A new trial has found evidence that omega-3 supplementation can reduce the harmful effects of air pollution (1).
The randomised, controlled trial, soon to be published in Environmental Health Perspectives, found that fish oil supplements can counter the effects of air pollution, helping to protect city dwellers from heart disease.
It is widely accepted that the air pollution of city living increases the risk of heart disease.
In fact, city centre residents are almost twice as likely to develop the first signs of heart disease than people who lived in less polluted urban and rural areas, according to recent research (2).
Air pollution is a complex mixture of noxious gases, liquids and other particles that raise blood pressure, increase coagulation (blood clots), raise levels of inflammation and promote build up of deposits in the arteries.
While air pollution is a concern all year round, the summer months can be particularly troublesome. Air becomes stagnant owing to the longer days, and the increased amount of sunlight and ultraviolet radiation. The sunlight helps to form new, harmful compounds are formed that weren't there before.
To reflect these city pollutants, the researchers used an ‘air pollution chamber’ filled with ambient fine and ultrafine particles, as well as another ‘clean’ chamber filled with filtered air.
Twenty-nine healthy, middle-aged participants were given 3g daily of either fish oil or olive oil for four weeks before they entered the chamber. Each participant then spent two hours in the ‘clean’ chamber and the ‘polluted’ chamber. The researchers measured cardiac response before, immediately after and 20 hours after exposure to the pollution. They also measured blood lipids of the participants.
In those who took the placebo olive oil capsules, levels of LDL cholesterol and triglycerides rose immediately after the exposure to pollution. Levels of LDL and triglycerides are linked with heart disease risk. There was no such response in the fish oil group.
Heart rate variability (HRV) was also measured in each group. HRV simply means the way that heart beat varies. A lower heart rate variability is linked to poorer heart health, whereas the beat of a healthy heart is constantly changing as the body finds the most efficient way to operate.
Those in the placebo group showed reduced HRV after pollution exposure, reflecting the harmful effects of their exposure to the pollution chamber. Those in the fish oil group showed no reduction in HRV.
The findings of the study suggest that fish oil supplement may help protect against both the cardiac and lipid effects of air pollution. Although a small study, it does appear to add to the vast weight of evidence for the benefits of omega-3 supplementation. Those of us who live in town and cities might do well to take a regular fish oil supplement for daily protection.
1. J. Lambrechtsen, O. Gerke, K. Egstrup, N. P. Sand, B. L. Nørgaard, H. Petersen, H. Mickley, A. C. P. Diederichsen.The relation between coronary artery calcification in asymptomatic subjects and both traditional risk factors and living in the city centre: a DanRisk substudy. Journal of Internal Medicine, 2012; 271 (5): 444
2. Tong H, Rappold AG, Diaz-Sanchez D, Steck SE, Berntsen J, Cascio WE, Devlin RD, Samet JM. Omega-3 Fatty Acid Supplementation Appears to Attenuate Particulate Air Pollution Induced Effects and Lipid Changes in Healthy Middle-Aged Adults. Environ Health Perspec. 2012 Apr 19. [Epub ahead of print]