Climate can explain intestinal trouble
Chronic inflammation of the colon is more common in colder regions. Climate, particularly temperature, can have an influence on the reasons behind the disease, scientists believe.
Norwegian researchers have discovered a relationship between temperature and the severe bowel disease ulcerative colitis. Nearly 1,000 Norwegians are given this diagnosis each year. The illness is characterized by inflammation of the colon mucosa and causes bleeding and diarrhoea.
The muscles of the intestine also become irritated, which can cause painful contractions.
Researchers have observed that more people are affected in regions in the far north or the far south.
In recent decades, moreover, the number of patients has increased, according to a study published in the journal BMC Public Health.
Climate as an explanation?
The Norwegian researchers behind the study suspect that temperature may be a cause. They believe that a colder climate reduces the diversity of the microorganisms in the gut.
This may cause greater vulnerability when it comes to chronic bowel disease, according to a statement from The Norwegian Institute of Public Health.
The Norwegian researchers found that the risk drops by nine percent when the temperature rises by one degree Celsius.
Previous studies have shown that people in warmer regions have a higher diversity of bacteria in the gut. This is believed to strengthen the immune system.
“Temperature can be important”
Geir Aamodt, Senior Scientist at the Public Health Institute, says the study is important in two ways.
“Firstly, it shows that a factor we cannot control, the temperature, may be an important cause of ulcerative colitis. Secondly, this fact may contribute to our understanding of the mechanism behind the development of the disease.”
This reasoning is closely related to another hypothesis that has often been used to explain the increased incidence of ulcerative colitis in recent years, that the immune system is weakened because we are no longer exposed to the same number and diversity of microorganisms as before.
Read the Norwegian version of this story at forskning.no
Translated by: Lars Nygaard
- Aamodt Geir, Bengtson May-Bente, Vatn Morten Harald. Can temperature explain the latitudinal gradient of ulcerative colitis? A cohort of Norway study. BMC Public Health. 2013; 13:530.