Why is dementia different for women?

Understanding the differences between men and women in their risk of dementia could help scientists develop better treatments. We discuss these differences, as well as why dementia researchers still have a long way to go to fully understand them.

In this blog, we use the term ‘women’ to refer to those born with female sex, including female chromosomes and hormones, rather than gender.

We currently have very little research evidence specific to people with less common gender status, such as transgender or intersex.

Do women have a higher risk of dementia? 

Yes. Women have a greater risk of developing dementia during their lifetime.

In fact, around twice as many women have Alzheimer’s disease – the most common type of dementia – compared to men.

The main reason for this greater risk is because women live longer than men and old age is the biggest risk factor for this disease.

It’s much less clear if men and women of the same age have different levels of dementia risk.

Some studies have suggested that women over 80 years may be more likely to have Alzheimer’s disease than men of the same age. However, up until this age the risk appears to be about the same for both sexes.

Other studies have found no difference in dementia risk between men and women – even in the oldest age groups. So, it’s really not at all clear whether being a woman means that you’re more likely to develop dementia than a man of your age.

This doesn’t necessarily mean that sex isn’t an important factor in understanding dementia risk. It seems quite likely that each sex has a different blend of risk factors.

Why might women have different dementia risk factors?

Over the course of a lifetime, women tend to have very different experiences than men – particularly women from older generations.

Some of these are caused by differences in biology, such as menstruation, pregnancies and menopause.

Others are more related to traditional differences in gender roles, such as education, work and lifestyle. Many of these have an impact on dementia risk.

Two people sit in a cafe with mugs and a teapot

For example, we know that having a full education and opportunities for lifelong mental stimulation helps to delay dementia in old age – something known as ‘cognitive reserve’.

Historically, opportunities to go to university or work for many years in highly-skilled occupations have been less available to women, which has led some scientists to wonder if this might be an important risk factor for women.

Women may also be more severely affected by some risk factors than men.

Genetics

An important example of this is women’s greater risk when they have the ‘ApoE4’ gene variant.

Genes are the second biggest risk factor for dementia.

Nearly two thirds of people with Alzheimer’s disease – the most common types of dementia – have at least one copy of the ApoE4 gene.

Although men and women are just as likely to have the ApoE4 gene variant, its effect on dementia risk seems to be greater in women than it is in men. The reasons for this difference are not fully understood.

However, it could be extremely important for understanding how future medicines for treating dementia might have different levels of effectiveness for men and women.

Brain injury

Traumatic brain injury (TBI) is another dementia risk factor where there may be important differences between the sexes.

Women are more vulnerable to concussion and its long-term effects on the brain. This has led some to call for greater priority to be given to preventing concussion in women’s sport, such as football and rugby.

Sex, menopause and dementia risk

Risks of dementia associated with menopause

A major difference between older men and women is the menopause. This is when levels of sex hormones, such as oestrogen and progesterone, fall dramatically in women during late middle age.

Oestrogen is thought to have a range of protective effects on brain health, including an ability to block some of the harmful effects of substances involved in Alzheimer’s disease.

This has led some researchers to suggest that if a person has more exposure to oestrogen throughout their life, they might be less likely to develop dementia. For example, if they:

  • start periods at a younger age
  • have at least one pregnancy (when levels of oestrogen are greatly increased)
  • start menopause later.

By contrast, a very early menopause caused by surgical treatments for cancer may increase the risk of dementia in later years.

We also now know that most of the diseases causing dementia start developing in the brain around 10-20 years before clinical symptoms show, which for many women is around the time of their menopause.

It’s tempting therefore to connect the loss of this brain-protecting hormone with the start of processes in the brain that ultimately lead to dementia.

However, the relationships between sex, menopause and dementia risk are extremely complex and until recently researchers have not prioritised menopause as an opportunity to learn more about dementia. We need a lot more research before we can draw any firm conclusions.

A group of people sit around a table laughing

Hormone replacement therapy and dementia

The sex hormones oestrogen and progesterone are commonly used as medicines to treat the symptoms of menopause, such as hot flushes, sleep problems, anxiety and brain fog. This is sometimes called ‘hormone replacement therapy’ (HRT).

During the early days of HRT, there was concern that treatment might have health risks for women in later life, including a greater risk of dementia.

One major study from the US initially suggested this might indeed be the case but further studies found no effect or even a protective effect on dementia risk.

Over the last two decades, the way HRT is provided has been made safer and more efficient, so the potential for long-term risks has been greatly reduced.

