Think about the drink you reach for at three in the afternoon. For a lot of people, it's a cold can of soda. Maybe it's a sweet fizzy drink grabbed from the store cooler on the way home.

You know plain water is better for you. But plain water can feel like a chore. The can wins on the bite. Cold, sharp bubbles hit your tongue, and the slump lifts for a minute.

Here's what rides along with that bite. A 12-ounce can of regular cola holds about 39 grams of sugar. That's close to ten teaspoons, stirred into water and gone in a few gulps.

But the bubbles were never the problem. The first fizzy drink ever made had no sugar in it at all. It was plain water, and a man in England made it beside a brewery...

Linda did everything she was told to do.

Cholesterol coming down. Blood pressure steady. Two miles a day. Eating clean. Five different doctors over five years, and every one of them cleared her with a smile.

Twenty-one days after the last of those appointments, her husband found her on the bathroom floor.

She survived. That night an ER doctor said seven words to him that he has not been able to put down since: her cholesterol numbers had nothing to do with this.

Five doctors were not careless. They were looking at the things they are trained to look at. Nobody thought to look at the other thing.

👉 Find out what five doctors never thought to check

In the summer of 1767, a minister named Joseph Priestley moved to Leeds, in the north of England. His new house sat right next to a large brewery. And Priestley was a man who could not leave a question alone.

A layer of gas hung over the vats of brewing beer. People back then called it "fixed air." Today we call it carbon dioxide, the same gas you breathe out.

Priestley saw that water held close to that gas soaked some of it up. Soon he learned to make the gas at home, with no brewery at all. He shook it into water until the water fizzed. The drink tasted sharp and clean, a lot like the bubbly spring water from a famous German spa.

In 1772 he put the method in a short booklet that anyone could follow. He hoped his fizzy water might keep sailors safe from scurvy on long trips. The navy was keen enough to try it at sea.

It did nothing for scurvy. The fix for that was fresh fruit, not bubbles. Yet the drink caught on. In 1783, a jeweler in Geneva named Jacob Schweppe started to sell it in bottles.

Then came the turn. Over the next hundred years, shops began to stir sweet syrup into the fizz. By the late 1800s, drugstore counters all over America poured sugared soda from morning to night. The bubbles stayed. But the plain water got lost.

So the first fizzy drink is the one most of us now skip. And that's the one worth bringing back...

Let me explain what happens with a can. The sugar in soda is already loose in water. You don't chew it, and nothing holds it back. So it floods into your blood quickly.

Your body answers with insulin. That's the hormone that moves sugar out of your blood and into your cells. Once in a while, this works just fine.

Every day for years is a different story. The system that clears sugar can start to tire. That's one road toward type 2 diabetes, the kind that most often shows up in adults.

A team in England wanted to know how much one daily drink matters. They used the Norfolk study, which signed up more than 25,000 men and women aged 40 to 79 in the 1990s. Each person kept a food diary for a full week and wrote down every drink.

Then the team, led by Dr. Nita Forouhi, waited. In about 11 years, 847 of those people got type 2 diabetes. From there, they looked back at who had been drinking what.

The Norfolk study, 2015: Each daily serving of soft drink was linked to about a 21% higher risk of type 2 diabetes. Trading one daily soft drink for water, or for tea or coffee with no sugar, tracked with about 14% lower risk. For sweet milk drinks like milkshakes, the same trade tracked with up to 25% lower risk.

Here's the part I didn't expect. Trading a sugary drink for a diet soda showed no clear drop in risk once body weight was counted. Water did.

A food diary can show a link. It can't prove the trade caused anything. So a team at the University of North Carolina at Chapel Hill put it to a test.

Deborah Tate and her group split 318 adults into three groups for six months. One group was asked to swap at least two sweet drinks a day for water. They could pick still water or plain sparkling water. A second group switched to diet drinks. The third got general diet advice and nothing more.

After six months, the water group had lower fasting blood sugar than the advice group. That's your sugar level first thing in the morning, before you eat.

Of course, none of this is a sure thing. The Norfolk study watched people. It didn't change what they drank. Its trade numbers are math on habits, not a trial. And its water side counted plain tea and coffee drinkers too.

The Chapel Hill test has limits of its own. Most of the people were women, with an average age of 42. All three groups lost a little weight, and the gaps between them were too small to count. A bottled-water company paid for the trial and gave the water, though it had no say in the results.

So here's what I believe. One cold glass of plain fizzy water won't fix your blood sugar. But it costs almost nothing, it feels like a treat, and the studies we have all lean the same way...

A dental team at the University of Birmingham in England soaked pulled teeth in drinks. Sparkling water with nothing added wore away about a hundred times less tooth than soft drinks did. But flavored sparkling waters, with acid added for tang, were about as rough as orange juice in their lab tests. Check the label and skip any with citric acid.

Drop a few thin coins of cucumber and a torn mint leaf into the glass. Or add four or five whole raspberries. You get color and a soft hint of flavor, with no syrup at all. When the glass is empty, eat what's left at the bottom.

Tonic sits right next to the plain fizz on the shelf, and it looks just as clean. But a 12-ounce bottle carries about as many calories as a can of soda. Seltzer is just water and bubbles. Club soda adds a pinch of salts. Look for zero sugar on the label.

Priestley gave the world a drink made of two simple things: water and gas. Within a lifetime, the rest of us had poured sugar into it.

You can take the sugar back out. Keep the cold and the bite. Clean water was always the point, and the bubbles just make it easier to choose.

Trade one sweet drink a day for the next seven days. Then notice which one you miss.