There are conflicting cultural beliefs about human evolution; one sphere thinks early man was eating berries and plants while the other contends they were more carnivorous. In every case diets were local. In Halloween Science I discussed things early mummies in various regions had in common and what it also revealed about local diets and customs.
If people had meat, they ate meat. But when it comes to evolution, carbohydrates like high-fructose sugar from honey and fruit don't get enough respect.
Low carbohydrate and no carbohydrate diets have been popular in culture (and they work, any crash diet that shocks the system will) but the celebrities that set off the craze by embracing them have been subtly undermined by writers. Like in soon-to-be-classic The Fall Guy, where the stuntman reminds the actor he replaces for action scenes that his diet is making his thinking addled:
"Tom, you need carbs. Your brain runs on glucose. For simple cognitive functions, you need them." - Colt Seavers (Ryan Gosling) to in-movie movie-star Tom Ryder (Aaron Taylor-Johnson)
A new paper says that caveman diets get a lot more credit then they deserve, at least for brain evolution. Honey and fruit matter. There is no question our brain size increase, 500 percent over 4,000,000 years was helped by meat and fat, and size can be a proxy for higher intelligence, but it is only part of the story. Evolution has no plan, nature is all about destruction and regeneration and imbalance, humans did not die off like billions of other species did because we adapted. That our brains require so strongly on sugar is a lot of evidence that we must have used it early and often. Evolution would not happen any other way. Even our appendix once had a function. Our mitochondria evolved to turn protein, fat, and sugar into a common energy currency because they were a happy confluence lead to where we are today; watching AI cat videos.
What is intriguing about the new paper is not what we basically knew; that a brain now is 2 percent of our body weight but takes up 20 person of our energy (and a lot higher in children) but how much sugar is needed when it comes to reproduction.
Women may be smarter because they burn more glucose. Don't tell that Caveman Diet guy.
A no-carb diet isn't bad as a one-off, French women can also drink a glass of wine every day during pregnancy and have no more birth defects than women who believe any wine creates fetal alcohol syndrome(1), but on a population level it would clearly be a negative.
There is circumstantial evidence to show that meat gave us a big boost more recently but once sugar was no longer once a year (we could grow and store it) the benefit can be found in our teeth and eyes.
Fire and cooked meat made us great but sugars from fruit and honey made us; because women of reproductive age need it, and if they hadn't gotten it, we wouldn't be wondering what it would be like if Darth Sidious was the star of Ace Ventura: Pet Detective instead of Jim Carry.
Citation: Jennie Brand-Miller, Karen Hardy, David Raubenheimer, and Les Copeland, 'A central role for dietary sugars in human evolution'. Science393,574-581(2026).DOI:10.1126/science.aed8437
NOTE:
(1) 1970s epidemiology is rightly considered a disaster when it comes to public trust in science and health and some things, like this, still linger. I don't drink alcohol, alcohol is a legitimate class 1 carcinogen and I like my brain, but I have ironically been called a shill for Big Booze by noting that the teetotaler claims regarding any wine during pregnancy are based on a paper so shoddy you might as well believe horse dewormer cured COVID-19 or weedkillers cause cancer; so dumb that predatorts hope you will be on the jury when they sue over whatever nonsense they are suing over this year.
Some things are smart to avoid, though. Japanese women have different immune biology than Americans so I'd avoid sushi if you don't eat it all of the time. Alcohol is metabolized so you really have to be execessive for an infant to be impacted but Listeria crosses the placental barrier directly.
