Professor Kummerow
In 1953, Professor Kummerow, at the time a professor of food technology at the University of Illinois, Urbana-Champaign, set up his lab in the animal sciences building on campus.
Fred A. Kummerow, a German-born biochemist and lifelong contrarian whose nearly 50 years of advocacy led to a federal government ban on the use of trans-fatty acids in processed foods, a ruling that could prevent tens of thousands of premature deaths a year, died on Wednesday at his home in Urbana, Ill. He was 102.

His family announced his death. He had been a longtime professor at the University of Illinois, Urbana-Champaign.

Artificial trans fats — derived from the hydrogen-treated oils used to give margarine its easy-to-spread texture and prolong the shelf life of crackers, cookies, icing and hundreds of other staples in the American diet — were ruled unsafe by the Food and Drug Administration partly in response to a lawsuit that Professor Kummerow filed against the agency in 2013, two months shy of his 99th birthday. The ban, announced in 2015, goes into effect in 2018.

He had been one of the first scientists to suggest a link between processed foods and heart disease. In the 1950s, while studying lipids at the university, he analyzed diseased arteries from about two dozen people who had died of heart attacks and discovered that the vessels were filled with trans fats.

He followed up with a study involving pigs that were given a diet heavy in such artificial fats. He found high levels of artery-clogging plaque in them.

Professor Kummerow published his findings about the role of trans fats in 1957, a time when the prevailing view held that saturated fats like those found in butter and cream were the big culprit in atherosclerosis.

His report, which appeared in the journal Science, was not merely criticized. It was dismissed. Detractors pointed out that his research had been conducted on animals, which sometimes react very differently than humans do.

"For many years, he was a lonely voice in the wilderness," said Michael Jacobson, president of the Center for Science in the Public Interest, a health advocacy organization based in Washington that in the 1980s began working to require the use of safer oils in food products.

Interviewed for this obituary in 2016, Professor Kummerow said that in the 1960s and '70s the processed food industry, enjoying a cozy relationship with scientists, played a large role in keeping trans fats in people's diets.

"Other scientists were more interested in what the industry was thinking than what I was thinking," he said. He was often heckled by industry representatives when he presented his research at scientific conferences, he said.

But he gradually won over key members of the scientific establishment. Dr. Walter Willett, a professor of epidemiology and nutrition at the T. H. Chan School of Public Health at Harvard, credited Professor Kummerow with inspiring him to include trans fats for analysis as part of Harvard's highly influential Nurses' Health Study, the results of which were published in 1993.

One finding showed a direct link between the consumption of foods containing trans fats and heart disease in women. It was a turning point in scientific and medical thinking about trans fats.

Yet it took another two decades for Professor Kummerow's research to be translated into regulatory action. The American Heart Association began warning about trans fats around 2004. Finally, in 2015 — 58 years after Professor Kummerow published his findings — the F.D.A. ruled that trans fats were not considered safe and could no longer be added to food after June 18, 2018, unless a manufacturer could present convincing scientific evidence that a particular use was safe.

Dr. Willett estimated that the elimination of industrial trans fats will prevent 90,000 premature deaths a year.

Fred August Kummerow was born on Oct. 4, 1914, in Berlin into a poor family. His father, a laborer, moved the family to the United States in 1923 to join relatives in Milwaukee, where he found a job at a cement block factory. Professor Kummerow said he would likely have been destined for similar work had he not received a chemistry set from his uncle on his 12th birthday. "It opened the world of science to me," he said.

He received a chemistry degree from the University of Wisconsin at Madison in 1939 and continued there for graduate studies. He received a Ph.D. in biochemistry in 1943.

During and immediately after World War II, while conducting research into lipids at Kansas State University, Professor Kummerow was awarded contracts by the Army Quartermaster Corps to help eliminate rancidity in frozen turkeys and chickens sent to troops overseas. A simple change in the poultry feed solved the problem, making possible the sale of frozen poultry in grocery stores.

Professor Kummerow moved his lipid research program to the University of Illinois in 1950 and remained there for the rest of his career.

Funding for the study of heart disease increased significantly after President Dwight D. Eisenhower had a severe heart attack in 1955. Grants from the National Institutes of Health enabled Professor Kummerow to conduct the research that led to the discovery of trans fats in diseased arteries.

He traveled frequently behind the Iron Curtain, speaking with scientists in the Soviet Union, as well as in Hungary, Romania, Bulgaria and East Germany. After the meetings, he sent reports to the State Department.

Professor Kummerow began his campaign to halt the use of trans fats when he found that food manufacturers had continued to rely heavily on trans fats even after his findings were corroborated by other scientists. In 2009 he filed a petition with the F.D.A. to ban the use of trans fats but, he said, received no response. He then sued the agency in 2013.

He is survived by a son, Max; two daughters, Jean and Kay; three grandchildren; and a great-grandson. His wife of 70 years, Amy, died of Parkinson's disease at 94.

Dr. Willett, of Harvard, said trans fats had also been implicated in diabetes. In 2001, he co-wrote a paper showing a diet low in trans fats could help prevent Type 2 diabetes in women. "Heart disease was the tip of the iceberg," he said.

Professor Kummerow was one of the first scientists to suggest that the saturated fat in butter, cheese and meats did not contribute to the clogging of arteries and was in fact beneficial in moderate amounts. This hypothesis, controversial at the time, was proved correct.

His own diet, he said, included red meat, whole milk and eggs scrambled in butter.