Antioxidants Don’t Seem to Benefit Friedreich’s Ataxia Symptoms, Reviewers Conclude

Antioxidants do not seem to improve neurological symptoms in Friedreich’s Ataxia, according to a literature review conducted by a team of international scientists and published in Cochrane Database of Systematic Reviews.

The evidence is based on two small, published clinical trials. A third unpublished clinical trial testing the effect of idebenone on Friedreich’s Ataxia, also found no benefits of the drug for heart and neurological symptoms.

“When published, this trial will very likely influence our quality assessments and conclusions,” wrote Mary Kearney, MD, of the Irish College of General Practitioners in Dunlavin, Ireland, and co-author of the review titled “Pharmacological treatments for Friedreich ataxia.”

Antioxidants found in various foods in very low amounts are thought to protect cells from the harmful effects of free radicals. Therefore, some researchers attempted to use antioxidants such as idebenone, coenzyme Q10 and vitamin E to treat Friedreich’s Ataxia. However, these studies yielded conflicting results on their effect on the heart.

In the most recent review, researchers conducted a wide search of the medical literature in order to find clinical trials where participants took antioxidants for at least a year. They found four randomized controlled trials, but only two of them had published results in peer-reviewed scientific journals.

The first one included 28 participants and compared the effect of idebenone to placebo. The second included 44 participants and compared the effect of high-dose and very low-dose of coenzyme Q10 and vitamin E. The two unpublished trials looked at the effect of the diabetes drug pioglitazone in 40 participants and idebenone in 232 participants respectively, but no results are yet available.

The results of the first published trial suggested that idebenone might have a slight beneficial effect on the heart since the total mass and thickness of the heart wall decreased in participants taking idebenone compared to those on placebo. However, according to the authors of this review, “the quality of this evidence was low, or very low, and the importance of these findings is not clear.”

They concluded there currently is not enough evidence to support or refute the effect of antioxidants in Friedreich’s Ataxia.