Posted on 05/12/2025 7:12:58 AM PDT by Red Badger
Researchers crack the code behind powerful sugar cravings
In a nutshell
* Scientists have mapped the exact structure of taste receptors that make us crave sweet foods, revealing how a single receptor recognizes both natural sugars and artificial sweeteners.
* The TAS1R2 protein in our taste buds contains a pocket that grabs onto sweet molecules, which could help food scientists design better-tasting artificial sweeteners without calories.
* This discovery explains why some animals (like cats) don’t care about sweets and offers potential new solutions to combat sugar-related health problems like obesity and diabetes.
====================================================================================
NEW YORK — That chocolate cake calling your name? Blame it on your sweet taste receptors. Scientists at Columbia University have just mapped the exact molecular structure that makes us love sugar and artificial sweeteners alike, potentially unlocking a future of better-tasting, healthier food alternatives.
In a study published in the journal Cell, researchers have revealed for the first time how our bodies detect sweetness at the molecular level. Using cutting-edge technology, they’ve captured 3D images showing precisely how sugar and artificial sweeteners hook up with receptors on our taste buds.
The Sweet Tooth Mystery Solved
The Columbia team employed a technique called cryo-electron microscopy, freezing the receptors to near absolute zero temperatures to capture their structure. This required extracting these delicate proteins, then taking thousands of images from different angles to reconstruct their 3D structure.
“A single taste receptor starts the whole process – it’s what makes us react to both regular sugar and zero-calorie sweeteners,” explained the research team led by Charles Zuker, whose lab in the Zuckerman Institute at Columbia oversaw the study. This molecular hook is what makes that morning donut so hard to resist.
The discovery answers a question that’s stumped scientists for decades: how can such wildly different substances – from table sugar to chemicals like aspartame – all taste sweet to us?
The answer lies in a remarkably versatile receptor with a shape resembling a Venus flytrap. When you eat something sweet, specific proteins on your taste buds called TAS1R2 and TAS1R3 work together to catch sweet molecules. These proteins act as the gatekeepers that decide what triggers that pleasurable “sweet” signal to your brain.
According to the study, the TAS1R2 subunit binds the sweeteners while TAS1R3 helps transmit the signal. Using powerful electron microscopes that can see objects smaller than a virus, the team watched these receptors in action as they grabbed onto sweeteners like sucralose (found in Splenda) and aspartame (in many diet sodas).
“Defining the binding pocket of this receptor very accurately is absolutely vital to understanding its function,” says study co-author Anthony Fitzpatrick, in a statement. “By knowing its exact shape, we can see why sweeteners attach to it, and how to make or find better molecules that activate the receptor or regulate its function.”
Why Your Cat Doesn’t Care About Cookies
This research offers fascinating insights into animal behavior too. Ever wonder why cats couldn’t care less about the cookie you dropped? Cats have lost functional sweet receptors through evolution – their DNA changed over time because meat-eating felines don’t need to detect sugars. The paper specifically notes that “some mammals that rely on a single diet (e.g., vampire bats) and some obligatory carnivores (e.g., cats) that get their full complement of sugar from eating other animals” have lost their sweet receptors over evolutionary time.
To confirm they’d identified the right spots, the researchers created altered versions of the receptor with tiny changes to the binding site. These modified receptors lost their ability to detect sweetness, confirming the team had pinpointed the crucial molecular machinery.
The Future of Sweet Without the Calories
For the food industry, this breakthrough opens new possibilities. Current artificial sweeteners often leave an unpleasant aftertaste or don’t quite mimic sugar’s sensation. With detailed knowledge of the sweet receptor’s structure, scientists could potentially design sweeteners that fit it perfectly – delivering sugar’s satisfaction without the calories or blood sugar spike.
Excessive sugar consumption fuels growing worldwide health concerns including obesity, diabetes, and heart disease. Better sugar alternatives could help reduce calorie intake while still satisfying our evolutionary drive for sweetness.
Studies also show that current artificial sweeteners are linked to various health problems. The findings could also help scientists create a new sugar substitute that wouldn’t carry the same risks as other products.
“The artificial sweeteners that we use today to replace sugar just don’t meaningfully change our desire for sugar. Now that we know what the receptor looks like, we might be able to design something better,” says study co-first author Juen Zhang, a postdoctoral fellow in Zuker’s lab, in a statement.
