According to a research published in Nature Neuroscience, the human brain may be able to compensate for some of the early changes seen in Alzheimer’s disease.
The study suggests some people recruit extra nerve power to help maintain their ability to think.
Scientists hope the findings could shed light on why only some people with early signs of the condition go on to develop severe memory decline.
However, experts warn much more research is needed to understand these processes.
The study, led by researchers at the University of California, involved 71 adults with no signs of mental decline.
The human brain may be able to compensate for some of the early changes seen in Alzheimer’s disease
Brain scans showed 16 of the older subjects had amyloid deposits – tangles of protein that are considered a hallmark of Alzheimer’s disease.
All participants were asked to memorize a series of pictures in detail while scanners were used to track their brain activity.
They were then asked to recall the gist and later the detail of all the pictures they had seen.
Both groups performed equally well but those with tangles of amyloid in their brains showed more brain activity when remembering the images in detail.
Scientists say this suggests their brains have an ability to adapt to and compensate for any early damage caused by the protein.
Scientists say they need to understand why some people with an accumulation of this protein are better at using different parts of their brain than others.
Dr. William Jagust, a researcher on the study, said: “I think it is very possible that people who spend a lifetime involved in cognitively stimulating activity have brains that are better able to adapt to potential damage.”
A new study has found that human brain can be trained to prefer healthy food over unhealthy high-calorie foods, using a diet which does not leave people hungry.
Scientists from Tufts University say food addictions can be changed in this way even if they are well-established.
They scanned the addiction centre in the brains of a small group of men and women.
The results showed increased cravings for healthy lower-calorie foods.
Prof. Susan B. Roberts, senior study author and behavioral nutrition scientist at the Boston university, said: “We don’t start out in life loving French fries and hating, for example, wholewheat pasta.
“This conditioning happens over time in response to eating – repeatedly – what is out there in the toxic food environment.”
Human brain can be trained to prefer healthy food over unhealthy high-calorie foods, using a diet which does not leave people hungry
Scientists know that once people are addicted to unhealthy foods, it is usually very hard to change their eating habits and get them to lose weight.
Prof Susan B. Roberts’ research, published in the journal Nutrition & Diabetes, suggests the brain can learn to like healthy foods.
They studied the part of the brain linked to reward and addiction in 13 overweight and obese men and women, eight of whom were taking part in a specially designed weight-loss program.
This focused on changing food preferences by prescribing a diet high in fiber and protein, and low in carbohydrates, but which did not allow participants to become hungry because this is when food cravings take over and unhealthy food becomes attractive.
The other five adults were not part of the weight-loss program.
When their brains were scanned using MRI at the start and end of a six-month period, those following the program showed changes in the brain’s reward centre.
When participants were shown pictures of different types of food, it was the healthy, low-calorie foods which produced an increased reaction.
The study said this indicated an increased reward and enjoyment of healthier food.
The brain’s reward centre also showed decreased sensitivity to the unhealthy, higher-calorie foods.
The Boston researchers say that gastric bypass surgery, while solving the problem of weight loss, can take away food enjoyment rather than make healthier foods more appealing.
“There is much more research to be done here, involving many more participants, long-term follow-up and investigating more areas of the brain,” Prof Susan B. Roberts said.
US researchers have found a clue to why memory deteriorates with age.
Experiments on mice suggested low levels of protein RbAp48 in the brain may be responsible for memory loss.
It is hoped the discovery could lead to treatments to reverse forgetfulness, but it is a big leap from the mouse to a human brain.
The study, published in the journal Science Translational Medicine, said age-related memory loss was a separate condition to Alzheimer’s disease.
Experiments on mice suggested low levels of protein RbAp48 in the brain may be responsible for memory loss
The team at Columbia University Medical Centre started by analyzing the brains of eight dead people, aged between 22 and 88, who had donated their organ for medical research.
They found 17 genes whose activity level differed with age. One contained instructions for making a protein called RbAp48, which became less active with time.
Young mice genetically engineered to have low RbAp48 levels performed as poorly as much older mice in memory tests.
Using a virus to boost RbAp48 in older mice appeared to reverse the decline and boosted their memory.
One of the researchers, Prof. Eric Kandel, said: “The fact that we were able to reverse age-related memory loss in mice is very encouraging.
“At the very least, it shows that this protein is a major factor, and it speaks to the fact that age-related memory loss is due to a functional change in neurons of some sort. Unlike with Alzheimer’s, there is no significant loss of neurons.”
It is still not know what impacted adjusting levels of RbAp48 in the far more complex human brain or even it if is possible to manipulate levels safely.
