Artificial sweeteners are considered safe for most people, but researchers are investigating their effects on gut microbiome health.

Artificial sweeteners may disrupt gut health, throwing off the balance of beneficial bacteria in the gut and shifting the composition of the microbiome.

Fake sugars may disrupt metabolic health.

Artificial sweeteners aren't very helpful for weight loss.

Aspartame was a surprise discovery from a lab working on gastric ulcers

As with saccharin and cyclamate, the aspartame discovery arose from its discoverer tasting something sweet from his workplace. In 1965, American chemist James Schlatter licked a white powder off his finger as he picked up a piece of paper and was startled to discover it tasted sweet. He applied for a patent for the substance, and received it in 1970. It is now one of the most popular artificial sweeteners. (Some users may experience a paywall.)

The WHO labeled aspartame as 'possibly carcinogenic' but US regulators consider it safe

The International Agency for Research on Cancer, an arm of the World Health Organization, labeled aspartame—the artificial sweetener in Diet Coke—as one of several hundred possible cancer-causing substances in 2023. The determination was based on animal and human studies and "limited" evidence linking it to liver cancer. The WHO and US Food and Drug Administration both say the substance is safe at moderate levels. The FDA says a person weighing about 132 pounds would need to have 75 packets daily to reach an unsafe level.

Sugar alcohols, a type of carbohydrate used as a sweetener, may elevate risk of heart attacks and strokes.

Multiple sugar substitutes were accidental discoveries when lab workers didn't wash their hands.

See how sugar stacks up against the sweetness of sugar alternatives, which can sometimes be hundreds of times sweeter than their sugar counterparts.

Saccharin was banned in Canada in the 1970s, but regulators may allow its use once again

The product, commonly known as Sweet'N Low, was banned in Canada in the late 1970s due to research indicating that the sweetener could cause cancer in lab rats. Subsequent studies have found that the rodent findings didn't hold true for humans, and so Canadian regulators state that they are considering updating their stance to allow the product to be added to certain foods (the product is currently allowed in the US).

Xylitol, a sugar alcohol, is sometimes added to foods at 1,000 times the level seen naturally in foods

This article covers the latest research in sugar alcohols and heart health. Some work indicates that after consuming sugar alcohols erythritol or xylitol people are at an elevated risk of developing blood clots, which can cause heart attacks and strokes. Both substances occur in low levels naturally in fruits and vegetables and are also produced by the human body, but as sweeteners in foods they are present at exponentially higher levels.

This 2022 study is one of the findings that prompted WHO to label aspartame as 'possibly carcinogenic'

This French study analyzed online periodic self-reported food journals from more than 100,000 people for a median of almost eight years and linked aspartame consumption to a roughly 15% increased cancer risk. It found that the people who consumed higher levels of aspartame had elevated cancer numbers—particularly breast and obesity-related cancers.

See how much daily sugar substitute intake the FDA considers to be safe

The agency states in this PDF graphic that a person weighing about 132 pounds would have to consume roughly a couple dozen sweetener packets daily—or more—to reach unsafe levels of consumption. The accumulated consumption would be across all sources, including diet beverages, sugar-free candies, and actual packets added to coffee.

Saccharin was widely used in WWI when sugar was rationed

The substance was discovered by chemists in 1878, but its use became more common during World War I and also afterward as a result of sugar rationing. It had become a typical household item in the US and Europe by 1917. During World War II, the artificial sweetener again saw significant popularity.

Stevia has been used to treat burns and indigestion

The substance, which is roughly 300 times sweeter than sugar and scientifically known as Stevia rebaudiana, comes from a plant that grows in Paraguay and Brazil. It has long been used medicinally and as a sweetener by indigenous communities in those locations.

Teddy Roosevelt was once given a daily dose of an artificial sweetener, prescribed by his doctor.

Stevia is a plant-derived sweetener but the plant isn't approved for eating

Steviol glycosides, the sweet-tasting stuff in the plant leaves, are purified and highly processed before they end up in the food or drinks sold in stores. The US Food and Drug Administration does not allow the use of stevia leaf or crude stevia extracts in food, and the agency also bars them from being imported into the US for use as sweeteners.

Gummy vitamins have candy-level sugar—and that sweetness is linked to overdoses

A typical gummy vitamin contains about the same amount of sugar in a single serving as one Sour Patch candy. It's linked to the increase in pediatric overdoses for products including multivitamins and melatonin. Gummy formulations also degrade quickly, so they often include much higher levels of the product in each serving than the label advertises—boosting overdose risks due to this unchecked variability. (Some users may experience a paywall.)

