Heart can ‘taste’ sweetness without your tongue, study finds

In the quiet rhythm of your heartbeat, something unexpected might be happening—something as surprising as tasting sweetness without your tongue. Scientists have discovered that your heart can actually sense sweetness, thanks to special receptors once thought to live only on your tongue. These tiny sensors, known as TAS1R2 and TAS1R3, respond to sweet substances like aspartame, and when activated, they can change how your heart beats.

This discovery could change how we think about heart function and how we treat heart disease. Researchers from the Biophysical Society highlighted a brand-new way the body might regulate heart rhythm and strength.

Taste receptors help you enjoy the flavor of your favorite foods, but now we know they do more. Scientists have already found taste receptors in unexpected places like the gut, pancreas, and brain. Now, for the first time, they’ve found sweet taste receptors in heart muscle cells.

By using lab-grown heart cells from both humans and mice, the researchers tested how these receptors respond to sweeteners. They used aspartame, a common sugar substitute found in diet sodas and low-calorie foods. When they applied aspartame to the heart cells, the cells reacted strongly. The heart muscle contracted with greater force, and calcium moved more quickly in and out of the cells. Both of these reactions are important for a healthy and steady heartbeat.

“These receptors aren’t just sitting there,” said Micah Yoder, a graduate student working in the lab of Jonathan Kirk at Loyola University Chicago. “They’re functional. They’re doing something real.”

After eating a meal, your body goes through several changes. Your heart rate and blood pressure often rise. Scientists used to believe this happened because of signals from the brain and nerves. But this new study offers another explanation. Yoder explained, “We’re proposing a more direct consequence, where we have a spike in our blood sugar after eating a meal, and that’s binding to these sweet taste receptors on the heart muscle cells, causing a difference in the heartbeat.”

This means that sugar doesn’t just provide energy—it might directly affect how your heart works. If sweet taste receptors on your heart detect sugar, they may trigger the heart to beat harder or faster. This could help explain some of the body’s natural responses after eating.

The team also made a startling discovery when they looked at heart tissue from people with heart failure. They found more sweet taste receptors in those hearts than in healthy ones. This may be the heart’s way of adjusting to its own energy needs.

Yoder explained it this way: “During heart failure, the heart is changing its energetic landscape and prioritizing glucose uptake and glucose usage. So, it’s possible that during this energetic change, the heart might need to change its nutrient sensing abilities to accommodate this switch.”

In simpler terms, a failing heart may rely more on sugar for fuel. To make that switch, it might use these sweet receptors to sense when sugar is available. This could be part of how the heart tries to survive when it's under stress.

Artificial sweeteners have long sparked debate. While they help reduce sugar intake, some studies link them to health risks. This research adds a new concern. When the scientists overstimulated the sweet receptors in the heart with high amounts of aspartame, they noticed something troubling—heart cells began to behave irregularly.

That behavior resembled arrhythmias, or abnormal heart rhythms, which can be dangerous. “We found that overstimulation of these sweet taste receptors led to an increase in arrhythmic-like behavior in the heart cells,” said Yoder.

This might explain why some people who drink a lot of diet soda or use large amounts of artificial sweeteners have a higher risk of heart rhythm problems. The sweet taste receptors in their hearts may be getting too much stimulation, throwing off the heart’s normal pattern.

Still, scientists caution that they need more research to understand the full effects. They don’t yet know if the sweet taste receptors could be safely targeted to help treat heart failure. But the findings open the door to a new line of study in both medicine and nutrition.

The discovery of sweet taste receptors in the heart raises big questions. Could future drugs target these receptors to help hearts beat stronger? Might doctors one day measure sweet receptor activity to predict or treat heart problems?

Before those answers come, more studies must follow. Researchers want to learn how long-term exposure to artificial sweeteners affects heart function and how these receptors behave under stress. They also want to understand why the heart increases its sweet receptors during heart failure and whether that change helps or harms the heart.

What’s clear now is that the heart does more than pump blood. It senses, it reacts, and it might even taste. And with each beat, it may be responding not just to your emotions or activity—but to what you eat.

Note: The article above provided above by The Brighter Side of News.

Like these kind of feel good stories? Get The Brighter Side of News' newsletter.