Sunday, August 25, 2013
Eating too much red meat could increase the risk of Alzheimer's: Scientists warn build-up of iron may damage the brain (?)
All that has been shown so far is higher levels of iron in one brain region of Alzheimer's sufferers. All the rest is theory. No causal inferences can be drawn from the evidence so far
Eating too much red meat could trigger Alzheimer's, suggests new research. Scientists found that a build-up of iron - abundant in red meat - could cause oxidant damage, to which the brain is particularly vulnerable. Researchers say this could in turn increase the risk of Alzheimer's.
Professor George Bartzokis, of UCLA in the United States, said that more studies have suggested the disease is caused by one of two proteins, one called tau, the other beta-amyloid.
As we age, most scientists say, these proteins either disrupt signaling between neurons or simply kill them.
He and colleagues looked at two areas of the brain in patients with Alzheimer's and they compared the hippocampus, which is known to be damaged early in the disease, and the thalamus, an area that is generally not affected until the late stages.
Using brain-imaging techniques, they found that iron is increased in the hippocampus and is associated with tissue damage in that area. But increased iron was not found in the thalamus.
Professor Bartzokis said that most research had focused on the build up of the proteins tau or beta-amyloid that cause the plaques associated with the disease.
But he believes the breakdown occurs further 'upstream', and it is the protein's destruction of myelin, the fatty tissue which enables nerve signals to be sent along fibres, which disrupts communication and promotes the build-up of the plaques.
These amyloid plaques in turn destroy more and more myelin, disrupting brain signaling and leading to cell death and the classic clinical signs of Alzheimer's.
He points out that myelin is produced by cells called oligodendrocytes. These cells, along with myelin itself, have the highest levels of iron of any cells in the brain, Bartzokis says.
He adds that although iron is essential for cell function, too much of it can promote oxidative damage, to which the brain is especially vulnerable.
Hypothesising that elevated iron in the tissues could cause tissue breakdown, he targeted the vulnerable hippocampus, a key area of the brain involved in the formation of memories, and compared it to the thalamus, which is relatively spared by Alzheimer's until the very late stages of disease.
They found increased iron levels in patients with Alzheimer's.
Prof Bartzokis said: 'It is difficult to measure iron in tissue when the tissue is already damaged.'
But the MRI technology we used in this study allowed us to determine that the increase in iron is occurring together with the tissue damage.
'We found that the amount of iron is increased in the hippocampus and is associated with tissue damage in patients with Alzheimer's but not in the healthy older individuals - or in the thalamus.
'So the results suggest that iron accumulation may indeed contribute to the cause of Alzheimer's disease.'
The link to iron could mean that dietary changes and surgical interventions could lower the chances of the developing the disease, he said.
He explained: 'The accumulation of iron in the brain may be influenced by modifying environmental factors, such as how much red meat and iron dietary supplements we consume and, in women, having hysterectomies before menopause.'
He said drugs are already being developed to remove iron from tissue and the new study may allow doctors to determine who is most in need of such treatments.
Does working long hours make you a bad father? Men who do overtime are more likely to have 'delinquent and aggressive' sons
It seems highly likely that the overtime workers were mostly working class -- and they have more pathologies anyway
Boys whose fathers work very long hours are more likely to become tearaways, according to new research.
A study of more than 1,400 children found those whose fathers worked more than 55 hours a week were more delinquent and aggressive than their peers, yet the same phenomenon was not identified in daughters.
Further research now needs to be carried out to discover why this happens in males, and to look for ways to tackle it.
The study was run by the Social Science Research Centre in Berlin, but was based in Western Australia where one in five fathers work at least 55 hours week when their children were between five and eight.
Mothers' working hours did not seem to matter, although few Australian mothers worked long hours, according to the study, and no firm conclusions could be drawn from this comparison.
The culture of working long hours, which has crept into many jobs should be the next policy frontier, said the researchers.
In Germany, 15 per cent of fathers of children aged three and four worked 55 or more hours a week in 2011.
Dr Jianghong Li, of The Social Science Research Centre, Berlin, said: 'It is possible when fathers work very long hours, children are less well monitored after school, especially if mothers also work full time hours.
'There is some evidence pre-adolescent boys are less well monitored than girls when fathers have high work related demands, including long hours, and as a consequence have more conduct problems.'
The children's behaviour was monitored by the researchers when they were five, eight and ten using a recognised checklist.
The researchers claim that the findings may be due to the fact when fathers work long hours, children are less well monitored after school, especially if mothers also work full time hours.
The researchers claim the behaviours may be due to the fact when fathers work long hours, children are monitored less after school, especially if mothers also work full-time. However, they add that more research needs to be carried out into why it doesn't happen with daughters
Dr Li said: 'Although the average amount of time parents spend with their children has increased in recent years, the quantity and quality of parent-child time is still raised as a concern.
'Studies in the U.S and Australia point to a desire among parents to work fewer hours and spend more time with their children and a wish among children parents would come home from work less tired and stressed.
'The findings on fathers' long work hours are associated with higher levels of child behavioural problems is important, given the limited prior research specifically examining fathers' work hours.'
Policy has traditionally focused on enabling flexibility for mothers in balancing their work and family responsibilities.
Added Dr Li: 'The results of this study challenge public and policy concern that mothers' absence due to paid work may have a negative impact on children's development.
'This study provides evidence to support equal opportunities for mothers and fathers to share parenting and work responsibilities.
'Instead of focusing on negative effects of mothers' work hours, policy attention should be given to negative consequences of fathers' long work hours for children's emotional well being.
'Fathers should be given incentives not to work long hours but to have a greater share of parenting responsibilities.'
The findings were reported in the Journal of Marriage and Family.
Posted by jonjayray at 12:24 AM