Michael Sveda discovered cyclamate by accident

When this lab researcher brought his hands to his lips to smoke his cigarette in 1937, he tasted something sweet, which he called cyclamate. It was quickly used in diet sodas, but it was banned from the US in 1969 after being linked to rodent bladder cancer in lab experiments.

The dark side of modern sugar production

Humanity's ancestors evolved to wring more calories from sugary fruits by storing excess sugar as fat, an adaption that's culminated in many peoples' palettes preferring calorie-rich sweet. Now, the desire for sugar has both contributed to a widespread health crisis and been at the center of atrocities around the world.

Gut microbiome rewrites may help reduce allergies

Researchers are investigating different strategies to determine if one day they could give people a combination of gut microbes to set them up for fewer allergies. In animal research, scientists have already prevented severe allergic responses in allergy-prone mice—supplying them with gut microbes from healthy, non-allergic human babies.

How our sense of taste evolves as we age

Kids are hardwired to prefer sweets over greens, with sweetness a shorthand for calorie-rich and bitter flavor warning of potentially noxious plants. This holds true even in the womb, where fetuses have been seen via ultrasound scans grimacing as their hosts consume kale capsules. As they age into double digits and beyond, their taste cells and sense of smell diminish, leading to broader and less sensitive palates.

Miracle berries make things that normally taste acidic or sour, such as lemons, taste sweet, like sugar-coated candy, by binding a special protein called miraculin to taste buds.

The myth of sugar rushes vs. the reality of sugar crashes

It's generally accepted that sugar rushes are a myth, and that hyperactivity is a more psychological experience. However, there is real science behind the rare sugar crash that primarily impacts those with diabetes. Read this article to understand how historical and cultural factors have shaped sugar perceptions, and how low blood sugar can trigger shakiness, fatigue, weakness, and more in diabetes patients.

The ancient Romans invented the first known artificial sweetener—it involved lead.

Risks of GLP-1s include health side effects, counterfeit drugs, and more

This episode interviews researchers and patients who have used semaglutide to explore some of the potential risks associated with using the drug to lose weight. These include insurance challenges, health scares related to counterfeit versions of these drugs, and some users lose their ability to enjoy food.

What happens when the gut microbiome is out of whack?

An imbalance in gut microbiome flora can lead to a condition known as dysbiosis. This condition is typically characterized by a drop in microbiota diversity and an increase in harmful unicellular and acellular organisms, such as viruses, that can negatively impact the host's immune system and overall health. Genetics, infections, dietary choices, antibiotics, food additives, artificial sweeteners, and other lifestyle and environmental factors can cause dysbiosis.

Kava, kratom, St. John's Wort, and green tea extract present health concerns

Consumer Reports, which tests supplements for safety, urges consumers to avoid these four supplements due to safety warnings from researchers and public health authorities.

Monosodium glutamate is a sodium salt form of a naturally occurring amino acid

Monosodium glutamate myths originate from a 1968 letter to the New England Journal of Medicine, in which unpleasant symptoms after eating Chinese food were dubbed Chinese restaurant syndrome without medical data. Subsequent studies show this savory flavor enhancer—found in tomatoes, mushrooms, and other foods—is safe in moderation.

In June 2026, EU food safety regulators approved sales of a GLP-1-inducing food additive, a change that may lead to 'supercharged' cereals and breads in Europe within a year. (free w/email)

Acrylamide forms naturally during high-heat cooking through the Maillard reaction

While studies have shown it can damage DNA and potentially cause cancer in mice, humans absorb and metabolize acrylamide at different rates, introducing uncertainty in the research's applicability to humans. Some international health agencies have nonetheless recommended avoiding darker roasts when cooking starchy foods.

Food companies are exploring 'GLP-1 friendly' diet labels

Producers of foods like Healthy Choice frozen meals are placing "GLP-1 friendly" labels on their food, but there's no regulation about what that label means. Nutritionists say that GLP-1s can help reduce appetite, but healthy, balanced diets are a necessary complement to the medications. Data shows that about half of GLP-1 users quit these medications within a year and then rapidly regain weight, underscoring the importance of also prioritizing healthy eating.

BPA-free plastics may still pose health risks because they often contain other structurally similar chemicals.

