Air pollution linked to obesity in young adults

A study has found that exposure to air pollution could contribute to obesity in young adults by slowing down their metabolism.

Published in Environment International, researchers from California examined how exposure to both short and long-term roadside air pollution affected the weight and cardiovascular health of young adults between the ages of 17 and 22.

From 2014 to 2018, 158 people participated in a study to assess obesity and cardiometabolic health, which is how the body processes glucose and insulin.

This was then combined with average air pollution exposures for one month and one year from where they lived, including levels of nitrogen dioxide (NO2), nitrogen oxide (NOx), ozone (03) and particulate matter (PM10 and PM2.5).

They found that higher levels of long-term NO2 exposure were associated with up to an 11.3 milligrams per deciliter (mg/dL) higher level of cholesterol and a 9.4mg/dL higher level of low-density lipoproteins (LDL)-cholesterol, which is often referred to as ‘bad’ cholesterol.

For obese participants, associations between long-term NO2 exposure and total cholesterol and LDL-cholesterol were 4.5 and 9 times larger than the associations in non-obese participants.

Researchers also found a ‘significant association’ with short-term O3 exposure and cholesterol levels.

The researchers conclude that higher exposure to air pollutants, particularly NO2, was associated with higher levels of cholesterol. These associations were more pronounced in obese participants, suggesting obesity may exacerbate the effects of air pollution exposure on cholesterol levels in young adults.

Responding to the study, Maeva May, head of policy at the British Heart Foundation (BHF) told AirQualityNews that links between air pollution and obesity need to be further investigated.

‘Although this study suggests a possible link between air pollution, obesity and poor cardiovascular health in young people, more research still needs to be done to truly understand the association,’ she said.

‘Research funded by the BHF, found that harmful air pollution seriously affects heart and circulatory health. Fine particulate matter can cause damage to the heart and circulatory system, increasing the risk of a heart attack or stroke. In fact every year, there are around 11,000 air pollution-related deaths in the UK due to a heart attack or stroke.

‘It’s vital that we see bold action taken to tackle poor air quality to protect people’s health and help save lives. This starts with the adoption of legally-binding World Health Organisation (WHO) limits across the UK.’