Talking to my friends and looking at my own reactions, I believe that memory loss is one of the most feared disabilities of aging. Since, as we age, most of us experience some degree of memory loss, it is easy to wonder if what we are experiencing are the first steps to dementia. Witnessing someone with Altzheimer’s Disease can be a really unsettling experience, particularly if is a genetic relative. I have Parkinson’s Disease which has a much higher incidence of dementia than the general population, so my memory failings can be very disconcerting. Our memories and ability to function mentally constitutes the essence of who we are, defining our personalities and our abilities. For a few, memory loss is massive and devastating and is accompanied by loss of many other functions such as their ability to function socially, behave appropriately, make sound judgments, solve problems and take care of oneself. The loss of that complex of functions we label dementia. For most memory loss is much less severe and is part of the normal process of aging. It can be annoying, frustrating and worrisome (Am I developing Altzheimer’s Disease?), but it is circumscribed. This post is mainly about normal memory loss, but I will start with describing dementia.
Dementia: Dementia is not a disease; it is a collection of symptoms, which include memory loss and a group of other cognitive dysfunctions including personality changes, inability to carry on normal relationships and activities. The brain lesions seen in dementia are widespread. Alzheimer’s Disease is a leading cause of dementia, but it is not the only cause. Vascular dementia resulting from damage to many small blood vessels throughout the brain is another common cause, and there are a variety of other less common diseases that can lead to dementia. One, which we have heard a lot about recently is dementia resulting from multiple concussions or head trauma, such as occurs in some contact sports, boxing, football or hockey.
Unlike the mild memory impairment that most of us over 65ers suffer, dementia is characterized by loss of many functions. Patients with dementia usually have little ability to acquire new memories, forgetting new events almost as quickly as they occur. They are often unaware of their loss with family members complaining about the problem much more than the patient does. They may lose interest in social activities, may behave inappropriately and have great difficulty solving even simple problems.
Normal memory loss: The aging brain does undergo changes that result in slowing of the ability to process information and to acquire and recall memories. It manifests as absentmindedness (Where did I leave my keys?), missed appointments or forgetting what you set out to do (Why did I come into the kitchen?). We also notice the forgetting of names and past events. Some of this is related to a lessened ability to focus on acquiring new information (i.e. names) particularly when distracted by other events, and some is related to the gradual fading of unused memories (use it or lose it).
All of these things result from some degree of deterioration of brain functioning due to a declining number of neurons (brain cells) and neurotransmitters (dopamine, serotonin, etc.). The processes particularly affect the hippocampus and frontal lobes, the areas most associated with laying down and retrieving memories. The bad news is that this is the inevitable result of wear and tear, and it progresses naturally as we get older. The good news is that it has been discovered in recent years that the brain can grow new cells and actually improve function in some areas, even in later years. So there is some reason to believe that the process can be slowed down.
The amount of deficit that we develop as we age is highly variable. All people have some loss, and the longer we live, the more it is likely to be. However, as we all know, some people remain remarkably intact into their 90s, and others have more memory impairment earlier. The loss of function generally is in the acquisition and retrieval of information. So, we are slowed in the processing and recalling of facts, but retain the ability to interpret information. Fortunately that means that one’s ability to function, relate, reason and make judgments continues unimpaired. A wise person remains wise, however many details of memory are lost.
What makes memory loss greater, and what makes it less? There are a number of risk factors, some of which we can change and some we can’t. We can’t change our genes, and the likelihood of severe memory loss is affected by the genetic legacy of our parents. Other risk factors include obesity, diabetes, hypertension, high cholesterol, smoking and certain medications. Depression may contribute to memory loss, or it may be an effect of it. Hearing loss doesn’t affect memory itself, but it makes it more difficult to acquire new information. Many of these factors can be at least influenced by our behavior.
Importantly, there are a variety of factors that evidence suggests reduce the risk of dementia and memory loss. The first among them is physical exercise. None of the studies of this are definitive, but there are many that indicate that moderately vigorous exercise 3-4 times per week reduce the incidence of dementia and memory loss. It is not known exactly why, but exercise reduces the risk of diabetes, high blood pressure and stroke, themselves risk factors, and it may improve oxygen transmission to the brain and increase the connections between brain cells. In any case, there is certainly evidence that regular exercise improves physical functioning and is linked to longevity, so building it into one’s life seems prudent and may help to slow memory loss.
Mental exercise is also linked to reduced incidence. Many experts believe that challenging you brain with activities such as reading, learning a language or learning other subjects, games that demand mental exercise, social interaction, and challenging work all delay or lessen the onset of dementia and memory loss. There are studies that are suggestive of this, although, again, none of them are definitive. There are a number of commercial, interactive, computer programs now that profess to improve mental functioning, but there is not yet clear evidence as to whether they have an effect beyond learning how to play their games better. However, as with physical exercise, there is no down side in engaging in mental activity that stimulates the brain to work.
There are some studies that suggest that those following a Mediterranean diet rich in whole grains, fruits, vegetables, fish, nuts and vegetable oils have a lower incidence of Altzheimer’s Disease. This is also the case with moderate use of alcohol; however, there is clearer evidence that heavy drinking and the use of illegal drugs have a negative effect on mental functioning.
All of us are aware that getting a good night’s sleep improves mental functioning the next day. The challenge for over 65ers is that sleep tends to deteriorate with age. We may need less sleep than when we were younger, but sleep is often interrupted making it less effective than sleeping straight through. I know that I suffer from interrupted sleep like many others. I offer no solution, but following the usual suggestions such as no caffeine late in the day, minimal fluids after dinner, quiet reading until tired before going to bed, consistent schedule, avoiding long daytime naps, all help. Also, it is useful to give yourself enough time in bed. If you require 6 hours sleep to be well rested, schedule 7 hours in bed to make up for the interruptions and awake times.
In summary, some memory loss is part of the normal process of aging, and for most people it does not cause major impairment, at least until they get very old. For some the losses progress more quickly, and to some extent it is chance whether you are in that category. However, there is now scientific evidence that there are things one can do to positively affect the retention of memory and that the brain is much more plastic and renewable than we ever imagined. Staying as active as one can, both physically and mentally and avoiding bad health habits is all one can do, and then hope for the best. For someone who wants to read more about this subject, much of what I have written is elaborated in more detail in a Harvard Medical School special health report entitled “Improving Memory”.
Al Martin, M.D., 75, is a former associate professor of medicine at University of California San Francisco Medical Center and Chief Medical Officer of Blue Shield of California. He writes a blog, Age with Spirit.