Edition 8 March 2019, by Stephen Swai
According to the results of a study by the Erasmus MC hospital, published in scientific journal PLos Medicine, a healthy lifestyle increases one’s life span by six years.
The study used data about more than 9,000 participants from the Ommoord neighborhood in Rotterdam, whose health and deaths were documented for almost 30 years, since the study started in 1989.
The participants in the study were 55 years old or over at the start, and as of now 3,000 of them have already died. The population of Ommoord was taken as a sample of the entire Dutch population.
“We had the data that enabled us to draw conclusions about complex combinations of diseases and risk factors, because we have been keeping track of the health of this elderly group from Ommoord for a long time,” said Professor of Epidemiology Arfan Ikram.
The Rotterdam study looked at the six diseases that are the leading causes of death according to the World Health Organization (WHO): cancer, stroke, degenerative brain diseases (e.g. dementia), cardiovascular diseases, diabetes and chronic lung disease (CPOD).
The study showed that people who lived a healthy lifestyle, for example by not smoking in their middle age, less often experienced high blood pressure and obesity and would live longer than their unhealthy peers.
Smoking, high blood pressure and obesity were singled out as important risk factors for illness and an early death. “It is clear that smoking, high blood pressure and obesity play a major role in the development of various diseases such as cancer and diabetes,” said Ikram.
Ikram explains how chronic illness occurred through the example of stroke. “A stroke is caused by a clot or a tear in a blood vessel in the brain. High blood pressure causes blood vessels to stiffen (arteriosclerosis). An inflammatory process can take place in people who smoke,” he said.
Of the 55-year-olds who experienced all three risk factors, one in seven already suffered from chronic illness. However, the same percentage of chronic illness was reached only at the age of almost 63 by those who lived more healthily when they were younger. Ikram explained: “These people prevented other diseases through their lifestyles. Of course they will die of something, but if you live healthily, you can enjoy a life without disease for longer,” he added.
Which disease was the first to attack the group? Among the people with all three risk factors, most people experienced a heart disease, cancer, COPD or diabetes as the first life-threatening disease. Together, these accounted for 87 percent of the first diseases.
People without the three risk factors only experienced their first chronic illness a year or two before the patients with the risk factors died. However, bad luck, the degree of happiness and genetic predisposition could change the scenario for everyone, including those who had spent their lives healthily.
Although there was no explanation, it was noticed that men were more likely to develop heart disease, while women were at a higher risk for conditions such as dementia and Parkinson’s disease.
No fewer than ninety percent of healthy participants over 55 developed dementia later in life. Even among people without any of the three major risk factors, up to 90 percent would eventually develop one of the six illnesses. So, even if you do your best to live healthily, these diseases might eventually affect you.
What was striking was that those who lived healthily had a 20 percent chance of developing dementia, compared to 4 percent of those who didn’t lead healthy lifestyles. According to Ikram, that difference could be explained by the fact that healthier people generally became ill at a later age, which meant that the chance of contracting an old-age disease such as dementia simply increased.
Those who prevented or postponed a disease through healthy living eventually saw other illnesses waiting to strike their aging body, from what the experts called the ‘replacement disease’. Ikram had words for a satisfied smoker who, upon looking at the graphs, might exclaim “smoking protects me against dementia.” Ikram said: “Smoking increased the risk of dementia, but other diseases occur even more among people with one or more risk factors.”
The World Health Organization and the Lancet magazine are keen to help experts who are working on how to best reduce the burden of disease throughout the world.