Are artificial sweeteners bad for you? The truth about popular sugar replacers

Artificial sweeteners, also called non-nutritive sweeteners or sugar substitutes, have been a controversial topic for decades. Do artificial sweeteners cause cancer? Can they affect my risk of dementia? Will they make me gain weight?

To help alleviate the confusion, we’re answering common questions about artificial sweeteners.

But first, let’s review some of the basics on these sugar substitutes or sugar replacers.

What are artificial sweeteners?

Artificial sweeteners are manufactured sugar substitutes. They may be made from naturally occurring substances, such as a plant, herb or sugar itself. Artificial sweeteners are considered intense sweeteners because they are several times sweeter than regular sugar.

There are six artificial sweeteners approved by the Food and Drug Administration (FDA). The FDA has also established acceptable daily intakes of the approved sweeteners. The acceptable daily intake of sweeteners is much higher than anyone could possibly consume in one day.

These sugar substitutes are attractive alternatives since they contain almost no calories. In addition, you need only a small amount compared to table sugar to achieve the same sweetness.

Artificial sweeteners are widely used in processed foods, such as:

• Soft drinks and other beverages
• Baked goods
• Candy
• Puddings and yogurts
• Canned foods
• Sweet spreads like jam

Types of artificial sweeteners

Here’s a list of FDA-approved artificial sweeteners, along with the recommended acceptable daily intake (ADI):

• Acesulfame K: A combination of organic acid and potassium. Unlike similar sweeteners, it is stable when heated, so many baked goods contain acesulfame potassium. (ADI 15 mg/kg)
• Advantame: A sweetener derived from aspartame that is heat-stable and approved for general use. (ADI 32 mg/kg)
• Aspartame: Approved as a general-use sweetener. Very little is needed since it contains a high intensity of sweetness. (ADI 50 mg/kg)
• Neotame: Approved as a general sweetener, but rarely used in foods. (ADI 18 mg/kg)
• Saccharin: The oldest approved non-nutritive sweetener. It is approved as a food additive for gums, cosmetics and pharmaceuticals. (ADI is 15mg/kg)
• Sucralose: A derivative of the sucrose molecule. (ADI 5 mg/kg)

In addition to the sweeteners classified as food additives, the FDA has identified three plant-based and fruit-based sweeteners as generally recognized as safe (GRAS). This means the substance is not harmful as it has a long history of safe consumption or through research and scientific consensus.

These approved sweeteners include:

• Monk fruit
• Thaumatin
• Steviol glycosides from the stevia plant

Are artificial sweeteners bad for you?

So, are artificial sweeteners a good option? Let’s review the research on a few areas of concern.

Artificial sweeteners and cancer

Concerns regarding artificial sweeteners and cancer began in the 1970s when studies showed a link between the artificial sweetener saccharin and bladder cancer in laboratory rats.

Most recently, the World Health Organization’s (WHO) International Agency for Research on Cancer (IARC) labeled aspartame as “possibly carcinogenic to humans.”

But this does not mean aspartame is actually linked to cancer.

The committee reported that there was no strong evidence from animal or human studies that aspartame causes harm. The IARC said that its conclusions were based on “limited evidence” of cancer in humans, specifically liver cancer.

The group also reaffirmed that aspartame is safe to consume within the acceptable daily intake of 0-40 mg/kg body weight.

The National Cancer Institute also provides helpful information regarding artificial sweeteners and cancer risk. Studies looking at a possible link between artificially sweetened beverages and overall cancer risk have shown mixed results, with no consistent conclusions.

This may be partly because the studies are epidemiological rather than experimental. Epidemiology looks at patterns in groups of people to understand which risk factors are linked to certain diseases. But because these studies only observe what happens, they can’t show what actually caused a disease.

Artificial sweeteners and cognitive decline

Another recent concern for artificial sweeteners is the how they impact your brain health, specifically, if it causes your brain to age faster than it should.

This study looked at the intake of low and no-calorie sweeteners (LNCS) and cognitive decline. The study assessed people’s memory, verbal fluency, processing speed (how fast your brain works) and executive function—the skills you use to plan, organize and focus.

The highest intake of LNCS was associated with a faster decline in cognitive function. People consuming the highest amount of artificial sweeteners were eating or drinking an average of 191 milligrams, or around 1 teaspoon per day.

But it’s important to understand a few limitations about this study before jumping to conclusions.

Since this study was an observational study, it can be difficult to draw conclusions from the data. Factors like age, socioeconomic factors, diet and lifestyle behaviors can make it appear like there’s a link, even if there’s not.

For example, in this study, the link between low‑ and no‑calorie sweetener (LNCS) use and cognitive decline was stronger in people living with diabetes than in those without diabetes. However, people who regularly use artificial sweeteners are also more likely to have obesity, diabetes or lower overall diet quality. These factors on their own can contribute to a higher risk of cognitive decline, making it difficult to know whether the sweeteners themselves are responsible.

