Popular Antioxidant Supplement Considered "Miracle" Is Associated With Birth Defects

A recent study investigated whether the use of antioxidant supplements by healthy men before conception could affect the development of their children. Antioxidants help combat oxidative stress, a process that can damage cells. However, when male mice received antioxidant supplements before reproduction, their offspring showed changes in facial shape, even without signs of health problems in the parents.

Many people use antioxidant supplements believing they are always beneficial to health. These products, present in vitamins and dietary supplements, are known to help the body fight unstable molecules called free radicals, which can damage cells. However, new research suggests that the indiscriminate use of these supplements may have unexpected effects, especially when consumed by men before having children.

In the human body, there is a delicate balance between molecules that cause cell damage and the defense mechanisms that neutralize them. When this balance is broken and there is an excess of these reactive molecules, oxidative stress occurs.

This process can affect cell function and alter how certain genes are activated or deactivated. These changes do not directly alter the DNA, but they influence how it functions. This type of regulation is called epigenetics, a set of mechanisms that control gene activity without modifying the genetic sequence.

Previous studies have shown that environmental factors, such as diet, exposure to toxins, or alcohol consumption, can cause epigenetic changes in reproductive cells, such as sperm, and that these changes can affect the development of offspring.

Animal research, for example, indicates that chronic alcohol consumption by the father can cause changes in fetal development, including alterations in the placenta and the facial shape of the offspring. These changes are also associated with problems in the functioning of mitochondria, structures within cells responsible for producing energy.

Based on these findings, some scientists have suggested that antioxidant supplements could help reduce these negative effects. Antioxidants are substances capable of neutralizing reactive molecules and protecting cells against damage. Among the most studied antioxidants are N-acetylcysteine, a compound that helps the body produce glutathione, an important cellular defense molecule, and selenium, an essential mineral that participates in enzymes that protect cells against oxidative damage.

Dr. Michael Golding, from Texas A&M University, led the research. Credit: Jason Nitsch, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University.

However, recent studies have begun to show that these supplements may not be entirely harmless. In some experiments, researchers observed that antioxidants can alter how certain genes are regulated in male reproductive cells, even when there is no oxidative stress in the body. This raises the possibility that excessive use of these supplements could interfere with the normal programming of the development of future offspring.

To investigate this hypothesis, scientists conducted a study with mice. Healthy adult males received antioxidant supplements for six weeks before reproduction. After that, they were mated with females that received no treatment.

The researchers then analyzed the development of the offspring using advanced imaging techniques, including micro-computed tomography, a form of scanning that creates detailed three-dimensional images of the body, similar to a miniature medical CT scan.

The results showed something unexpected. Although the parents treated with antioxidants showed no apparent signs of health problems, their offspring exhibited changes in facial shape.

These changes were observed in both males and females, but were more pronounced in females, who showed a smaller distance between their eyes and a reduced head area. Interestingly, these changes occurred without alterations in placental weight or the metabolic health of the parents.

These findings suggest that the chemical balance of the father's body before conception may influence how the embryo develops. This does not mean that antioxidants are always harmful, but it indicates that their indiscriminate use can interfere with delicate biological processes. Therefore, researchers warn that antioxidant supplements, often considered completely safe, can have complex effects when used without medical necessity.

The image shows how scientists compare the facial shape of offspring using reference points on the face. By connecting these points in a geometric model, it is possible to measure small differences in shape that are not easily visible to the naked eye.

In this study, researchers observed that offspring of parents who received antioxidants showed changes in facial shape compared to offspring in the control group. These differences help reveal how factors present before conception can influence the development of offspring.

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Therapy to teratology: chronic paternal antioxidant supplementation alters offspring placental architecture and craniofacial morphogenesis in a mouse model

Destani D. Derrico, Katherine Z. Scaturro, Erin E. Murray, Eliezar Guillen, Nathan S. Truss, Katherine A. Fairly, Samantha L. Higgins, Sanat S. Bhadsavle, and Michael C. Golding

Frontiers in Cell and Developmental Biology. Volume 13 - 2025 

DOI: 10.3389/fcell.2025.1697843

Abstract:

Oxidative stress is an important regulator of the mammalian epigenome, with redox imbalances triggering stress-responsive epigenetic modifications linked to various diseases. Accordingly, antioxidant therapies are commonly used to reduce oxidative damage and are widely employed in cases of male infertility. Interestingly, in ostensibly healthy males, recent research suggests that antioxidants may have a negative influence on sperm DNA methylation, indicating a potential epigenetic liability. However, whether male antioxidant treatment can induce paternal effects on offspring growth and development remains untested. Here, we employed micro-CT imaging and geometric morphometrics to determine whether chronic antioxidant supplementation in healthy male mice affects placental growth and craniofacial development in their offspring. Adult C57BL/6J male mice were given a six-week preconception regimen of N-acetyl-L-cysteine and selenium, then paired with treatment-naïve females. Although we observed sex-specific changes in the decidua and junctional zone, we did not detect changes in placental weight and efficiency. In contrast, we observed significant changes in facial shape in both male and female offspring, with female offspring exhibiting significant reductions in eye spacing and head area. These changes occurred without any macro changes in paternal metabolic health, indicating that alterations in developmental programming may occur independent of changes in overall health. Our findings highlight the need for caution in the indiscriminate use of antioxidants, showing that supplementation in healthy males is not harmless and that perturbing the paternal redox balance may alter developmental programming and induce teratogenic outcomes.