Why do people
get diabetes?
has a “fasting glucose” line
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The full narration of the video.
People who barely touch sweets can still get diabetes. Because diabetes was never simply about eating sugar. In China, about one adult in eight has it.
Take a guess: out of ten adults, how many are already close to the line? Nearly four. To see why, follow a mouthful of rice after you swallow it.
Rice breaks down into sugar and enters the blood. Blood vessels are roads, and sugar is the trucks on them. The trucks deliver sugar to warehouses, your cells, which burn it as fuel. But warehouse doors don't open on their own. They need an opening notice, called insulin.
Insulin comes from small clusters of cells in the pancreas. They're called islets. After a meal, trucks pile up, so the islets send more notices, the doors open, and the roads clear. The trouble starts at the warehouse.
When belly fat builds up and fat creeps into the liver and muscles, the doors start to rust. One notice no longer opens the door. That's called insulin resistance. So the islets send more, two, three at a time, and force the doors open.
At this stage, blood sugar often still looks normal, and you feel nothing. The islets work overtime like this for years. Until one day they wear out and can't keep up.
Trucks jam the roads, unable to unload, and sugar piles up in the blood. Meanwhile the warehouses run short, so you feel tired and hungry. This is type 2 diabetes, over ninety percent of all cases.
So sugar itself doesn't break the islets. But too many sugary drinks turn into fat, and the doors rust all the same. And stuck sugar slowly wears down the roads, your blood vessels, and your eyes and kidneys too. There's also type 1 diabetes. It's rarer, and usually starts in children and young adults.
The immune system mistakes the islets for invaders and destroys them. It has nothing to do with sugar or weight. Asians have an extra handicap: at the same weight, fat tends to settle on the belly, and the islets have less in reserve. So you don't have to look heavy to get it.
Your checkup report has a line called fasting glucose. It measures how many trucks are stuck on the road. If it reaches seven or higher, it's time to see a doctor. The good news: while the rust is shallow, moving more and trimming the waist can loosen the doors again.
A trial in Daqing, China: people with high blood sugar who ate less and walked more were about forty percent less likely to get diabetes over six years. For what to do, follow your doctor. Diabetes is what happens when the islets work too long for doors that rusted shut.
When did you last check your fasting blood sugar?
In one line
Diabetes is not simply caused by eating sugar. It is the islets working overtime for a rusty door, for years, until they wear out.
In China, about one adult in eight has diabetes. Fewer than four in ten of them know it.
Take a guess
Out of ten adults, how many have blood sugar close to the line?
Nearly four.
Doctors call this “prediabetes”: not over the line yet, but standing right next to it.
How sugar moves
through your body
When the door rusts,
the islets work overtime
Put simply: the door rusts first, the islets wear out later, and there can be many years in between.
Why does
the door rust?
So people who are not overweight can get it too. In many Asian people, belly fat is less visible and islet reserve is smaller, so doctors suggest screening Asian Americans from a BMI of 23, without waiting until they look overweight.
One kind
is different
the body attacks its own islets The immune system mistakes the islets for intruders and destroys them, so almost no notices go out. It often starts in childhood or youth and has little to do with diet or weight.
Which line to read
on your checkup
One line is fasting glucose. It measures how many trucks are stuck on the road. At 7 mmol/L (126 mg/dL) or higher, go see a doctor.
Next to the line, there is still time to step in. A trial in Daqing, an oil city in northeast China, found that people with high-ish blood sugar who ate better and walked more had about 40% fewer new cases over six years.
For what to do, follow your doctor.
Read next: How does a blood test spot illness? · Why thin people can gain fat at the gym · Can you skip meals if you are not hungry?
check your
fasting glucose?
Quick check
How does type 2 diabetes, the most common kind, usually develop?
First the doors get hard to open, so the islets send extra insulin. After years of that they wear out, and blood sugar crosses the line.
