These Failing Rat Hearts Run Partly on Spinach

Rats with failing hearts pumped better after bits of spinach were injected into the muscle. The spinach only delivered when a red laser shone through their chests.

A struggling heart runs short of ATP, the molecule cells spend on work. Mitochondria usually supply it. In heart failure they falter, and the shortfall can deepen the damage.

Plants make ATP too, from light, inside membranes called thylakoids. A team at Union Hospital of Huazhong University of Science and Technology in Wuhan pulled thylakoids from spinach, broke them into nanoscale fragments and coated them in membranes stripped from cardiac muscle cells. That disguise helped rat heart cells in a dish absorb them, and under red light their ATP rose. The paper ran in Small.

The animal study used 24 rats in four equal groups. To mimic heart failure, the team surgically narrowed aortas, straining hearts until they enlarged and weakened. Four weeks later, particles went straight into the heart every three days, and one group got a 10-minute red laser session.

On ultrasound, rats given spinach plus light pumped better than untreated rats with the same surgery, with less scar tissue and fewer abnormally enlarged muscle cells. Spinach in the dark produced no statistically significant gain.

Nobody showed that particles sent through a vein would arrive at the heart in meaningful amounts. Light crossing a 2-millimeter (0.08-inch) slab of rat chest wall still raised ATP in cultured cells, just less, and whether enough could cross a human chest is unknown. The spinach machinery faded under long illumination. The researchers propose gels or patches on the heart's surface that release particles slowly.

Deep in a rat's chest, a scrap of spinach leaf was doing photosynthesis. Its sun was a laser.

Read the full story at Phys.org, October 11, 2026

Hot Take: Popeye got his strength from a can. These hearts need a shot every three days and somebody to keep the lights on.