Now most of the public interest is focused on whether HRT might actually reduce the risk of dementia.

Our dementia advisers are here for you.

Sex and dementia research

The importance of dementia research that can see differences between the sexes

It may surprise most people to find out that the vast majority of experiments and clinical trials carried out by dementia researchers have not been designed to see differences between male and female participants.

This runs all through the research process. Most older studies involving mice used only males and the first phase of some clinical trials also only recruit male human volunteers.

Most of the time there is a good reason for this bias towards male participants.

Experiments involving animals try to control the situation as tightly as possible so that the only difference between groups of animals is the subject of the research – for example, whether they’ve been treated with a drug or not.

We also need to protect younger women who might be pregnant in case a new experimental drug is unsafe for their baby.

However, the wider implications of doing research like this is that we still have a poor understanding of how diseases causing dementia might work differently in females.

Things are slowly improving as scientists start to appreciate the importance of sex differences in dementia research, but it will take a while to catch up.

How to reduce your risk of dementia

Although getting older is the biggest risk factor for dementia, evidence shows there are things you can do to help reduce your own risk. 

Find out more

35 comments

What is the average age to get Alzheimer’s My Dad had Alzheimer’s. Is hereditary
Hi I have just found this blog and find all the research facinating

Hi Carole, Just revisited this blog, Thanks for your interesting comments as you say not everyone fits the pattern of poor education ect your husband certainly sounds an exception to the best known risk factors, if you would like to share more please do.

Hi! I have been wondering, has anyone made a study, can there be a relation between cosmetics and alzheimer? We girls are most likely using all sort of chemicals... Dying our hairs, using all sort of products just few centimeter away from our most important organ... And skin is not waterproof...🤔🤔🤔

Hi Kati, thanks for your comment.

As far as we know, no research has been published on this topic. All beauty products that are sold in the UK are subject to safety testing by a qualified professional like a pharmacist to check that they are safe for people to use: https://www.gov.uk/guidance/making-cosmetic-products-available-to-consu… This makes it very unlikely that using cosmetics would increase a person's risk of dementia.

Read more about what can increase a person's risk of dementia: https://www.alzheimers.org.uk/about-dementia/risk-factors-and-preventio…

We hope this helps,

Alzheimer's Society website team

Very interesting theories re why females out number males with regards to Dementia. Has anyone ever thought about the dramatic drop in the "male" hormone TESTOSTERONE in post-menopausal females? Women suffer a very marked decline in this vital hormone but in the UK it is rarely considered important to replace this hormone. Why not? It may be the "missing link" to the mystery of why women seem prone to this horrible disease.

Women use scents from an early age
Other professions (lab techs, nurses,, hairdressers. etc) are exposed to strong scents. Could this have a bearing on this?

Hi Reg, thanks for your comment.

The link between dementia risk and solvent exposure is still unclear and not much research has been carried out in this area. We have a page on our website which discusses the link between dementia and air pollution, and how more work is needed to solidify if pollutants can influence dementia risk. You can read that here:
https://www.alzheimers.org.uk/about-dementia/risk-factors-and-preventio…

Hope this helps,

Alzheimer's Society website team

My mother and her 3 sisters, and now my own sister all had and died of Alzheimer’s. I had my mother and one of her sisters tested over a few months years ago by their geriatric doctors and a team from a hospital for Alzheimer’s. They tried to understand the difference between two of the sisters. My mother was married many years, had four children, suffered the loss of a young child. Her sister was never married and had no children. They all began small symptoms about age 75 (I’m 74) my sister is 83 and has been in a hospital about 6 yrs. none of them had any other illness or were on medication . They all died in about 10 yrs around 86. They were all educated , professionals, no obesity and avid readers and loved news papers and cross word puzzles. My sister played golf at least three times a week. I of course am scared to death of suffering that sad ending.

Hello Nancy,

We're really sorry to hear about your family. This must be a difficult time for you, and it's understandable that you feel worried.

It sounds like you may benefit from joining our online community, Talking Point, where people affected by dementia can share experiences, and offer advice and support. This could be a great place for you to chat with other people who have been in, or are going through, similar situations:
https://www.alzheimers.org.uk/get-support/dementia-talking-point-our-on…

Remember that you can always call our Dementia Connect support line on 0333 150 3456 for more dementia information, advice, and support specific to your situation. More details about the support line (including opening hours) are available here: https://www.alzheimers.org.uk/dementia-connect-support-line

We hope this helps, Nancy.

