The week’s most astounding developments from the neobiological frontier.

February 10, 2022

Human trial of calorie restriction reveals potential anti-aging target

Severely restricted diets of 50 percent fewer calories than normal diets were discovered to induce longer lives in laboratory animals as far back as 1935, but translating that into a longer human lifespan is fraught. There may be negative trade-offs—like stunted growth, loss of gray matter in the brain, impaired immunity, and bone density loss—not to mention the simple fact that many people would never follow such a severe diet. But maybe they won’t have to. Analyzing the effect of moderate caloric restriction (14 percent) on people in a clinical trial called Long-Term Effects of Reducing Intake of Energy (CALERIE), a team of researchers at Yale discovered the diet lowered levels of an immune system protein known as platelet activating factor acetylhydrolase (PLA2G7). They report that deactivating the Pla2G7 gene in normal-feeding mice mimicked the effect of calorie restriction and improved their metabolic health, which suggests targeting it in people could do the same. Science

Caloric restriction rejuvenates the human thymus. Courtesy V.D. Dixit, CALERIE-II study, and NIH grant R01AG031797.

Gut microbiome influences midlife cognition

Maintaining strong cognitive function as you age doesn’t take a lot of guts, just a healthy one. According to a recent study at the University of North Carolina, the gut microbiome plays a key role in midlife neurologic function. While scientists have previously examined this relationship in animal studies and small clinical trials, there has been limited evidence to support a community-wide association. Now, in a cross-sectional study including nearly 600 middle-aged adults (~55 years old) across four community centers, the researchers found a significant association between measures of cognition and community microbial composition. The team sequenced DNA from adult stool samples and showed that gut microbial diversity was associated with better results on six standard cognitive tests. JAMA Network Open

How brain connectivity supports real-life creativity

The cognitive basis for creativity is not fully understood, but one of the leading theories hypothesizes that creative cognition involves the ability to generate meaningful links between unrelated concepts—which in the brain may require interactions between several brain networks, including different semantic memory structures. Researchers at Sorbonne University in Paris tested this “associative” theory of creativity by taking fMRIs of 101 people aged 21–40 years while they were asked to judge how related 35 pairs of words were. They showed that the properties of the semantic memory network in someone’s brain relates to their real-life creativity, and they found that people with more compact and less modular semantic memory structures in their brains exhibited more creative accomplishments. Science Advances

The “Einstein effect” increases the credibility of scientists

Whether or not someone believes something is highly influenced by that person’s perception of its source—the more credible they perceive that source to be, the more likely someone is to believe them. Now a large, diverse study involving 10,195 people from 24 countries shows people tend to imbue scientists with loads of credibility, even across cultures and irrespective of one’s religious worldview. Led by researchers at the University of Amsterdam, the study presented people with obscure, meaningless gobbledygook—statements which, believe it or not, are technically dubbed “pseudo-profound bullshit.” In the study, the statements were attributed either to a spiritual guru or a scientist, and the researchers found that people considered gobbledygook from scientists to be more credible than the same gobbledygook from spiritual authorities—even people who are highly religious. The researchers dubbed this “the Einstein effect.” Nature Human Behavior

The way to a man’s fly’s heart is through his stomach

While Netflix & chill was once the buzz among casual daters, a recent study involving sex-seeking Drosophila melanogaster fruit flies suggests a protein-rich dinner date could be more effective in physiologically motivating a male’s courtship efforts. A team at the University of California, San Diego found that food and sex-starved male fruit flies choose food over sex until they consume a protein-rich meal. Then, just minutes after eating, their priorities flip. The same was found for Drosophila that were not food starved, just to a lesser extent. Why does this happen? According to the researchers, the amino acids from protein consumption turn on a switch, which triggers the release of diuretic hormone 31 (DH31) in the gut, which acts like a molecular aphrodisiac, stimulating brain neurons that inhibit feeding and increase courting. Perhaps buying your sexy beau a hot meal is more than just good etiquette. Nature