STOCKHOLM — Japanese biologist Yoshinori Ohsumi won the Nobel Prize in medicine on Monday for discoveries on how cells break down and recycle content, a garbage disposal system that scientists hope to harness in the fight against cancer, Alzheimer’s and other diseases.

The Karolinska Institute honored Ohsumi for “brilliant experiments” in the 1990s on autophagy, a phenomenon that literally means “self-eating” and describes how cells gobble up damaged content and provide building blocks for renewal.

Disrupted autophagy has been linked to several diseases including Parkinson’s, diabetes and cancer, the prize committee said.

“Intense research is now ongoing to develop drugs that can target autophagy in various diseases,” it said in itscitation .

Ohsumi, 71, from Fukuoka, Japan, is a professor at the Tokyo Institute of Technology. In 2012, he won the Kyoto Prize, Japan’s highest private award for global achievement.

Ohsumi said he never thought he would win a Nobel Prize for his work, which he said involved studying yeast in a microscope day after day for decades.

“As a boy, the Nobel Prize was a dream, but after starting my research, it was out of my picture,” he told reporters in Tokyo.

“I don’t feel comfortable competing with many people, and instead I find it more enjoyable doing something nobody else is doing,” Ohsumi added. “In a way, that’s what science is all about, and the joy of finding something inspires me.”

Nobel committee secretary Thomas Perlmann said Ohsumi seemed surprised when he was informed he had won the Nobel Prize.