Hormone Replacement Therapy: It Might Be Good For Your Brain?
Every now and then I have the pleasure of featuring a guest blogger – someone whose medical opinions are particularly intriguing or controversial. Dr. Avrum Bluming submitted a really interesting post last month about cancer – and whether or not we scientists really do understand it fully. In this post, Dr. Bluming reviews the scientific literature on Hormone Replacement Therapy, and finds some interesting evidence that estrogen might actually be good for the brain – to reduce the risk of dementia. He also suggests that “chemo brain” – the mental fog associated with cancer therapy (especially breast cancer), may be caused by a rapid decrease in estrogen. Read his comments carefully and let me know if you find his analysis convincing… And watch out for the passionate “zinger” at the end!
————
The April 29th 2007 issue of the Sunday New York
Times carried a front-page article about the mental fog following treatment of
cancer with chemotherapy.(1) This fog, referred to as chemo brain, usually
clears, but, in approximately 15% of treated patients, may persist for years,
according to the article. All the patients presented
in the article were women, most or all were breast cancer survivors, and the
article does state that a possible cause of chemo brain in these women may be
the lowered estrogen in their bodies, due to their being catapulted into
premature menopause by treatment. The article further states that abrupt
menopause leaves many women fuzzy headed in a more extreme way than natural
menopause, which usually develops gradually. The article goes on to say that
studies of chemo brain have been conducted, overwhelmingly among breast cancer
patients because they represent the largest group of cancer survivors and
because they tend to be sophisticated advocates, challenging doctors and
volunteering for research.
In 1996 a
14-year study concluded that estrogen replacement therapy may be useful for
preventing or delaying the onset of Alzheimer’s disease.(2)
In 1997 a Columbia University study reported a significant
reduction in the risk of Alzheimer’s disease among postmenopausal women taking
estrogen.(3)
In 2000 that same group reported lower levels
of circulating estradiol, the most common form of circulating estrogen, among
women who developed Alzheimer’s disease compared to those who did not.(4)
Estrogen
has been reported to stimulate nerve growth and synapse formation.(5) (Synapses
are nerve to nerve connections), and to play a beneficial role in nerve response to injury.(6)
In 2003 researchers at the University
of Southern California
identified a mechanism for estrogen-mediated nerve cell protection, which
involved preventing the accumulation of calcium within the mitochondria of the
nerve cells.(7,8)
Estrogen
has also been shown to prevent the buildup of the abnormal chemical called
hyperphosphorylated tau protein, characteristic of Alzheimer’s disease.(9)
Estrogen
administered to female rats who have had their ovaries removed enhanced the
rats’ learning ability.(10,11)
Estrogen
administration to postmenopausal women has been associated with improved verbal
memory.(12-14)
A 2001 analysis of 29 published studies concluded that hormone replacement therapy was
associated with a 34% decreased risk of dementia.(15)
A 2002 study from Johns Hopkins reported a 67% decreased incidence of Alzheimer’s
disease associated with hormone replacement therapy.(16)
A 2006 study from Stanford and the University
of Adelaide in Australia
concluded that early initiation of hormone replacement therapy, from around the
time of menopause may contribute to improved cognition with aging and may delay
dementia.(17)
One can
often selectively quote the medical literature to support a particular point of
view. However, in the face of all these previously quoted studies, one should
at least look skeptically upon the 2003 report from the Women’s Health
Initiative, which found that combination estrogen plus progestin hormone
replacement therapy increased the risk for dementia when started in women over
age 65. The study reported increased dementia as early as 12 months after
starting HRT, but no increased incidence of mild cognitive impairment
associated with HRT use.(18) If HRT
were really harmful to the brain, a finding that goes against most of what we
think we understand about the beneficial effects of estrogen on brain function,
one would expect early cognitive impairment to become apparent before
full-blown dementia was encountered.
A June, 2004 update of that same study concluded that even estrogen alone increased the
risk for dementia. This update reported an increase in mild cognitive
impairment as well, but the results for mild cognitive impairment were not
statistically significant after women who had this impairment at the start of
the study were excluded from analysis.(19)
The report
on chemo-brain from the New York Times should force us to look again at the
role of estrogen in maintaining normal brain function. Throughout history, male
dominated societies have adopted practices harmful to women. These include foot
binding, genital mutilation, and withholding privileges such as the right to
vote, hold office, and participate in government and education activities. We
should not add premature elimination of HRT, based on facile conclusions and
conflicting data to this list.
