Abkhasia in the Caucasus, the Hunza region of Pakistan, Okinawa in Japan and Vilcamba in Ecuador. These are the four areas Robbins focuses on to try to find the secrets of longevity, sifting through largely epidemiological research to try to identify common factors in these four areas with a reputation for above average life expectancy.
Of these Okinawa is arguably the most useful case study, on three grounds. First Okinawa has a well maintained written record of births and deaths stretching back to 1879, so we can be reasonably sure how long each individual has lived. Second, Okinawa isn’t at the same high altitude as the other three examples, thereby excluding one possible influencing factor not available to most of us (research published in the Journal of Epidemiology and Community Health in 2005 found that mountain dwellers tend to live longer than their lowland counterparts). Third, we have a range of evidence of changes in the lifestyle of Okinawans, which we can then correlate with longevity and which appear to confirm the observation quoted from John W. Rowe, president of the Mount Sinai School of Medicine, ‘’With rare exceptions, only about 30 per cent of physical ageing can be blamed on our genes, and as we grow older genetics become less important.” The research reported by Robbins identifies that where Okinawans have moved to other countries and adopted their diet and lifestyle or remained in Okinawa and adopted Western diets and life styles, their longevity has fallen significantly ie diet and lifestyle appear to have had greater impact than genetics.
We can’t all choose to live in the mountains, like the people of Abkhasia, Hunza and Vilcamba but we can choose to adopt a healthier lifestyle and Robbins identifies other common factors from these areas we can choose to apply in our daily lives. These include eating a little less than 2000 calories per day, but with a natural healthy diet with fresh fruit and vegetables and little meat and protein and fat of almost entirely vegetable origin and plenty of whole grains (in line with research findings on the anti cancer benefits of whole grains in the Journal of the American Dietetic Association in 2001) and typically at least 90% of the diet from plant foods.
One interesting point Robbins identifies is that most of these societies have great respect for age (with ‘you’re looking old today’ a compliment in Abkhasia) and that there is often no concept of (or even word for) ‘retirement’ – suggesting that positive cultural perceptions of ageing may also influence longevity.
Robbins compares the findings from these four areas of high longevity with research in America and elsewhere and appears to find significant correlation – including attitude and social engagement (such as family, friends, church, voluntary groups or marriage) - with loneliness identified as more likely to lead to premature death in a number of studies.
Robbins also reports on the large scale China Study in the 1980’s, which identified the diseases of ‘poverty’ usually due to inadequate nutrition and poor sanitation – but also the diseases of ‘affluence’ (including diabetes, coronary heart disease, obesity and many forms of cancer) usually linked to nutritional excess and foods of animal origin.
Robbins accepts the value of wild fatty fish such as Alaskan salmon but is concerned by the risk of toxic chemical and pollutants in farmed fish such as Atlantic salmon and suggests linseed as a plant based alternative, providing not only omega –3 but also lignans.
He quotes from Dr Walter M Bortz, former President of the American Geriatrics Society, who coined the term ‘disuse syndrome’ to describe how a lack of physical activity can destroy health and lead to premature ageing and notes A New England Journal study in 2002 showed the value of exercise in preventing diabetes.
Much of the research Robbins relies on is epidemiological ie population studies. It is important to recognize that in any epidemiological study a wide range of factors may be at work and which precise factors, in which combination, can sometimes be difficult to be sure about.
Having said this the volume of epidemiological evidence and the fact that it appears to point so clearly in one direction is persuasive.
It is also persuasive that Robbins has adopted a realistic rather than uncritical approach to what he has found. For example he notes that some initial research in three of these areas of longevity may have accepted too uncritically estimates of age in societies where written records are scarce and age brings status. Since this book was written further doubt has been cast on the longevity reported in some of the areas, with claims, for instance, that some individuals adopted the identities of older relatives who had died, to avoid military service. Robbins is also realistic enough to recognize that we may neither wish nor be able to replicate the simple agricultural lifestyle of the four areas.
He also recognizes that diet, lifestyle and relationships are not a panacea. Indeed he gives the example of a couple who practiced yoga and meditated, ate healthy foods and exercised regularly – but where the husband nevertheless died of cancer in his fifties. He cites other potential factors, from teenage sunburn possibly leading to skin cancer decades later to some cancers possibly starting in the womb, in part as a result of the food our mothers ate and the chemicals in their environment.
However, he argues that diet, lifestyle and relationships are factors we can influence and which can make a difference, so are worth pursuing – and this is a persuasive thesis.
Healthy at 100 – John Robbins (Hodder & Stoughton 2006 – ISBN – 13: 978 0340 909454)