The paragraph you quoted references (but does not cite) studies about the effect of excessive iron consumption, not evidence for a causal link from blood donation to reduced cardiovascular risks.

It seems that there is some correlation between cardiovascular risk and blood donation, but this might just be due to a confounding factor: healthy people tend to donate blood more.

E.g. this study [1]:

Despite the significant difference in QRISK2 parameters between study groups, none of these parameters was correlated to the extent of donation when controlling for age, BMI and smoking status.

Or this one [2]:

No significant associations were found between blood donation and the risk of myocardial infarction in analyses restricted to men with hypercholesterolemia or those who never used antioxidant supplements or aspirin. The study results do not support the hypothesis that reduced body iron stores lower CHD risk.

Ironically this other Dutch study [3], shows an association (not causal) between frequent blood donation and cardiovascular health in women but not in men.

[1]: https://pubmed.ncbi.nlm.nih.gov/28797569/ [2]: https://www.ahajournals.org/doi/full/10.1161/01.cir.103.1.52 [3]: https://heart.bmj.com/content/105/16/1260

My recollection is that the inference that men should donate blood to protect their heart health is based at least in part on the fact that women see an increase in heart disease around the time they stop menstruating:

Once women reach the age of 50, about the age of natural menopause, their risk for heart disease increases dramatically.

https://www.webmd.com/menopause/guide/menopause-heart-diseas...

> Once women reach the age of 50, about the age of natural menopause, their risk for heart disease increases dramatically.

Wouldn't the hormonal changes associated with menopause be a more likely explanation for the increase in heart disease risk than the fact they are no longer losing blood periodically?

The correct answer is probably "both" rather than only one or the other. It's humans that like to create simple explanations and clear cut categories, not nature. Nature gives us egg-laying mammals because nature didn't ask our opinion beforehand.

How different is the increase of heart disease risk for men above 50?

A quick search indicates men actually see an increase after age 45. Some additional stats from the below source:

The average lifetime risk of developing cardiovascular disease was around 52% for men and 39% for women.

Lifetime risk jumped to 69% for men and 50% for women who had two or more cardiovascular risk factors by age 50.

Lifetime risk was just 5% among men and 8% among women who had optimal risk factors for cardiovascular disease at age 50.

https://www.webmd.com/heart-disease/news/20060206/how-great-...

Any thoughts on what Americans consume more of that gives them more iron?

Aside from the obvious (meat, nuts), fortification of processed foods is more common in the US than other countires, and the FDA has some mandatory fortification rules. Breakfast cereals and flour are required to be fortified with iron, amongst other things.