Cancer patients treated with doxorubicin, a common chemotherapy drug, may suffer heart damage, including reduced heart function, irregular heart rhythms and heart failure. A 2025 study published in Nature investigated whether astaxanthin, a natural antioxidant found in certain seafood and algae, could help reduce the damage.

The researchers divided study rats into a group that received only doxorubicin, two groups that received doxorubicin along with different doses of astaxanthin, and a control group. They used ultrasound scans to check blood markers for heart injury, examined heart tissue, measured cellular energy levels and analyzed proteins related to mitochondrial health.

Rats given doxorubicin alone experienced heart damage, mitochondrial disruptions and lower energy levels in the heart. By contrast, rats treated with astaxanthin showed improved heart function compared to the doxorubicin group, fewer signs of injury, healthier heart tissue and higher cellular energy levels. Astaxanthin also protected the structure and function of mitochondria.

Further research in humans is needed to confirm whether astaxanthin could safely and effectively be used alongside chemotherapy.