Switching from driving to cycling to work may lower the risk of heart disease.
Active commuting - by means of walking or cycling to and from work and for other purposes, such as grocery shopping and transporting children - is a form of exercise that can be a part of everyday life.
For many, walking and cycling not only contribute to daily health-enhancing physical activity levels, but also provide cost- and time-effective alternatives to commuting by car or public transport - while reducing traffic congestion and air and noise pollution.
Though active commuting has been previously linked to a lower risk of heart disease and premature death, few studies have specifically assessed the cardiovascular health benefits of commuting by bike - or investigated the impact of changing modes of commuting to work, from car and public transport to active commuting.
The aim of the Circulation study was to examine the association between cycling, changes in cycling habits, and risk of coronary heart disease in Danish men and women.
Findings showed that the 45,000 Danish adults aged 50-65 years who regularly cycled to work or for leisure had between 11-18 percent fewer heart attacks over the course of a 20-year follow-up.
The analysis indicated that some protection against heart disease was achieved with as little as 30 minutes of biking per week. Participants who changed their behavior and took up cycling in the first 5 years of follow-up had a 25 percent reduced risk of developing heart disease, compared with men and women who remained non-cyclists in the subsequent 15-year period.
While the findings are promising, the researchers say they do not prove that cycling for commuting or leisure prevents heart attacks. The results do highlight, however, that the participants who cycled on a regular basis had fewer cardiovascular events and is, therefore, a strong indicator that cycling is beneficial for cardiovascular health.
Regular cycling could have prevented over 7 percent of heart attacks
"Finding time for exercise can be challenging for many people, so clinicians working in the field of cardiovascular risk prevention should consider promoting cycling as a mode of transportation," advises Anders Grøntved, M.Sc., M.P.H., Ph.D., senior study author and associate professor of Physical Activity Epidemiology at the University of Southern Denmark.
Participants were questioned about their cycling habits at the start of the study and then again 5 years later. Additionally, Grøntved and colleagues recorded the exercise habits, physical activity levels, and frequency of bicycle riding of all participants as well as heart disease risk factors, such as blood pressure, weight, cholesterol, smoking, diet, and alcohol consumption.
Overall in the 20-year follow-up, there were 2,892 heart attacks, of which, cycling on a regular basis could have avoided more than 7 percent, the team says.
"Because recreational and commuter biking is an easy way to make physical activity part of one's routine in a non-structured and informal fashion; based on the results, public health authorities, governments, and employers ought to consider initiatives that promote bicycle riding as a way to support large-scale cardiovascular disease prevention efforts," says Kim Blond, M.Sc., lead author and research assistant at the University of Southern Denmark.
In the Journal of the American Heart Association study, similarly, researchers examined the potential relationships of cycling to work at the start of the research with a change in commuter cycling, with 10-year incidence of obesity, hypertension, hypertriglyceridemia, and impaired glucose tolerance in men and women from Northern Sweden.
The team also assessed whether genetic and other factors modified the relationships, and they examined the percentage of these risk factors for cardiovascular disease that could be prevented if all participants continued to cycle or switched to commuting by bicycle to work, during a 10-year follow-up period.
Switching from passive to active commuting reduced all risk factors
Over a decade, more than 20,000 individuals in their 40s, 50s, and 60s had their commuting habits, weight, cholesterol levels, blood glucose, and blood pressure assessed.
At the study onset, compared with passive commuters - who drove to work or used public transport - participants who cycled to work were found to be 15 percent less likely to be obese, 13 percent less likely to have high blood pressure, 15 percent less likely to have high cholesterol, and 12 percent less likely to have pre-diabetes or diabetes.
The researchers revealed that after 10 years, the individuals who switched from passive to active commuting were also less likely to be obese, have hypertension, have elevated cholesterol levels, or develop diabetes, when compared with the inactive commuters.
Paul Franks, Ph.D. - senior study author, professor in the Department of Clinical Sciences at Lund University in Sweden and guest professor at Umeå University in Sweden - and team found that after 10 years, people who started cycling to work or continued to cycle to work collectively had 39 percent decreased risk of obesity, 11 percent lower risk of high blood pressure, 20 percent reduced risk of high cholesterol, and had a decline in diabetes risk by 18 percent.
"We found active commuting, which has the additional advantages of being time-efficient, cheaper and environmentally friendly is also great for your health. The multiple advantages of active commuting over structured exercise may help clinicians convey a message that many patients will embrace more readily than being told to join a gym, go for a jog, or join a sports team."
Paul Franks, Ph.D.
The researchers note that while individuals who cycled for a longer duration or more frequently experienced small additional gains in risk reduction, there was no minimum amount of time or distance required to reduce the risk of cardiovascular risk factors.
According to the study authors, it is estimated that switching from passive to active commuting may have prevented 24 percent of obesity cases, 6 percent of hypertension diagnoses, 13 percent of high cholesterol diagnoses, and 11 percent of the diabetes cases.
"The really good news here is that it's never too late to benefit from an active lifestyle. People who switched from passive to active commuting saw considerable gains in their cardiovascular health," Franks concludes.