How much red meat can increase the risk of colorectal cancer?

The article was written by doctors of Internal Oncology Department, Vinmec Times City International General Hospital.

Consuming even moderate amounts of red and/or processed meat is associated with an increased risk of developing colorectal cancer, according to a new finding.

The study authors found that consuming an average of 76 grams of red or processed meat per day, was associated with a 20% higher risk of colorectal cancer compared with consuming only about 21 grams per day. Drinking alcohol also increases the risk of colorectal cancer, but eating foods rich in fiber from breads and cereals lowers the risk.
According to a study by the University of Oxford, UK published online April 17 in the International Journal of Epidemiology, researchers found that people who ate red and processed meat four or more times per week had a higher risk of bowel cancer than those who ate red and processed meat less than twice a week. The World Health Organization [WHO] classifies processed meat as carcinogenic and red meat as carcinogenic – but most previous studies have looked at people of the 1990s or earlier and processed Dietary intakes have changed dramatically since then, so this study provides a more up-to-date insight that is relevant to meat consumption today.
The American Institute for Cancer Research and the World Cancer Research Fund have published several reports over the past 10 years on the effects of diet, nutrition, and physical activity on the risk of cancer. number of cancers. The most recent study published in 2017, found that consuming red and processed meat can increase the risk of colorectal cancer, similar to drinking more than two alcoholic drinks per day. On the other hand, daily intake of whole grains and increased physical activity may reduce the risk.
In 2015, WHO's International Agency for Research on Cancer (IARC) classified processed meat as a human carcinogen (group 1) on the basis of sufficient evidence for colorectal cancer. In addition, the team said, there was a positive association with stomach cancer.
IARC has also classified red meat as carcinogenic to humans (group 2A). This decision is based on relevant data showing strong mechanistic evidence for a carcinogenic effect. This association was observed mainly for colorectal cancer but also for pancreatic cancer and prostate cancer.
The authors of the current study point out that most of the previous studies that showed an increased risk of colorectal cancer in people who consumed a lot of red and processed meat were done in the 1990s or before there, and the pattern of meat consumption has changed.
In a recent study of 475,581 people aged 40 to 69 between 2006 and 2010, by filling out a food frequency questionnaire they ate. Then the serving size was measured again on 175,302 people.
At a mean follow-up of 5.7 years, 2609 cases of colorectal cancer occurred.

According to the multivariable analysis, the risk ratio (HR) for colorectal cancer was 1.20 among those who consumed an average of 76 g/day of red or processed meat compared with those who consumed the average 21 g/day (for people eating over 50 -g/day this ratio is 1.17).
For red meat, the HR was 1.15 for those consuming an average of 54 g/day compared with those who reported consuming an average of 8 g/day (and >50 g/day the HR was 1.18).
For processed meat, HR was 1.19 for those consuming 29 g/day compared with those consuming an average of 5 g/day (and > 25 g/day, HR was 1.19).
Regarding alcoholic beverage consumption, beer was associated with an increased risk of colorectal cancer (HR for every 10 g/day increase in alcohol from beer 1.11). For each 10 g/day increase in alcohol from alcohol, HR is 1.05; for each 10 g/day increase in alcohol from spirits, the HR was 1.08.

The researchers assessed the effects of other foods and alcohol. They found that fiber intake from breads and breakfast cereals was associated with a reduced risk of colorectal cancer, but this finding was not clear for the amount of fiber in vegetables and fruits.
Commenting on the study, Gunter Kuhnle, PhD, associate professor of nutrition and health at the University of Reading, UK, told Medscape Medical News that he feels the study largely confirms previous results. showed an association between eating red or processed meat and colorectal cancer. "This has been shown in a number of observational studies," he said. ''By confirming these results, the study clearly strengthens the evidence, especially when it was carried out on people from very different eras from previous studies. "In my opinion, the more interesting aspect of the study is the fiber results," added Kuhnle. ''Again, they are not new but confirm and reinforce the evidence we have that suggests that fiber intake can reduce the risk of colorectal cancer posed by red/processed meat' '.

Source: Medscape April 2019