Scientists have theorized for decades about how the human brain evolved and grew dramatically in size. Now, new research points to one common ingredient that may have played a crucial role in the brain’s evolution over time: sugar.

A research team at the University of Sydney and the University of Glasgow created a model comparing modern nutrition with that of our ancestors over a span of four million years. The findings suggest that our ancestors relied on naturally occurring carbohydrate-rich foods, which could have played an important role in not only their overall dietary nutrition but also the evolution of the human brain.

These new findings challenge an older scientific model that emphasizes meat as a primary driving force behind human evolution.

“Raw starch does not release glucose, meaning early humans likely relied on naturally sweet foods long before grains became a regular part of the diet,” said lead author Professor Jennie Brand-Miller, Professor of Human Nutrition at the University of Sydney Charles Perkins Center and School of Life and Environmental Sciences, in a statement. 

While meat played a role in our ancestors’ diets, the new research suggests that the amount of energy required by a growing brain also needs to be considered. Throughout human evolution, brain size increased from roughly 300 grams in early hominins to approximately 1,500 grams in modern humans. Glucose is the brain’s primary energy source, creating increasing nutritional demands as brain size grew over time.

“While animal foods were important, the brain’s need for glucose has largely received little attention from anthropologists,” Professor Brand-Miller said.  

The Research

To better understand this hypothesis, the team created a model encompassing six evolutionary stages. Researchers estimated the “obligatory glucose demand” of the brain and other glucose-dependent tissues, including red blood cells, kidneys, and reproductive tissues. They then compared these glucose requirements with the carbohydrate sources that would have been readily available to humans during different stages of evolution.

“The human brain is unusually large for our body size and requires substantial amounts of energy,” Professor Brand-Miller said.  “Glucose is the brain’s primary energy source, and for much of human evolution, would have come from carbohydrates found in foods such as fruit and honey.” 

The model incorporated evidence from numerous fields, including metabolism, food composition, fossil isotope studies, dental morphology, archaeology, primate diets, and genetics.

Overall, the research suggests that early hominins, including Australopithecus, Homo habilis, and Homo erectus, were highly dependent on carbohydrate-rich foods, with fruit representing an important source. Later, as humans began using fire to cook food, starch-rich plants could also provide significant amounts of glucose. Grains, meanwhile, appear to have entered the human diet much later. The researchers point to archaeological evidence of seed grinding dating to around 65,000 years ago.

“People often think of carbohydrates as breads and cereals, but for most of human evolution carbohydrates came from fruits, honey and underground plant foods,” said Professor Brand-Miller. “The earliest evidence of seed grinding is 65,000 years ago, when we see the first evidence of grinding stones to make flour.” 

The study also examined the role of glucose in reproduction and pregnancy. Pregnancy and lactation significantly increase glucose demands, since energy is required not only by the mother but also by the developing fetus and placenta, as well as for milk production.

The new findings may also help explain humans’ longstanding attraction to sweet foods. For much of human evolution, naturally sweet foods such as fruit and honey provided concentrated sources of energy while also supplying fiber, vitamins, minerals, and other nutrients.

That doesn’t mean people should start making a run for the candy aisle. The findings do not suggest that modern humans should consume more refined sugar. Instead, the researchers distinguish between naturally occurring sugars found in whole foods and highly processed foods containing large quantities of added sugar.

Sugar was also not the human brain’s only source of fuel, nor were carbohydrates the sole dietary factor influencing human evolution. Rather, the researchers argue that glucose requirements have often received less attention than other dietary factors, including meat, fat, and protein. Our ancient appetite for naturally sweet, carbohydrate-rich foods, however, may have helped fuel the extraordinary expansion of the human brain.

Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.

A team of researchers from the University of Sydney and the University of Glasgow argues that dietary sugars, not animal foods, may have played the decisive role in the expansion of the human brain over the past 4 million years, as hominin brain size grew nearly fivefold, from about 300 grams in early relatives like […]

The post Study Points to Sugar, Not Just Meat, as Fuel for Human Brain Evolution appeared first on Sci.News: Breaking Science News.

A study found that unsweetened sparkling water lowers oral pH less than soda sweetened with sugar. A sip of sparkling water briefly makes the mouth more acidic, but not nearly as much as sugar-sweetened soda, according to a comparison of several common beverages. The findings suggest that choosing an unsweetened carbonated drink instead of soda [...]