Our relationship with sweetness starts with our first taste of mother’s milk and shapes our food choices throughout life. By mapping the molecular machinery behind this fundamental taste, scientists have taken a major step toward healthier food options that don’t sacrifice sweetness – potentially bringing us closer to winning the battle against our sugar addictions.
VIDEO: Cryo-EM map of the human sweet taste receptor (blue and green) changing shape as it binds a molecule that tastes sweet (red and green). (Credit: J. Zhang et al.)
Paper Summary
Methodology
The Columbia University researchers used a sophisticated imaging technique called cryo-electron microscopy (cryo-EM) to determine the structure of human sweet taste receptors. They first created specialized protein constructs and purified the receptors from cells. The samples were then rapidly frozen to preserve their natural structure and examined under powerful electron microscopes. The team took thousands of images from various angles to build detailed 3D models. To verify their findings, they created mutant versions of the receptor with altered binding sites and tested their responses to sweeteners in cell-based experiments.
Results
The study revealed that the human sweet taste receptor consists of two protein subunits, TAS1R2 and TAS1R3, that work together. The TAS1R2 component contains the binding pocket that captures sweetener molecules, while TAS1R3 remains in an open formation and helps transmit the signal. Both artificial sweeteners tested – sucralose and aspartame – bind to the same pocket in TAS1R2. When sweeteners attach, they cause structural changes in the receptor that activate a signaling cascade, ultimately sending “sweet” signals to the brain. The researchers identified six specific amino acids in TAS1R2 that are critical for sweetener recognition.
Limitations
The researchers faced challenges studying natural sugars because the receptor has relatively low affinity for these compounds compared to artificial sweeteners. Technical constraints made it difficult to capture clear images of the receptor bound to natural sugar molecules. Additionally, while they successfully determined the structure with sucralose and aspartame, another sweetener used in the study (PEG400) wasn’t clearly resolved. The team also noted difficulties obtaining high-resolution images of the complete receptor complex with signaling proteins attached.
Funding/Disclosures
This research was funded partially by a grant from the Berrie Foundation and supported by the Howard Hughes Medical Institute, where lead researcher Charles Zuker serves as an investigator. The authors declared no competing interests related to the research.
Publication Information
The paper titled “The structure of human sweetness” was published in Cell (Volume 188, pages 1-13) on July 24, 2025. The research team included Zhang Juen, Zhengyuan Lu, Ruihuan Yu, Andrew N. Chang, Brian Wang, Anthony W.P. Fitzpatrick, and Charles S. Zuker from Columbia University and the Howard Hughes Medical Institute. The paper can be accessed online at
https://doi.org/10.1016/j.cell.2025.04.021.
Man does not live by Twinkies alone . . there’s also Froot Loops, Little Debbies, Chocolate McFlurry and soda.
I certainly want to blame my sweet cravings on SOMETHING other than me!
You do put up the best threads!
I could live on Snickers alone.................
When the off switch is available, I definitely want to know.
So you eat even more junk food? One of the points MAHA is making is that even if it be [intentional use of the English present subjunctive that the college board is trying to drive out of literate English] the case that hyper-processed foods are not directly poisoning us, the displace the eating of healthy food that provide the nutrition required for health.
who needs heroin when there’s Key Lime Pie and German Chocolate cake?
I had a girlfriend years ago with a t-shirt that said that.
Can’t these assclowns leave anything alone? I don’t want fake foods. I want calories. I don’t want anything that tastes good that has no food value.
Maybe add this ‘switch’ to vegetables??
Good.
Now figure out how to turn it off. Permanently.
I want the cat’s indifference to sweets.
See, see, all the more reason to have litter boxes in classrooms.
Aspartame sends me rushing to the, uh, library.
I found out that I was allergic to aspartame after a pizza party held at the 2ID JAG Office at Camp Casey in Korea. There was a case of Diet Coke remaining after the party, which I “liberated” back to my room. I drank that case over the rest of the weekend and, by Monday, my digestive tract was in such a state I could hit the toilet on the fly from across the room.
I’ve met so many people over the years, mostly men, who refuse to eat most or all vegetables. One guy might like canned peas and that’s it, another will eat certain raw vegetables with ranch dip, etc.
I like most of them, but I stay away from cooked leafy greens like spinach or collard greens. They just don’t do it for me.
We’ve known for ages, they’re called “taste buds”. We all have them.
Having to be around Pickles 24/7 could lead to becoming anorexic.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.