Read this analysis indicating which traditional stevia medical uses have scientific evidence

This research paper investigates the various uses of Stevia rebaudiana leaves and their extracts and concludes that the substances do hold significant potential for improving cardiovascular health and inflammatory disorders in adults, among several other potential applications. Its authors suggest that further research should examine safe dosage questions and chronic disease management approaches.

Probiotics, which are living bacteria and yeasts, are not recommended for most patients.

The research that led to sour

Scientists are trying to figure out if there are unique receptors that respond to the molecules that make up flavors we associate with calcium, blood, batteries, and other items that often escape dinner menus. Taste researcher Dr. Danielle Reed says the minimum evidence for a taste category typically involves identifying dedicated receptors and then removing them to show the taste vanishes.

The gut microbiome may play a major role in autoimmune disease and symptom flare-ups

Certain unhealthy foods can promote gut bacterial growth and inflammation in the lining of the gut, potentially disrupting its lining—leading to a leaky gut that may allow pathogens to dribble out into the bloodstream, fueling further inflammation that can both cause disease flare-ups and set the stage for future disease development.

Cats have a mutation that prevents them from tasting sweetness, and goldfish rank among the world's supertasters.

How semaglutides are both better and worse than we know

The drugs were developed for use treating diabetes and, later, weight loss, but they have proven helpful with the heart, kidneys, and colon. On the flipside, it may slow digestion and lead to gastroparesis, or stomach blockages, and unexpected babies resulting from the slow effect of birth control pills.

Researchers are investigating how altering the gut microbiome may influence the development of rheumatoid arthritis, which is an autoimmune disease.

Natural toxins produced on plants or consumed by animals may cause food poisoning

When humans eat plants with certain natural toxins on them—including a family of toxins called aflatoxins that fungi produce on crops like peanuts and corn— they can become ill with food poisoning. Toxins can still harm humans even if animals or plants appear fine to the human eye. The World Health Organization advises that we should throw away moldy or discolored foods, refrain from eating wild plants or mushrooms that aren’t definitively nonpoisonous, and remember that just because something is “natural” it’s not always safe to eat.

The five most common chemicals found in modern food

Most modern processed foods rely on a number of preservatives to stay fresh from production to our plates. The most common include citric acid (preservative and flavor), sodium benzoate (preservative), xanthan gum (thickening and stabilizing), carrageenan (thickening), and red dyes 3 and 4 (for color).

Ultra-processed foods are made to maximize cravings and encourage overeating

Often disguised as healthy options like granola bars and low-fat yogurt, these foods silently fuel chronic diseases, despite dominating diets. Reviewing labels for ingredients like stabilizers and emulsifiers can serve as indicators to help identify these products.

GMOs sound scary, but you eat them every day

Why are GMOs bad? They aren't. We've been eating them for decades with no ill effects, which makes sense, because a genetically modified organism is simply an organism, like every other organism, produces hundreds of thousands of proteins, but one or two of them are proteins that were chosen specifically by humans. Watch this 11-minute video for more.

Unlike its Mexican counterpart, American Coca-Cola contains high-fructose corn syrup rather than sugar

There are a few reasons why American Coke turned away from sugar in the 1980s, but none of them are related to consumer health. This Reader's Digest article breaks down the history behind Coke's recipe change, explaining why the company continues using high-fructose cough syrup.

Neural replays in mice help explain food aversions

Princeton University scientists published research in 2025 analyzing how mice learn to associate certain foods or flavors with feeling ill—even when there’s a time gap between eating something and feeling sick. The work, performed with grape Kool-Aid and injections of a substance that made mice sick, traced the literal “gut reaction” of how gut distress signals are linked to neural replays of what the mouse ate.

Can the gut microbiome drive addiction?

New research suggests an imbalance of gut microorganisms may influence the likelihood of addiction and addictive behaviors by increasing the severity of withdrawal symptoms, triggering brain inflammation in regions of impulse control, and more.

In 2026, University of Cambridge researchers reported that a group of gut bacteria called CAG-170 may be a key marker of good health, occurring far more often in healthy individuals and less commonly in people with chronic diseases.

Research shows that microplastics and nanoplastics can accumulate in major arteries, and patients with these deposits are significantly more likely to suffer heart attacks, strokes, or death.

Gut bacteria are evolving and can acquire as many as 100 new genes per year, on average.

What constitutes a 'healthy' diet?

A natural diet, typically high in plant-based foods and low in processed foods, appears to be the main contributor to a healthy, diverse gut microbiome.