Adjunct Professor of Nutrition
MD, University of Copenhagen, Denmark
MSc Epidemiology, London School of Hygiene and Tropical Medicine, UK
DMSci (dr.med.), University of Aarhus, Denmark
PhD, University of Aarhus, Denmark
Advanced Course in Research Management, Copenhagen Business School, Denmark
Dr. Sjurdur Frodi Olsen has throughout his research carrier focused on the impact of maternal diet on child health. His initial research interest was to examine impact of long chain n-3 fatty acids on pregnancy outcomes. He and colleagues were the first to suggest and show that fish oil in pregnancy could postpone timing of spontaneous delivery and reduce risk of preterm delivery (Lancet 1986, Lancet 1992, BJOG 2000, BMJ 2002), a contention which has only relatively recently been corroborated by others in equally well conducted randomized controlled trials (e.g. Makrides M et al. JAMA 2010; 304 (15): 1675-83, see table 4; and Hauner H et al. Am J Clin Nutr 2012; 95 (2): 383-94, see table 3). The original observations were that birth weights and pregnancy durations were found to be at higher levels in the Faroe Islands compared to Denmark and other geographically defined populations (JECH 1985, Lancet 1986), and that fish oil supplementation in Danish pregnant women appeared to increase pregnancy durations to similar levels to those observed in women in the Faroe Islands (Lancet 1992). In a multicenter clinical trial, undertaken in seven European countries (BJOG 2000), Olsen, Secher and other colleagues found that fish oil supplementation was associated with reduced recurrence risk of preterm delivery. Olsen and colleagues have conducted many studies addressing various aspects of these issues, including studies considering effects of low doses of long chain n-3 fatty acids (BJN 1990, JECH 1993, BMJ 2002, EJE 2006); studies using biomarkers to represent intake of marine n-3 fatty acids in pregnancy (JIM 1989; AJOG 1991; BJN 1995a; BJN 1995b); historical studies of early trials in the field (BJN 1990; eBMJ 1998; BMJ 1999; JRSM 2006); studies of changes over time in birth weight (JECH 2001) and cause-specific perinatal mortality patterns (BJOG 1995, AOGS 2000) in the Faroe Islands; a study in rats (PLEFA 1990); a ‘second thoughts paper’ considering the theoretical possibility that specific dietary exposures – notably, marine foods – could be underlying the association that had been observed between low birth weight and increased risk of cardio-vascular diseases in adulthood (JCE 1993); and a review paper examining the basis (which included the seemingly fast effect of dietary fatty acids on the delivery mechanism) for believing that long chain n-3 fatty acids and fish oil might have the potential to become part of future acute tocolytic treatment regimen for women in preterm labor (AOGS 2003) [for references, please see list of selected publications].
Dr. S.F. Olsen is part of the team that established the Danish National Birth Cohort. He is member of its Management Group and he has been responsible for the introduction, implementation, and conduct of the maternal dietary component of DNBC. During 1996 to 2003 seventy thousands of the pregnant women responded to a comprehensive general dietary questionnaire, generating the first large database worldwide of its kind (Olsen SF et al. Paediatr Perinat Epidemiol 2007).
Dr. Olsen and colleagues have during the last few years established intensive follow-up studies of birth cohorts and pregnancy trials stemming from the early studies that he and his colleagues did. For instance, in one study 965 pregnant women, who delivered during 1988-89, had a detailed dietary assessment during mid-pregnancy and gave blood samples that have been stored since then. The offspring are being followed by registry linkages and have been invited to complete questionnaires and participate in a comprehensive clinical examination program (e.g. see Halldorsson, … , Olsen SF, Environ Health Perspect 2012), making this cohort one of the prospective studies of effects of maternal nutrition with the longest follow-up time. In another follow up study, Olsen and colleagues are examining long term effects of fish oil supplementation in pregnancy on offspring risk of developing asthma (Olsen SF et al. Am J Clin Nutr 2008) and cardio-metabolic diseases (e.g. see Rytter, … , Olsen SF. Am J Clin Nutr 2011 and BJN 2012).
Dr. Olsen is involved in several international collaborative efforts. In a European context, he was partner in the Framework Programme (FP) 5 project NUTRIX and Theme Leader in the FP6 Integrated Project EARNEST, both of which focused on effects of early nutrition on health; and he is partner in the recently established Early Nutrition Project, a Large-Scale Integrated Project also funded by the European Commission, under FP7. He is Danish co-PI in the NIH/NICHD initiated ‘Diabetes and Women’s Health Study’ which is seeking to identify determinants (medical, lifestyle, genetic and their interactions) for the progression from gestational diabetes to type 2 diabetes; this US-Danish collaborative study is based on long term follow up of approximately 5,000 women with diabetes in pregnancy in the two major cohorts, the US Nurses’ Health Study II and the Danish National Birth Cohort. Furthermore, together with Dr ZHOU Weijin he initiated a randomized controlled trial with fish oil supplementation that is presently being undertaken in China.
Dr. Olsen has served on several expert committees. While he was a member of the Danish Nutrition Council, he chaired the Council’s expert panel that in 2005 published an extensive report reviewing the scientific evidence underpinning dietary advice in relation to pregnancy. As member of the expert group on ‘Pregnancy and Lactation’ (PAL), he is currently contributing to updating the 5th version of the Nordic Nutrition Recommendations (‘NNR5’) financed by The Nordic Council of Ministers.
