What HRT Starting Age Means For Alzheimer’s Risk

…and other items from this week’s health science news:

The brain needs hormones too

Women get Alzheimer’s at nearly twice the rate than men do, and deteriorate more rapidly after onset, too.

It’s tempting to think that estrogen might be to blame, but Alzheimer’s typically happens after menopause, so what gives?

A recent study followed 183,450 postmenopausal women for an average of 13.3 years, covering more than 2.43 million person-years and 3,948 dementia cases, investigating the relationship between HRT starting age and dementia risk.

The overall finding: HRT use was associated with an average 10% lower risk of all-cause dementia compared with non-use.

However, there is some nuance, as that global average contains quite a lot of different scenarios:

For most people, HRT was associated with lower dementia risk when started between ages 46 and 56, but not when started after 56. The strongest overall association was seen when HRT began at 51–56 years, corresponding to a 23% lower risk, suggesting an ideal “window of opportunity” for starting.

However, women who had surgical menopause showed a stronger association still, with HRT linked to a 26% lower dementia risk (or 28% lower in those with the APOE ε4 genetic variant that’s associated with increased Alzheimer’s risk), regardless of age of starting.

Additionally, HRT was also associated with an even lower Alzheimer’s disease risk specifically. The association was stronger after surgical menopause, at 32% lower risk, compared with 11% lower risk after natural menopause.

In other words, it’s not really about age, so much as it’s about minimizing the low/no-estrogen phase, which also explains why for those with a naturally later menopause, starting HRT commensurately later wasn’t a problem (because those people had still had their endogenously produced E-levels for longer, before menopause and then starting HRT after that).

Read in full: HRT linked to lower dementia risk, but timing and menopause type matter ← unclear why the article header photo currently shows someone loosely holding a sterile pad to their upper arm. Our hypotheses: a) they thought this was an HRT patch (it’s not) and that that would be a good site for an HRT patch (it’s not), or b) they thought the upper arm was a good site for HRT injections (it’s not) and additionally thought that this was the way to hold a sterile pad to stem bleeding (it’s not).

Related: Alzheimer’s Sex Differences May Not Be What They Appear

What does “plant-based” actually mean?

While the term “plant-based” gets used a lot, it has no single agreed-upon meaning, just a large consensus, and even that general consensus varies by age.

In numbers:

• Vegan interpretation: 56% of respondents understood “plant-based” to mean vegan, with no animal products.
• Plant-forward interpretation: 35% interpreted it as eating plenty of plant foods while still consuming some meat, dairy, and eggs.

As for the age differences, 63% of adults ages 65–94 equated “plant-based” with vegan, compared with 51% of adults ages 18–34.

At 10almonds, we agree with the majority consensus there, i.e. that which is incidentally also the interpretation as generally used by relatively older people.

But since we’re aware of the potential ambiguity, we usually try to remember to clarify that we indeed mean “entirely plant-based”.

Read in full: The term ‘plant-based’ diet is ambiguously used in US. Interpretation differs between older and younger adults

Related: Be A Plant-Based Woman Warrior – by Jane Esselstyn & Ann Esselstyn

The shingles vaccine and your heart

Researchers (Dr. Fabiana Corsi-Zuelli et al.) analyzed US electronic health records from the TriNetX network, covering more than 100 million people across approximately 60 healthcare organizations, and found some heartening results about the US transition from the live-attenuated shingles vaccine to the recombinant vaccine.

In few words:

• Overall cardiovascular disease: 9% lower overall cardiovascular disease burden over seven years.
• Heart failure: the recombinant-vaccine group had a 12% lower burden of heart failure.
• Ischemic heart disease: the burden of ischemic heart disease was 10% lower.
• Atrial fibrillation: atrial fibrillation was 7% lower in the predominantly recombinant-vaccine group.

As for how this probably works: Dr. Corsi-Zuelli and her team suggest that the recombinant vaccine’s AS01 adjuvant could influence immune and endothelial function. It may cause longer-lasting changes in monocytes and reduce inflammatory responses involving interleukin-6 (IL-6), thus lowering cardiovascular risk. Have you got yours?

Read in full: The US switch in shingles vaccines revealed an unexpected heart health pattern

Related: Could the shingles vaccine lower your risk of dementia?

Take care!