No exercise-induced increase in serum BDNF after cycling near a major traffic road

• Published in: Neuroscience letters Vol. 500; no. 2; pp. 129 - 132
• Main Authors: Bos, I., Jacobs, L., Nawrot, T.S., de Geus, B., Torfs, R., Int Panis, L., Degraeuwe, B., Meeusen, R.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 15.08.2011; Elsevier
• Subjects: Acute exercise; Air Pollutants - toxicity; Air pollution; Bicycling; Biological and medical sciences; Brain-derived neurotrophic factor; Brain-Derived Neurotrophic Factor - blood; Commuting; Cross-Over Studies; Environmental Exposure - adverse effects; Exercise; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Middle Aged; Particulate matter; Traffic; Vehicle Emissions - toxicity; Vertebrates: nervous system and sense organs; Acute exercise; Air pollution; Brain-derived neurotrophic factor; Commuting; Particulate matter; Traffic; Physical exercise; Pollution; Acute; Brain derived neurotrophic factor
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2011.06.019

► Commuting by bike is healthy, exercise increases BDNF and brain plasticity. ► Air pollution exposure is linked to negative neurological effects. ► We examined acute effects of exercise and air pollution exposure on serum BDNF. ► Volunteers cycled once in filtered air and once near a busy traffic road. ► BDNF increased after cycling in filtered air, but not after cycling along the road. Commuting by bike has a clear health enhancing effect. Moreover, regular exercise is known to improve brain plasticity, which results in enhanced cognition and memory performance. Animal research has clearly shown that exercise upregulates brain-derived neurotrophic factor (BDNF – a neurotrophine) enhancing brain plasticity. Studies in humans found an increase in serum BDNF concentration in response to an acute exercise bout. Recently, more evidence is emerging suggesting that exposure to air pollution (such as particulate matter (PM)) is higher in commuter cyclists compared to car drivers. Furthermore, exposure to PM is linked to negative neurological effects, such as neuroinflammation and cognitive decline. We carried-out a cross-over experiment to examine the acute effect of exercise on serum BDNF, and the potential effect-modification by exposure to traffic-related air pollution. Thirty eight physically fit, non-asthmatic volunteers (mean age: 43, 26% women) performed two cycling trials, one near a major traffic road (Antwerp Ring, R1, up to 260,000 vehicles per day) and one in an air-filtered room. The air-filtered room was created by reducing fine particles as well as ultrafine particles (UFP). PM10, PM2.5 and UFP were measured. The duration (∼20 min) and intensity of cycling were kept the same for each volunteer for both cycling trials. Serum BDNF concentrations were measured before and 30 min after each cycling trial. Average concentrations of PM10 and PM2.5 were 64.9 μg/m 3 and 24.6 μg/m 3 in cycling near a major ring way, in contrast to 7.7 μg/m 3 and 2.0 μg/m 3 in the air-filtered room. Average concentrations of UFP were 28,180 particles/cm 3 along the road in contrast to 496 particles/cm 3 in the air-filtered room. As expected, exercise significantly increased serum BDNF concentration after cycling in the air-filtered room (+14.4%; p = 0.02). In contrast, serum BDNF concentrations did not increase after cycling near the major traffic route (+0.5%; p = 0.42). Although active commuting is considered to be beneficial for health, this health enhancing effect could be negatively influenced by exercising in an environment with high concentrations of PM. Whether this effect is also present with chronic exercise and chronic exposure must be further elucidated.