Is Sucralose (Splenda) Good or Bad?

Excessive amounts of added sugar can have harmful effects on your metabolism and overall health (1).

For this reason, many people turn to artificial sweeteners like sucralose.

However, while authorities claim that sucralose is safe to eat, some studies have linked it to health problems.

This article takes an objective look at sucralose and its health effects — both good and bad.

Sucralose is a zero calorie artificial sweetener, and Splenda is the most common sucralose-based product.

Sucralose is made from sugar in a multistep chemical process in which three hydroxyl groups are replaced with chlorine atoms (2).

Supposedly, it was discovered in 1976 when a scientist at a British college allegedly misheard instructions about testing a substance. Instead, he tasted it, realizing that it was highly sweet.

The companies Tate & Lyle and Johnson & Johnson then jointly developed Splenda products. It was introduced in the United States in 1998 and is one of the most popular sweeteners in the country (3, 4).

Splenda is commonly used as a sugar substitute in both cooking and baking. It’s also added to thousands of food products worldwide.

Sucralose is calorie-free, but Splenda also contains the carbohydrates dextrose (glucose) and maltodextrin, which brings the calorie content up to 3.36 calories per gram (g) (5).

However, the total calories and carbs Splenda contributes to your diet are negligible, as you only need tiny amounts each time.

This is because sucralose is approximately 600 times sweeter than sugar (3).

Most studies show that sucralose has little or no effects on blood sugar and insulin levels (6).

For instance, one small study found that daily consumption of sucralose had no impact on sugar metabolism or insulin sensitivity in healthy adults (7).

Another study had similar findings, reporting that consuming sucralose with each meal for 12 weeks had no effect on insulin, fasting blood sugar levels, or hemoglobin A1c, a marker of long-term blood sugar control (8).

However, a few other studies have turned up conflicting results, with some noting that sucralose could reduce insulin sensitivity and increase blood sugar and insulin levels (9, 10, 11).

Therefore, more high quality research on the effects of sucralose on blood sugar and insulin levels is still needed.

Splenda is considered to be heat resistant and good for cooking and baking. However, recent studies have challenged this.

It seems that at high temperatures, Splenda starts to break down and interact with other ingredients (12).

One 2010 study found that heating sucralose with glycerol, a compound found in fat molecules, produced harmful substances called chloropropanols. These substances may raise cancer risk (13).

On the other hand, a more recent study reported that sucralose doesn’t form these compounds when heated and is safe for cooking and baking. However, note that this study was funded by Tate & Lyle, the manufacturers of Splenda (14).

While more research is needed, some people may prefer using other sweeteners when baking at temperatures above 350°F (175°C) in the meantime (15, 16).

The friendly bacteria in your gut are extremely important for your overall health.

They may improve digestion, benefit immune function, and reduce your risk of many diseases (17, 18).

Interestingly, one 2-week study found that consuming 20% of the acceptable daily intake for sucralose per day had no effect on the beneficial bacteria in the gut (19).

Another study showed that consuming high doses of sucralose for 7 days did not alter the gut microbiome (20).

However, although these studies suggest that short-term sucralose consumption is unlikely to affect gut health, animal studies on long-term sucralose intake have found that it could have negative effects.

For example, one study in mice showed that 6 months of sucralose consumption disrupted the balance of the gut microbiome and increased inflammation (21).

Therefore, more studies on the long-term effects of sucralose on gut health in humans are needed.

Products that contain zero-calorie sweeteners are often marketed as being good for weight loss.

One review of 56 studies found that non-nutritive sweeteners could have a small beneficial effect on body mass index (BMI). However, researchers also noted that most of the studies were low quality (22).

On the other hand, a 2014 review of observational studies found no connection between artificial sweetener consumption and body weight or fat mass, but reported a small increase in body mass index (BMI) (23).

Meanwhile, according to the review, randomized controlled trials — the gold standard in scientific research — show that artificial sweeteners reduce body weight by around 1.7 pounds (0.8 kilograms) on average (23).

Like other artificial sweeteners, sucralose is highly controversial. Some claim that it’s entirely harmless, but evidence on its safety and long-term health effects is conflicting.

For example, though most research shows that it is unlikely to increase blood sugar or insulin levels, other studies suggest that it could have negative effects (6).

Additionally, while short-term studies in humans have found that it has no impact on gut health, long-term animal studies have turned up conflicting results (19, 20, 21).

The safety of sucralose at high temperatures has also been questioned. Therefore, some people may want to opt for other sweeteners when cooking or baking (13).

That being said, the long-term health effects are still unclear, but health authorities like the Food and Drug Administration (FDA) do consider it to be safe.

If you like the taste of sucralose and your body handles it well, it’s probably fine to use in moderation. There’s certainly no clear-cut evidence that it’s harmful to humans.

Still, some people may prefer to choose other sweeteners when cooking or baking, as its stability at high temperatures is unclear.

If you choose to avoid sucralose or artificial sweeteners in general, there are plenty of great alternatives.