Wednesday, May 05, 2010

Alzheimer's risk is SIX times higher if your partner has it

This is a very large effect (albeit based on a rather small sample) and clearly raises the possibility that an infectious agent (a prion?) is involved

Perhaps I am being irresponsible but I believe that truth is always best in medical matters. So let me decode what is said below. The implausible spin below is designed to distract people from the posibility that an infectious agent is involved. Why? Because if people believe Alzheimer's to be infective, it will be very difficult to find carers for them

Those who nurse a spouse with dementia are six times more likely to develop the devastating condition themselves, research shows.

It is thought the physical and mental stress of caring for a loved one with Alzheimer's and other forms of the condition can do lasting damage to the brain's memory centre. [Rubbish! There are lots of stressful occupations]

Although all forms of caring are hard, watching the mental decline of dementia is particularly tough, say the researchers, with men feeling the effects particularly keenly.

With the number of people with dementia expected to explode as the population ages, they say a better understanding of the phenomenon is vital and call for more research. The study team from Utah State University in the U.S. spent 12 years tracking the health of more than 1,200 couples who had been married for an average of 49 years.

None had dementia at the start of the study, but by the end 225 couples were affected. In 125 of these, the husband was diagnosed and in 70 it was the wife. But in 30 couples, both spouses were affected.

When factors such as genetics and social class were taken into account, it became clear that having a husband or wife with the disease raised a person's risk of developing it themselves six-fold.

The study, reported in the Journal of the American Geriatrics Society, found husbands to be three times were vulnerable than wives, although the small numbers involved mean this might just be down to chance.

The researchers believe the emotional stress of watching the mental decline of a loved one could be at least partly to blame. In addition, dementia usually strikes later in life, making the psychological burden heavier for ageing spouses.

But the team called for more research on shared lifestyle and environmental factors.

At least 600,000 people in England have some form of dementia while an estimated 1.4million Britons will be sufferers within 20 years.

Rebecca Wood, of the Alzheimer's Research Trust, said last night: 'It should be made clear that the majority of participants whose spouse had dementia did not develop the condition. 'Scandinavian researchers have found that being married in old age generally reduces risk, maybe because of the greater social interaction couples experience'.


Organic farms bad for small birds and only half as productive

Birds such as the skylark and lapwing are less likely to be found in organic fields than on conventional farms, according to a study that contradicts claims that organic agriculture is much better for wildlife.

It concludes that organic farms produce less than half as much food per hectare as ordinary farms and that the small benefits for certain species from avoiding pesticides and artificial fertilisers are far outweighed by the need to make land more productive to feed a growing population.

The research, by the University of Leeds, is another blow to the organic industry, which is already struggling because of falling sales and a report from the Food Standards Agency that found that organic food was no healthier than ordinary produce.

Organic farmers who shun herbicides may also impose higher costs on nearby farms because the weeds that they have tolerated spread to neighbouring fields.

In the most comprehensive study to date of the impact of organic agriculture on biodiversity, the researchers studied 192 fields on 32 farms in central southwest England and the north Midlands. Half were organic and half conventional.

The research found that organic farms had, on average, 12 per cent more biodiversity in terms of the number and variety of plants, birds, earthworms and insects. But the yield from organic fields was 55 per cent lower than from conventional fields growing similar crops in the same areas. While there were more plants and butterflies on organic farms, there was no difference in the number of bees and there were 30 per cent more hoverflies on conventional farms.

Organic fields contained more magpies and jays but 10 per cent fewer small birds such as yellowhammers, corn buntings, linnets, skylarks and lapwings. The researchers found that the larger birds, which were attracted to organic farms by their denser patches of woodland, were scaring away the smaller birds and preying on their nests.

Tim Benton, who led the study published in the journal Ecology Letters, said: “Our results show that to produce the same amount of food using organic rather than conventional means, we’d need to use twice the amount of land for agriculture. As the biodiversity benefits of organic farming are small, the lower yield may be a luxury we can’t afford, particularly in the more productive areas of the UK.”

Professor Benton said that previous studies, which claimed that organic fields contained up to twice as much wildlife as ordinary fields, had failed to compare like with like. They had tended to study organic farms with small fields and lots of hedges and woodland and compare them with more open landscapes.

Professor Benton’s research, supported by the government-funded Rural Economy and Land Use Programme, also found that isolated organic farms made little difference to the level of biodiversity. Greater benefits were detected where there were clusters of organic farms.

The researchers concluded: “Organic methods may be a useful part of the land management mix for the less productive parts of the UK, particularly if policies can encourage farmers to co-ordinate activities to maximise the benefit to wildlife across a larger area. However, given the lower yield and the limited biodiversity benefit of organic farming, it isn’t sustainable to promote it as the best or only method of agriculture. To meet future demands of food production, we will need to keep farming our most productive areas in the most intensive way we can — and potentially offset that by managing some of our remaining land exclusively as wildlife reserves.”

Organic farms account for 4.3 per cent of all British agricultural land but their number is growing steadily. Sales of organic food, drink and other products fell by 12.9 per cent to £1.84 billion last year, according to the Soil Association’s Organic Market Report.

Lord Melchett, the association’s policy director and an organic farmer in Norfolk, said that the productivity of organic farming should be judged according to the total resources used per unit of output, including the oil consumed to produce artificial fertilisers, rather than simply the yield per hectare. He added that the decline in sales in 2009 was a temporary blip caused by the recession.


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