Preventing Dementia: Hormones and Brain Health

By Susan E. Sklar, M.D.

Preventing dementia is a challenge. 30% 0f people aged 85[1] will have the diagnosis of dementia. There are connections between hormones and brain health. The purpose of this blog is to help you understand the incredible importance of hormones to good brain health and cognition.

older couple thinking

What are hormones?

First let’s get our definitions straight. Hormones are messengers. They are made in your glands and then circulate long distances to carry messages to other parts of your body. Hormones regulate everything that goes on in your body. They regulate reproduction, the rate at which you age, your moods, the health of your heart, and the health of your arteries. They regulate our metabolism and energy. Very importantly hormones regulate your brain health. They help neuroplasticity, the ability of your brain to learn new things.

What is cognition?

Cognition is the ability to learn, retain, and recall information. As humans, our brains are highly evolved, more than any other animal, in this ability. Our cognition is very complex. It is a multidimensional set of intellectual functions like judgment and evaluation. We know lower animals can get out of danger. They can recognize danger. They form emotional attachments. We know our dogs and cats do. But the ability to judge and evaluate really is a human ability.

What do we mean by dementia?

Dementia is a condition where your brain is not working properly and you are no longer able to carry out your usual daily activities such as work,  shopping or taking care of your house.  You might have memory problems, difficulty organizing or personality changes.

What is neuroplasticity?

Scientists know that your brain can grow new nerves. Moreover, a damaged brain also can improve the communication between one nerve and another. This is what is known as neuroplasticity. To understand the idea, think of your nerves as a freeway system. If you have a stroke or other health problem that damages your nerves, part of that freeway system is blocked.

It’s the same thing that happens if you normally take this freeway to work and there is a huge accident blocking your route. You will find another way to get to your destination. You might get off the freeway and go through city streets to get there.

Your brain can do the same thing by rerouting its electrical circuits. If one part of your brain isn’t working well, another part can learn to take over. Therapists who work with stroke patients who were not able to walk help to train other areas of their brain to take over. It takes a lot of work to retrain your brain, but it can be done.

What are the signs of cognitive problems and early dementia?

Brain Fatigue

Preventing dementia is possible if you know the signs. Brain fatigue is one of the possible signs that you may have be having problems with your cognition. This is where you start to watch a movie or a TV show and find you’re having trouble following the plot. The reason for this is your brain just lacks the energy to continue the constant requirements of paying attention and absorbing new information.

Brain Fog and Depression

Brain fog is another possible sign. This is where you feel like things are unclear and your thinking feels fuzzy. This is a classic sign of inflammation in the brain. Also, a feeling of depression is another sign. We know that in Alzheimer’s often the first sign of a problem is depression.

The reason depression is a sign of early dementia is because of brain anatomy. Your memory center in your brain is right next to your emotional center. A condition that affects one of them can easily affect the other.

Trouble Concentrating

Another sign of cognitive change is difficulty concentrating. As mentioned before, fatigue while reading or watching TV or watching a movie can be a sign. When someone who used to read three books a week and now they cannot even get through a single book, we know they have had a change in cognition. They read, and they don’t remember.

Change in Personality

A radical change in personality is another sign of a problem. A person who changes from conservative politics to far left shows a radical change in personality. Or someone who has always been modest or prudish, now acting flirtatious and dressing provocatively. Or someone who has always acted appreciative and been generally content becoming irritable, withdrawn, and insulting. This may be a sign of trouble.

When should you do something about your cognition?

When is it time to be concerned?

  • Persistent brain fog.
  • Being more forgetful.
  • Often misplacing things and it’s not typical for you.
  • Memory lapses in the middle of a sentence. This happens to lots of people. But if it’s happening all the time and you can’t get back to where you were, you may have a problem.
  • Taking longer to learn new things.

These symptoms don’t mean that you have dementia or Alzheimer’s, but they mean that you could have a problem starting. Therefore, we recommend that you don’t write it off to age, stress or anything else. If you’re having consistent problems, you must do something about it.

What are the Causes of Dementia?

Dementia is a complex condition. There are multiple causes of dementia. Lifestyle problems like stress, lack of exercise, poor diet, and lack of sleep are important factors.  We know that prior head injuries, even if they are not  severe concussions are  risk factors for dementia.

Exposure to toxins[2] accounts for a lot of the dementia in the modern world.  We are exposed to numerous toxic chemicals from gas emissions, home cleaning products, contaminated water and food sprayed with pesticides. We also see exposure to water damaged buildings and subsequent mold growth causing dementia.

Dementia is also a disease caused by infections. Many of the infections such as Lyme, Epstein-Barr, and herpes virus infections can become activated later in life and cause cognition problems. By recognizing and treating these causes, we can prevent dementia.

We also see that hormone changes can be a significant cause of dementia and cognition problems. Women are more susceptible than men and one theory to explain this is decline in hormones.

Dementia is not a simple disease that one pill is going to solve.

What is the Role of Hormones in Preventing Dementia?

