Dear Diet Coke: This Might Be Our Breakup Letter (Might.)

Some people crave chocolate. Others, wine. Me? Fountain Diet Coke from McDonald’s — through the proper straw, thank you very much. If you get it, you get it.

Yes, I know better. I know the ingredients — like aspartame, phosphoric acid, and caramel color — aren’t doing my brain or body any favors. And I do care deeply about brain health — it’s personal for me. Yet... here I am, fully aware and still occasionally in that drive-thru line, counting down the moments until the first cold, fizzy sip hits my lips. There is always an audible ahhh moment. The dopamine hit is real.

But this isn’t just about willpower or bad habits. For those of us who grew up in the Pepsi vs. Coke era — where brand loyalty practically defined you — the pull runs deeper than taste. We were conditioned by a culture that glorified soda. It was everywhere, all the time. Our parents drank it. Our friends drank it. TV commercials made us think it was the greatest gift (“I’d like to buy the world a Coke…”).  Is it any wonder some of us still reach for it today?

This is the story of how I got hooked, why I still crave it, what it’s actually doing to my brain, and why — like so many things in this fourth quarter of life, I haven’t given up on my goal to cut it out completely — I’m just learning to give myself a little grace (and time) along the way. Progress over perfection.

If loving you is wrong, I don’t want to be right. (At least not yet.)

My Ritual — The McDonald’s Magic

Why McDonald’s Diet Coke? I’ll admit it — I’m picky. Not all Diet Cokes are created equal, and fountain Diet Coke from McDonald’s is in a league of its own.

There are urban legends, of course: precise carbonation and syrup ratios, metal delivery tanks, proper balance of ice. Whether it’s science or marketing magic, we believe — and that belief makes it taste better. I’ve sampled plenty of Diet Cokes in my day, but none hit quite like a McDonald’s one.

For me, it’s a ritual. I pull into the drive-thru and order (they recognize me, and they know my fur baby by name). I hear the satisfying snap of the lid going on the cup. And then comes the moment of truth — that first icy, fizzy sip through the straw. There’s always an audible ahhh. Every. Single. Time.

But I’ll admit — the anticipation is so great that when there’s an issue, I might not be super sweet about it. Or if they hand me one that’s flat because the carbonation ran out? Or worse — tell me they’re temporarily out of Diet Coke and ask if Diet Dr Pepper would be ok? Seriously!? I’ll drive across town to another McDonald’s, zero shame (but a bit annoyed).

And yes, I keep extra straws — in my glove box and at home. When it was rumored that McDonald’s might switch to paper straws, I started stockpiling them like it was going to be a soda armageddon. I have hundreds. That’s bad. I know. Don’t get me started on what they did instead with that trial run of a flimsy clear straw that cracked every time. Let’s just say... I wasn’t amused.

My Diet Coke is my morning coffee — In fact, back in the day, I had a small framed sign on my work credenza that said, “no diet cokee, no workee”.  Though the size of soda that I order has changed (32 oz is now a 12 oz), I still need that morning ahhh moment. 100% transparency — it’s also a treat to myself when I’ve earned it, when I deserve it, when we’re going for a drive, having popcorn (or pizza), my birthday, a beautiful day... you get the picture —special exceptions.

My husband knows this well. On “one of those days,” he’ll offer to run and get me one. Sweet? Absolutely. Also self-preservation? Probably. Either way, I don’t argue.

It’s not about the caffeine. It’s not even about the taste entirely. It’s about the ritual — that small, familiar pleasure in the middle of a grown-up day. Maybe that’s why, in this fourth quarter of life, it still holds such power.

We Are The Cola Wars Generation

Part of why this ritual runs so deep? We are the Cola Wars generation. Yeah, it’s a real thing — no pun intended.

If you grew up in the ‘60s, ‘70s, or ‘80s, soda wasn’t just something you ordered at a restaurant — it was everywhere. Homes. Birthday parties. School events. Vending machines. Fast food counters. Movie theaters. TV trays in front of the television. It was stacked in garage fridges. Poured into glasses for family dinners. Packed in coolers for road trips and ball games. There weren't as many options as there are now, it was thee thing to drink.

And the marketing? Relentless.

That iconic song and commercial — “I’d like to buy the world a Coke…” — was practically burned into our collective memory. The Pepsi Challenge — where consumers were invited to a blind taste test between Pepsi and Coke — was pure pop culture.  

And let’s not forget the “New Coke” debacle, which invoked chaos when the loyalists revolted.

Coke vs. Pepsi wasn’t just a casual preference — it was identity. It was loyalty. Kids picked sides. Families picked sides. You were either a Coke family or a Pepsi family — and you absolutely knew which you were. The Cola Wars weren’t just a marketing campaign — they were cultural conditioning at its finest.

