HRT and Dementia Information

Our Commissioning Programme Lead for Dementia has provided the following information regarding the claim Hormone Replacement Therapy is protective against dementia.

1. Clarity is important to distinguish between:
   • The effect in the present that the menopause can have on the brain, e.g. “brain fog”, and other symptoms that can be severe. These things aren’t dementia, although they sometimes cause women to worry that it might be.
   • The future risk of development of dementia in later life.

1. The Alzheimers Society says that “Studies looking at whether replenishing oestrogen levels using HRT can reduce women’s risk of dementia have been inconclusive and contradictory” [my emphasis] www.alzheimers.org.uk/about-dementia/risk-factors-and-prevention/hormones-and-dementia
   
   So, the findings of the Arizona study are eye-catching, but it’s important to point out that other recent studies find differently, e.g.: This study reported in the British Medical Journal last year is an example of research with different, and nuanced, findings: www.bmj.com/content/374/bmj.n2182
2. The British Menopause Society, in its statement on the documentary, takes a neutral position regarding future risk of dementia:
   
   “Women should be reassured that HRT is unlikely to increase the risk of dementia or to have a detrimental effect on cognitive function in women initiating HRT before the age of 65. However, HRT should not be initiated for the purpose of reducing the risk of dementia in postmenopausal women and at this time, there is not enough evidence to support prescribing HRT for prevention of dementia.”
   https://thebms.org.uk/2022/05/bms-comment-on-channel-4-programme-davina-mccall-sex-myths-and-the-menopause/
3. Finally, the detail is important when looking at research, in particular:
   • Studies must control for known modifiable risk factors for developing dementia. Women who have taken HRT for long enough to be included in research studies, may also be healthier in other ways. Eg. doing more exercise & healthy eating, and smoking less; things that are known to reduce dementia risk. https://www.thelancet.com/article/S0140-6736(20)30367-6/fulltext
   • Differences between oestrogen-only HRT and combined oestrogen+progesterone.
   • Different effects for:
     • women who start HRT at a younger age because of surgery;
       compared to…
     • women who go through menopause at the ‘natural’ time in their life-course.

Which in turn make it harder to interpret studies which combine these groups.