Cancer Trends In People Under 50

According to the the journal, Cancer Discovery, there has been an increase in early onset cancers - cancer before the age of 50 - and the proposed cause is the higher percentage of people who are obese. To be specific, the occurrence of 14 of the total 33 cancer types increased in a younger age group (under than 50).

It is a known fact that obesity is linked to cancer, however, how exactly is it a cause? Currently, obesity is linked to breast, colorectal, esophageal, kidney, gallbladder, uterine, pancreatic, and liver cancer. Obesity is known to also increase the risk of dying from cancer and cancer recurrence.

Pati et. al (Obesity and Cancer: A Current Overview of Epidemiology, Pathogenesis, Outcomes, and Management) explore the biological relationship between obesity and cancer.

Adipocyte tissue, commonly known as body fat, might be contributing to carcinogenesis - the initiation of cancer formation - and formation of metastases (the spread of cancer in the body). Altered fatty acid secretion and metabolism (all things that happen in obese people), and changes in the gut microbiome is also linked to carcinogenesis.

Biological Relationship between Obesity and Cancer, Figure 1. (Pati et. al), Obesity and Cancer: A Current Overview of Epidemiology, Pathogenesis, Outcomes, and Management

Increasing fatty acids in the body disrupts normal metabolism and this occurs when the body has excess glucose or carbohydrates. Disrupted metabolism can also possibly act as a sign that cancer cells had reprogrammed metabolism in order to aid their rapid growth.

Additionally, changes in the gut microbiome is a telling sign of obesity. Gut microbiomes can be changed by a variety of factors: diet, medicines, environment, and genetics. In obesity, gut microbiomes change due to diets high in processed foods, sugar, and unhealthy fats. Eating these unhealthy foods reduces the diversity of the gut microbiome since processed foods lack fiber, which is a food source for helpful gut bacteria. On the other hand, harmful gut microbes survive off sugar and fat. A lack of microbiome diversity can lead to inflammation, which then can promote tumor growth.

However, there are three, more broad, primary biological mechanisms that pose a risk and the previously mentioned unfavorable changes in the body fall in one of these categories.

The first mechanism is when adipose tissue (fat) releases chemicals and enzymes. This mechanism causes more creation of estradiol. Estradiol is a form of estrogen, which is a female sex hormone. This contributes to the risk of breast and ovarian cancers. While excess estrogen, or estradiol, does not directly cause cancer, too much of the hormone influences growth and acts as fuel for certain cancer cells. This is similar in males as well: excess testosterone has been linked, though not directly, to prostate cancer.

The second mechanism is hyperinsulinemia due to increased BMI. Hyperinsulinemia (yes, a mouthful) is a condition of chronically (long-term) elevated insulin levels in the blood (remember the altered fatty acid secretion?). Elevated insulin levels lead to insulin resistance because prolonged exposure to lots of insulin desensitizes cells to its signals. Therefore, the body is unable to break down glucose and it piles up in the body.

This is directly linked to colon, renal, and endometrial cancer. Cancer cells rely on aerobic glycolysis (where the cell takes in glucose when they are not supposed to) and use that to consume large amounts of glucose. Although the pile up of glucose does not cause cancer, it feeds cancer cells that are already existing, which then furthers the severity of the cancer since the cells are able to take in a large amount of energy.

The third mechanism is a proinflammatory environment caused by increased levels of body fat. Excess fat cells leads to adipocyte hypertrophy and cell death. Adipocyte hypertrophy is a condition in which fat cells are enlarged because of impaired metabolism and insulin resistance. This then leads to inflammation in the body.

All these factors cause oxidative stress (which we went more in depth here), which damages DNA and thus leads to an increase in risk of having cell mutations.

In conclusion, the buildup of fat cells is positively linked to the risk of developing cancer. Although it seems as though there are so many things that may go wrong in the body in order to cause cancer, this pattern is mostly seen in obese people, or, those characterized by a BMI over 30.

Additionally, there are many ways to prevent cancer. Healthy diet and regular exercise (that does not have to be extreme) can reduce the risk of cancer by 50%, which are very good odds. Exercise manages hormones, thus decreasing the risk of breast, ovarian, and prostate cancer, and gives the immune system a boost and helps it better detect cancer. Healthy diet decreases inflammation and gut health, which lowers the amount of toxic substances in the gut and lowers risk of colorectal cancer.