Tag Archives: brains

A positive outlook on life helps brain function in later life, new research reveals.

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Researchers have found that pensioners aged between 80 and 100 who have a positive outlook on life can enjoy better cognitive function that people in their fifties.
Medical experts were stunned when they carried out research on ‘super-agers’, who despite having many symptoms associated with dementia, seemed not to be affected by the condition.

In spite of the fact many of the super-agers had unhealthy habits including smoking and drinking, researchers found what they had in common was a positive attitude in life and an unusually high proportion of the rare brain called called the von Economo neuron.

Professor Emily Rogalski, of the Northwestern University in Chicago, examined the brains of 10 super-agers who underwent examination while they were alive and after they had died. They were part of a group of 74 super-agers followed by the research.
Rogalski said in a paper she is presenting to the American Association for the Advancement of Science she is presenting today: “The findings suggest that super-agers have unique personality profiles.Excellent memory capacity is biologically possible in late life and can be maintained for years even when there is significant neuropathologic burden.'”

Her research found that 71 per cent of super-agers smoked and 83 per cent drank alcohol regularly. However Rogalski estimated that less than five per cent of the population are super-agers.

The von Economo neurons which were present in super-agers are only found in the brains of large mammals and are believed to offer highspeed connections between different regions within the brain. They are known to develop in the late stages of pregnancy and early childhood and could be down to luck.

Rogalski’s study could provide a breakthrough in dementia research. In contrast to much of the dementia research carried out to date, it does not focus on trying to reverse the spread of amyloid and tau, deformed proteins that form lumps in the brains of people with dementia.

 

Brain exposure to insulin may damage longevity, say US scientists

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Los Angeles: Keeping a healthy weight may help people live longer by limiting brain exposure to insulin, say US scientists.

A study in mice found that reducing insulin signals inside brain cells increased lifespan.

In a report in the magazine Science, the researchers said a healthy lifestyle and weight reduce insulin levels in humans and may have the same effect.

Experts said, if proven, insulin would be just one of many factors, such as genes, that influence longevity.

Previous research in fruit flies and roundworms has suggested that reducing the activity of the hormone insulin, which regulates blood sugar levels, can increase lifespan.

The latest study looked at the effects of a protein, IRS2, which carries the insulin signal in the brain. Mice who had half the amount of the protein lived 18% longer than normal mice.

Despite being overweight and having high levels of insulin, the mice were more active as they aged, and their glucose metabolism resembled that of younger mice.

The researchers said the engineered mice were living longer because the diseases that kill them, such as cancer and cardiovascular disease, were being postponed due to reduced insulin signalling in the brain, even though circulating levels of insulin were high.

They said, in the future, it may be possible to design drugs to reduce IRS2 activity to reproduce the same effect, although they would have to be specific to the brain.

Study leader Dr Morris White, an investigator at the Howard Hughes Medical Institute, said the simplest way to encourage longevity was to limit insulin levels by exercising and eating a healthy diet.

He said: “Our findings put a mechanism behind what your mother told when you were growing up – eat a good diet and exercise, and it will keep you healthy.

“Diet, exercise and lower weight keep your peripheral tissues sensitive to insulin.

“That reduces the amount and duration of insulin secretion needed to keep your glucose under control when you eat.

“Therefore, the brain is exposed to less insulin.”

This is an interesting study as the work done on mice could suggest that insulin is playing a role in the ageing process

His team is now planning to look at possible links between IRS2 signalling and dementia, which research has shown is associated with obesity and high insulin levels.