Taken from Eclectic Gardener @ www.teachinggarden.org
Written by Alan Hickman

From time to time a copy of Gardening Australia shows up, sent by a correspondent who gardens between Sydney Harbour and Botany Bay. Like Canada, Australia is a big place with a range of climate zones. Unlike Canada, which goes from arctic cold to downright chilly, Oz goes from stinking hot tropical in northern Queensland to quite nippy-on-the-nose southern Tasmania.
Although the countries are polar opposites - it’s mid winter now - an Australian gardening magazine makes for interesting and useful reading. The global spread of plant material and products is perhaps the most obvious feature. David Austin roses, rotating compost bins and shredded bark mulches are as much a part of garden business in the antipodes as they are here.
There are some translations and adjustments to be made: read Swiss Chard for Silverbeet for instance, and, if the number of references to ‘chooks’ was an indication, every Auzie would have a run of chickens in the backyard. On the whole though, going from the south end of Ontario to the south end of Australia is not that much of a leap.
What caught my eye in the June issue of the magazine was a brief piece referring to some on-going Australian health-research known as the ‘Dubbo Study of the elderly’. Dubbo is a city of about 40,000, some 400 km by road NW of Sydney.
The objective of the study is to identify risk factors for dementia. With the primary or secondary reason for institutional placements being related to dementia in 64% of admissions, understanding the risk factors is an essential in planning for an aging population.
Everyone born prior to 1930 and resident in the Dubbo Local Government Area was eligible for assessment for the study and, in 1988, 2,805 men and women aged 60 and older were selected and have been followed ever since. The findings to date were published in the January 2006 edition of the Medical Journal of Australia and they are of significant interest to gardeners everywhere.
After sixteen years of follow-up, three things were found to be clear predictors of reduced risk for dementia: years of education, intake of moderate amounts of alcohol and daily gardening activity. For the group as a whole, any intake of alcohol or daily gardening activity at the time of evaluation (1988) predicted a reduced risk of dementia. (34% lower risk for alcohol and 36% lower risk for gardening). Alone, plain physical exercise does not seem to be a reliable indicator of future dementia. Daily walking did predict a 38% reduced risk for men but had no significant predictive value for women.
The study offers no explanation as to why gardening is good for the brain but, to quote directly from the report: "Our findings suggest some public health messages for reducing the future incidence of dementia in our aging society. Excess alcohol intake needs to be avoided, but it would appear safe and reasonable to recommend the continuation of moderate alcohol intake in those already imbibing, and the maintenance of physical, leisure and mental activity, especially daily gardening."
Along with predictors for decreased risk, the study found indicators for increased risk. Those which related to gardening are ‘impaired peak expiratory flow’ and depression. Shortness of breath is one of the many debilitating effects of being overweight and it is responsible for up to an 84% increase in risk of dementia. Those with diagnosed depression - another condition often associated with obesity - have up to a 50% increased risk.
I can vouch for the beneficial effects of gardening for weight control. Over three months, from the start of the gardening season in April, I dropped from 157 pounds to 145 pounds - close to an ideal weight for someone my height. The diet didn’t change. I still managed occasional jelly donuts, fish and chips and Swiss Chalet, not to mention macaroni and cheeses - made with butter and cream and topped with breadcrumbs and full-fat cheese and a drizzle of sun-dried tomato oil - and all the other regular weekly comfort foods.
Considering that it’s the only exercise I get, gardening has looked after me quite well. For a body that has been either ignored or abused for nigh three score and ten, the structure remains in surprisingly good shape. Gluteus maximus being an exception, and that, sadly, is beginning to resemble a trombone’s ancestor.
The full Dubbo Study report is available on the web but with a long URL. Type ‘Dubbo Study’ into Google and the report will come up. For those who are not up on their Renaissance or Baroque orchestras, a precursor of the trombone was the sagbut.