by Matt Stemley


Did cancer cause your ability to think, focus or remember to shift? Read this to learn why this happens and what to do to fight off your “Chemo/Cancer brain”



The late and side effects of cancer treatment are so DIVERSE.  Today we are going to focus on just 1-side effect that perhaps you have noticed as you have undergone your battle with cancer.  Today’s blog will talk about how cancer affects your cognitive health which impacts your memory, attention span and ability to concentrate/focus.


Understanding the 2 types of stressors:  Eustress vs. Distress

The heading here is succinct yet summarizes the root cause of many of these cognitive changes that occur in the brain of a cancer patient.  Let’s dive into it a bit more.

In life we have 2 different kinds of stress:  eustress and distress.  Eustress is a positive stress that drives a positive physiological adaptation.  Take your workouts for example, the “STRESS” of working out causes our muscles to contract and develop microtears.  Ideally, we then sleep, eat healthy foods and get plenty of water which will facilitate the recovery of the muscle.  In the end, this type of stress will cause your muscle to get bigger and stronger (yay you just increased the horsepower of your engine to do more work!!).  The opposite of “eustress” is “distress”.  Distress is a negative stress response that incites negative physiological adaptations in the body, this is done as a protective mechanism to make sure we stay alive and conserve as much bodily functioning as possible.

In response to “eustress” one of the hormones we secrete are adrenal hormones.  In response to “distress” one of the hormones we secrete is cortisol.  Both hormones have opposing effects upon the SAME structure…YOUR BLOOD VESSELS.  Our blood vessels consist of the arteries, veins, arterioles and venules. ALL of them have a muscular lining to them and in the presence of adrenal hormones our blood vessels undergo vasodilation (they get MUCH wider) but, in the presence of cortisol our blood vessels undergo vasoconstriction (they get MUCH narrower).  


Putting it all together:  the “Aha” moment

Muscles are very plastic….they are highly adaptable and will adapt to the position they are in most often.  If someone was to sit for a long period of time, they would most likely get tight hip flexors and tight hamstrings (hence why you see so much hamstring stretching and hip flexor stretching given to the elderly or those with desk jobs).  The same thing happens in your blood vessels.  During periods of prolonged stress our bodies are CONSTANTLY dumping cortisol into the blood.  Overtime, the muscular lining of your blood vessels will adapt to this and decide to just stay tight all the time because of all the chronic cortisol exposure.  

Think of you body like a garden, if you try to water your backyard with the straw from your Chick-Fil-A cup you will most likely not get to water your entire backyard by the time the sun goes down.  As a result the under watered areas will wither until you can get to watering them.

Apply this to your body…ALL of your nutrients, your oxygen, the phytochemicals from the healthy foods you eat are trapped in your blood and the rest of your body depends on the blood supply to SUPPLY your organs, peripheral tissues etc with adequate nutrition to function properly.  When people are chronically stressed their blood vessels become “hypertonic” or “tight”.  This “hypertonicity” leads to “hypoperfusion” or decreased perfusion of nutrients from the blood to a target tissue along with decreased removal of waste.  Decreased waste removal means inflammation sits in the body longer (increased joint pain and lethargy), decreased nutrient delivery means that the living tissues and organs cannot perform at their highest function anymore (one of those tissues is the brain).

Our brain is a big pile of nerves and blood vessels (emphasize the blood vessels).  In terms of the human brain we have many “non-essential” regions to the brain.  During times of stress the body will preserve “essential structures” over “non-essential structures”.  The base of the brain is absolutely essential, it contains the means for sexual reproduction, hunger, thirst and emotions.  Those things are all vital to life, however the cerebrum contains many “non-essential structures”.  The occipital lobe is responsible for vision (we know this is not necessary because people can still live while being blind), the temporal lode is responsible for hearing (we know that people can live while being deaf), also in the middle of the brain we have the hippocampus which converts short term experienced into long-term memories (we know that people can live for periods of time Alzheimer’s), in the front we have the frontal lobe where speech resides (we know that people can live while not being able to speak), in the frontal lobe we also have the ability to focus/concentrate (we know that people live with ADHD and ADD which impairs their ability to focus for long periods of time).  So you see there many of the regions of the brain that are not 100% essential to life (although they do make it a whole lot easier).  The way to think of the brain is like a flash drive, the largest the lobe the more storage potential it has.  Someone with ADHD is NOT less intelligent than someone else, they just have trouble focusing because their “flash drive” fills up quicker, and when a flash drive “fills up” it is no longer able to be used.).  So it is during prolonged periods of stress when your body and brain goes without adequate nutrient perfusion that you can start to see cognitive effects.  Namely atrophy, a decrease in size of the lobe that contributes to the lobe being maximally stimulated and no longer being able to do its job.  Again, the most common affected areas are of the hippocampus (conversion of short to long-term memory), and the frontal lobe which codes for concentration, focus and even serves as an emotional check-point.  Yes, when our frontal lobe atrophies we can actually become MORE emotional/LESS able to filter our emotions.  When we are angry or upset about something our brainstem tells us that we are angry or upset BUT it is our frontal lobe that decided whether or not that is a valid emotion given the context of the situation at hand (if you are feeling like since being diagnosed with cancer you are less able to control your emotions then do not worry, you are not a “mess” your frontal lobe is probably just being maximally stimulated due to all the stress and emotional processing, as a result you will not be able to filter and process your emotions as easily as you used to).


Taking action:  How do we use exercise to combat this?

Exercise is a “eustress” or positive stress.  In response to exercise we release adrenal hormones that cause our blood vessels to “vasodilate” or get larger.  By staying regular and consistent with your exercise you can increase your output of adrenal hormones that can actually “stretch” your blood vessels back out again little-by-little.  Each bout of exercise will cause those hypertonic blood vessels to stretch just a little bit more and overtime it can lead to better and normalized resting blood vessel diameters.  Once your resting blood vessel diameter improves your body will receive better blood supply aiding in better nutrient dispersion and waste removal. Studies show that by engaging in regular exercise a person can actually improve the size of their hippocampus which will improve their memory.  It is important to note that this was just REGULAR exercise, no fancy brain games.  The biggest thing to know is that cognitive changes will stem from stress.  


Ending thoughts

Cancer patients lead a stressful life, while their treatments get rid of the cancer those same treatments will make it significantly harder for the patient to do all the things they had been doing before.  From the time you are told “you have cancer” your stress begins to rise…you have a new doctor you have never heard of…you have new strange sounding medications you have to take, and you get hooked up to tubes, wires and bombarded with scans.  All of this can feel overwhelming and dehumanizing (which is stressful).  If you go into remission you may have nerves about “how long will I stay in remission”.

It is important to find time to reduce your stress!  Make time for yourself to reduce your stress.  Make time for reading, laughing, going out to dinner and being with people you love….ALSO…make time for EXERCISE!

At Maple Tree Cancer Alliance, we are striving to become the national standard in the field of Exercise Oncology, our patients have significantly lower feelings of depression and anxiety, likewise our patients have a remarkably higher sense of control/empowerment over their life.  We know that exercise is a HIGHLY EFFECTIVE and SAFE means to regulate stress and help you achieve better cognitive health.  If you feel less emotionally prepared to conquer your life, if you feel less able to remember things or you feel less able to concentrate then just know that EXERCISE is something you SHOULD BE DOING!!!