Hormones promote brain health and prevent dementia in multiple ways. The first is enhancing neuroplasticity. Hormones are protective against some of the toxins mentioned previously. In addition, hormones encourage the growth of new neurons (nerve cells in the brain). Hormones also dampen inflammation which causes significant damage to our brains. They increase the speed and efficiency of our brains.

There are a number of different types of hormones. Some are called steroid hormones. The ovaries, the testes, and the adrenal glands are the producers of the steroid hormones. The ovaries produce estrogen, progesterone and testosterone hormones that control a woman’s physical appearance, reproductive and sexual functions. Likewise, in men the testes produce testosterone that regulate men’s appearance such as muscle mass, and strength. Of course, testosterone controls sexual desire and drive for both men and women.

The adrenal glands produce steroid hormones also. The adrenals make cortisol which controls your metabolism, immune system, blood pressure, and stress response. Too much stress and too much cortisol hurts your brain and causes it to shrink. Keeping your brain healthy and preventing dementia depends on keeping stress levels under control. The adrenal glands also produce DHEA and pregnenolone, two important steroid hormones for brain health and preventing dementia.

There are other hormones such as thyroid hormone that are important for brain health. Thyroid hormone decreases inflammation and improves nerve efficiency.


Estrogen and progesterone prevent dementia

Estrogen and progesterone benefit cognition and prevent dementia. They do this by damping down inflammation. Inflammation is a fire inside your body that damages your organs.  Inflammation is the underlying cause all the chronic diseases. Chronic diseases like heart disease, cancer, and dementia are all caused by the damage inflammation does to our arteries, tissues and brain. Estrogen and progesterone act to dampen down the fire inside your brain.[3]

Also, estrogen helps to increase the connection between one nerve and the next. The connection between nerves is very important in overall function of the brain. Moreover, estrogen controls moods such as anxiety and depression. Estrogen improves the speed between the nerves of the brain.

Estrogen slows down degeneration of nerves. There is a certain amount of degeneration of the nerves of the brain with age, exposure to toxins, and with exposure to stress. Estrogen does a lot toward actually dampening our stress response. So, estrogen works not only directly to help the nerves in our brain.

Estrogen regulates plasticity, the ability to lay down new pathways.  Estrogen improves detoxification by helping our brains get rid of toxins that enter. Also, estrogen maintains brain speed. There have been studies done on women who had a hysterectomy and had their ovaries removed prior to menopause. They had no longer had a source of estrogen and their brain speed decreased by 15%.[4] So that’s a really a very concrete example of how estrogen helps brain speed.

Even men have some estrogen. Researchers think that a lot of the benefits of testosterone in a man’s body comes from the fact that a small amount of gets converted to estrogen and provides these estrogen benefits.

Estrogen Blocks the Harmful Effect of Cortisol

Cortisol is the fight or flight hormone. It is the red fire alarm reaction in our bodies. Estrogen blocks the harmful effects of cortisol and makes our bodies more resilient to stress.

Progesterone Protects the Brain

Progesterone does a lot of similar things. It helps the memory connections and it helps to maintain a healthy blood-brain barrier. The blood-brain barrier is a protective barrier between the brain and outside toxins.  The healthier it is, the less likely you are to have problems with toxins and inflammation entering your brain. This is one way progesterone helps to protect your brain and prevent dementia.

Testosterone is Essential to Men’s Brain Health

Low testosterone in men has been associated with increased risk of dementia and Alzheimer’s disease. Testosterone is important for spatial memory. The ability to stay oriented when you are going places, driving, and walking involves spatial memory. Spatial memory is the ability to know whether leftovers from dinner are going fit a little storage container. So, we see that testosterone is important for that and both men and women. We think a lot of the benefits of testosterone come from its conversion into estrogen for men.[5]

What are the hormone changes through the lifecycle?

Women have the most dramatic changes

Women have a tremendous amount of change in their hormones through their life cycle. Initially before puberty we don’t really have much in the way of hormones circulating in our bodies. Then in our teens it starts to get really erratic. As any of you that have dealt with teenage girls, they are as erratic as their hormones change.

Then people do grow up. Moving through the adult years we have the ups and downs of the menstrual cycle. Some women are so sensitive to the effects of estrogen that their cognition varies during the menstrual cycle. There are times in the menstrual cycle when estrogen levels are high and times when it is very low. And there are women who notice changes in their cognition with those peaks and valleys in estrogen during the month.


Pregnancy is a time of especially huge hormone changes. And then another very erratic time is perimenopause and menopause. A lot of women and the people around them really suffer because of mood problems, hot flashes, insomnia, and other symptoms during this period in the life cycle. Then, finally in menopause, the ovaries stop producing hormones.


Hormone changes level out for some women during menopause. For many women, they don’t. Some women have hot flashes for years and years, even after they stop having menstrual periods. This is probably due to the storm of inflammation that occurs when women lose their estrogen in menopause.

Researchers use animals to study ways of preventing dementia. They use mice because they’re mammals. They’re little mammals but they have a much shorter life span than humans. Therefore, they can see what happens to them over their lifespan. So, researchers take out the little mice ovaries. This made them menopausal.

