Dr Liisa Laakso | A Ray of Hope for Mitochondrial Disease

The idea that Laakso is investigating is called photobiomodulation – or ‘PBM’ for short. PBM uses safe, carefully selected light wavelengths to stimulate mitochondria, the ‘powerhouses’ inside our cells. In lab studies, these kinds of light treatments have been shown to boost mitochondrial activity, reduce inflammatory stress, and tweak cellular signalling. The hope is that, by giving mitochondria a gentle nudge, PBM could ease the fatigue and energy deficits that people with MELAS live with.

Because MELAS is rare and varies so much between individuals, Laakso’s team designed a clever clinical approach. They will use a series of rigorous single-person trials, to test whether PBM therapy is safe and whether it seems to help each individual.

Each participant will go through a baseline phase where they receive no treatment; then a placebo phase involving a non-active light treatment; then a break; and finally, the real PBM therapy for eight weeks. By comparing how the person fares in each phase, the team will be able to assess whether changes are likely due to the light or just natural fluctuations.

Participants will use an LED device at home that emits blue light, red light, and near-infrared on their thighs, calves, and abdomen. The device is a medically approved model, and safety is one of the study’s core priorities.

People will self-report their fatigue using a validated questionnaire that captures exhaustion, motivation, concentration, and more. The researchers will also measure muscle function, blood biomarkers, mood, and even mitochondrial markers using magnetic resonance techniques.

One key marker they aim to monitor is lactate: if it decreases, that could mean the muscle is relying less on non-mitochondrial pathways and more on mitochondrial energy production.

Laakso and her collaborators are well aware that a small pilot trial can’t definitively prove that PBM works for everyone with MELAS. Placebo effects, individual differences, and challenges in translating lab dosages to humans all pose risks.

But this work is a careful stepping stone: if the results are positive, they can guide larger trials, refine dosing strategies, and move toward a new light-based tool to help people living with this tough condition.