Dimitrios Trichopoulos, Greek epidemiologist, oncologist, and academic (b. 1938)
Dimitrios Trichopoulos (Greek: Δημήτριος Τριχόπουλος; December 9, 1938 – December 1, 2014), was a Mediterranean Diet expert and tobacco harms researcher. He was Vincent L. Gregory Professor of Cancer Prevention and Professor of Epidemiology, and a past chair of the Department of Epidemiology, in the Harvard School of Public Health in Boston.

Trichopoulos conducted research and taught in the field of cancer epidemiology and prevention. He published more than 1,000 scientific papers, from seminal research linking secondhand smoke (SHS) from cigarettes with increased susceptibility to risk for lung cancer, and hepatitis B virus and tobacco smoking with increased risk of primary liver cancer (hepatocellular carcinoma), to findings documenting that surgically induced and early natural menopause reduced breast cancer risk. Beyond oncology, his paper linking psychological stress after an earthquake in Athens to increased risk of cardiac death was included in a 1997 list in The Lancet of 27 papers deserving to form a core canon of medical literature that every health professional should read.

His oncology epidemiology and prevention research career included significant "firsts": He was first, with a 1990 paper in The Lancet, to propose that in utero exposures play a major role in breast cancer causation. He also was first in 1981, along with an independent paper published a few days later, to report that secondhand smoke increases the risk of lung cancer. Dimitrios Trichopoulos studied 51 nonsmoking women in Greece who had been hospitalized with lung cancer, then he compared them with age-matched women who had been hospitalized (also in Greece) for other problems. Though seemingly self-evident, researchers were able to determine statistically that these cancer patients were significantly more likely to have been exposed to their husband's cigarettes. Follow-up studies then began to confirm the risks of smoke inhalation by children in smoking households or in nonsmokers who live nearby smoking, in adjacent apartment units.

A native of Greece, Dimitrios studied at the University of Athens Medical School, where he earned an M.D. in 1963 and a Ph.D. in 1971. In 1968, he earned a S.M. in Boston at the Harvard School of Public Health and held several teaching appointments there over the next two decades (lecturer, 1969–1970; visiting professor, 1981–1985; adjunct, 1988–1989).

Harvard appointed him a full professor in the Department of Epidemiology in 1989, which department he began to chair that same year succeeding Brian MacMahon, and serving in that role until 1996. Initiatives under his leadership included a series of collaborations with investigators now at the Karolinska Institute in Stockholm, Sweden. In 1993, he was named Vincent L. Gregory Professor of Cancer Prevention, and also began a four-year appointment as director of the Harvard Center for Cancer Prevention.Trichopoulos also was a Member of the Athens Academy and president of the Hellenic Health Foundation in Greece. He held teaching appointments at the University of Athens Medical School and the Karolinska Institute in Sweden.

His awards and distinctions include honorary doctorates, the Brinker International Award for Breast Cancer Clinical Research, Harvard School of Public Health's Julius Richmond Award (2004) and Alumni Award of Merit (2009), and the Medal of Honor of the International Agency for Research on Cancer, World Health Organization.

He is survived by his wife Antonia Trichopoulou, who is known as "mother of the Mediterranean Diet".