The first clinical study to understand the potential effects of time-restricted eating in people with Huntington’s disease finds that time-restricted eating is feasible, safe, and linked to improvements in disease markers.
In a 12-week pilot study, researchers found that people with early-stage Huntington’s Disease were able to safely follow a form of intermittent fasting known as time-restricted eating—limiting food consumption to a six-to-eight-hour window each day. Participants avoided unintended weight loss and showed improvements in measures of disease severity; in a blood biomarker linked to nerve cell damage; and in cellular energy production.
“This is the first time this approach has been formally studied in people with Huntington’s disease,” said Russell Wells, a medical student at Oregon Health & Science University. “We found that participants were able to follow the eating schedule, maintain their weight and show encouraging improvements in clinical and biological measures that are important in Huntington’s disease. These results suggest time-restricted eating deserves further study in a larger clinical trial.”
Huntington’s disease is a rare, inherited neurological disease that gradually damages nerve cells responsible for movement, cognitive and emotional regulation. Although researchers have known the genetic cause of the disease for decades, no treatments have been approved that slow or stop its progression.
Prior research in animal models suggests that intermittent fasting can activate cellular pathways that help protect brain cells. Yet researchers were unsure whether the approach would be safe for people with Huntington’s disease because unintended weight loss is already a concern.
“When Russell first brought me the idea, I was skeptical,” notes Amie Hiller, MD, professor of neurology in the OHSU School of Medicine and director of the Portland Veteran’s Administration Northwest Parkinson’s Disease Research, Education and Clinical Center. “Weight loss is a major challenge for many people with Huntington’s disease, so asking them to eat within a limited time window seemed counterintuitive.
“What was exciting about this study is that participants were able to maintain their weight while showing signs that the intervention may be positively affecting the disease itself,” Hiller notes.
The 20 participants selected an eating window that fit their daily routine, typically between late morning and early evening, and followed it for 12 weeks. Researchers encouraged participants to maintain their normal calorie intake and monitored weight and safety throughout the study.
The approach appeared well-tolerated. Participants followed the eating schedule on average more than five days per week; reported few side effects; and maintained both body weight and lean muscle mass. Most adapted to the schedule within the first one to two weeks. Participants used a smartphone app to document their first meal of the day with a photo and timestamp.
Participants experienced an average improvement of 0.5 points on a widely used Huntington’s disease severity scale known as the composite Unified Huntington’s Disease Rating Scale (cUHDRS). The score typically declines by about one point annually in people with early-stage disease.
In addition, blood levels of neurofilament light, a biomarker released when nerve cells are damaged, fell by an average of 13%. In Huntington’s disease, those levels usually increase over time as the disease progresses.
“We saw a reversal of the trend we would normally expect,” Wells said. “Neurofilament light typically rises as neurodegeneration continues, but after three months we observed a significant decrease. For a pilot study, that was a remarkable finding.”
The research team also examined mitochondrial function in participants’ blood cells and found improvements in several measures of mitochondrial activity after the intervention.
“One theory is that fasting acts as a mild stressor that prompts cells to become more efficient,” Wells said. “If cells, including brain cells, become better at producing energy and handling stress, they may be more resilient to the disease process.”
Because the study was small and did not include a comparison group, researchers caution that the findings should not be considered proof that time-restricted eating slows Huntington’s disease. Larger, randomized controlled trials will be needed to determine whether the benefits are real and sustained over time.
Still, researchers say the results are especially promising because the intervention is relatively simple and could be accessible to many people as there are no disease-modifying treatments for Huntington’s disease currently available. The team is currently pursuing funding for a larger, randomized clinical trial that would compare time-restricted eating with standard dietary habits.
