You brush at night. Then you floss. And some mornings there's still a thin pink swirl in the sink.

A little blood is easy to write off as brushing too hard. Take a look at the numbers, though. The Centers for Disease Control and Prevention counts more than 42% of adults past 30 with some form of gum disease. Past 65 it runs to almost 60%.

It gets pricey, too. A deep cleaning runs a few hundred dollars. Gum surgery climbs into the thousands, and most dental plans cap out long before that.

But your gums are built out of something you can eat. It's in the produce aisle all year. It costs about a buck and a half. And one of them holds more than two days' worth...

Does your ear ringing seem to get LOUDER the quieter the room gets?

Especially at night?

If yes, there’s an unusual reason this happens.

And an even more unexpected way researchers are targeting it.

No hearing aids.

No white noise playing beside your bed.

>> See the unexpected approach to nighttime ringing to stop it at the source

So how do we know any of this? The trail starts in Szeged, a town in southern Hungary, in the early 1930s.

Albert Szent-Györgyi had pulled a strange compound out of animal glands. It acted like a sugar and an acid at once, so he named it hexuronic acid. Getting more of it was the hard part. Citrus juice held some, but the sugar in the juice made the stuff a nightmare to clean up.

Then his wife put fresh red paprika on the dinner table.

He didn't want to eat it. In his own words: "I did not feel like eating it so I thought of a way out. Suddenly it occurred to me that this is the one plant I had never tested." Down to the lab it went. By midnight he had his answer. The red pepper was loaded with the stuff.

Within weeks he had three pounds of it, pure white crystal. It got a new name: ascorbic acid, which means "the anti-scurvy acid." You know it as vitamin C. The Nobel Prize came in 1937.

So a red pepper is not the orange's runner-up. That's the fruit that first gave the world vitamin C by the pound...

Here's why your gums care.

A gum is not skin. Under the surface it's a tight weave of fibers that lash the gum down to the root of each tooth. The main fiber is collagen — think of it as rope. And rope is only as strong as its knots.

Vitamin C is the tool your body ties those knots with. Short on it, the new rope comes out slack. The weave loosens, the gum lifts off the tooth a little, and it bleeds when you brush. A small pocket opens where the gum used to sit tight. That pocket is where the trouble moves in.

Old sailors knew the far end of that road. Spongy gums, blood, then loose teeth — the first signs of scurvy, centuries before anyone knew the reason.

One more thing about this vitamin: your body can't stockpile it. Whatever you don't use washes out in a day or two. So the rope needs fresh knots all week long, not once in a while.

By the numbers: One cup of chopped raw red bell pepper carries about 190 mg of vitamin C, by the U.S. Department of Agriculture's count. A grown woman needs 75 mg a day, a man 90 mg. So one pepper covers you, and then some.

Take a look at what a team at the University at Buffalo dug up.

They went through a big national health survey — 12,419 American adults, each one with a real dental exam on file, not just a questionnaire. Then they lined that up against what people ate. The less vitamin C in the diet, the more gum disease they found. It stepped down in order, too: the lowest eaters carried about 1.5 times the risk of the highest. Smokers took the worst of it. Their work ran in the Journal of Periodontology in 2000.

That's a snapshot, though. Which way does the arrow point?

A dental team at Friedrich Schiller University in Germany went at it from the other side. They took 58 people who already had gum disease and had them eat grapefruit every day for two weeks. No new brushing routine, no cleaning, nothing else changed. Blood levels of the vitamin climbed. And in the non-smokers, gum bleeding fell by roughly a third. Two weeks of fruit. Their report ran in the British Dental Journal in 2005.

Now the fair part, because it matters. Hand people vitamin C tablets, lozenges or chewing gum instead of food, and the results go thin and mixed. Hold the pill studies loosely. It's the plate studies that keep holding up — which is the whole point of this letter.

A green bell pepper and a red one are the same fruit. Only the calendar is different.

Green means it was picked early. Left on the plant, that pepper ripens to red, sweetens up, and its vitamin C climbs as it goes. Same plant, later in life, more inside. Color is doing your shopping for you — which is the old idea behind eating the rainbow. Red on the plate has always stood for vitality, and here it's literal.

Peppers don't work alone, of course. Parsley is quietly one of the cheapest ways to punch up the vitamin C in any meal, and most people push it to the side of the plate. Strawberries carry a good load. So do kale and Brussels sprouts. Variety beats any single food, every time.

Vitamin C is fragile. Heat breaks it down and boiling water carries it off into the pot. A raw red pepper, cut into strips, keeps nearly all of it. Roast them if you love them roasted — just don't let cooked be the only way you eat them.

Whole peppers hold their vitamin C for a week or more in the crisper drawer. Once cut, the clock speeds up, and those pre-sliced trays have often been open for days. Buy them whole, slice what you need, and leave the rest of the pepper intact.

Smoking burns through this vitamin, so the official daily target goes up by 35 mg for smokers. Notice that the Buffalo numbers were also ugliest in that group, and the German bleeding results were weakest there. If you smoke, your gums are working with less. Eat like it.

Szent-Györgyi didn't want to eat his paprika. He was curious about it instead, and that curiosity handed the world a vitamin.

The odd part is how little has changed since. His answer was a red pepper. Ninety-odd years and a whole industry of bottles later, a red pepper is still the answer...

Your gums are rebuilding their rope all week, whether you give them anything to work with or not. Give them something. Cut a red pepper into strips this week, and watch the sink on Friday.