• Posted March 29, 2026

Study Links High Antioxidant Intake To Changes in Offspring Development

Antioxidants are often seen as a good, simple way to boost health, but taking too many may come with some risks, new research suggests.

A study from Texas A&M University found that high doses of certain antioxidants may affect sperm and lead to developmental changes in offspring.

The research, published recently in the journal Frontiers in Cell and Developmental Biology, focused on two antioxidants: N-acetyl-L-cysteine (NAC) and selenium.

Male mice given these supplements for six weeks went on to have offspring with noticeable changes in skull and facial structure. 

The fathers themselves appeared healthy, researchers said.

The study suggests that too many antioxidants may alter sperm DNA, which could affect how offspring develop.

"We know alcohol causes oxidative stress and we were looking to push back on it by adding a supplement known to lower oxidative stress," said lead researcher Dr. Michael Golding, a professor in the Department of Veterinary Physiology & Pharmacology at Texas A&M University. 

"When we realized that offspring born to males that had only been given NAC were displaying skull and facial differences, it was a surprise because this molecule is universally thought to be good," he added in a news release.

While the results of research in animals are not always the same in people, the findings raise concerns for men who regularly take high-dose supplements, especially for those planning to have kids.

Antioxidants like NAC are widely used and are often included in multivitamins. But more is not always better, experts said.

"When we sat down to think it through, we realized that it makes sense — you take a multivitamin to ensure that you're in balance, but if the thing that you're taking to ensure you're in balance is unbalanced (the dose of antioxidants is too high), then you're not doing a good thing," Golding said.

Previous research has also found that very high antioxidant intake can reduce the benefits of exercise and affect athletic performance.

"Sperm health is another performance metric; it’s just not one that we think about in everyday life," Golding added.

Researchers also noticed stronger physical changes in female offspring, including smaller skulls and closer-set eyes.

These traits are oftentimes linked to conditions like fetal alcohol syndrome, the researchers said.

"There's a very commonly accepted truism in pediatric medicine that the face mirrors the brain, because the brain and the face form at the same time," Golding said. 

"So, if you see abnormalities in the midline of the face, you're probably going to see midline abnormalities in the brain," he added.

Researchers said it’s still unclear whether these changes affect brain function. 

The findings show that even supplements that are considered healthy can cause harm if taken in such large amounts.

And many supplements contain these very high doses.

"If your vitamins are providing 1,000% of the recommended daily amount, you should be cautious," he said. "If you stick to the 100% range, then you should be OK."

More information

Yale New Haven Health has more on the effects of taking too many vitamins.

SOURCE: Texas A&M University, news release, March 27, 2026