Over the decades we have had an idea of our life expectancy. Hundreds of years ago it was amazing if we lived to reach the age of 55. Now we are looking to our 80s.
Some researchers believe that the idea of living up to 120 is within reach. If this sounds more science fiction than reality, two major shifts in longevity and health suggest scientists may be on to something.
There is no doubt that we are living longer. The US Census Bureau estimates that the average American can expect to live for 79.5 years by 2020, which is an increase from the average life expectancy of just 70.8 in 1970 – a rise of nearly 10 years in the last 50 years alone.
A major Australian study found that for the first time in history, more of us are dying from non-communicable diseases (NCD) than from infectious ones. Each year, around 38 million people die from a NCD, such as cancer or heart disease, a figure that equates to two-thirds of all deaths around the world (Biochim. Biophys. Acta., 2013).
Many NCDs are caused by poor lifestyle choices such as a bad diet, smoking or lack of exercise. This suggests that living a long and healthy life is very much in our own hands. In fact, a study into the causes of cancer supports this view.
Living a long and healthy life is very much in our own hands
Researchers from the Stony Brook University Cancer Centre in New York found that up to 90 per cent of cancers are caused by environmental or lifestyle factors. It is down to how we choose to live our lives.
The US National Institute on Ageing says: “Disease and disability were once considered an inevitable part of growing older, but that is no longer true.” The idea that lifestyle has a lot to do with longevity is supported by statistics, which show that the largest clusters of the long-lived are found in countries that have a good diet and close-knit communities. Japan has the world’s highest proportion of centenarians (42 per 100,000 people), followed by France (36 per 100,000). The US has the most centenarians, however. This is a reflection of the large population, as their incidence is just 17 per 100,000.
Intrigued by Japanese figures, researchers have concluded that five factors influenced longevity in the region:
1. A diet of predominantly grains, fish and vegetables.
2. Low-stress lifestyle.
3. A close and caring community in which the elderly are not isolated. The Japanese often live with the concept of moai, which translates to ‘meeting for a common purpose’.
4. High levels of physical activity, a later retirement age, exercise and hobbies like gardening.
5. A sense of purpose, including spiritual beliefs. The Japanese often refer to ikigai, which translates to ‘a life worth living’.
These five concepts come up time and time again in research on longevity and seem to form the five golden rules for living a long and healthy life. They’ve even been supported by research.
A healthy diet is defined as including plenty of fresh fruit and vegetables. Various studies have followed people who eat this type of diet, including fresh fish, nuts and olive oil, finding they were less likely to die from any disease. Another study looked at the lifestyle of the Yi, an indigenous people in southwest China who almost never develop high blood pressure. The traditional Yi diet features rice, a small amount of meat, fresh fruit and vegetables. Grains such as oats and buckwheat are also consumed. This diet helps keep blood pressure under control.
Raised levels of stress over long periods contribute to a range of diseases we usually associate with ageing. High levels of cortisol, a hormone released when the body is under stress, are often seen in heart-attack patients. Stress also increases blood pressure, creates harmful free radicals and raises levels of homocysteine that can damage the inner linings of the arterial walls. Studies in Japan have shown that those suffering greater stress were twice as likely to have a fatal heart attack or suffer cancer.
One of the most compelling examples of the effect of isolation has become known as the ‘Roseto effect’. Roseto, a small town in Pennsylvania, is unremarkable in many ways except one. In the 1960s the inhabitants had far less heart disease than the US national average.
In 1966, cases of heart disease among Roseto men were virtually nil. This made no sense, as most men were working in a slate quarry, their diets were appalling and their cholesterol was high. The answer became apparent when the wealthier began to move away or to the outskirts of the town. Previously, three generations of family had lived together under the same roof. The townspeople did everything together: walks, social clubs and church festivals. There was considerable conformity. This sense of community shows that our health is affected in isolation, while community helps give us a longer life.
kathryn@maltanet.net