And the biggest preventable threat to your brain is…

I can’t think of a more appropriate time to share this next study than on the heels of yesterday’s conversation about stopping Alzheimer’s symptoms before they start.

Why? Because it’s the largest investigation into dementia risk factors of its kind. And its conclusion serves as a stark reminder to anyone concerned with warding off cognitive decline. (And really, who doesn’t fall into this category?)

This nationwide observational study appeared late last month in The Lancet Public Health. It featured data from more than one million French adults. And it found that alcohol abuse was the biggest preventable risk factor for all types of dementia. In fact, a whopping 57 percent of early-onset cases — that is, cognitive decline that starts before the age of 65 — were directly attributable to chronic heavy drinking.

Heavy drinking, according to the World Health Organization, amounts to more than three standard drinks daily for women. And more than four to five drinks daily for men. And it’s worth noting that men are disproportionately impacted by this risk. While women made up the overall majority of dementia patients, two-thirds of the early-onset cases were male.

The bottom line: No matter your gender, alcohol clearly poses a potentially devastating threat.

Don’t get me wrong. I don’t mean to make a case for teetotaling. I learned about the “Goldilocks” approach in medical school — namely, that too much alcohol isn’t good, but too little isn’t good either. And research supports the wisdom of moderation in this department.

In fact, studies show that light to moderate drinking — basically, any amount of alcohol below the limits listed above — can actually improve memory and reverse brain shrinkage.

As with most things, there’s a “U”-shaped curve when it comes to the benefits of booze. Staying within this sweet spot is essential — but so is making smart beverage choices.

My advice? Call it quits after two drinks. Regardless of your beverage of choice, your body puts everything on hold to metabolize alcohol first. So stopping at two drinks is just plain good sense—minimizing metabolic and sleep disruptions, while limiting hangovers, and keeping you from making poor diet decisions and gorging yourself on “late-night munchies”.

As for sensible beverage choices, I recommend sticking with spirits. The dangers of alcohol may be up for debate — but the lethal effects of sugar are not. Beer, champagne, and any cocktail that uses juices, sugar-sweetened sodas, or simple syrups — all deserve a hard pass in my book. And while some experts may disagree, I don’t consider red wine to be a safe drink of choice either (mainly in part to its high sugar content ¾ and the same goes for white wine). Clear liquors and sugar-free mixers (like club soda) with a twist of lemon or lime are best.

So, feel free to toast to your good health (just as long as you’re mindful about what you put in your glass). Cheers!