Two recent studies, published in prestigious scientific journals, have demonstrated the increasingly close link between overweight (and obesity) and cancer. We talked about it with Professor Alberto Mantovani, scientific director of Humanitas.
The studies published in the Cancer Journal for Clinicians and in Nature
According to one of the latest reports published by the journal ‘CA: A Cancer Journal for Clinicians’, the epidemiologists of Imperial College London and the prestigious Harvard T.H. Chan School of Public Health in Boston, overweight is responsible for almost 4% of the cancers diagnosed each year in the world.
The study group analyzed a vast amount of data, both globally and by geographical region, on overweight and cancer. In 2016 – the report says – about 40% of adults and 18% of children between 5 and 19 years of age had an excess weight, equal to almost 2 billion adults and 340 million children globally. In addition, an estimated 4 million deaths in one year are attributable to overweight.
In particular, the study linked obesity and overweight to 13 different types of cancer: breast cancer (after menopause), cancer of the rectum, cancer of the uterus, cancer of the esophagus (adenocarcinoma), cancer of the gallbladder, cancer of the kidneys, liver, ovaries, pancreas, stomach and thyroid gland, as well as meningioma and multiple myeloma.
Recently also the journal Nature published a research in which the possible genetic relationships between obesity, cancer and metabolic syndrome were examined. The study revealed that there are 38 genes that can be perfectly superimposed between subjects suffering from breast cancer, for example, diabetics and obese, so those who suffer from obesity would have a greater chance of genetic type to develop this type of tumors.
They are studies “that shed new light on how obesity, and more generally overweight, disorient our immune system,” explained Professor Alberto Mantovani, scientific director of Humanitas.
To confirm that “obesity is a primary cause of cancer” – added the professor – also the data of the IARC in Lyon, the International Agency for Cancer Research of the World Health Organization.
Obesity and overweight disorient the immune system
Overweight, in addition to increasing the risk of typical cardiovascular diseases, also affects other aspects of our body that is very complex: for example “disorientates our body because some of the ‘policemen’ in our defense, called macrophages, become ‘corrupt’ and help the enemy, then cancer, and paralyze the cells NK – Natural Killer, which are the first line of defense against infections and cancers”, clarified Professor Mantovani.
“The adipose tissue is composed not only of fat cells, which act as ‘energy stores’ and ‘reservoirs’ of our organism, but also of cells of the immune system that are very important because they make that we burn at the right time our fuel and our energy”, said the Professor. “When you are overweight, or even obese, these cells are disoriented and send the wrong messages to our body. “Macrophages produce inflammatory signals that help the development of cancer in many ways, for example by promoting metastases.
For this reason it is essential to have a correct lifestyle, which Prof. Mantovani suggests with the formula “zero – five – thirty: zero smoking, five servings of fresh fruits and vegetables at least on the day, thirty minutes of physical exercise”.
Some data in Lombardy and Milan
In Europe about 17% of adults are in a state of obesity, in Italy the percentage drops to 10% (like Lombardy), while in Milan the inhabitants considered obese are 6.6%. According to Professor Mantovani, the situation of ‘future adults’, that is, children, is different and “worrying”: in our country one child in ten is obese (10.6%) compared to 5% of the European average; in particular, in Lombardy children between 3 and 17 years considered obese are 6%.
This is a “very serious figure, because it means that in a few years time the current virtuous aspect of our country will be reversed compared to the rest of the Western world”, clarified the scientific director of Humanitas. “If on the one hand we can be happy and proud like Lombards and Milanese, we cannot underestimate the direction in which the country is going”, because the weight of ‘extra pounds’ on cancer cases is undoubtedly destined to increase in the coming decades.