Research into the connection between sugar consumption and type 2 diabetes is ongoing. Most doctors argue that sugar alone does not trigger diabetes. It is a complicated condition that develops due to a range of factors.
In this article, we look at emerging studies that explore the possible link between sugar consumption and the development of type 2 diabetes.
Excess sugar intake and diabetes
The link between sugar and diabetes is complicated.
Both type 1 and type 2 diabetes affect the body's ability to regulate blood glucose levels.
Type 1 diabetes, on the other hand, is an autoimmune condition, which causes a person's immune system to attack the cells that produce insulin. Damage to these cells undermines the body's ability to manage blood glucose.
Once a person has diabetes, eating too much sugar can make symptoms worse, as diabetes makes it more difficult for the body to manage blood sugar levels. People with type 1 diabetes still need to be careful about sugar intake.
The link between sugar and type 2 diabetes
Although eating sugar does not directly cause type 2 diabetes, some evidence suggests that the greater overall availability of sugar makes diabetes more common.
A 2016 review found that although current research has found convincing patterns to suggest that sugar consumption has direct and indirect links to diabetes, it has produced no significant data.
The review suggests that the direct mechanisms of sugar that lead to diabetes involve a sugar called fructose. The liver absorbs fructose without regulating the intake, potentially leading to a buildup of liver fats and a decrease in insulin sensitivity.
Insulin sensitivity shapes how effectively cells use glucose, removing it from the bloodstream. When this decreases, blood sugar can become persistently high, potentially leading to type 2 diabetes.
However, the study author accepts that not enough evidence is available from direct studies on humans.
A 2013 study that examined people in more than 175 different countries found that more sugar in the food supply led to increased diabetes rates.
Specifically, for every additional 150 calories of sugar available per day per person, diabetes levels rose by 1 percent. This change continued even when researchers controlled other factors with links to diabetes, such as obesity, exercise, and overall calorie consumption.
This research suggests that sugar consumption does affect diabetes risk, at least at the level of the wider population.
The study did not examine individuals, so does not biologically support the claim that sugar consumption causes diabetes. However, it suggests a correlation.
A 2012 review of previous research suggests that consuming some forms of sugar could increase the risk of diabetes. Drawing upon previous research, the study suggested that sugary drinks were likely to increase the risk of type 2 diabetes.
While dietary sugar might seem to have a relationship with blood sugar, researchers do not fully understand its links to diabetes.
Other sugar-related health risks
Eating too much sugar might lead to tooth decay.
Though the link between sugar and type 2 diabetes is uncertain, the link between sugar and other health conditions is much clearer.
Research published in 2014 linked excessive sugar consumption to an increased risk of death from cardiovascular disease (CVD).
People who got more than 25 percent of their daily calories from sugar were more than twice as likely to die from heart disease as participants who got 10 percent or fewer of their calories from sugar.
Diabetes increases the risk of CVD, so people with the condition should be mindful of sugar intake.
Other risks associated with eating too much sugar include:
- liver disease, including non-alcoholic fatty liver disease
- hormone changes
- high cholesterol
- weight gain and obesity
- chronic illnesses, such as polycystic ovarian syndrome (PCOS)
- chronic inflammation and immune dysfunction
- tooth decay
Sugar intake recommendations
The body needs glucose to function. Glucose is widely present in food and therefore impossible to avoid. However, there is no need to add extra sugar to snacks or meals.
Sweetened sodas, candy, and processed foods are particularly harmful.
The American Heart Association (AHA) recommend the following limits on added sugars each day:
- For the average male: No more than 9 teaspoons, 36 grams, or 150 calories from sugar.
- For the average female: No more than 6 teaspoons, 25 grams, or 100 calories from sugar.
Rather than focusing on any specific type of sugar, such as high-fructose corn syrup, the AHA advise limiting all added sugars.
Limiting sugar intake to less than 10 percent of daily total calories is another way to keep sugar consumption under control. This prevents excessive sugar consumption regardless of how many calories a person needs.
The American Diabetes Association offer additional recommendations. They suggest that people with diabetes should do the following:
- Eat carbohydrates with a low or medium glycemic index (GI), such as whole-wheat bread, oatmeal, or fruit.
- Choose fiber-rich foods to provide more sustainable energy for the body and help control blood glucose.
- Opt for lean proteins, and choose healthful fats to reduce food cravings. These will help people feel fuller for longer.
- Consume non-starchy vegetables, such as artichokes, broccoli, eggplant, mushrooms, okra, and turnips.
- Limit or avoid sugary snacks and alcoholic drinks.
- Avoid low-nutrient, processed foods, which can be high in sodium, added sugars, and unhealthful fats.
- Limit sodium consumption to 2,300 milligrams or less per day.
- Eat smaller meals more frequently. Large meals can cause blood sugar spikes, and hunger in between meals can lead to unhealthy snacking.
Consuming sugar is not a direct risk factor for type 2 diabetes, although it can have indirect effects, such as weight gain, that make the condition more likely to develop.
Risk factors for type 2 diabetes include:
- being overweight or having a large waist circumference
- being 45 years of age or older
- having a family history of diabetes
- experiencing gestational diabetes during pregnancy
- having consistently high blood glucose
- developing insulin resistance
- having high blood pressure
- a sedentary lifestyle
- having high levels of fats called triglycerides in the blood
- low high-density lipoprotein (HDL) or "good" cholesterol levels in the blood
- blood vessel or circulatory issues in the brain, legs, or heart
- being Native American, Asian American, a Pacific Islander, Latinos, or African American
Regular exercise can help keep diabetes at bay.
While the link between sugar and diabetes is unclear, reducing added sugar and processed food in the diet can help a person prevent type 2 diabetes.
Other lifestyle adjustments can reduce the risk of type 2 diabetes or help people with diabetes manage their symptoms and prevent complications.
- Weight management: If a person loses 5–7 percent of their body weight, it can lower the risk of diabetes.
- Regular physical activity: Getting 150 minutes of light-to-moderate exercise per week can help regulate blood glucose and reduce body weight. Too much exercise can also be harmful, so avoid overexertion.
- Portion control: Eating smaller, more controlled portions of food with enough fiber, protein, and healthful fats can support blood glucose control. This also means that people with diabetes do not need to give up their favorite foods, just make adjustments in preparation and portion size.
Women who develop gestational diabetes can reduce their risk of diabetes by managing body weight, avoid excessive weight gain during pregnancy, and increasing physical activity before a planned pregnancy.
Speak with a doctor about the safest levels of weight gain and exercise for your body during pregnancy.
Scientists are not yet certain whether sugar directly causes diabetes.
While research is not yet conclusive, increased sugar consumption seems to accompany higher rates of diabetes across the wider population. Fructose, in particular, can increase the risk of liver disease.
Sugar does increase the risk of other health problems, such as heart disease. The AHA suggests that people should limit all added sugars.
People can prevent diabetes or its complications by exercising for more than 150 minutes per week and eating a balanced diet that is high in fiber, protein, and saturated fats.
Is fat linked to the development of type 2 diabetes?
No, calories from fat are not directly linked to type 2 diabetes. However, being overweight is a risk factor.
Recommendations for diet include eating healthy foods in moderate portions and eating lean meats, whole grains, and low-GI fruits and vegetables.Deborah Weatherspoon, PhD, RN, CRNA Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.