Exposure to air pollution raises your blood pressure, Chinese study shows
Even brief exposure to chemicals found in air pollution can adversely affect blood pressure. Also in the news: women smokers more likely to give up by timing their quit date with their period
Both short- and long-term exposure to some air pollutants commonly associated with coal burning, vehicle exhaust, airborne dust and dirt are associated with the development of high blood pressure, according to new research in the American Heart Association’s journal Hypertension.
“In our analysis of 17 previously published studies we discovered a significant risk of developing high blood pressure due to exposure to air pollution,” says Tao Liu, lead study author from the Guangdong Provincial Institute of Public Health in China. “People should limit their exposure on days with higher air pollution levels, especially for those with high blood pressure; even very short-term exposure can aggravate their conditions.”
The 17 studies involved a total of more than 108,000 hypertension patients and 220,000 non-hypertensive controls. The meta-analysis found high blood pressure was significantly associated with short-term exposure to sulphur dioxide, which mainly comes from the burning of fossil fuel, and particulate matter (PM2.5, the most common and hazardous type of air pollution, and PM10). It was also significantly associated with long-term exposure to nitrogen dioxide (NO2), which is produced from combustion, and PM10.
No significant associations were found between hypertension and short-term effects of ozone and carbon monoxide exposure. Researchers said ozone and carbon monoxide’s links to high blood pressure requires further study.
Female smokers more likely to kick the habit by ‘timing’ their quit date with their menstrual cycle
Women who want to quit smoking may have better success synchronising their quit date with the period of time following ovulation and prior to menstruation, according to a new study from the University of Pennsylvania’s Perelman School of Medicine. This period, according to the study published in Biology of Sex Differences, is when brain circuitry involved in making “good decisions” is optimal.
Penn researchers recruited 38 physically healthy, premenopausal women aged between 21 and 51 years of age who smoke and who were not taking hormonal contraceptives. Functional MRI scans were done on the women to examine how regions of the brain that help control behaviour are functionally connected to regions of the brain that signal reward.
Results revealed that during the follicular phase – which begins at menstruation and continues until ovulation – there was reduced functional connectivity between brain regions that helps make good decisions and the brain regions that contain the reward centre, which could place women in the follicular phase at greater risk for continued smoking and relapse. Using smoking cues (pictures of smoking reminders such as an individual smoking) was associated with weaker connections between cognitive control regions in follicular females.
“Interestingly, the findings may represent a fundamental effect of menstrual cycle phase on brain connectivity and may be linked to other behaviours, such as responses to other rewarding substances [such as alcohol and foods high in fat and sugar],” says study senior author Teresa Franklin.
Long-term memory test could aid earlier Alzheimer’s diagnosis
People with Alzheimer’s disease could benefit from earlier diagnosis if a long-term memory test combined with a brain scan were carried out, a study suggests. University of Edinburgh scientists, in collaboration with colleagues in the US, studied long-term memory in young mice, some of which had the equivalent of very early stage Alzheimer’s disease, and some of which were healthy.
They say testing memory over a long timescale reveals early deficits in the brain’s ability to remember that go undetected by checks for short-term forgetfulness, which is the current practice for diagnosis. They add that the type of memory loss revealed by such tests could potentially be reversed by the development of new treatments.
In the study, the mice were taught to locate a hidden platform in a pool filled with water, using signs on the wall of the room to navigate. When tested shortly after the initial task, both groups of mice were able to remember the way to the platform. However, when tested one week later, the mice in the Alzheimer’s group had significantly more difficulty remembering the route.
Professor Richard Morris, who led the research, says: “We recognise that tests with animals must be interpreted with caution, but the use of these genetic models in conjunction with appropriate testing is pointing at an important dimension of early diagnosis.”