The top two causes of death worldwide are cardiovascular disease and cancer. Both conditions are associated with well-known risk factors, including low levels of physical activity. A large, new meta-analysis has examined the link between physical activity and the risk of death and revealed some interesting results.
Higher levels of physical activity are known to be associated with a lower risk of mortality overall, as well as a lower risk of developing cardiovascular disease (CVD) and some forms of site-specific cancer.
Previous meta-analyses have used different methods to examine the interaction between physical activity and the risk of death. While the 2019 Global Burden of Disease (GBD) study considered the impact of physical activity on disease, it included job-related, or occupational, activity, which is difficult to measure accurately. Even when it is well-measured, the health benefits of occupational activity are not as clear as those obtained by non-occupational physical activity.
Researchers at the University of Cambridge led a new study that sought to clarify the results of previous meta-analyses, looking specifically at the association between non-occupational physical activity and the risk of death. Undertaking the largest pooled data analysis of its kind, researchers only used studies with more than 10,000 adult participants, leading to a sample size of more than 30 million. The evidence base was largest for mortality of all causes, the incidence of CVD and cancer.
The researchers found that, generally, two out of three participants reported moderately intense activity levels below 150 minutes per week. Less than one in 10 participants did more than 300 minutes a week.
People who did 150 minutes of moderately intense physical activity per week were shown to have a 31% lower risk of death from all causes and a 29% lower risk of death from CVD. This level of exercise also decreased the risk of death from cancer by 15%. Doing more than 150 minutes per week of moderate-intensity activity showed only a marginally reduced reduction in the risk of early death.
Notably, appreciable benefits were seen by doing half this amount of physical activity. For those that did 75 minutes of moderately intense physical activity a week, the risk of early death fell by 23%. That equates to a little over 10 minutes a day.
"If you are someone who finds the idea of 150 minutes of moderate-intensity physical activity a week a bit daunting, then our findings should be good news. Doing some physical activity is better than doing none. This is also a good starting position – if you find that 75 minutes a week is manageable, then you could try stepping it up gradually to the full recommended amount," said Dr Soren Brage, corresponding author of the study.
Doing 75 minutes of activity a week reduced the risk of developing CVD by 17% and cancer by 7%. For certain types of cancer – head, neck and stomach cancer, myeloid leukemia and myeloma – the risk reduction was even greater at 14% to 26%.
The analysis showed that if all participants had done at least 150 minutes of moderate-intensity activity a week, 16%, or around one in six, early deaths would be prevented. And that one in nine (11%) cases of CVD and one in 20 (5%) cancer cases would be prevented.
If participants had done 75 minutes a week, around one in 10 (10%) early deaths would be prevented. One in 20 (5%) cases of CVD and almost one in 30 (3%) cancer cases would be prevented.
"Moderate activity doesn't have to involve what we normally think of exercise, such as sports or running," said Dr Leandro Garcia, lead author of the study. "Sometimes, replacing some habits is all that is needed. For example, try to walk or cycle to your work or study place instead of using a car, or engage in active play with your kids or grandkids. Doing activities that you enjoy and that are easy to include in your weekly routine is an excellent way to become more active."
The study was published in the British Journal of Sports Medicine.
Source: University of Cambridge
