Early-stage cancer is on the rise worldwide, and experts blame modern Western diets, the rise in obesity and poor sleep patterns among adolescents for the rise.
Researchers at Brigham and Women’s Hospital in Boston, Massachusetts, collected data on 14 types of cancer from 44 countries around the world and found that early-onset cases are increasing almost everywhere.
The research team speculates that several factors play a role. Increased alcohol consumption, overuse of antibiotics, increasing average height, sedentary lifestyles and higher rates of obesity, devastating smoking rates in the late 20th century, and poor sleeping habits have all plagued the age cohort hardest hit by this increase, and are all associated with increases in cancer risk.
They say these factors are related to the “Western” diet, in which a person consumes more processed, high-fat foods and sugary drinks. Many in the West also live a sedentary lifestyle. In America in particular, the Centers for Disease Control and Prevention revealed last week that only 25 percent of the population was achieving weekly fitness scores.
Researchers found that early-stage cancer rates are increasing worldwide and have linked the increase to many different factors, affecting different parts of the world in different ways (file photo).
“According to our data, we observed something called the birth cohort effect. This effect shows that each successive group of people born later (eg, ten years later) have a higher risk of developing cancer later in life, likely due to risk factors they encountered when young been exposed to for years,” Dr. Shuji Ogina, a professor at Brigham who participated in the research, said.
“We have found that this risk increases with each generation. For example, people born in 1960 had a higher risk of cancer before the age of 50 than people born in 1950, and we expect this level of risk to continue to rise in subsequent generations.’
Researchers, who published their findings in Nature this week, have collected data from 44 countries since 2000.
They then found individual studies from each of the included nations that would estimate risk factors for different types of cancer. These include, for example, studies showing trends in obesity in the United States and other countries.
Cases of early-onset kidney cancer rose the most in the United States in both men and women. Rates of early-onset myeloma decreased in men and early-onset esophageal cancer decreased in women. Almost every other cancer has seen increases in both sexes.
Further research on trends in each of the included countries found that 10 risk factors for cancer have become more common for this generation than for their previous cohort.
Obesity is one of the biggest factors, with the condition being considered a risk factor for many different types of cancer.
“Of the 14 types of cancer we looked at, eight were linked to the digestive system. The food we eat feeds the microorganisms in our gut,” said Dr. Tomotaka Ugai, lead author of the study, who works in the Department of Pathology at Brigham.
“Diet directly affects the composition of the microbiome, and ultimately these changes can affect disease risk and outcome.”
The “Western diet” has been a major contributor to obesity and diabetes rates around the world, which are two major risk factors for many cancers
The researchers found that global obesity rates have skyrocketed in recent decades, rising from 3.2 percent to 10.8 percent in men and 6.4 percent to 14.9 percent in women from 1975 to 2014.
Obesity is a major problem, particularly in America, where the CDC reports that more than 40 percent of adults have the condition.
Other factors also played a role in the jump. While alcohol consumption actually fell across Western Europe, the researchers found that drinking rates increased in Eastern Europe, Asia and the Middle East.
Drinking has been linked to liver, colon, breast cancer and more.
The overuse of antibiotics that swept the world in the late 1990s and early 2000s also likely plays a role.
Some experts fear the powerful drugs have damaged many users’ gut microbiomes, leaving them vulnerable to gastrointestinal cancers.
While smoking rates have declined in the West, tobacco industries are beginning to boom in many Asian countries, making lung and oral cancer more common among younger people.
People are bigger now too. While this could be viewed as a relatively positive thing, taller people are thought to have an increased risk of developing cancer.
Children are also sleeping less now than in previous years. There are several reasons for this. First, the increased use of devices such as cell phones and computers has disrupted nightly routines in many households. The blue light emitted by these devices is also likely to cause problems.
One of the most notable risk factors mentioned by the researchers was the impact of the Western diet.
The diet is high in saturated fats, processed and red meats, and sugary items, while being low in fruits, vegetables, and whole grains.
Poor dietary habits contribute to many risk factors for cancer, such as obesity and diabetes. Many of the ingredients in processed foods and sugary drinks — most notably high fructose corn syrup — have been linked to the development of cancer.