Open your bathroom cabinet. You'll probably see a few skin creams in there. One jar softens lines. Another promises to fade spots. Some cost more than a nice dinner out. After 50, most of us spend real money to look well.

But your skin isn't built from the outside. It grows from the inside, from what you eat. And the best food for it may already sit in your kitchen. That food costs about a dollar.

It's a plain orange root. The humble sweet potato. It won't just feed your skin — it can lend it a soft, healthy glow. And a lab in England proved how...

Ian Stephen is a scientist in England. He wanted to know one simple thing. What makes a face look healthy to other people?

Most of us would guess a tan. A bit of sun, a golden glow, and you look well. So Stephen and his team put that hunch to the test at the University of Nottingham.

They let people change the color of a face on a screen. Turn it any way to make it look most well. And the choice surprised them.

People didn't reach for a tan. They reached for a faint gold — the exact tint that food gives skin. Not the brown of sun. The soft gold of fruit and veg.

So what does that mean for you? A tan fades as soon as the sun goes. But food-made gold builds up slowly as you eat well, day after day. And it never once burns your skin to get there.

Stephen's team went further with a second test. They asked a group of people to eat more fruit and veg for six weeks. By the end, their skin had shifted toward that warm gold. Faces that once looked plain now read as healthy to others.

Here's what's going on. A sweet potato is packed with beta-carotene. That's the bright pigment behind its orange flesh. Your body turns it into vitamin A.

Vitamin A is a gift to your skin. It tells old skin cells to renew. The same vitamin helps build collagen — the mesh that keeps skin firm and smooth. As that mesh holds up, skin looks fuller and lines soften.

There's more your skin gets from it. Vitamin A helps calm the redness that sun and age bring on. It also shields the cells from daily wear. Cells that stay strong hold water better, so skin looks plump instead of dry.

The pigment does one more thing. Some of it settles just under your skin. There it casts a warm, golden tone. That's the healthy look Stephen's team found — grown from your plate, not the sun.

The University of Nottingham: Dr. Ian Stephen's team studied 82 people and found a clear link — the more colorful fruit and veg someone ate, the more gold their skin showed. That gold, not a suntan, was the tone people read as healthy.

People have leaned on this root for a very long time. It fed whole villages when money ran short. Cheap to grow and easy to store, it kept through the cold months when little else did. Folk cooks prized it as a food that builds you back up.

One baked sweet potato is a big dose of vitamin A. Just one covers more than a full day's worth. And it's cheap, filling, and sweet on its own.

The root brings help for collagen, too. It holds vitamin C, and your body needs that to lock the mesh in place. So the potato feeds both halves of firm skin at once.

It's not the only orange food that helps. Carrots, squash, and cantaloupe carry the same pigment. Leafy greens hide it under their green. Eat a mix of colors, and your skin drinks it all in.

Water plays a part here too. Skin that runs short on water looks tired and drawn. So drink through the day, and let the food do its slow work. A spoon of olive oil on your plate helps in two ways at once — better taste, and more gold soaked up.

You might wonder about a beta-carotene pill instead. Skip it. Two big trials linked those pills to higher lung-cancer risk in smokers. The whole food carries no such worry — it works as a team of nutrients, the way food should.

The pigment needs fat to get into your body. Roast your sweet potato with a spoon of olive oil. That one move can lift how much you soak up by half or more. A slice of avocado on top works just as well.

The color is the pigment. So the darker the orange flesh, the more good stuff inside. Leave the skin on when you can, since gold and fiber sit right beneath it.

Your skin renews on a slow clock. Fresh cells take about a month to reach the top. Eat these foods for six weeks straight, and that's when the glow tends to show. Quick fixes skip that step.

The look you chase in a jar was never really in the jar. It grows in the ground, for about a dollar. Your grandmother knew this root well. She just called it dinner.

So skip one trip down the beauty aisle this week. Buy a bag of sweet potatoes instead. Roast them, eat the skin, and add a little olive oil. Then give your face a few weeks to catch up.

The glow you want starts on your fork. Try it, and watch your skin by fall.