Akira Endo, a Japanese biochemist whose research on fungi helped to lay the groundwork for widely prescribed drugs that lower a type of cholesterol that contributes to heart disease, died on June 5. He was 90.

Chiba Kazuhiro, the president of Tokyo University of Agriculture and Technology, where Dr. Endo was a professor emeritus, confirmed the death in a statement. The statement did not give a cause or say where he died.

Cholesterol, mostly made in the liver, has important functions in the body. It is also a major contributor to coronary artery disease, a leading cause of death in the United States, Japan and many other countries.

In the early 1970s, Dr. Endo grew fungi in an effort to find a natural substance that could block a crucial enzyme that is part of the production of cholesterol. Some scientists worried that doing so might threaten cholesterol’s positive functions.

But by 1980, Dr. Endo’s team had found that a cholesterol-lowering drug, or statin, lowered the LDL, or “bad” cholesterol level, in the blood. And by 1987, after other researchers in the field had published additional research on statins, Merck was manufacturing the first licensed statin.

Such drugs have proven effective in reducing the risk of cardiovascular disease, and millions of people in the United States and beyond now take them for high levels of LDL.

Akira Endo was born on Nov. 14, 1933, in Yurihonjo, a city in a mountainous area near the Sea of Japan. His parents were farmers, and he developed an interest in mushrooms and molds, which would influence his work as a scientist.

He worked in rice fields by day and attended high school, against his parents’ wishes, by night. He was partly inspired by a desire to help farmers struggling with agricultural pests, said Kozo Sasada, a spokesman for Endo Akira Kenshokai, a group that honors Dr. Endo’s legacy.

Dr. Endo said his career was also inspired by a biography he read of Alexander Fleming, the Scottish biologist who discovered penicillin in the 1920s.

“For me Fleming was a hero,” he told Igaku-Shoin, a Japanese medical publisher, in 2014. “I dreamed of becoming a doctor as a child, but realized a new horizon as people who are not doctors can save people’s lives and contribute to society.”

After studying agriculture at Tohoku University, he joined Sankyo, a Japanese pharmaceutical company, in the late 1950s. His first assignment was manufacturing enzymes for fruit juices and wines at a factory in Tokyo.

He developed a more efficient way of cultivating mold by applying a method he had used as a child to make miso and pickled vegetables, he later told M3, a website for Japanese medical professionals. His reward was a promotion to the company’s microbiology and chemistry laboratory.

In the 1960s, he received a doctoral degree in biochemistry from Tohoku University. He also lived for a few years in New York City, where he worked as a research associate at the Albert Einstein College of Medicine.

At the time, he later told M3, he wanted to invent a cure for stroke, the leading cause of death in Japan. Strokes had caused the deaths of his father and his grandparents.

“But when I went to the States,” he said, “I learned there were many heart disease cases, so I switched.”

Back at Sankyo, he grew more than 6,000 fungi in the early 1970s as part of an effort to find a natural substance that could block a crucial enzyme involved in the production of cholesterol.

“I knew nothing but mold, so I decided to look for it in mold,” he said.

He eventually found what he was looking for: a strain of penicillium, or blue mold, that, in chickens, reduced levels of an enzyme that cells need to make LDL cholesterol.

Dr. Endo’s survivors include his wife, Orie; a son, Osamu; and a daughter, Chiga, according to Endo Akira Kenshokai. Complete information on survivors was not immediately available.

After Dr. Endo left Sankyo in the late 1970s, he worked as a professor at several Japanese universities and served as the president of Biopharm Research Laboratories, a Japanese pharmaceutical company. In 2008, he received a Lasker Award, the most prestigious prize in medicine next to the Nobel, for his medical research.

Dr. Endo said in the 2014 interview that he had tried to build a career around solving a problem that was global and not particular to Japan. He likened his work to scaling peaks much taller than Mount Takao in Tokyo.

“If I were to climb a mountain,” he said, “Mount Everest would be better.”

Orlando Mayorquín and Gina Kolata contributed reporting.