What if I told you there was a pill you could take every day that would reduce your risk of heart disease, prevent several types of cancer, and even reduce your risk of premature death? This pill doesn’t exist (yet), but in one of the largest studies to date, researchers at the University of Cambridge found the best thing: 11 minutes of daily physical activity.
You read correctly. Just over 10 minutes of walking, jogging, playing a sport, exercise or physical activity – essentially anything other than sitting or lying down – reduced the risk of cancer by 10%, heart disease by 19% and death from any cause 23 percent, compared to no activity. These results come from a meta-analysis of studies involving more than 30 million people in total and published on February 28 in the British Journal of Sports Medicine.
“We know that physical activity, such as walking or cycling, is good for you, especially if you feel it increases your heart rate,” study co-author and public health modeling researcher at Cambridge University said James Woodcock in a press release. “But what we’ve found is that there are substantial benefits for heart health and lowering your risk of cancer, even if you can only manage 10 minutes a day.”
The World Health Organization recommends that adults get at least 150 to 300 minutes of physical activity per week, corresponding to 21 to 43 minutes per day. But in the researchers’ analysis, the authors found a dose-response relationship between activity and heart disease, cancer and death, meaning the more activity the better. However, they found that even exercising below the recommended amount could have significant benefits. Activity that met WHO recommendations, meanwhile, was associated with a 15% reduction in cancer risk, 29% reduction in cardiovascular disease and 31% reduction in death compared to no activity. .
“If you’re someone who finds the idea of 150 minutes of moderate-intensity physical activity a week a little daunting, then our results should be good news,” said the physical activity epidemiologist of the University of Cambridge. and study co-author Soren Brage said in the press release.
Two years ago, another meta-analysis from a group in Norway looked at how activity and sedentary time affected the risk of death in studies of a combined total of more than 44,000 people. Being sedentary for long periods increased participants’ risk of death, although high levels of physical activity may counteract some of these negative effects, the researchers found.
If all of this sounds unbelievable, know that there are reasons to be cautious about the results. First of all, the risk reductions presented by the authors may seem high because they are compared to the very rare (if not quite implausible) situation of a person doing absolutely no physical activity per week. Still, there were meaningful comparisons to be made between more relevant groups of people: for example, someone who is active for 21 minutes a day had an 8% lower risk of death than someone who is active for 11 minutes.
This meta-analysis and the one from 2020 are both based on data from observational studies, which means that participants are not asked to change their habits. For this reason, the researchers cannot be certain that they have controlled for potential inherent differences between more and less active people.
In the study, the researchers attribute at least some of the striking findings to a phenomenon called reverse causation. This means that the outcomes they studied – and specifically cancer diagnoses – could cause a person to be less physically active, rather than the other way around. For example, cancer is likely to make a person less physically active due to the “often prolonged trajectory to disability and disease”, according to the authors of a JAMA Oncology comment. Cancer, in turn, also increases a person’s risk of death.
Additionally, some studies they reviewed excluded people with underlying conditions, while others did not; the authors reported that studies that did not exclude people on the basis of pre-existing conditions tended to see stronger associations between physical activity and death, heart disease or cancer, strengthening evidence for a reverse causation.
Even so, physical activity is likely to play a role in preventing cancer, heart disease, cancer, and ultimately death. Exercise can improve heart health by slowing a person’s heart rate, lowering blood pressure and increasing levels of “good” cholesterol. And according to the National Cancer Institute, physical activity can reduce certain hormones and signaling molecules, reduce inflammation, and improve the immune system, which can reduce cancer risk and progression.
Or, as Brage put it, “Doing physical activity is better than not doing any at all”.