Sjurdur Frodi Olsen

Sjurdur Frodi Olsen


Sjurdur Frodi Olsen, Professor, Epidemiologisk Forskning / Føtal progammering
T. +45 32683955 @.

Professor, Fetal Programming, Department of Epidemiology Research

Research Areas

My group is focusing on impact on health of dietary intake in pregnancy and during the adolescent years. A central research resource is the Danish National Birth Cohort, where we are following a cohort of 90,000 born during 1996-2003. My group has, together with associated groups, published >200 peer reviewed articles relating pregnancy diet to various health outcomes. A special line has been to study whether marine n-3 fatty acids can delay spontaneous delivery and prevent preterm birth. I and colleagues, in a paper in the Lancet, initially suggested this hypothesis, which in 2018 was corroborated by an extensive Cochrane review of randomized trials. Experiences from our studies, including our Chinese trial published in 2019 (see list of Selected publications), collectively suggest that the delaying effect of marine n-3 fatty acids on timing of spontaneous delivery might be fast but of short duration. In our data, there is also evidence to suggest that the relationship might be non-linear, with a low “saturation point”; and that small doses may have substantial effects in women who are below the saturation point. A recent international clinical practice guideline, published in Am J Obstet Gynecol MFM on behalf of six associations including the European Society for Paediatric Research, provided recommendations on marine n-3 fatty acid supply in pregnancy for risk reduction of preterm and early preterm birth.

1984 MD, University of Copenhagen 
1987  MSc in Epidemiology, London School Hygiene & Trop. Medicine 
1993   DMSci (, Aarhus University 
1994   PhD, Aarhus University 
1997   Authorized specialist course in Public Health 
2007   Course in Research Management, CBC 

Employment after doctorate
1993  Post Doc, London School of Hygiene & Tropical Medicine, UK 
1994  Senior Scientist, since 1997 leader of Maternal Nutrition Group, SSI 
2005-2007         Full (Ordinary) Professor of Epidemiology, University of Aarhus 
2006-  Adjunct Professor in Nutrition, Harvard School of Public Health, Boston, USA 
2007  Senior Scientist, Department of Epidemiology Research, SSI 
2009-  Chief Physician, Department of Epidemiology Research, SSI
2010-2019 Centre Leader, Centre for Fetal Programming, SSI
2019-  Professor of epidemiology with particular focus on foetal programming, at University of Copenhagen

Professional Activities and Leadership 
1999  Member, Scientific and Management Group of the Danish National Birth Cohort  
2001–2004 Member, Danish National Nutrition Council 
2005-2013 Member, Scientific Advisory Committee of Nutricia Research Foundation 
2007–2011 Leader, Theme 2 (on longitudinal epidemiology) of the FP6 Integrated Project, EARNEST 
2015-  Member, Steering Committee of the International Childhood Cancer Cohort Consortium (I4C) 
2015-   Member, International Life Science Institute (ILSI) Expert Group on “Nutritional Management of Gestational Diabetes: the scientific evidence to date” 
2017- Deputy PI – and member of the Scientific and Management Group – of the Danish National Birth Cohort

Prizes and Honours
1995  Simon Spies Medical Research Prize 
2004  Professor Johannes Ipsen Lecture  

Selected Publications
Olsen SF. A follow-up from a randomized controlled trial suggests that fish oil in pregnancy may increase the risk of obesity and metabolic syndrome in the offspring—a reason for concern? Editorial. Am J Clin Nutr. 22 February 2024.
Cetin I, Carlson SE, Burden C, Fonseca EBD, Renzo GCD, Hadjipanayis A, Harris WS, Kumar KR, Olsen SF, Mader MS, McAuliffe FM, Muhlhausler B, Oken E, Poon LC, Poston L, Ramakrishnan U, Roehr CC, Savona-Ventura C, Smuts CM, Sotiriadis A, Su KP, Tribe RM, Vannice G, Koletzko B. Omega-3 fatty acid supply in pregnancy for risk reduction of preterm and early preterm birth. Am J Obstet Gynecol MFM. 2023 Dec 7:101251. doi: 10.1016/j.ajogmf.2023.101251. Epub ahead of print. PMID: 38070679.
Noorzae R, Junker TG, Hviid A, Wohlfahrt J, Olsen SF. Risk of Type 1 Diabetes in Children Is Not Increased After SARS-CoV-2 Infection: A Nationwide Prospective Study in Denmark. Diabetes Care. 2023 Jun 1;46(6):1261-1264. doi: 10.2337/dc22-2351. PMID: 37058353.
Halldorsson TI, Birgisdottir BE, Brantsæter AL, Meltzer HM, Haugen M, Thorsdottir I, Olafsdottir AS, Olsen SF. Old Question Revisited: Are High-Protein Diets Safe in Pregnancy? Nutrients. 2021 Jan 29;13(2):440. doi: 10.3390/nu13020440. PMID: 33572843; PMCID: PMC7911198.
Bjerregaard AA, Halldorsson TI, Tetens I, Olsen SF. Mother's dietary quality during pregnancy and offspring's dietary quality in adolescence: Follow-up from a national birth cohort study of 19,582 mother-offspring pairs. PLoS Med. 2019 Sep 12;16(9):e1002911. doi: 10.1371/journal.pmed.1002911. Erratum in: PLoS Med. 2019 Nov 26;16(11):e1003004. PMID: 31513597; PMCID: PMC6742222.
Olsen SF, Halldorsson TI, Li M, Strøm M, Mao Y, Che Y, Wang Y, Duan F, Olsen J, Zhou W. Examining the effect of fish oil supplementation in Chinese pregnant women on gestation duration and risk of preterm delivery. J Nutr 2019;149(11):1942-1951
Antvorskov JC, Halldorsson TI, Josefsen K, Svensson J, Granström C, Roep BO, Olesen TH, Hrolfsdottir L, Buschard K, Olsen SF. Association between maternal gluten intake and type 1 diabetes in offspring: national prospective cohort study in Denmark. BMJ 2018;362:k3547 (Published 19 September 2018) 
Hansen S, Strøm M, Maslova E, Dahl R, Hoffmann HJ, Rytter D, Bech BH, Henriksen TB, Granström C, Halldorsson TI, Chavarro JE, Linneberg A, Olsen SF. Fish oil supplementation during pregnancy and allergic respiratory disease in the adult offspring. J Allergy Clin Immunol. 2016 Apr 25. pii: S0091-6749(16)30155-5. doi: 10.1016/j.jaci.2016.02.042. [Epub ahead of print] PubMed PMID: 27246522. 
Olsen SF, Houshmand-Oeregaard A, Granström C, Langhoff-Roos J, Damm P, Bech BH, Vaag AA, Zhang C. Diagnosing gestational diabetes mellitus in the Danish National Birth Cohort. Acta Obstet Gynecol Scand 2017;96:563-569. 
Olsen SF, Birgisdottir BE, Halldorsson TI, Brantsaeter AL, Haugen M, Torjusen H, Petersen SB, Strøm M, Meltzer HM. Possibilities and considerations when merging dietary data from the world's two largest pregnancy cohorts: the Danish National Birth Cohort and the Norwegian Mother and Child Cohort Study. Acta Obstet Gynecol Scand 2014;93:1131-1140.