Researchers have detected a sugar in the interstellar medium for the first time. Sugars are central to life. They help form the structural backbone of DNA and RNA and participate in essential metabolic reactions. They are also thought to have been necessary for the formation of the earliest nucleic acids. Yet researchers studying life’s origins [...]

Scientists have discovered an abundance of molecules in the cosmos, but for the first time ever, they were able to detect one in interstellar space very familiar to us here on Earth: sugar. 

The discovery, made in the vast clouds of gas and dust between stars, could help scientists better understand how some of the chemical ingredients necessary for life formed long before Earth existed.

Researchers at the Centro de Astrobiología, part of the Spanish National Research Council (CSIC), identified the sugar molecule erythrulose within the interstellar medium.

Sugars are considered fundamental building blocks of life. On Earth, they play vital biological roles, including forming the backbone of RNA and contributing to the chemistry that ultimately supports DNA, while also serving as an important source of energy. Scientists studying the origins of life have long sought to understand how the first sugars formed, since they are essential ingredients in the molecules associated with life’s earliest development.

“The detection of erythrulose is very exciting because it opens up the possibility of discovering in space other sugars such as ribose, which is part of RNA, and other important molecules for the origin of life,” says Carlos Briones, co-author of the study, in a statement. 

Even so, one major question remains: where did the first biologically important sugars originate?

Previous studies have identified sugars such as ribose and glucose in meteorites and asteroid samples, suggesting that some organic compounds may have been delivered to the early Earth from space. Until now, however, no sugar had been directly detected in the cold molecular clouds where stars and planets form.

The newly identified molecule, erythrulose, was found in the molecular cloud G+0.693−0.027 near the center of the Milky Way. On Earth, erythrulose is a naturally occurring four-carbon ketose sugar.

The discovery was made using highly sensitive radio astronomy observations from the Yebes Observatory’s 40-meter radio telescope and the 30-meter telescope operated by the Institute for Radio Astronomy in the Millimeter Range. Researchers analyzed the unique radio signatures, or spectral fingerprints, emitted by molecules in space.

The team identified 12 spectral lines matching laboratory measurements of erythrulose, confirming the molecule’s presence.

The findings also challenge some existing ideas about how complex molecules form in space. Scientists have generally proposed that interstellar chemistry builds larger molecules by gradually adding carbon atoms. Yet erythrulose proved to be more abundant than related three-carbon sugars that researchers expected would appear first.

“This finding was unexpected, as the prevailing view in astrochemistry is that interstellar molecules grow in size through the sequential addition of carbon atoms,” said Izaskun Jimenez Serra (CAB), the lead author of the recent study. 

Instead, the researchers found that erythrulose could form inside icy dust grains from simpler two-carbon alcohols and aldehydes. These frozen environments may function as natural chemical laboratories, allowing increasingly complex organic molecules to develop over time.

The team estimates that during the Late Heavy Bombardment—roughly 4.1 to 3.8 billion years ago, when Earth experienced intense asteroid and comet impacts—between 500,000 and 50 million tonnes of erythrulose may have been delivered to the planet’s surface.

The discovery adds another piece to the puzzle of life’s origins, suggesting that some of its essential ingredients may have arrived with something surprisingly sweet.

This paper was published in the journal Nature Astronomy.

Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.

It’s the first time a sugar molecule has been detected in interstellar space. The discovery provides tantalizing new clues into how life may have arisen on Earth.

Using the Yebes 40-m and IRAM 30-m radio telescopes, astronomers have discovered erythrulose, a four-carbon sugar commonly found in raspberries and sunless tanning cosmetics, in the molecular cloud G+0.693-0.027.

The post Astronomers Detect Sugar in Interstellar Space for First Time appeared first on Sci.News: Breaking Science News.

In a mouse study conducted by scientists at the Dasman Diabetes Institute in Kuwait, rodents fed a sucrose-free diet developed insulin resistance, gut microbial imbalances and signs of fatty liver disease despite maintaining similar body weight.

The post Eliminating Sucrose from Low-Fat Diet Alters Gut Microbiome, Animal Study Suggests appeared first on Sci.News: Breaking Science News.