The popular weight-lifting supplement creatine has been shown to be a safe and possibly effective treatment in slowing the progression of early stage Huntington's disease.

High-doses of the nutritional supplement were found safe and well tolerated by most participants in a phase II clinical trial led by H. Diane Rosas, a research doctor at MassGeneral Institute for Neurodegenerative Disease. The study’s novel design allowed participants to enroll without fear of learning whether they carried the mutation that causes the disease, though all had family histories and thus a genetic risk.

"More than 90 percent of those in the United States who know they are at risk for Huntington’s disease because of their family history have abstained from genetic testing, often because they fear discrimination or don't want to face the stress and anxiety of knowing they are destined to develop such a devastating disease," Rosas said in a statement. "Many of these individuals would still like to help find treatments, and this trial design allows them to participate while respecting their autonomy, their right not to know their personal genetic information."

The genetic mutation, an altered form of the huntington protein, damages brain cells by disrupting cellular energy production and thus depleting levels of ATP, the molecular powerhouse of most of the body’s biological processes. Researchers say creatine has been shown by numerous studies to help restore ATP along with cellular energy. The compound is also being investigated as a potential treatment for other neurodegenerative conditions, such as Parkinson's disease, amyotrophic lateral sclerosis, and spinal cord injury.

Past study showed no effect from creatine in low doses of 10 grams or less, including in patients who had developed the disease. In this study, researchers recruited 64 adults who were at risk of carrying the genetic mutation that causes the disease, including 19 who were aware they carried the mutation. The other 45 participants knew they faced a 50 percent chance of carrying the heritable mutation, as many pre-symptomatic sufferers prefer to live without knowing

Genetic testing revealed that another 26 participants in the study carried the genetic mutation, leaving a comparison group of 17 who did not carry the mutation. For six months, one randomized group in the study received twice-daily creatine pills at 30 grams per day, while the other received a placebo. In the next phase of the study, researchers gave all of the participants creatine for a year, assessing them at regular intervals with a brain-imaging scan conducted thrice during the study.

At the very least, researchers found, creatine did no harm. However, brain imaging tests — useful in diagnostics — might have failed to discern much notable difference during the short study period, study author Steven Hersch said.

"The results of this trial suggest that the prevention or delay of ...symptoms is feasible, that at-risk individuals can participate in clinical trials — even if they do not want to learn their genetic status — and that useful biomarkers can be developed to help assess therapeutic benefits," Hersch said. "In addition, we believe our study design sets an important precedent for other genetic diseases and will help inform discussions of how clinical research can coexist with deep concerns about genetic privacy and patient autonomy."

Source: McCusker, Elizabeth A., Myers, Richard H. Feasibility Of Huntington Disease Trials In The Disease Prodrome. Neurology. 2014.