How Does Too Much Sugar Affect Your Body?

Chances are you already know that eating too much sugar isn’t good for you. Yet you’re probably still overdoing it: Americans average about 20 tablespoons of added sugars per day, compared to the recommended 6 tablespoons for women and 9 tablespoons for men. (That doesn't include sugar found naturally in foods like fruits and milk.) 

Sugary drinks, candy, baked goods, and sweetened dairy are the main sources of added sugar. But even savory foods, like breads, tomato sauce, and protein bars, can have sugar, making it all too easy to end up with a surplus of the sweet stuff. To complicate it further, added sugars can be hard to spot on nutrition labels since they can be listed under a number of names, such as corn syrup, agave nectar, palm sugar, cane juice, or sucrose. (See more names for sugar on the graphic below.)

No matter what it’s called, sugar is sugar, and it can negatively affect your body in many ways. Here’s a closer look at how sugar can mess with your health, from head to toe.

Your Brain

Eating sugar gives your brain a huge surge of a feel-good chemical called dopamine, which explains why you’re more likely to crave a candy bar at 3 p.m. than an apple or a carrot. Because whole foods like fruits and veggies don’t cause the brain to release as much dopamine, your brain starts to need more and more sugar to get that same feeling of pleasure. This causes those “gotta-have-it” feelings for your after-dinner ice cream that are so hard to tame.

Your Mood

The occasional candy or cookie can give you a quick burst of energy (or “sugar high”) by raising your blood sugar levels fast. When your levels drop as your cells absorb the sugar, you may feel jittery and anxious (a.k.a. the dreaded “sugar crash”). But if you’re reaching into the candy jar too often, sugar starts to have an effect on your mood beyond that 3 p.m. slump: Studies have linked a high sugar intake to a greater risk of depression in adults. 

Your Teeth

You probably rolled your eyes at age 12, but your mother was right: Candy can rot your teeth. Bacteria that cause cavities love to eat sugar lingering in your mouth after you eat something sweet. 

Your Joints

If you have joint pain, here’s more reason to lay off the candy: Eating lots of sweets has been shown to worsen joint pain because of the inflammation they cause in the body. Plus, studies show that sugar consumption can increase your risk of developing rheumatoid arthritis.

Your Skin

Another side effect of inflammation: It may make your skin age faster. Sugar attaches to proteins in your bloodstream and creates harmful molecules called “AGEs,” or advanced glycation end products. These molecules do exactly what they sound like they do: age your skin. They have been shown to damage collagen and elastin in your skin -- protein fibers that keep your skin firm and youthful. The result? Wrinkles and saggy skin.

Your Liver

An abundance of added sugar may cause your liver to become resistant to insulin, an important hormone that helps turn sugar in your bloodstream into energy. This means your body isn’t able to control your blood sugar levels as well, which can lead to type 2 diabetes.  

Your Heart

When you eat excess sugar, the extra insulin in your bloodstream can affect your arteries, part of your body’s circulatory system. It causes their walls to grow faster than normal and get tense, which adds stress to your heart and damages it over time. This can lead to heart disease, heart attacks, and strokes. Research also suggests that eating less sugar can help lower blood pressure, a major risk factor for heart disease. Plus, people who eat a lot of added sugar (where at least 25% of their calories comes from added sugar) are twice as likely to die of heart disease as those whose diets include less than 10% of total calories from added sugar.    

Your Pancreas

When you eat, your pancreas pumps out insulin. But if you’re eating way too much sugar and your body stops responding properly to insulin, your pancreas starts pumping out even more insulin. Eventually, your overworked pancreas will break down and your blood sugar levels will rise, setting you up for type 2 diabetes and heart disease.  

Your Kidneys

If you have diabetes, too much sugar can lead to kidney damage. The kidneys play an important role in filtering your blood sugar. Once blood sugar levels reach a certain amount, the kidneys start to let excess sugar into your urine. If left uncontrolled, diabetes can damage the kidneys, which prevents them from doing their job in filtering out waste in your blood. This can lead to kidney failure.  

Your Body Weight

This probably isn’t news to you, but the more sugar you eat, the more you’ll weigh. Research shows that people who drink sugar-sweetened beverages tend to weigh more -- and be at higher risk for type 2 diabetes -- than those who don’t. One study even found that people who increased their sugar intake gained about 1.7 pounds in less than 2 months.

Your Sexual Health

You may want to skip the dessert on date night: Sugar may impact the chain of events needed for an erection. “One common side effect of chronically high levels of sugar in the bloodstream is that it can make men impotent,” explains Brunilda Nazario, MD, WebMD’s associate medical editor. This is because it affects your circulatory system, which controls the blood flow throughout your body and needs to be working properly to get and keep an erection. 

WebMD Article Reviewed by Michael W. Smith, MD on March 23, 2017

Sources

American Heart Association.

American Diabetes Association.

Harvard School of Public Health.

National Institutes of Health.

The Journal of Nutrition.

British Medical Journal.

The American Journal of Clinical Nutrition.

Diabetes Teaching Center at the University of California, San Francisco.

DiabetesForecast.org.

National Kidney Foundation.

Proceedings of the National Academy of Sciences.

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