Why are scientists redefining Alzheimer's disease?

Alzheimer's disease is a progressive neurodegenerative disorder, thought to be caused by buildup of proteins in the brain. But there is increasing evidence that different biological processes are at the heart of the disease, providing scientists with a different approach to possible therapies.

In a plenary session delivered at the Alzheimer's Association International Conference (AAIC) 2017, held in London, United Kingdom, Julie Williams, Ph.D. - a professor in the Division of Psychological Medicine and Clinical Neurosciences at Cardiff University in the U.K. - challenged the traditional views of Alzheimer's disease by saying that "immunity is playing a significant role" in the disease.

Alzheimer's disease is the sixth leading cause of death in the United States, affecting more than 5 million adults in the country.

The traditional view is that proteins accumulate in the brains of patients, leading to neuronal death. The culprits are the amyloid beta peptide and the tau protein.

How are scientists challenging the traditional view that abnormal protein buildup in the brain is to blame for the neurodegeneration seen in Alzheimer's disease?

Joint efforts to identify new genetic variants

Until 2009, only four genes were known to be associated with Alzheimer's disease. Mutations in three of these - APP, presenilin 1, and presenilin 2 - cause the inherited form of Alzheimer's. This typically develops early in life, between the ages of 30 and 50. It is also known as early-onset Alzheimer's disease.

Less than 1 percent of Alzheimer's disease patients have this inherited form of the condition, in which an overproduction or abnormal folding of amyloid beta in the brain can be observed.

The majority of patients have the sporadic form of Alzheimer's. Despite the fact that mutations in the apolipoprotein E gene (APOE) were known to be involved in susceptibility and earlier age of onset, only a subset of patients have the variant associated with the disease.

Predicting an individual's risk of developing the disease with accuracy is, therefore, a challenge. For many years, there was a serious lack of progress in research looking to establish the underlying causes of susceptibility.

Today, we know that sporadic Alzheimer's disease has a large genetic component, with its heritability being in the range of 58 to 79 percent. This means that other genetic variants must be involved.

Identifying individuals at risk

In a study published in the journal Neurobiology of Aging in 2017, Prof. William's team used their knowledge of susceptibility genes to test how accurately they could predict an individual's risk of Alzheimer's disease.

Using data from 17,000 Alzheimer's patients and 37,000 controls, and looking at 87,583 mutations, they were able to identify the condition with an accuracy of 74.5 percent.

Prof. Williams explained that they were "now able to predict quite a lot of the risk of AD [Alzheimer's disease] and it's better than looking at APOE."

So might the amyloid buildup seen in Alzheimer's patients be less of a problem with excess production and more to do with other processes?

Prof. Williams challenged the audience to imagine a scenario wherein there was no historic knowledge of the genes implicated in amyloid processing being involved in Alzheimer's disease. "Alzheimer's disease is more of an autoinflammatory disease, than anything else," Prof. Williams said.

"What we are seeing with immunity is happening quite early in the disease and maybe a primary event that is happening alongside amyloid [accumulation]," she added. "What we need to do is to understand mechanisms."

The team's latest discovery was published this week in Nature Genetics, and it supports this theory.

This study, performed by the IGAP group, identified two new genetic variants that confer Alzheimer's disease risk. The genes - phospholipase C gamma and B-3-domain-containing transcription factor ABI3 - are highly expressed in microglial cells in the brain, which are part of the immune system.

Prof. Williams told the audience that scientists around the world are now studying genetic models to better understand how the immune system is involved in the neurodegeneration seen in Alzheimer's.

What is really important is how researchers are putting this new knowledge and redefinition of the condition to use.

The above are excerpts taken from a story published in MNT Weekly story By Yella Hewings-Martin, PhD, Published Thursday 20 July 2017. It is an important and for the full story please go here

Walking your dog is good for you

A new study has shown that walking a dog on a regular basis, boosts levels of physical activity in older people, especially during the winter.

Published in the Journal of Epidemiology and Community Health, the study used data from the EPIC Norfolk cohort study, which is tracking the health and well-being of thousands of residents of the English county of Norfolk.

The researchers from the University of East Anglia (UEA) and Centre for Diet and Activity Research (CEDAR) at the University of Cambridge found that owning or walking a dog was one of the most effective ways to beat the usual decline in later-life activity, even combatting the effects of bad weather.

Dog owners were sedentary for 30 minutes less per day, on average. More than 3000 older-adults participating in the study were asked if they owned a dog and if they walked one. They also wore an accelerometer, a small electronic device that constantly measured their physical activity level over a seven-day period.

As bad weather and short days are known to be one of the biggest barriers to staying active outdoors, the researchers linked this data to the weather conditions experienced and sunrise and sunset times on each day of the study.