The study also used food frequency questionnaires (FFQ) to assess dietary intake, which can be unreliable. The FFQ tool requires people to recall how often they eat specific foods over a period of time in order to determine their usual intake. These can be inaccurate due to people not remembering correctly, or someone underestimating how much they actually ate.

If you’re concerned about your risk of cognitive decline, keep in mind that lifestyle factors, including a healthy diet, are one of the best ways to improve your memory and brain health.

The Alzheimer’s Association recommends the MIND diet. The diet includes:

• Leafy greens and other vegetables
• Berries
• Whole grains
• Poultry
• Fish
• Beans and legumes
• Nuts
• Extra virgin olive oil

The MIND diet also limits:

• Red and processed meats
• Butter
• Margarine
• Cheese
• Fried foods
• Sweets

Have a conversation with your doctor about ways to protect your brain as you age through healthy diet and lifestyle changes.

Artificial sweeteners and blood clots

Another common area of concern around artificial sweeteners is their impact on heart health, specifically the risk of blood clots.

Reducing added sugar is a recommended strategy to help prevent obesity and heart disease. The World Health Organization (WHO) recommends limiting your added sugar intake to less than 10% of total daily energy intake—the number of calories you consume in a day.

Artificial sweeteners have been marketed to reduce the intake of added sugars and, in doing so, potentially improve your cardiovascular health.

Based on current research, the long-term effects and safety of artificial sweeteners on heart disease risk still need further research. At this time, it’s difficult to take current research and turn it into concrete dietary guidelines.

A 2023 study researched erythritol, a common sugar alcohol, and found that people with the highest blood levels experienced more cardiovascular events like heart attacks and strokes. But erythritol is also made naturally in the body from glucose, and higher levels may reflect internal production rather than higher consumption from food and drinks.

Conditions such as prediabetes, diabetes, higher glucose and fructose intake and oxidative stress can all raise the body’s erythritol levels. In fact, the group with the highest levels had about three times more people with diabetes, suggesting erythritol may be more of a marker of an underlying condition, rather than a cause.

Other studies have shown the benefits of erythritol, including reduced weight gain, antioxidant activity, protection of blood vessels from damage, and lower levels of blood sugar in rodent models of diabetes.

Because test tube and animal studies often don’t translate directly to humans, these findings should be interpreted cautiously. And while more trials in humans are needed, the limited research available on artificial sweeteners and heart disease hasn’t shown consistent results.

If you’re looking to reduce your risk of heart disease and stroke, focus on eating a diet full of whole foods. Instead of reaching for sugary foods and drinks, opt for fruits and vegetables that are naturally sweet to reduce added sugar in your diet. Talk to your doctor or dietitian if you need help building a sustainable diet that supports your heart health.

Will artificial sweeteners help me lose weight?

One of the main reasons people reach for artificial sweeteners is to aid in weight loss or weight management. Reducing overall daily intake of calories is challenging for most people, so replacing calories from sugary foods with zero-calorie sweeteners seems like an easy fix.

But artificial sweeteners’ effect on weight, appetite and calorie intake has been scrutinized.

It has been publicized that artificial sweeteners may cause weight gain due to many factors, including negative effects on the gut microbiome, increasing cravings for sweet foods and interfering with the metabolism of sugar.

However, many high-quality research studies show that consuming artificial sweeteners in place of regular sugar reduces body weight.

Think about it this way. Sugar contains around 20 calories per teaspoon. The average American consumes 17 teaspoons of sugar per day according to USDA census data. If you replace the 17 teaspoons of sugar with a zero-calorie artificial sweetener, you should lose almost one pound in a week.

In addition, several studies have shown that people experience less hunger and therefore consume fewer calories when using artificial sweeteners. Since weight loss is created by achieving an overall daily calorie deficit, cutting out calories from sugar can help.

Keep in mind that if you rarely consume sweets or added sugars, then you won’t be reducing your daily calorie intake by including artificial sweeteners in your diet. Also, it doesn’t work if you replace the calories lost with other foods or bigger portions.

If you’re trying to lose weight, the best approach is to moderately reduce your daily calorie intake (by around 300-400 calories) and increase how many calories you burn through exercise (by around 200-300 calories expended). This is more sustainable long-term.

Bottom line on artificial sweeteners

If your goal is to work toward eating a healthier, less processed diet, then choose whole foods, such as fruits and vegetables. Many are naturally sweet and have the added benefit of essential vitamins and minerals that your body needs every day. Whereas artificial sweeteners have no nutritional value.

However, if you’re trying to lose weight and you already regularly consume sugar sweetened beverages or other sugary foods, replacing them with artificially sweetened options is a good way to reduce your overall intake of calories.

If you have questions about how to build a sustainable plan for weight loss or make healthy changes to your diet, talk to your doctor or find a dietitian near you.