We have understood a lot about the link between lifestyles and cancer, but much still remains to be understood. Above all, we need fresh data on new habits: food and lifestyle in general. Which is precisely the objective of an ambitious Italian study in which everyone (aged 18 and over) can participate. Is called YouGoody and some may already know him, given that he officially left last February.
To date there are 15,000 members but the aim is for a much higher number: 100 thousand, from all over Italy, men and women (who for the moment are the vast majority: 8 out of 10, between 45 and 65 years old, and almost all from the North). The National Cancer Institute of Milan conceived and launched the study thanks to the support of Esselunga.
“Where do tumors come from?”
But before explaining how to participate, let’s see why, and we do it starting from afar. In the early 1900s absolutely nothing was known about “where” cancer came from. Experiments in the 1930s then showed the possibility of inducing tumors in laboratory animals, for example through contact with tar.
Between the 40s and 50s there was an explosion of studies on chemical carcinogenesis, linked to great industrial development. Thus we arrived at the 70s and 80s with the widespread idea that cancer was caused by chemical carcinogens, such as polycyclic aromatic hydrocarbons, or physical ones, such as asbestos. However, these contribute to causing only some tumors, not all.
“When I started working at the National Cancer Institute, in 1978 with Veronesi, as a research assistant in the Epidemiology Unit, the problem we asked ourselves was: where do breast tumors come from? And colon tumors and of the prostate? In 20 years of research on chemical, physical and biological carcinogens, in fact, absolutely nothing had come up. We then began to think that we were probably looking for something that wasn’t there”, he says Elio RiboliProfessor of Epidemiology and Cancer Prevention at the School of Public Health, Imperial College London and European Coordinator and Principal Investigator of EPIC (European Prospective Investigation into Cancer and Nutrition)one of the largest international studies on lifestyle and cancer, born at the National Cancer Institute of Milan in the early 1990s and from which practically all the knowledge we have on the subject today derives.
“However, there was other evidence: studies that since the early 1900s had begun to investigate, in animal models, the effect of physical activity and nutrition on mice, and which then found confirmation in the 1940s”, continues Riboli. To put it simply, it was observed that if mice were given a wheel to run on, they developed fewer tumors than those without a wheel, given the same food. And again: mice that were given too much food got sicker. There must, therefore, be another mechanism for the development of cancer, which the researchers called metabolic carcinogenesis.
The EPIC study
“Today, also thanks to the EPIC study, we know that tumors are also controlled by metabolic factors”, continues the expert: “In the 90s we started this large collection of very precise data on the way of life, on nutrition, on physical activity, anthropometrics (such as body mass index, ed). The goal was to involve 350 thousand people, and we reached 500 thousand. We were the first to publish data on the correlation between consumption of red and processed meat and the risk of colon cancer; the first to have definitive evidence on the protective effect of cereal and vegetable fibers on that same tumor and on others; the first to link lifestyle and obesity to insulin resistance and, from this, to tumors. Today we have the data to explain why a sedentary lifestyle and excess visceral adipose tissue increase the risk of colon and breast cancer after menopause. From the hypothesis, we moved on to knowing the mechanisms: it is not a philosophical idea that certain diets and certain ways of living are bad for you. It’s physiology.”
Changing lifestyle produces positive effects at any age
In short, this information, together with many others, has consolidated from a scientific point of view the value of a diet rich in fruit, vegetables, whole grains and relatively low in red meat, sausages and foods rich in animal fats, and has highlighted which negative mechanisms are triggered in the body in case of excessive consumption of alcohol and sweet drinks, both sugar-based and artificial sweeteners. And the beauty of all this data is that it tells us that changing lifestyle produces positive effects at any age.
Obviously this does not mean that metabolic factors are the only ones that have an impact: there are also genetic factors (one of which is the mutations of the BRCA genes), as is well known thanks to DNA studies from the 1990s onwards. Beyond the hereditary-family risk, however, there is no doubt that all these issues also raise an ethical issue: that of social responsibility and the impact that society has on individual lifestyles.
by Tina Simoniello
Living in a place where the grocery shopping proposition is healthy, for example, can make a difference. As well as culture. This is a delicate aspect of communication, to avoid blaming individuals, while at the same time providing the knowledge to make more informed choices.
Why YouGoody is needed
And now we come to the reason for a new study: in these thirty years, food tastes have changed, as have alcohol consumption habits, and there is a different structure of society, with many more people living alone, which which may have led to a different concept of meals. “The information on diet is stuck in the 90s – he summarizes Sabina SieriDirector of the INT Epidemiology and Prevention Complex Structure and responsible for the YouGoody project – With this new study we will update them and be able to follow their progress over the years, with the aim of understanding if there is a relationship between these changes and the risk of illness, even in a positive way”.
Any examples of what we will try to understand? Here it is: “In EPIC we observed, for example, contradictory data in those who follow a vegetarian or vegan diet – continues Sieri – While the reduction in cardiovascular risk is very evident, it does not seem to reduce the risk of colon cancer. This data has given us surprised, because we would have expected it to have a protective role. A possible explanation is that when one follows a restrictive diet by eliminating food groups, they are probably consumed more than others, which are not always healthy. For example, in vegans, a increase in sugar consumption. It’s a hypothesis, but to answer this question we need more data.”
Just think of how different it can be to live in a society with a centuries-old vegetarian culture or suddenly decide to stop eating meat and replace it with plant-based but ultra-processed foods.
Another open question concerns breast cancer in young, pre-menopausal women. What we have seen, in this case, is a paradox: those who are slightly overweight between the ages of 18 and 45 seem to have a 10% lower risk than those who are very slim, bordering on underweight. After menopause, however, exactly the opposite happens. But if the reason why overweight and obesity after menopause increase the risk is very clear (linked to the production of estrogen from adipose tissue and insulin resistance), the reason for what happens before is a puzzle.
How to participate
Participating in YouGoody therefore means being part of a Citizen Science project, i.e. participatory science, also carried out with the help of citizens. And now let’s see what it consists of. To join, simply log in to www.yougoody.it. Volunteers (all adults) who give their consent will be able to access, via an individual account, the platform developed by the National Cancer Institute of Milan.
Participants in the study are invited to fill out various questionnaires: a generic one on socio-demographic information, 7 questionnaires on diet, 4 questionnaires on lifestyle (physical activity, consumption of alcoholic beverages, smoking habits and, for women only, information on reproductive life) and one relating to health status.
Eating habits and risk factors will be measured every two years through further questionnaires, in order to observe and evaluate how any changes in behavior modify the state of health. The personal data of the participants will be processed only by researchers of the National Cancer Institute of Milan.