The Shocking Way Sugar Affects Your Brain


If I offered you one million dollars to do it, could you hold your breath underwater for 15 minutes?

Unless you’re an amphibian, the answer is no; the brain’s drive for oxygen would override any willpower to win the money.

And guess what? If you’re living on a steady diet of sugar, your brain is similarly re-wired, demanding that next “hit” — and your willpower has as much chance of resisting it as it does of keeping you underwater.

We all know sugar is bad for us, but this stunning example by Mark Hyman, MD, about its impact on our brain — and our difficulty to resist the drive for more sugar — really drove the message home. You see, I’m a reformed sugar addict. During residency, a long ER shift called for a couple bags of Skittles. Or a studying session meant Swedish Fish. But instead of being satisfying, these sugar hits always led to a crash — and a craving for even more.

Your Brain on Sugar

Sugar acts within the brain’s “Reward Center” mechanism (it’s like the brain’s equivalent of your elementary school gold star chart). Eat sugar and the brain releases dopamine, the “feel good” hormone — the same hormone that’s triggered by other things that make someone happy, such as sex, exercise, or, on the bad side of the spectrum, drugs like cocaine and meth.

Unfortunately — through the same mechanisms as drug addiction — frequent sugar intake means that the brain eventually gets accustomed to that high and becomes less sensitive to sugar. So to get the same rush, your brain requires more and more sugar over time.

Here’s how it works: You eat a sugary food. Sugar levels spike in your body, causing it to release dopamine (yay!) and insulin (to help you store the sugar as fat). Sugar levels then plummet, making you feel tired, hungry, and needing to reach for the next sugary treat. It’s chemistry, my dear, and it’s overriding your willpower to eat healthier.

Breaking the Sugar Cycle

So, what? Does that mean you’re a victim of your brain? Hardly. Just like excess sugar rewired your brain in the first place, cutting back on sugar can reverse that dependence. But it’s hard to cut back on sugar, in part because:

  • It’s everywhere. Added sugar is high — sometimes the second or third ingredient — in over 70 percent of packaged foods. Think everything from breakfast cereals to BBQ sauce to salad dressings and so-called “healthy snacks” like granola bars, or even those “heart approved,” refined carb breakfast cereals.
  • Sugar exists in many forms, making it easy for the food industry to hide added sugar, calling it other names in foods you might not even think of as “sugary.”

The Let’s-Be-Realistic Bottom Line

Look, we all know the white stuff is going to sneak in somewhere, sometime, into our own and our kids’ diets. You don’t need to become the sugar police or a biochemist. You can still have a sugary treat here or there. But if you’re tired of this sugary chemistry experiment going on in your brain, follow these three steps and you’ll minimize the majority of added sugar:

1. Learn its disguises

As tricky as this seems, sugar is almost never called just “sugar” on ingredient lists, so you have to be smart about spotting where it hides.

There are at least 61 different names for sugar on food labels. I may be a science nerd at times, but even I don’t expect you to memorize them. Here are tricks: avoid anything ending in “-ose” like sucrose or maltose. Look out for the buzzwords of “syrup,” “nectar,” “cane” and “sweetener.” Plus, be mindful that even natural sugars, like agave or honey, still contribute to your daily sugar limit (24 grams per day for women and 36 for men, per the American Heart Association). If sugar (or any of these terms) is in the top five ingredients, it’s a treat, and not a nutritious food.

2. Cut out liquid sugar

Drinking sugar-sweetened beverages? News flash — your brain doesn’t even recognize these calories as food, leading you to drink even more. Public enemy number-one is soda, where up to 46 grams in a single 12-oz can, can put you over the sugar limit for the entire day. Multiple studies have suggested the link between increased soda consumption and obesity in the US.

But it’s not just soda — watch out for the “healthy juice” too: many juices and seemingly healthy drinks contain added sugar. For the most part, unless you’re talking a fresh-pressed and unsweetened juice made largely of veggies, you’re better off eating a whole piece of fruit rather than the juice made out of it. (BTW, while fruit does contain sugar, it’s nothing compared to added sugars in all the other foods I’ve mentioned here. So I don’t tell people to limit their fruits — they’re a great way to get a little sugar, fiber, and nutrients in a delicious bite).

3. DIY it:

You don’t have to completely cut out everything sweet; I don’t like my coffee black or my yogurt plain. But it’s a lot easier to control the amount of sugar you’re adding if you do it yourself. Add a half-packet to coffee instead of letting the barista talk you into a fancy sweetened frappe. Buy plain Greek yogurt and add berries and honey; I guarantee it will have less sugar than the fruit-flavored, sugar-laden packaged kind. As it often does, it comes down to a simple truth: it’s a lot easier to know what’s going on in your body if you control what you put into it.