Alzheimer's Society blog team

So interesting yesyes

I live with 25 people who have various stages of dementia. I find it fascinating how they relate differently to certain stage of activities .

Gail,
I'm new to this conversation, but I hope you might explain more about your comment regarding relating differently to certain stage of activities.

Thank you very much.
Barbara Taber

My mother was diagnosed with premature dementia after a lifetime of physical and mental abuse from my Father, my Sister developed dementia and my brother has been diagnosed with Lewy bodies, both my sister and brother drank heavily I am wondering what are my chances of developing dementia.

My mom repeats everything and worrys alot telling me what am i going to do i cant remember anything. She will ask the same question over and over for 4 to five hours i explain and tell her we have problems solved and she still says what am i going to do repeating and starting conversation over. Need advice.

Hello Linda, thanks for getting in touch.

People with dementia often carry out the same activity, make the same gesture, say the same thing, make the same noise or ask the same question over and over. Often if someone is repeating the same question, they need reassurance rather than information. Learn more about repetitive behaviour, and read some tips: https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/sym…

For further advice on what to do, we'd recommend speaking with one of our trained dementia advisers who can listen to the situation and provide support. You can call the Dementia Connect support line on 0333 150 3456: https://www.alzheimers.org.uk/dementia-connect-support-line

Some people also find it helps to talk to others going through a similar situation. If that appeals to you, take a look at our online community, Talking Point. You can share your experiences and ask questions of the community, or just read what other people have to say: https://forum.alzheimers.org.uk/

We hope this is helpful. Remember to call our helpline whenever you need dementia advice or support.

Alzheimer's Society blog team

that is a very common behavior with people with dimentia. I work in a memory care and we have all these people that shows the same behavior like your mom.

When my mother did this, we wrote down answers to reassure her. She like to read and could read what I printed out for her again and again without having me to repeat. This helped since I worked part time from home and needed to focus. We also wrote other things like the day of the week and so on to help her be more oriented.

I agree with the comment made above, but one has to be careful of who they are talking about.

my wife has FTL dementia I spend a lot of time trying to work out why she has this, one thing I wonder is could being sterilised after having our children be a cause or other medical procedures ? There is nothing in her family.

Hi David,
Thanks for getting in touch.
We are often asked by our supporters whether general anaesthetics used in surgical procedures might increase risk of dementia, but the research on this subject is not conclusive: https://www.alzheimers.org.uk/about-dementia/risk-factors-and-preventio…
In most cases, however, researchers think dementia is caused by a range of different factors, rather than one single cause. These include things such as genetics, lifestyle and other environmental factors.
It is very difficult to know for any individual exactly what may have caused their condition.
-
Alzheimer's Society Research team

Hi Georgina, a good link to begin with is:
Does Brain Development in Childhood Set the Stage for Dementia?
Series - Alzheimer's Association International Conference 2015:
20 Aug 2015
It’s clear by now that in dementia, a disease mostly of old age, trouble starts decades earlier—but how early? Well—how about in the womb? Data presented at the Alzheimer's Association International Conference, 2015, held July 18-23 in Washington, D.C., lend some support to this radical idea. Scientists presented epidemiological, imaging, and even genetic studies that drew associations between early brain development and some atypical forms of Alzheimer's disease.
They also grappled with what those associations mean. “Might how your brain is wired in early stages influence how it degenerates later in life? That’s an extremely interesting concept,” said Jonathan Schott, University College London. Zachary Miller, from the University of California, San Francisco, stressed that early developmental patterns are not necessarily risk factors for later disease. "A more parsimonious explanation is that if you are going to get some form of dementia, then where it presents first, or the ‘locus of least resistance,’ might be determined by how your brain has developed," he told Alzforum. Whatever the cause and effect, researchers agreed that studying how learning disabilities and brain development influence later dementia could yield valuable insights into the disease processes, and even provide an opportunity for very early intervention.

Researchers have suspected for some time that there is a connection between learning problems and dementia. In 2008, researchers led by Marsel Mesulam at Northwestern University, Chicago, reported that people with learning disabilities..

The rest of the article is online..
My focus of interest is now on the daily and seasonal circadian rhythm, if you google Images for serotonin and melatonin it speaks volumes about insomnia.

I have often wondered if having ADHD makes dementia more likely. I mean - forgetting stuff is part of ADHD.

It would be really useful to have a link to the research studies mentioned in the articles to read. Apologies if I have missed it!