Living in a cold climate could make people more likely to get cancer, a study has found.
Inuits have the highest rate of cancer, followed closely by Scandinavian people, while chilly Britain has a cancer rate three times higher than that of India and twice the rate of Thailand.
Evidence now suggests people are at greater risk in colder countries because of their genes.
The same genes, which stop our cells dying in freezing temperatures, are also linked to breast and bowel cancer and leukaemia.
A researcher says the genes contributing to cooler climates are the same, which increase the risk of malignant tumours forming in the body.
The study published in the journal Molecular Biology and Evolution, also found a link between people living at altitude and cancer rates.
Author of the study from the University of Cyprus’ Medical School, Dr. Konstantinos Voskarides, said: “The findings of this study provide evidence that genetic variants found to be beneficial in extreme environments, can also predispose for cancer.
“Cell resistance at low temperatures and at high altitude probably increases the probability for malignancy.”
Also, research led by the University of Saskatchewan in Canada has discovered that the diabetes drug metformin might reduce the development of multidrug resistance in vitro in breast cancer cells and may reverse resistance once it has occurred.
Dr. Terra Arnason, an associate professor and clinician scientist in the Department and College of Medicine — and colleagues led the study. Their findings were published in the journal PLOS ONE.
Multidrug resistance (MDR) occurs when several cancers develop resistance to chemotherapy drugs. MDR is a significant factor in the failure of many types of chemotherapy, and it is often a terminal event. It affects individuals with blood cancers and solid tumors, including those with breast cancer.
Also, another new study published in the journal Nature has uncovered the mechanism and the molecular pathway through which the popular alcohol-aversion drug disulfiram can fight off cancer.
This study was conducted by an international team of researchers led by Jiri Bartek, of the Danish Cancer Society Research Center in Copenhagen.
Disulfiram — also known by the brand name Antabuse — has been used for decades to treat chronic alcohol abuse. While the drug is not a cure for chronic alcoholism, it does discourage those with alcohol abuse issues from drinking.
Meanwhile, previous research from 2010 found grim weather in northern parts of the world may make men more vulnerable to prostate cancer, perhaps due to a lack of vitamin D from the sun.
However the new study – which compared international rates of cancer with 240 genetic studies of cancer and seven others in cold and high-altitude countries – suggests where people live affects their genes.
Extreme cold can cause our cells to die, so that people in freezing countries have genetic mutations to prevent cell death and repair Deoxy ribonucleic Acid (DNA)/genetic material.
These same processes are closely related to leukaemia and breast and bowel cancer, the study states.
Analysis of global cancer rates found 186 human populations had cancer rates mirroring their average temperatures.
The strongest links included more cases of bowel, lung and oesophageal cancer In Siberian Eskimos and a higher incidence of leukemia in the Oromi – a high-altitude population living in Ethiopia.
Voskarides said: “Evidence was found that cancer rates have been increased in those populations through natural selection procedures. This is the first study that provides evidence that high cancer risk may be a result of evolutionary adaptation in certain environmental conditions.”
Dr. Sophie St-Hilaire, who carried out the study on the link between cold weather and prostate cancer, said it was difficult to be sure how genes worked in cancer patients. But she added: “It is well known that exposure to certain pollutants is higher when the air temperature is colder than when it is warmer.”
This suggests pollution in colder countries may increase cancer rates, with diesel fumes known to be linked to lung cancer.
Source: The Guardian Newspaper