In my childhood home, Diet Pepsi was the beverage of choice for Mom — so naturally, it became the beverage of choice for the rest of us, too. I watched her lug home a big crate of glass bottles from the grocery store each week and unapologetically drink a couple a day. Her favorite snack when she was pregnant with my little sister? Diet Pepsi and sliced tomatoes. Some things you can’t unsee.

I don’t know for sure when my allegiance shifted to Diet Coke, but I’m certain it happened after I grew up and moved away. Maybe it was the influence of friends, or a simple change in taste. Or maybe, deep down, it was my small act of soda rebellion.

Given how much I’ve worked to support my brain health in recent years, you’d think I would have ditched my Diet Coke habit by now. But habits — especially ones we were groomed for — die hard. Unfortunately, the more I dig into what this stuff actually does to the brain… the more it stings. Apparently, my brain lights up like Times Square when I sip the stuff. Terrific.

So What Is It Doing to My Brain? Asking for a Friend…

Knowing that my soda habit could be chipping away at my brain health is... sobering.

Here’s a quick look at what some of those ingredients can do to our brains — no wonder this is a work in progress. (Sources below.)

👉 It lights up the brain’s reward centers — but in a confusing way. Brain scans show that sweet tastes — even from artificial sweeteners like aspartame — activate dopamine-related areas such as the ventral striatum and orbitofrontal cortex. But because there’s no real sugar or calories delivered, the brain doesn’t get the "expected reward," which can lead to increased cravings and disrupt normal satiety and reward cycles. (Well, that explains a lot. And here I thought it was just the straw magic.)

👉 It may alter the gut-brain connection — which affects more than digestion. Artificial sweeteners can change gut microbiota, which may in turn affect mood, metabolism, and cognitive function through the gut-brain axis. Early studies show that these changes could potentially contribute to glucose intolerance, neuroinflammation, and disruptions in the gut-brain signaling that helps regulate overall brain health.  

👉 It’s been linked to higher risk of stroke and dementia — though research is still evolving. A large observational study found that daily diet soda intake was associated with an increased risk of stroke and dementia. While this doesn’t prove causation, it adds to growing concerns that long-term artificial sweetener consumption may not be as "safe" for the brain as once thought.

👉 It exposes you to unnecessary toxins — including 4-MEI. Caramel coloring used in colas often contain 4-MEI (4-methylimidazole), a potential carcinogen and neurotoxin in animal studies. While not banned, it’s one more source of chemical stress on the body — and for anyone concerned with brain health and reducing toxin load, it’s worth noting.

So yeah — that’s a lot to sip on. Let’s just say, knowing what I know now makes that next sip a lot less carefree. And yet, God help me, I still crave it — the crisp, fizzy satisfaction that cuts through everything, the dopamine rush that only Diet Coke seems to deliver for me. Ugh.

I am determined though, and I’m getting there — down from three large McDonald’s sodas to a single 12 oz per day. I must admit (seriously, no BS here), the less of it I drink, the better I feel. And not only that, but when I do splurge with a large soda because ‘I deserved it’, I feel jittery and not so great.  Feels like progress to me.  Now if only I could train my dopamine receptors to get this excited about kale.

Awareness, Intention, and a Little Grace

At this stage of life, breaking habits we’ve held for 50+ years isn’t easy. It isn’t just about willpower — for me, it comes down to awareness, intention, and choice.

We can honor the rituals that have shaped us, while staying mindful of the ones that no longer serve us well. It’s about noticing. It’s about choosing.

Let’s be clear: I’m not interested in a life of constant restriction. I am interested in aging with intention — and giving myself a little grace with imperfection.

I’m under no illusion that I’ll never crave a McDonald’s fountain Diet Coke again. I will. And maybe sometimes I’ll still have one. These days, though, it comes with a lot more awareness — and a little less blind ritual.

I’ll keep noticing. I’ll keep choosing. And I’ll keep showing up for myself — imperfectly, but with intention.

Progress, not perfection.

Stay curious, friends.

_____________________________________

Source Notes

A few of the articles and studies that informed this post — because sometimes it’s good to know what’s really going on behind those bubbles:

👉 Aspartame and brain/gut health:Humphries et al., European Journal of Clinical Nutrition (2008): Aspartame — neurobehavioral effectsSuez et al., Nature (2014): Artificial sweeteners and gut microbiome disruption

👉 Phosphoric acid and bone health:Tucker et al., American Journal of Clinical Nutrition (2006): Cola intake and lower bone density in women

👉 Caramel color (4-MEI):Smith et al., PLoS ONE (2014): 4-MEI levels in cola beverages

👉 Artificial sweeteners and brain reward pathways:Green & Murphy, Journal of Neuroscience (2008): Sweet taste and brain dopamine responseFrank et al., Physiology & Behavior (2015): Artificial sweeteners and reward processing

👉 Artificial sweeteners and stroke/dementia risk:Pase et al., Stroke (2017): Diet soda intake and risk of stroke and dementia

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