Then researchers gave the mice estrogen. They found that mice that were on estrogen, had better spatial memory than mice without ovaries. When they gave the mice estrogen their learning and memory improved consistently. For humans the scientific studies showed varied results. Sometimes estrogen showed benefit and sometimes it didn’t. And it turns out in the human studies, the estrogen used the most was Premarin. Premarin is not a bioidentical hormone but the mice got bioidentical hormones like estradiol. This probably accounted for different outcomes in the human and mouse studies and shows the importance of using bioidentical hormones which are identical to what our bodies make.


While women have a well-defined part of their lives when they no longer have regular periods and the reproductive system stops working, for men it is not so dramatic. But men do also go through some changes in their reproductive lives. The name of this is male menopause or andropause.

At about age 30 men start losing about 1% of their testosterone every year[6]. The lowering of testosterone as they age causes less sexual desire, less penile erections and for some men a generalized feeling of less well-being. One of the signs of low testosterone that affects brain function is becoming moody. These are the grumpy old men seen on television and the movies, like Oscar in the Odd Couple, but this happens in real life. Along with being grumpy, low testosterone has been associated with a decline in cognition.

Other Important Steroid Hormones that Prevent Dementia

Pregnenolone is a steroid hormone that most people haven’t heard about. It has been called the “grandmother” of all hormones since it is the first step in making our other steroid hormones.  It functions as a neurotransmitter in the brain and it functions as a neurotransmitter in the hippocampus, in the memory center of your brain. Our levels decrease with age.

DHEA is another steroid hormone made in the adrenal glands. It has brain protective effects and is very anti-inflammatory.

A well-functioning thyroid improves brain function

Having your thyroid functioning well increases your brain’s ability to heal itself. It improves nerve to nerve connections and grows new baby nerve cells, called stem cells. Thyroid enhances all the neurotransmitters, which are the chemical transmitters that send signals between nerves. Thyroid hormone helps to cut down the inflammation and degeneration of nerves that occurs after injury. So thyroid works as a protective in a few different ways.

Using Hormones for Preventing Dementia

Does everyone need to be on hormones?

Hormones are such an incredible brain protector, but should it be essential for all women and men? Does everybody have to do it? There are some men and women who get to very old age and who have great brain function and good physical function and never took  hormone supplementation. But, it’s definitely getting harder and harder for this to happen given the conditions of modern society. People are exposed to so many things that are bad for our brains, whether it’s stress from the news, toxin exposures, or difficulty getting healthy food sources that contain the nutrients that our brains require.

An Important step in preventing dementia is fixing hormone deficiencies

First, try to boost your hormones naturally. Younger people can improve their hormone production through lifestyle. This involves cutting out sugar as an important step. Vigorous exercise raises testosterone in younger men and women. Because testosterone is produced during the deepest sleep, getting adequate deep sleep is important.

However, once a woman goes through menopause or for older men, andropause, they are not capable of making adequate amounts of estrogen, progesterone or testosterone anymore. Even though lifestyle part is important as far as getting your brain to work better, it’s not going to help your hormone production. So, for that, we use hormone restoration.

Preventing dementia by avoiding toxins that are hormone disruptors.

I advise my patients to decrease environmental toxins coming into their bodies. Many toxins interfere with your body’s estrogen function. Things like pesticides, the phthalates that are in a lot of body products and the parabens that are in body products confuse your body. Your body thinks these are estrogen but they not healthy estrogens. And so those false estrogen-like compounds interfere with your own healthy estrogen benefits.

Hormone Restoration for Preventing Dementia

At the Sklar Center, we use safe bioidentical hormones. Bioidentical hormones replace the lost hormones from menopause and andropause.

Some of the hormones I use are:

Estrogen in a topical form as a cream or a gel or a patch.

Progesterone often as a capsule because it is very brain calming. When it is used in capsule form it calms anxiety and it helps restore natural healthy sleep. It doesn’t work like Ambien and the other pharmaceuticals which sedate you but don’t give you normal healthy sleep patterns.

Pregnenolone is a steroid hormone that most people haven’t heard about, but pregnenolone is a steroid hormone. It is available as a capsule.

DHEA is another hormone that we use as in capsule form as a supplement. It has a lot of brain protective effects. It’s very anti-inflammatory.

Thyroid improves brain speed and promotes growth of new nerve connections. If thyroid function is low we prescribe thyroid hormone replacement.

Melatonin is important for sleep. It’s also important because it’s an antioxidant and protects the brain.

Testosterone is important for protecting nerves, for helping our spatial memory.

How Do We Prescribe Hormones to Prevent Dementia?

We measure people’s blood hormone levels and treat according to symptoms and blood levels. We recommend a hormone restoration regimen, usually starting on the low side to reduce bothersome but minor side effects. There are very few side effects, but we want to avoid them. We have goals for optimal hormone levels. We retest every three months and adjust the regimen until hormone levels are optimized and symptoms improved or resolved.

As you can see, multiple hormones are involved in cognition and memory.  We restore hormones as part of our program to enhance cognition and prevent cognitive decline.  Here is a link to our Services page: Brain Health, Cognition, and Memory: Preventing Cognitive Decline.


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