Articles

Does Estrogen Reduce the Risk of Alzheimer's Disease?

By Brock Smith, R. Ph.

Do women who use estrogen replacement before the age of 65 decreases their risk of developing Alzheimer’s disease? The answer posed by the American Academy of Neurology’s 59th annual meeting in Boston is: yes.

The study was part of the Women’s Health Initiative (WHI) memory study which was a sub-study of the WHI study. The WHI was a large US study of postmenopausal women. The study followed 7,153 women aged 65-79 before they enrolled in the memory study. The women were followed on average for 5 years. Out of the study population, 106 women developed Alzheimer’s or dementia.

The study showed that women who started any form of estrogen replacement before age 65 were close to 50% less likely to develop dementia or Alzheimer’s than those who used no hormone replacement before age 65.(1)

Prior studies have shown that women who started estrogen prior to 65 had reduced onset of Alzheimer’s. It appears that the estrogen promotes the growth and survival of cholinergic neurons and decrease cerebral amyloid deposition. Results of the study showed estrogen use in postmenopausal women delayed the onset and decreased the risk of Alzheimer’s (2)

A study from July 2000 showed direct physical evidence that estrogen use can protect women from Alzheimer’s. The study compared brain scans in two similar groups of women, they found that the women receiving estrogen had younger appearing brains than those not receiving estrogen. The blood flow between estrogen and non estrogen users was significant with the hippocampus showing the largest difference. It is believed that the hippocampus is involved in memory formation. (3)

In the studies that we look at, it appears that the older studies showing that estrogen at menopause and continuing without interruption can decrease the chances of Alzheimer’s or dementia. The newest result start to confirm that information from the older studies has merit. Everyone does conclude that more studies are needed to support the findings of the studies and to learn how hormone replacement affects long term cognitive health of those who have begun therapy before age 65.

2. Tang, M ET el. "Effects of oestrogen during menopause on risk and age at onset of Alzheimer’s disease." Lancet 1996 Aug 17 348 429-432.

3. Journal Neurobiology of Aging: July 2000