East coast’s mad summer of cool one day, boiling the next, may be changing our gene expression, raising risk of disease
A landmark study by Monash researchers has linked significant variations in temperature over a short period, such as Melbourne is experiencing this Summer, with genetic changes that might increase the risk of diseases like cancer and schizophrenia.
The study of Australian siblings, led by Professor Yuming Guo, a climate health expert at the Monash School of Public Health and Preventive Medicine, and published in Environment International, reveals that temperature fluctuations within one day or over several days (up to seven days), can lead to epigenetic changes mapped to 64 genes associated with human diseases like cancer and mental health disorders.
The study is the first to assess epigenetic changes caused by short-term temperature fluctuations, which are becoming globally more common because of climate change. “While it has been known that sharp changes in temperature, regardless of whether the temperatures are extreme, can impact health, this study is the first to drill down to the actual genetic impact of these changes,” Professor Guo said.
The research, performed by PhD student Ms Yao Wu, looked at blood samples from 479 female siblings of 130 families enrolled in the Australian Mammographic Density Twins and Sisters Study (AMDTSS*) nationally. Daily temperatures data were obtained, linked to each participant’s home address – on the day the blood sample was taken and on the preceding one to seven days.
The study found that short-term temperature fluctuations can induce significant epigenetic changes- and that these changes were mapped to 64 genes linked to human diseases such as cancer (e.g. colorectal carcinoma, breast carcinoma, and metastatic neoplasms) and mental health disorder (e.g. schizophrenia, mental depression, and bipolar disorder).
According to Professor Guo, the results are important because “climate change is already exacerbating unstable weather conditions across the globe,” he said.
Studies have shown that significant changes in temperature over a single day or on neighbouring days, can increase mortality/morbidity risk, particularly for cardiovascular and respiratory diseases. “Numerous studies have reported a persistent association between TV (up to seven days) and mortality/morbidity risk and identified children, the elderly, people with respiratory disease as vulnerable populations,” Professor Guo added.
“Other studies have linked environmental temperature to epigenetic changes, but these have largely looked at the long-term impact on epigenetic markers by climate change-induced temperature changes, over weeks or years.”
According to the authors – the increased variation in daily temperatures, and its proven relationship to increased illness and death, may be explained by alterations in disease causing epigenetic markers, increasing the risk of illnesses such as cancer and schizophrenia.
*AMTDSS: female twins and their sisters were recruited through the Australian Twin Registry between 2004 and 2009. The inclusion criteria were as follows: (1) aged between 40 and 70; (2) not pregnant or breastfeeding; (3) without breast cancer. This study included 479 women from 130 families with DNA methylation measurements, comprising 66 monozygotic (MZ) twin pairs, 66 dizygotic (DZ) twin pairs, and 215 sisters of these twins.
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