What is brain health?
When I think of brain health, I think of the brain as an organ, in the same way we would think of liver health or kidney health. Brain health is determined by how the organ is functioning; how much blood flow, nutrients and oxygen it is getting; and how it is cleaning and filtering things like harmful proteins.
Can lifestyle practices boost brain health?
Exercise has a very positive impact on brain health. A 2011 study found that for older adults, aerobic training increases the size of the anterior hippocampus, leading to improvements in spatial memory. Conversely, older adults who do not engage in aerobic activity experience a reduction in the size of the hippocampus (the memory center of the brain) at a rate of 1% atrophy per year.
Other studies are recapitulating the importance of exercise in minimizing, preventing or delaying the onset of memory loss and dementia.
In addition, diet can play a role in brain health.
A 2011 study showed that a Mediterranean, heart-healthy diet can minimize adverse effects on memory and decrease the incidence of Alzheimer's and dementia. There's also a 2017 review that analyzed and compared the impact of different diets on cognition, revealing that the Mediterranean diet can be the most effective diet for memory and cognition.
Is sleep important?
A critical component of brain health is the amount of oxygen delivered to the brain. If you're not getting enough oxygen while you're sleeping, perhaps because of a health condition (for example, sleep apnea), your brain function can be adversely affected.
Studies show that higher quantity and quality of sleep lead to less amyloid (groups of proteins involved in Alzheimer's disease) buildup in the brain (possibly due to sleep's filtration and clearing of that amyloid protein) and therefore a decreased risk of cognitive diseases such as Alzheimer's.
Are there any other lifestyle factors that affect brain health?
Cognitive stimulation has also been shown to be an effective habit for preventing cognitive degeneration. Low education is a risk factor for dementia and degenerative disease, so stimulating the brain can be helpful in minimizing the risks of cognitive impairment and degenerative diseases.
Can healthy brain practices affect mood, memory or focus?
All of the above! By engaging in preventative practices like exercise and healthy eating, memory can improve. Also, we know that when eating healthy and exercising, endorphins are released which can stimulate cognitive functioning and mood improvements.
In addition to the endorphin rush that comes with health habits like exercise, there may be other chemicals involved -- and they are being studied. For example, BDNF (brain-derived nerve growth factor) -- which can help memory, focus and attention -- may increase as a result of physical activity.
How long does it take?
It depends. If you have a lot of vascular risk factors (for example, not exercising or eating healthy), you may need to compensate for quite some time to get to a healthy level before you start receiving benefits.
We know some of the proteins that increase the risk for Alzheimer's can start to deposit in the brain 15-20 years before the onset of symptoms. So, now is the time for prevention.
If you want immediate results, exercise is one habit that tends to produce quick changes in mood and cognition; but in terms of neurodegenerative prevention, we may not see results for a while.
Are there some aspects of brain health that are "fixed" and cannot be changed?
I used to tell patients, "Genetics are genetics and we can't change that." However, some studies now show that exercise can negate risk even if you have a genetic predisposition.
I often don't order the test for genetic predisposition because it's just a risk factor that we can't change, and people misinterpret it as causal. In other words, genetic predisposition doesn't mean that you will get Alzheimer's disease, and negative genetic testing doesn't mean that you won't.
Are some groups of people more at risk for Alzheimer's disease?
ApoE4 gene carriers have an increased risk. Depending on the literature you read, one copy of the gene can increase risk by 2-4 times the risk of the general population, and two copies of the gene may increase risk up to 10 times that of the general population. But that is risk, not cause.
The biggest risk factor is age. Research states that in people over age 65, 1-2% have Alzheimer's disease. Above 85 years old, the prevalence is 30-50%.
There are also some topics that we haven't studied enough. For example, women have a higher risk of Alzheimer's than do men. Could this just be because women live longer than men? Research, however, is suggesting a more complicated theory: women may have more physiological risks than men.
We also have not adequately studied Alzheimer's disease within specific ethnic groups and races. We need more volunteers to participate in studies.
Where does that leave us?
I think we all need to take care of our brains -- now, regardless of our age or what we were born with or what health problems we may have developed. It is never too late to start changing our lifestyle practices so that we can develop a healthy brain.
We don't have a magic pill or cure for Alzheimer's disease. However, emerging research points to ways we can minimize risk and slow progression. Don't view this disease as being only about older people; rather, take preventative action now, no matter your age.
A longer, original version of this piece appears on BeWell Stanford.
Image by geralt