International Agency for Research on Cancer (IARC). So, Elizabeth, it's absolute delight to to have you with us.

Dr Elisabeth Weiderpass: Good morning, Cary. It's a great pleasure to talk to you today.

Cary Adams: What are the links between nutrition and the risks of developing in the first place and then surviving cancer? What is IARC's perspective on that at the moment?

Dr Elisabeth Weiderpass: Your nutrition and metabolism branch is quite unique because it addresses different aspects of how poor diet and poor lifestyle affect obesity and how obesity affects cancer, and how diet and obesity can influence also cancer survival and development of cancer, the progression of cancer. So, for example, we study the effect of diet on inflammation because we know that inflammation causes cancer. And now we are studying how different nutrients and different food patterns can also cause inflammation and therefore cancer. And we have found an impact on inflammatory markers associated to diet and breast cancer risk in post-menopausal women. We have quite recently published about that. We are also doing lots of studies in what we call multi morbidity. That means how people can have several diseases at the same time, including cancer and how diet affect the risk of having these multiple diseases. And among all these diseases, what's very important in fact is type two diabetes. Obesity is a pandemic is all over the world, but also type two diabetes is a major challenge and both obesity and type two diabetes are related to nutrition, to metabolism, to diet and to cancer.

Cary Adams: You get the impression that we've made great advances in the last few years, actually, in this domain of understanding the link between diets, obesity and cancer. Is that the right perception?

Dr Elisabeth Weiderpass: I think now we have a very clear picture that obesity is related to many cancer forms. And in fact, with more than we thought before, and the most important being colorectal cancer, breast cancer, but several other cancer forms as well. We are also now making advances in the understanding in the role of ultra processed foods and their impact on health, including cancer. I don't know if you are familiar with this concept of ultra processed foods, but basically these these are all the foods that have a very large proportion of components such as sugar saturated and trans fatty acids, glycation products which are pro-inflammatory. And how these foods put together can affect our health. So we have a whole series of research in this area now of ultra processed foods. And we do find, of course, a strong effect on obesity, on diabetes. And now we are increasingly finding an effect on cancer as well.

Cary Adams: Now, hopefully in time, the general public will be better informed on what the impact is of the food that they're buying at a local supermarket will have potentially on their long term health. IARC is world renowned for top research in cancer, but you also play a role at the European level as well. I understand that you've contributed to the European Regional Obesity Report 2022. Is there anything that's come out there which you think is important and could actually change the way that Europe approaches the issue of the links between nutrition and also obesity and cancer?

Dr Elisabeth Weiderpass: It highlights the concern over the obesity pandemic and the devastating effects it has on health, but in particularly in cancer incidence. So the report also set goals for obesity reduction as a major public health challenge in Europe and elsewhere. And it also it indicates that obesity actually starts early in life, and obesity in the life course throughout our lives is very important. It indicates how nutrition, diet, physical activity can be used to frame the pandemic and hopefully to reverse it. So I think what what's. Important with this report is that it very clear indicates that we are living in what we call an obesogenic environment. And this is this environment where food is available everywhere, but also unhealthy food habits are very prevalent in Europe. Or culture sometimes has a large influence in the way we nourish ourselves, in the way we eat, and that we related to food, and that we will need to work together as a society, including with industry actors, to combat the obesity pandemic.

Cary Adams: I think most people will see me at the moment. Elizabeth will say, I'm carrying a few COVID kilos, having sat around for two years. But I mean, it's not just an individual choice, is it? I mean, governments can play a role here. We're well rehearsed in the commercial determinants of health. What can governments do, do you think, to address the issue of obesity? Because I'm not conscious of many countries that would be able to reverse the trend.

Dr Elisabeth Weiderpass: We living in a world where obesity is pandemic, so it affects most people. Actually, there is a very large proportion of people in each country which are obese. In some regions of the world, it's over 80% of the population. Some countries in the Middle East in particular face this problem. It's a major societal challenge. It's not only an individual or a family challenge is a societal challenge. I think governments can play a major role. They can play a role in in first addressing this in at policy level, because although the individual has a role, how he or she behaves with him or herself on the family, but also to the people who need to have access to healthy food, which is priced in a way that they can afford, and also that they are accessible close to where they live so that they are able to buy it. We know that in some societies healthy food is just not available. There are many areas where you cannot find healthy food like fruits and vegetables, but you can find foods which are ultra processed, which are at low price, and that many, many parts of society have to rely on that. So obesity is complex. There are multiple determinants. Most of them are societal, in fact, and the governments, unless they take this seriously, they will be faced with a tsunami of multimorbidity, including cancer associated with obesity and type two diabetes, and it will be extremely expensive to the governments to tackle and very, very detrimental for overall life quality of citizens and individuals.

Cary Adams: Well, one of the ways that the government, of course, can respond to that challenge, Elizabeth, is to reduce the number of buy one, get one free and the multipack packages because they tend to be focused on the unhealthy foods, ironically. But we are seeing pressure in some governments to actually reverse those sort of controls that they were planning to put in because of the cost of living rises. It's difficult, isn't it, for a government because on one end they want to restrict the amount of poor quality foods to people. But if prices are rising rapidly as they are, for example, in the UK at the moment, then of course they can't really restrict access by increasing taxation or whether it is on those those food products. That's a dilemma for governments, isn't it? How do they resolve that?