Avrum Bluming,
MD, MACP
Clinical Professor of Medicine
University
of Southern California
(References on next post)
This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
Jane Gross contacted me about the article she was working on (for The New York Times). My first realization that something was wrong (or different) came after chemo treatment #1. it affected nerve endings (hands, legs, feet) and cognitive function (losing moments of time and location) and I was told that it was normal and would last 9-12 months. It’s frustrating to have so little understood and published about the effects of chemo and the blood/brain barrier, what effects cancer, itself (possibly through emphasis that estrogen plays), immediate menopause, taking anti-cancer meds for 5 years has on the cognitive and nervous system functions. For 3 years I’ve had to deal with being a new person because I am aware of my cognitive difference (acquired brain injury – ABI) and yet I can’t function to a level in order to work and sustain myself and son. This has been a life altering occurence that makes it difficult to put my Breast Cancer experience behind me. Chemo Brain is real! The cognitive deficits show up on testing and even though it may be considered a mild ABI you cannot possibly return to the life you had before. The most difficult part is that it is an invisible disability and in our world today, many people don’t have a lot of patience. What is surprizing is how many BC survivors still get dismissed from their doctors and thus will not admit that there is a problem nor seek help.
I’ve always been very aware of my body and it’s functioning. Looking back, I would say that cancer, chemo and anti-cancer meds, menopause (lack of estrogen) all played a part in my mental changes(;mostly declines but a few new talents as well). What it boils down to is: my cancer was hormone driven so I can’t have estrogen or progestorone and I’m seriously effected by chemo brain/fog. What has surprized me is that there has not been a reference to cancer type (HER2 , hormone positive, etc.) in the studies that have been done. Dr. Bluming’s conclusion is right however, estrogen may help maintain cognitive function but it can also promote/feed cancer. As a Survivor I don’t want one more woman/person to have to go through the diagnosis and treatment and aftermath. Along with studying Estrogen and Brain function, we need to study chemo (types) and brain function, bio-identical hormones and cancer rates, providing more information and theraputic interventions for chemo-brain (because every therapist with tell you that the quicker that there is intervention for a brain injury, the better the results). I’m thrilled to be alive but the game got changed and no one told me this could happen!
Jane Gross contacted me about the article she was working on (for The New York Times). My first realization that something was wrong (or different) came after chemo treatment #1. it affected nerve endings (hands, legs, feet) and cognitive function (losing moments of time and location) and I was told that it was normal and would last 9-12 months. It’s frustrating to have so little understood and published about the effects of chemo and the blood/brain barrier, what effects cancer, itself (possibly through emphasis that estrogen plays), immediate menopause, taking anti-cancer meds for 5 years has on the cognitive and nervous system functions. For 3 years I’ve had to deal with being a new person because I am aware of my cognitive difference (acquired brain injury – ABI) and yet I can’t function to a level in order to work and sustain myself and son. This has been a life altering occurence that makes it difficult to put my Breast Cancer experience behind me. Chemo Brain is real! The cognitive deficits show up on testing and even though it may be considered a mild ABI you cannot possibly return to the life you had before. The most difficult part is that it is an invisible disability and in our world today, many people don’t have a lot of patience. What is surprizing is how many BC survivors still get dismissed from their doctors and thus will not admit that there is a problem nor seek help.
I’ve always been very aware of my body and it’s functioning. Looking back, I would say that cancer, chemo and anti-cancer meds, menopause (lack of estrogen) all played a part in my mental changes(;mostly declines but a few new talents as well). What it boils down to is: my cancer was hormone driven so I can’t have estrogen or progestorone and I’m seriously effected by chemo brain/fog. What has surprized me is that there has not been a reference to cancer type (HER2 , hormone positive, etc.) in the studies that have been done. Dr. Bluming’s conclusion is right however, estrogen may help maintain cognitive function but it can also promote/feed cancer. As a Survivor I don’t want one more woman/person to have to go through the diagnosis and treatment and aftermath. Along with studying Estrogen and Brain function, we need to study chemo (types) and brain function, bio-identical hormones and cancer rates, providing more information and theraputic interventions for chemo-brain (because every therapist with tell you that the quicker that there is intervention for a brain injury, the better the results). I’m thrilled to be alive but the game got changed and no one told me this could happen!