Hunger cues are influenced by more than just an empty stomach, with hormones like ghrelin playing powerful roles as appetite regulators. A recent study found that both exercise intensity and sex significantly influence ghrelin levels, markedly influencing appetite.
Researchers measured lactate threshold and peak oxygen consumption in 14 untrained males and females engaging in three different cycling sessions: a control session with no exercise, a moderate-intensity session at lactate threshold, and a high-intensity session at 75% of the difference between lactate threshold and peak oxygen consumption. Then, they assessed the participants' appetite perception.
They found that females had considerably higher total ghrelin and deacylated ghrelin levels at baseline than males. In both groups, high-intensity exercise promoted lower levels of deacylated ghrelin than moderate-intensity and no-exercise sessions. Notably, only females exhibited reduced acylated ghrelin levels during high-intensity exercise. Additionally, hunger scores were higher during moderate-intensity sessions than they were during no exercise.
Ghrelin, often called the “hunger hormone,” is primarily produced in the stomach and stimulates appetite. Deacetylated ghrelin has different effects on appetite regulation than its acylated counterpart.
These findings suggest that high-intensity exercise is more effective than moderate-intensity exercise in lowering ghrelin levels and suppressing hunger, with noticeable differences between sexes in this response. High-intensity exercise also promotes brain health. Learn more in this clip featuring Dr. Martin Gibala.
More than 10% of people worldwide have chronic kidney disease, a debilitating condition that progressively impairs the kidneys' capacity to filter waste and excess fluid from the blood. Evidence suggests that toxic exposures increase kidney disease risk. A recent study found that higher exposure to PFAS—so-called “forever chemicals"—was linked with decreased kidney function in young adults, potentially mediated by gut bacteria and metabolite changes.
The study involved 78 young adults at high risk for metabolic disease. Researchers measured their baseline PFAS levels, gut bacterial composition, and blood metabolite profiles. Then, they assessed the participants' kidney function.
They found that for each incremental increase in PFAS exposure, kidney function declined by roughly 2.4%. Shifts in specific gut bacteria and their metabolites, such as lower levels of Lachnospiraceae and increased levels of metabolites, explained up to half of the association between PFAS and reduced kidney function.
These findings suggest that PFAS contribute to kidney damage by disrupting gut health and metabolic processes. PFAS, short for per- and polyfluoroalkyl substances, are synthetic chemicals widely used in consumer products for their water- and stain-resistant properties. Microplastics often contain PFAS that can leach into the environment and accumulate in the body. Learn more about microplastics and PFAS exposure in this episode featuring Dr. Rhonda Patrick.
Lead exposure during pregnancy can harm a child’s developing brain, increasing the risk of autism-related behaviors. Some evidence suggests that folate, a B vitamin, might help protect against lead’s neurotoxic effects. A recent study found that higher folate levels during pregnancy may help reduce the risk of autism-like behaviors in children exposed to lead before birth.
Researchers analyzed data from a large mother-infant cohort study that tracked participants from pregnancy through early childhood. They measured blood lead levels and plasma folate concentrations during the women’s first and third trimesters. They assessed the children for autism-related behaviors when they were three to four years old. They also examined whether folic acid supplementation and MTHFR, a maternal genetic variant influencing folate metabolism, affected these associations.
They found that third-trimester blood lead levels were associated with more autism-like behaviors in children whose mothers had low third-trimester folate levels. They did not observe this association among mothers with higher folate levels. Additionally, folic acid supplementation appeared to reduce the harmful effects of lead exposure. The MTHFR genetic variant influenced the findings, but the effects were not statistically significant.
These findings suggest adequate folate levels during pregnancy may help protect against the neurodevelopmental harm linked to prenatal lead exposure.
Folate is the natural form of vitamin B9 found in foods, while folic acid is the synthetic form used in supplements and fortified foods. Folic acid has higher bioavailability, meaning the body more readily absorbs it than naturally occurring folate. Learn more about folate in this clip featuring Dr. Bruce Ames.