Is meat the new cancer?
With a population estimated at around one billion people, global meat consumption has become a major concern, especially in China, where consumption has surged since the introduction of a nationwide ban on the animal by 2020.
With the Chinese government now declaring it is a cancerous substance, it is becoming increasingly difficult to determine whether meat consumption is a risk factor for cancer, or just a bad habit.
Vegetarian sausage is one of the most popular dishes in China’s capital, Beijing, where meat consumption rose from one billion in 2010 to two billion in 2014.
(The figure was only slightly higher in Shanghai in 2016, where one billion Chinese eat meat.)
“The Chinese people have become more sensitive to the health concerns associated with meat consumption, particularly cancer,” says Peter Rabin, professor of public health and nutrition at the University of California, Los Angeles, who researches health disparities in China.
In addition, the rise of global meat production has resulted in a rising demand for meat from developing countries in the Middle East and Africa.
While the Chinese consumption of meat has been stable or declining since 2010, the number of meat-eaters in these countries has risen dramatically.
“The world is changing in a fast-moving, complex way,” says Michael Eisenstadt, a professor of epidemiology at the Icahn School of Medicine at Mount Sinai, who studies how food and health impact populations.
The rapid growth of China’s meat consumption raises an interesting question: Is meat a major driver of cancer risk?
“The evidence that has emerged from animal studies is not consistent with that,” says Andrew Kim, an epidemiologist at Harvard Medical School and a co-author of a paper in the Journal of the American Medical Association (JAMA) that looked at the evidence.
The growing popularity of vegetarian and vegan cooking techniques has made it easier to cook meat, which is more likely to be eaten in large quantities, says Rabin.
“We need to be careful to distinguish between the consumption of non-animal foods, like vegetables, and meat.”
The evidence suggests that the growth of meat consumption and the increased meat consumption in the developing world is contributing to cancer in many ways, he says.
In addition, there are health problems associated with the rapid growth in meat consumption.
“It’s becoming increasingly clear that the cancer risks from this growth are not simply a consequence of a lack of awareness,” says Kim.
In recent years, studies have suggested that meat consumption may have a negative impact on lung cancer, pancreatic cancer, ovarian cancer, and prostate cancer.
While there is no clear consensus on the role of meat in these cancers, the evidence does not support that it has a negative effect, Kim says.
“If we are going to be able to do a better job of reducing cancer, we need to get a better handle on what is causing it,” he says, adding that he is encouraged by a recent study that showed a link between diet and lung cancer in people with asthma.
Researchers from the Harvard School of Public Health and Harvard Medical Center collaborated with the Chinese Academy of Sciences on the study, which was published in the journal Epidemiology, the journal of the Royal Society of Medicine.
It found that the risk of lung cancer among people who consumed a lot of meat was increased by a third when they also had higher levels of lung inflammation, which indicates inflammation that may be linked to lung cancer.
While some studies have found an association between meat consumption at restaurants and lung cancers, other studies have not.
And other studies do not show a link with cancer in meat-eating people who are already predisposed to cancer.
“It is very important to understand that the association between increased meat intake and cancer is only one of many factors that influence risk,” Kim says, noting that many factors are at play.
“A lot of the epidemiology work has focused on diet and health in general, but it has not been very clear how the risk factors can relate to the consumption patterns.”