Last week, President Joe Biden announced that he’d like to be president for another four years and immediately the critics chimed in.

Mostly that he’s too old.

Biden is now 80 — the oldest American president ever — and if he served another four years, he’d be 86 years old when his second term ends.

His potential (lord help us) Republican challenger, Donald Trump, isn’t far behind — he’ll be 77 next month.

But as a woman who recently published a heavily researched book on busting the ageist and sexist narratives of aging as a woman — which, ahem, I am — and who lives in Marin, one of the oldest counties in the Bay Area, I am distressed by this kind of ageist talk.

Yes, it is ageist.

Some people are worried about Biden’s cognitive abilities and yet age isn’t always a good indicator of whether someone is still mentally sharp or not. In fact, some 3.9 million people across the globe between the ages of 30 and 64 are estimated to have dementia. And with more people living into their 100s than ever before, the mid-80s isn’t all “that” old anymore.

The problem is that the way some are talking about Biden feeds into one of the two harmful narratives we have for people in their so-called Third Age — one of illness, frailty, disability, decline, dependency and burden. Sadly, that narrative has gotten worse over the past two centuries, and we know from studies that internalized ageist and negative stereotypes can actually become self-fulling prophecies. You can see how that can be a problem.

The other narrative Third Agers face is the healthy, vibrant, active, fit, sexy senior — the kind of seniors you see in ads holding hands on the beach, jogging or cycling, or gazing lovingly into each other’s eyes in Viagra ads (yep, we know what happens next). While it seems like a kinder representation, it’s just as inaccurate and exclusionary as the decline narrative — overwhelmingly White, heterosexual and abled.

We certainly want our country’s leader to be mentally healthy. Biden clearly has demonstrated that he is so far. There was lots of speculation that former President Ronald Reagan had Alzheimer’s while he was in office as his son suggested, and not just when he announced it six years after he left office — he was considered “inattentive” and “inept” and would fall asleep during Cabinet meetings, according to staffers — but that has been debunked. But we have had many presidents who were not physically healthy and some who were disabled, and yet they did the job they were elected to do.

No matter where you fall on the political spectrum, ageism hurts us all.

And it matters because the world is rapidly aging. The number of people aged 60 or older is expected to more than double by 2050, according to United Nations calculations.

It’s projected that 38% of Marin County’s population will be 60 or older by by 2025 — less than two years away! — and the largest increase will occur among those age 85 and older.

While supervisors are attempting to address the issues around housing, transportation, community services and more that such a population change will likely bring — all essential things to plan for that we are already way behind on — the one thing that must be addressed first is ageism.

“It is essential that you move forward to address ageism,” Diane Lopez, who heads Marin’s Commission on Aging, told supervisors.

“It is a socially accepted form of prejudice, the most pernicious but least acknowledged.”

You’re ageist and I’m ageist. And I was surprised to learn in my research that some of the most ageist people around are old people! They want to distinguish themselves from the “old” olds. Go figure.

Would I like to see presidential candidates younger than in their 70s and 80s? Absolutely. I’d also like to see more women, LGBT people and people of color throw their hats into the ring (and win). It isn’t ageist to say that.

Age alone doesn’t matter. So stop worrying about Biden’s age. Unless and until his cognitive abilities are deemed problematic by medical professionals, it’s ageist.

Let’s be kind and gracious to our elders. If we’re so blessed, we’ll be one one day.

Vicki Larson’s So It Goes opinion column runs every other week. Contact her at vlarson@marinij.com and follow her on Twitter at OMG Chronicles.