Lead author of the paper, Dr Yu-Tzu Wu, said "We know that physical activity levels decline as we age, but we're less sure about the most effective things we can do to help people maintain their activity as they get older.

"We found that dog walkers were much more physically active and spent less time sitting overall. We expected this, but when we looked at how the amount of physical activity participants undertook each day varied by weather conditions, we were really surprised at the size of the differences between those who walked dogs and the rest of the study participants."

The team found that on shorter days and those that were colder and wetter, all participants tended to be less physically active and spent more time sitting. Yet dog walkers were much less impacted by these poor conditions.

Project lead Prof Andy Jones said: "We were amazed to find that dog walkers were on average more physically active and spent less time sitting on the coldest, wettest, and darkest days than non-dog owners were on long, sunny, and warm summer days. The size of the difference we observed between these groups was much larger than we typically find for interventions such as group physical activity sessions that are often used to help people remain active."

The researchers caution against recommending everyone owns a dog, as not everyone is able to look after a pet, but they suggest these findings point to new directions for programmes to support activity.

Prof Jones said: "Physical activity interventions typically try and support people to be active by focussing on the benefits to themselves, but dog walking is also driven by the needs of the animal. Being driven by something other than our own needs might be a really potent motivator and we need to find ways of tapping into it when designing exercise interventions in the future."

Article: Dog ownership supports the maintenance of physical activity during poor weather in older English adults: cross-sectional results from the EPIC Norfolk cohort, Yu-Tzu Wu, Robert Luben, Andy Jones, Journal of Epidemiology and Community Health, doi: 10.1136/jech-2017-208987, published online 24 July 2017.

Shape your life

Mid-September, time to dream a little as summer starts to fade away.  

If you were to be given some wicked power tools, plus a hammer, chisel, and ax, to craft, carve, and shape the life of your wildest dreams...

I'd bet you all the money in the world that you'd be really, really careful with each of your bangs, buzzes, and chops, huh? 

I mean, we both know how much you'd have riding on the line, right?

Well, that same extraordinary care and precision should be exercised when using your imagination, choosing your words, and dancing life’s dance.

Can computer games and activities improve cognitive abilities?

I was giving a workshop on “Knowing your Bladder” and we were talking about Kegel exercises and one of the women in the room, said, “Use it or lose it.”  I agree and this advice can apply to many situations but is often used to stress the importance of keeping our bodies and minds active in order to stay healthy, independent and mentally fit for as long as possible.

Research evidence supports this old adage “Use it or Lose it” and there are plenty of good options for staying physically active, but one of the questions I get when I give my seminars is, how can we best exercise our brains?  Well, there is one option for a cognitive “work out” and it is computerized cognitive training (CCT). There are various types of computer programs designed to strengthen overall cognition and improve memory, attention span and learning. With many options now available online, CCT is showing promise in helping to prevent cognitive decline.

For many seniors, Computerized cognitive training (CCT) is an enjoyable, easy and relatively inexpensive way to stay mentally fit. CCT contributes to short-term cognitive improvements in people with mild cognitive impairment. Small improvements were also seen in people with dementia.

More research is needed to find out the longer-term benefits of CCT, to see if it helps prevent people with mild cognitive impairment from developing dementia.

That question led researchers to investigate whether CCT could benefit those who have already experienced cognitive decline. So some research was done to include people with mild cognitive impairment (MCI) who have noticeable problems with thinking, memory, language and decision making but are still able to function independently, and people with dementia whose cognitive impairments interfere with daily activities.

People in the research participated in supervised computerized cognitive skills training, video games or virtual reality activities for at least four hours in total, after which their cognitive abilities were measured and compared to control groups who didn’t take part in CCT or did different types of training.

What the research tells us

Cognitive “brain games” may be screen time well spent! People with MCI experienced moderate improvement in their overall cognitive abilities after taking part in computerized cognitive training sessions, specifically in areas such as memory, attention, verbal and non-verbal learning, and psychosocial functioning. For people with dementia, the evidence was less encouraging but some minor improvements were noted.

Cognition tests were taken immediately after the completion of training, so the results don’t tell us much about the longer-term impacts of CCT. More research is needed to address those and other questions, including whether CCT can help prevent the progression of mild cognitive impairment to full dementia.

Although these results are promising, computer “brain games” should not be considered a one-step solution to keep our brains healthy and sharp. Research evidence shows that people with cognitive impairment, and their caregivers, benefit most when support programs have multiple components, including physical exercise and social interaction (5), and most of us can benefit from less sedentary screen time!

However, this research suggests that computer-based cognitive training can be considered one promising addition to treatment for people with cognitive impairment.

Source: https://www.mcmasteroptimalaging.org/blog/detail/blog/2017/07/24/computer-brain-games-for-treating-cognitive-impairment