- Sugar lurks in dozens of unsuspecting foods, from yogurt and salad dressings to granola bars and sauces.
- Another big source of sugar in our diets is high-carbohydrate food like bagels and rice, which are quickly broken down into sugar in our bodies.
- Occasionally indulging in a sweet treat isn’t a problem, but continuously eating high-sugar foods has been linked with a wide range of health issues.
Sugar lurks in dozens of unsuspecting foods, from yogurts and salad dressings to juices and sauces. Even when sucrose – the popular form of table sugar is not present in a food item, sugar’s cousins fructose and dextrose can likely be found somewhere on the label.
Thankfully, the bulk of scientific research suggests that you don’t have to go sugar-free see benefits for your brain and body. Instead, most experts simply recommend cutting back.
Still, given sugar’s omnipresence in our lives, reducing your consumption can be hard work. Here are some of the problems that can result when you consistently overindulge your sweet tooth.
Sugar is horrible for your teeth.
When bacteria in your mouth break down sugar, they produce acid, weakening the protective enamel that gives your teeth that glossy feel. If you’re only eating it occasionally, that’s no big deal – your teeth have a natural repair mechanism called remineralization that helps build back the enamel.
But when you indulge your sweet tooth too often, the repeated cycle of acid attacks can break down the minerals that keep your enamel strong, eventually producing a cavity.
The link between sugar and tooth decay is especially strong when it comes to sweet drinks like soda, since the combination of bubbles and sugar appears to be lethal for your pearly whites. A 2017 study of more than 20,000 adults published in the Journal of Public Health Dentistry found that consuming sugary beverages dramatically increased participant’s chances of losing between one and five teeth.
Sugar has been strongly tied to weight gain and obesity.
The authors of a review of 50 studies on diet and weight gain published in the journal Food and Nutrition Research found that, on average, the more refined carbohydrates (such as sugar) that someone ate, the more weight they tended to gain over the study period. Similarly, the researchers behind a large review of 68 studies published in the British Medical Journal found that the more sugar someone consumed, the more they weighed.
In other words, the amount of sugar in a participant’s diet could be used to roughly predict their weight, the researchers found.
Eating sugar may make you crave more.
When we eat carbs or sugar, the process involves the pancreas. That small, sweet-potato-shaped organ pumps out insulin, a hormone that mops up some of the sugar floating around in our blood stream. But when we consume large quantities of sugar, the pancreas goes into overdrive and pumps out so much insulin that we wind up craving more carbs or sugar.
Edward Damiano, a diabetes researcher and professor of biomedical engineering at Boston University, calls this “the insulin effect”: Ironically, you eat sugar, and then you crave more.
Studies have also tied excessive sugar to heart disease.
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A 2014 study of close to 12,000 US adults found a troubling link between how much added sugar people consumed and their risk of dying from heart disease.
Those who got about a fifth of their total daily calories from added sugars were significantly more likely to die of heart disease than people who got less than 10% of their caloric intake from the sweet stuff.
High-sugar diets have been linked to high blood pressure, too.
A 2016 review published in the journal Progress in Cardiovascular Disease suggested that excessive amounts of sugar was linked to high blood pressure, also known as hypertension.
The authors of the review explained that sugars promote inflammation and stress within cells, and may even directly cause hypertension. That effect was also seen in a small 2008 study, which found that giving healthy people a drink containing 60 grams of fructose led to a spike in blood pressure roughly two hours later.
There’s a troubling link between sugar and tumor growth.
In October, scientists concluded nine years of research into the link between sugar and cancer cells.
In a study published in the journal Nature Communications, a team of Belgian molecular biologists discovered that sugar has a unique ability to fuel the growth of cancer cells and thus could be a powerful catalyst behind the development of cancerous tumors.
Still, their research has not yet been translated into medical recommendations. Importantly, their work was in yeast cells, not humans. As a result, it’s impossible to say whether eating less sugar will decrease your likelihood of developing the disease. But the relationship is still an important one with a host of implications for future studies.
“This link between sugar and cancer has sweeping consequences,” Johan Thevelein, an author of the study, said in a statement. “Our results provide a foundation for future research … which can now be performed with a much more precise and relevant focus.”
Eating too much sugar has been tied to cognitive decline as well.
Many studies have suggested an indirect link between diabetes and reduced cognitive function. But a study published this January in the journal Diabetologia was one of the first to suggest that poor blood sugar control – independent of whether someone also had diabetes – also has a negative impact on the brain.
For their study, the researchers spent 10 years looking at the cognitive function and blood-sugar levels of more than 1,000 people whose average age was 66.
At the beginning of the study, there was no observable link between people’s blood-sugar levels and their performance on cognitive tests. But as the study progressed, people whose blood-sugar levels repeatedly spiked (which often happens when people ingest too much sugar), did worse and worse on the tests. This occurred even in people without diabetes, suggesting that there may be something fundamental about good blood sugar control and cognitive function.
Too much sugar may also play a role in liver failure.
- Kate Taylor
If you thought cutting back on alcohol was enough to protect your liver, think again.
A high-sugar diet has been tied to nonalcoholic fatty liver disease, a condition characterized by the overgrowth of fat cells in the liver that can lead to fatigue, scarring, and irreversible damage.
Common sense might tell you that fat is the chief contributor to the disease, but carbohydrates might actually play a stronger role, since they appear to have a unique ability to spurn the development of fat cells.
However, a 2015 review of studies came to the conclusion that while there are clear ties between sugar consumption and several risk factors for nonalcoholic fatty liver disease, there is no research yet that definitively says too much sugar is a cause of the disease.
People who eat too much sugar may develop insulin resistance, a precursor to diabetes.
- Hollis Johnson
A 2014 study published in the Journal of Nutrition found a worrisome link between consumption of sugary beverages like soda and insulin resistance – a phenomenon in which the body becomes less sensitive to the hormone insulin, which is responsible for converting the sugar we eat into energy we can use.
In people with insulin resistance, blood sugar levels can become erratic or remain high for long periods of time. If left untreated, the condition can contribute to the development of diabetes, a more serious condition characterized by the some of the same issues.
High-sugar diets may also increase your risk of diabetes.
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Roughly 100 million US adults – or nearly 10% of the population – have diabetes, according to the latest figures from the Centers for Disease Control and Prevention. Another 84 million Americans have prediabetes, a condition can lead to type 2 diabetes within as few as five years.
Characterized by an inability to control one’s blood-sugar levels, which can spike or plummet depending on the content of sugar or simple carbs in a meal, diabetes is a serious condition that can be fatal.
It’s important to know that eating too many Oreos in a single sitting will not give you diabetes. Instead, there appears to be an indirect link between high-sugar diets and weight gain. And being overweight is a known risk factor for diabetes.
Still, more research on that relationship is needed, as made clear by a 2017 review of more than 15 studies comprising more than 250,000 people.
“Current evidence does not allow us to conclude that fructose-containing sugars independent of food form are associated with increased risk of type 2 diabetes. Further research is likely to affect our estimates,” the researchers wrote in their paper.
Lauren Friedman wrote a previous version of this story.