Dr Elisabeth Weiderpass: Well, I think countries that have implemented taxation on foods of poor nutritional quality, it has been shown that it has a positive effect on the diet quality of populations without necessarily increasing costs. There are examples, for example, of taxation of sugary beverages in some countries and where this has been implemented, it has worked. So I think that it's it's a very good idea that governments do consider taxing foods with low nutritional content. That means foods in high sugar and with sweeteners, as well as high content of trans fatty acids, which have proved to be very detrimental to cardiovascular health and other health outcomes, that these foods should be highly taxed. And this taxation could revert to subsidize foods of high quality, such as fruits and vegetables, in particularly for population targets that have difficulties in assessing these high quality foods. I'm a strong believer that this taxation controls on foods of poor quality. Using the moneys to subsidize high quality food should be implemented across the world.

Cary Adams: What about the industry? What can governments do with industry to ensure that they take a more responsible approach to the way in which they preserve food? The way they package food and the way they promote food.

Dr Elisabeth Weiderpass: I believe the food industry has a major role to play in increasing the quality of nutrition worldwide. Together with governments, I believe it's very important that the colleagues from the food industry understand that it's in their interest actually to have healthier populations, populations that will be able to work more and to consume higher quality products. And for that, it's very important that the communication around the nutritional content of foods is transparent, is clear and is scientifically based. I believe that very easy to understand food labelling, where citizens can understand the quality of the products they are buying and what's their effect on health is of utmost important. In particularly we know that vulnerable groups of the population, children, toddlers and young adults are very vulnerable to obesity and once a child is obese, obesity is carried out throughout life. It's very difficult for an obese child to become a lean adult. So obesity must be avoided in particularly at young ages. And I believe that advertising of foods of poor quality to young children and children in general and young adults should be prohibited in most countries and at the very least be very strongly regulated. And I would like just to give you a very positive example, which is the government of Brazil. So the government of Brazil now has has prohibited the selling and advertising, of course, of sugary drinks at schools and in the Ministry of Health. So you cannot assess these sort of products that we know are obesogenic and they target young people and they cannot be assessed at at public settings such as the ones I mentioned. This sort of example could be replicated and will probably have an effect on on the health of populations.

Cary Adams: We talk about obesity in the broader sense around the world. But of course, the evidence suggests that it is becoming a larger issue in low middle income countries. It's occurring in a far more progressive way in countries which don't have the necessary infrastructure to deal with the cancer consequences of obesity. So is there anything we can do specifically in those areas?

Dr Elisabeth Weiderpass: So I think in low and middle income countries, the advertising of foods of poor quality is much more disseminating high income countries, including dissemination of advertising for young children and young adults. So I believe that this is one thing that should be in particular looked after, as well as availability of, for example, sugary drinks at schools, distribution of of sugary drinks at school for young children, which of course creates a market of potential consumers of these products throughout life. I have the honor and the pleasure to live in the Midwest in past years, and I believe the Middle East is a place mostly of high income countries. But they also have a major, major, major challenge with obesity. It's almost the reverse of the problem because people have access to very nutritious and high quality food. But there is a disincentive in a way to do physical activity. So physical activity is very rare. And I believe also their governments have a major role to play to in terms of population education, but also to to work with schools, with workplaces, to implement more programs, to help people to take good choices, and in particular to do more physical activity and make the ambience is actually feasible for people to be physically active, for example, by walking, biking and so on.

Cary Adams: Obesity starts early in life, and it's the same in smoking. The tobacco sector is very keen to get young smokers starting early so their addiction lasts a lifetime. And the return on investment of that marketing is enormous. There are stigmas attached to smokers who then develop cancer, lung cancer predominantly, of course. Do you feel that we run the risk that obese people, through potentially no fault of their own, are stigmatized and when they do get cancer or another NCD or diabetes, it is very much blamed on them rather than people being conscious that society itself has created an environment where it's in some ways quite difficult not to put on weight. How do you feel we can deal with that?

Dr Elisabeth Weiderpass: So a stigma surrounding obesity is really is hurtful and it's unfair because as we discuss, we know that obesity has many determinants. And some some of the determinants are, for example, genetic. And there are multiple other determinants that might be extremely difficult to to. Individual level information, education and speaking about the harmful effects of obesity. Of course it is important, but in a non judgmental way and always providing information to to empower people and societies to take choices which are pro health. I think these would be the attitude to to make. So always supporting and empowering individual.

Cary Adams: I think I agree with you there. Absolutely. We are delighted to know that you will be one of our plenary speakers at the World Cancer Congress in Geneva in October, and we've given you the daunting, daunting task to talk about the progress that we can see in innovation in cancer care in the future. It's a very broad topic, but what are the sort of things you you're optimistic about in the next ten years, which you think will you'll be talking about with the other panelists at the World Cancer Congress?

Dr Elisabeth Weiderpass: I'm so excited to be able to participate in the UIC World Cancer Congress. This will be a party. It will be a cancer research party. I would put my focus on what we call implementation research. That means to take the knowledge that we are developing as a research community and how to implement these on the ground for the benefit of populations and the individuals, of course. So I will also talk a little bit about the challenges of cancer in Europe. Europe has a very large burden of cancer, so we have only 10% of the population worldwide, but we have about 25% of the whole cancer burden.

Cary Adams: I look forward to seeing you in October in Geneva at the Congress. The beating cancer plan for Europe has inspired us to have another plenary based on the inspiration to say what else can we do at regional levels? So we'll be talking about that at least twice during the Congress. Elizabeth, as ever, it's great talking to you. Thank you very much to you, Isaac and all the team there for the great work that you do. You are a fantastic partner, companion to UHC and audience members, and I look forward to seeing you next time around.

Dr Elisabeth Weiderpass: Thank you very much.

Cary Adams: Thank you for listening to this episode of Let's Talk Cancer. If you like this podcast, please subscribe for more content from tobacco control to cancer prevention, treatment and care.