Physical activity is relaxing, so may reduce stress-related inflammation. It is also good for cardiovascular metabolism, especially by reducing blood pressure, which in turn reduces stress and inflammation throughout our organs, he notes. Exercise also helps you sleep better, which is another factor that reduces chronic stress and inflammation, he says.
An evening walk, and exercise in general, also helps with weight management, mobilises anti-tumour cells in our immune system and enhances the natural process of cell death, so that it’s “more likely that cells potentially becoming cancerous are cleared out before they have the chance to become nasty”, explains Dr James King, a senior lecturer in exercise physiology at Loughborough University. Each of these factors could play a role in reducing the risk of bowel cancer, he explains.
“An old wives tale, literally, as my grandma used to recommend going for a walk after dinner as it will ‘help your digestion’,” says Prof Greaves. “Maybe there is something in that as well?”
Lowers type 2 diabetes risk
Diabetes rates are at an all-time high in the UK, with an estimated five million people living with type 2 diabetes, which raises the risk of strokes, heart attacks and heart failure.
However, a paper from UCL researchers in 2016 found that walking briskly for an hour a day squashes the risk of developing the condition by 40 per cent.
While that study didn’t investigate the best time for a walk, scheduling one for after dinner “could be a great way to reduce the spike in blood sugar” that occurs after eating a meal – a result of the body breaking down carbohydrates into sugar, which then enters the blood, Prof Greaves notes. Blood sugar levels spike around 15 to 30 minutes after eating but how high they go and the rate at which they decline varies between people.
“Some scientists believe that spikes after eating are particularly important influences on the development of type 2 diabetes,” as high blood sugar damages insulin-producing cells in the pancreas, he explains.
Regular physical activity, such as an evening walk, can also help with keeping fat mass down, reducing inflammation and the build-up of fat in the muscle, liver and pancreas which can prevent the body from handling sugar and fat properly, Dr King notes.
Slashes dementia risk
No drug on the planet can halve your risk of dementia but studies suggest that walking could do the trick.
Researchers at the University of Sydney, who analysed the health and activity patterns of around 80,000 people, found that those who walked 3,800 steps per day (around two miles) had a 25 per cent lower risk of developing dementia compared to those who didn’t walk much at all, while those who hit 9,800 steps per day (around five miles) had a 51 per cent lower chance of developing the memory-robbing disease.
While the study was observational (so doesn’t prove that walking itself was to credit for the dramatic fall in dementia risk), separate research may offer an explanation.