Research news in brief

Vitamin D deficiency linked to childhood asthma

Researchers from the Telethon Kids Institute have found that children with vitamin D deficiency are more likely to develop asthma, according to a study published in the Journal of Allergy and Clinical Immunology. The authors tracked vitamin D levels from birth to age 10 years in a group of Perth children at high risk for asthma and allergy. The findings showed that allergic immune responses were more common in children with low current vitamin D in the first few years; repeated periods of vitamin D deficiency in the first decade were linked to higher rates of current asthma, allergy or eczema at age 10 years; and children with vitamin D deficiency at 6 months of age were more likely to experience two conditions previously associated with heightened asthma risk: increased colonisation of the upper airways by harmful bacteria and increased susceptibility to severe lower respiratory infections involving fever. Lead author Dr Elysia Hollams said that the findings shed new light on a controversial area of research. “We know vitamin D plays an important role in regulating the immune system and promoting healthy lung development,” said Dr Hollams. “But while it has been suggested that inadequate vitamin D may be a factor contributing to the surge in asthma rates over recent decades, previous studies investigating the relationship have yielded conflicting results. There has been a lack of research looking at whether vitamin D deficiency is more detrimental at certain periods in childhood. Our study is the first to track vitamin D levels from birth to asthma onset, and it has shown a clear link between prolonged vitamin D deficiency in early childhood and the development of asthma. Earlier research by our team and others around the world has identified the first 2 years of childhood as a critical period during which allergies and chest infections can combine to drive asthma development in susceptible children. Our new findings identify vitamin D deficiency as a co-factor that may promote this process.” However, the authors also point out: “We still don’t know what the optimal level of vitamin D is for good lung health and immune function, and we don’t know if supplementation would address this issue, or if healthy sun exposure is what is required, given that vitamin D is an indirect measure of recent sun exposure”.

Cancer cell structure decoded

Researchers from Swinburne University of Technology were part of an international team which has developed a model of how an important cancer-related molecule – the epidermal growth factor receptor (EGFR) – appears on the cell surface and how it functions. EGFR or HER1/ErbB1 is a cell-surface receptor tyrosine kinase that plays a fundamental role in the regulation of the cellular metabolism, growth and differentiation. It is linked to the growth of almost one-third of cancers including lung, breast and brain cancer. Associate Professor Andrew Clayton, from Swinburne’s Centre for Micro-Photonics, said: “For the very first time, we have a glimpse of how the molecule looks on the cell surface and how it works. By knowing how it works in greater detail we can design improved drugs”. The study was published in Nature Communications.

Sugary drink tax projected to save Mexican lives

Mexico’s 10% tax on sugar-sweetened beverages (SSBs), introduced in 2014, has been projected to prevent 189 300 new cases of type 2 diabetes, 20 400 incidents of strokes and heart attacks, and 18 900 deaths over 10 years among adults aged 35–94 years, and is expected to save $983 million in health care costs, according to a modelling study published in PLOS Medicine. Researchers from the University of California, San Francisco, developed a Mexico version of an established model of cardiovascular disease in the US (the Cardiovascular Disease Policy Model) and used survey data on household consumption in Mexico since the tax implementation to project health and health care cost impact in the next 10 years. The authors stated that “[t]he SSB tax may be an important component in a multifaceted strategy by the Mexican government to curb the obesity and diabetes epidemic in Mexico.”

Male sleep habits may increase cancer risk

Men who have worked night shifts for more than 20 years, or who work night shifts without daytime napping, or sleep for more than 10 hours per night on average may have an increased risk of cancer, according to a study published in Annals of Medicine. The Chinese study reviewed data obtained via interviews with middle-aged and older men in the Dongfeng-Tongji Cohort Study, a cohort of approximately 27 000 retired workers, of whom 11 373 were male, from the Dongfeng Motor Corporation. The researchers investigated the independent and combined effects of three sleep habits on cancer incidence – night shift work, daytime napping and night time sleep. A questionnaire asked individuals if they had worked night shifts for over 20 years, had a habit of taking daytime naps, and when they usually went to sleep at night and woke up in the morning. They found that men who had worked night shifts for over 20 years had a 27% increased risk of cancer incidence, and that men that did not nap during the day had double the risk of cancer of those who took a 1 to 30-minute nap. Men who slept for more than 10 hours per night had an increased risk of cancer. Male participants with at least two of these sleep habits had a 43% increased risk of cancer incidence and a two-fold increase in cancer mortality compared with those who exhibited none of the sleep habits. No significant relationship between sleep habits and cancer incidence was observed in either women or in the overall population. The authors noted some limitations with the study, including the self-reported nature of the lifestyle data, and the fact that ageing retired workers would be more susceptible to cancer and cancer-related death, leading to an over-estimation of the sleep-cancer association if generalised to younger groups.

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