The fundamental mechanism that underlies such seemingly disparate issues as autism, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and various other neurodegenerative conditions, is the process of inflammation. As you will note, this has been a central theme in my recent lectures, television programs, as well as books, as this is what current science is strongly supporting.
But it now looks as if this process, inflammation, may actually begin in the gut and subsequently affect the brain as a downstream mechanism. In a submission to the Journal of Neuroinflammation, researchers at Cedars-Sinai Medical Center in Los Angeles reported on a fascinating experiment.
Using a laboratory mouse, they administered a chemical, dextran sodium sulfate (DSS), into the drinking water of some of the animals. They then examined the brains of these animals at various times up to 26 days after the chemical was placed in the water. DSS specifically causes gut inflammation. Continue reading
Years ago, when I was in medical school, we were taught that humans lacked the ability to grow new brain cells. This was called the “central dogma” of brain physiology. Incredibly, the notion that the brain lacked the ability to grow new brain cells during adulthood persisted in medical education through the 1990s.
Nobel laureate Santiago Ramón y Caja was a Spanish pathologist and histologist and, based upon his work with the nervous system, he has been called the “father of neuroscience.” On the topic of regrowth of brain cells, this 19th century researcher is quoted as stating:
Once the development was ended, the founts of growth and regeneration of the axons and dendrites dried up irrevocably. In the adult centers, the nerve paths are something fixed, ended, and immutable. Everything may die, nothing may be regenerated. It is for the science of the future to change, if possible, this harsh decree.
Fortunately, the “science of the future” has arrived. It is now well accepted that brain cells do in fact continue to grow throughout one’s lifetime, and it just so happens that the area of the brain where this growth occurs is the brain’s memory center called the hippocampus. Obviously, this is very exciting news, especially for anyone concerned about failing memory or dementia in general.
As it turns out, the growth of new brain cells, a process called neurogenesis, is under the direction of a brain hormone, brain-derived neurotrophic factor (BDNF). BDNF does several things in the brain that are helpful. It strengthens brain cells to increase their survival, it enhances the ability of brain cells to communicate with each other by enhancing the formation of synapses, and it actually induces the growth of new brain cells, as mentioned above.
In the Journal of the American Medical Association specialty journal JAMA Neurology in January 2014, researchers published a very compelling report in which they studied more than 2,000 adults who were free of dementia at the beginning of the study. They measured their BDNF level at the beginning of the study and then followed the group for approximately 10 years. They found that those individuals who had the highest BDNF levels at the beginning of the study had a risk of developing dementia and Alzheimer’s disease that was less than half of those whose BDNF levels were low.
The authors concluded:
Higher serum BDNF levels may protect against future occurrence of dementia and AD. Our findings suggest a role for BDNF in the biology and possibly in the prevention of dementia and AD, especially in select subgroups of women and older and more highly educated persons.
What to study also described was that there are two powerful lifestyle factors that can lead to higher levels of BDNF. These include aerobic exercise, as well as reduction in calorie consumption.
While the idea that we could not grow new brain cells has certainly changed since I was in medical school, one thing that hasn’t changed is our lack of ability to treat dementia. Despite the vast amount of resources dedicated to Alzheimer’s research, there appears to be as yet, no cure in sight.
But look what the Journal of the American Medical Association is telling us. Higher levels of this brain protective hormone are associated with a reduced risk of getting Alzheimer’s in the first place. And you can raise your levels by simply cutting back on calories and adding in some aerobic exercise.
You’ve heard me speak extensively about the toxic role of sugar and carbohydrates in terms of brain health. I’ve even gone so far as to say that elevated blood sugar is correlated with shrinkage of the brain. Why would I say that? In this video we look at a study associating shrinkage of the hippocampus with elevated blood sugar. We now know that when blood sugar is elevated, it binds to protein and forms what is called AGEs or Advanced Glycation End Products. These AGEs then turn on inflammation by leading to leakiness of the gut, which is what affects the brain the most. This is the toxic effect of blood sugar as it relates to the brain.
Back in medical school we were told that we were given a certain number of brain cells and that was it for life. However, this idea that humans do not grow new brain cells is now fully demonstrated to be wrong. How exciting it is that we possess the ability to grow brain cells, a process called neurogenesis. Not only that, but we retain this ability throughout our entire lifetimes. So you might be wondering: what can I do to increase neurogenesis? In this video we will explore at least one way to make this happen.
We’ve all come to accept the notion that our brain will continue to shrink as we age. Nowhere is this decline more impactful than in the hippocampus, the brain’s memory center, one of the primary brain areas that’s first to decline in Alzheimer’s disease.
Researchers measuring the size of the hippocampus using MRI scans demonstrate a clear correlation between shrinkage of the hippocampus and declining cognitive function. So, at least as it relates to the hippocampus, size does matter.
Challenging the status quo notion that loss of hippocampal function is inevitable is new and exciting research showing that we have the potential to actually grow new cells in this vitally important are of the brain, expanding the hippocampus in size and enhancing memory function.