Dr. Olsen has had research employments at Academia Faeroensis, Aarhus University, London School of Hygiene and Tropical Medicine, Danish Epidemiology Science Centre, University of Copenhagen, and Statens Serum Institut. He established the Maternal Nutrition Group at Statens Serum institut, where he is Chief Physician. During two years, from Oct 2005 to Oct 2007, he was ordinary (full) professor of epidemiology at Aarhus University. Since 1995 he has visited Department Nutrition at Harvard School of Public Health many times; one of several important aims of his visits has been to seek advice in relation to effectuating the nutritional component of the Danish National Birth Cohort. He has collaborative projects on-going with researchers and doctoral students at the School, where he is a regular visitor and has been teaching at different courses; in Dec 2006 he became formally affiliated with Harvard School of Public Health as adjunct professor in nutrition.
On Jan 1, 2010, Sjurdur F. Olsen became the Leader of the Centre for Fetal Programming, which is a multidisciplinary research consortium funded for a five year period by the Danish Council for Strategic Research. The aim of the Centre is to examine and understand fetal programming of health related phenomena. The Centre is located in 12 different institutions and includes both epidemiological, animal experimental, and clinical physiological approaches.
Olsen SF, Joensen HD. High liveborn birthweigths in the Faroes: a comparison between birthweights in the Faroes and in Denmark. Journal of Epidemiology and Community Health 1985; 39: 27-32.
Olsen SF, Hansen HS, Sørensen TIA, Jensen B, Secher NJ, Sommer S, Knudsen LB. Intake of marine fat, rich in (n-3)-polyunsaturated fatty acids, may increase birthweight by prolonging gestation in humans. Lancet 1986; ii: 367-369. (Hypothesis Article.)
Olsen SF, Hansen HS. Marine fat, birthweight, and gestational age: a case report. Agents and Actions 1987; 22: 373-374.
Olsen SF, Hansen HS, Jensen B, Sørensen TIA. Pregnancy duration and the ratio of long-chain n-3 fatty acids to arachidonic acid in erythrocytes from Faroese women. Journal of Internal Medicine1989; 225, Suppl. 1: 185-189.
Olsen SF, Hansen HS, Jensen B. Fish oil versus arachis oil food supplementation in relation to pregnancy duration in rats. Prostaglandins Leukotrienes and Essential Fatty Acids 1990; 40: 255-260.
Olsen SF, Secher NJ. A possible preventive effect of low-dose fish oil on early delivery and preeclampsia: indications from a 50 year old controlled trial. British Journal of Nutrition 1990; 64: 599-609.
Olsen SF, Hansen HS, Sommer S, Jensen B, Sørensen TIA, Secher NJ, Zachariassen P. Gestational age in relation to marine n-3 fatty acids in maternal erythrocytes: a study of women in the Faroe Islands and Denmark. American Journal of Obstetrics and Gynecology 1991; 164: 1203-1609.
Olsen SF, Sørensen JD, Secher NJ, Hedegaard M, Henriksen TB, Hansen HS, Grant A. Randomised controlled trial of effect of fish-oil supplementation on pregnancy duration. Lancet 1992; 339: 1003-07.
Olsen SF, Grandjean P, Weihe P, Viderø T. Seafood intake in pregnancy as a determinant of birth weight: evidence for a dose dependent relationship. Journal of Epidemiology and Community Health 1993; 47: 436-440.
Olsen SF. Marine n-3 fatty acids ingested in pregnancy as a possible determinant of birth weight: a review of the current epidemiologic evidence. Epidemiologic Reviews 1993; 15(2): 399-413. Erratum appeared in American Journal of Epidemiology 1994; 139(8): 856.
Olsen SF. Further on the association between retarded fetal growth and adult cardiovascular disease: Could low intake of marine diets be a common cause? Journal of Clinical Epidemiology1994; 47: 565-569. (Second Thoughts Article.)
Olsen SF, Hansen HS, Sandstrom B, Jensen B. Erythrocyte levels compared with reported dietary intake of marine n-3 fatty acids in pregnant women. British Journal of Nutrition 1995; 73: 387-395.
Olsen SF, Hansen HS, Secher NJ, Jensen B, Sandstrom B. Gestation length and birth weight in relation to intake of marine n-3 fatty acids. British Journal of Nutrition 1995; 73: 397-404.
Olsen SF, Samuelsen S, Joensen HD. A clinico-pathological classification of perinatal deaths in the Faroe Islands. British Journal or Obstetrics and Gynaecology 1995; 102: 389-392.
Olsen SF. The first clinical trial with randomisation of individuals? eBMJ 1998; 317 (‘Eletronic reponses’ Article that can be seen here http://www.bmj.com.ezp-prod1.hul.harvard.edu/rapid-response/2011/10/27/first-clinical-trial-true-randomisation-individuals )
Olsen SF. Theobald’s trial from 1936 incorporated some aspects of randomisation. BMJ 1999; 318: 1352. (Letter to the Editor.)
Olsen SF, Secher NJ, Tabor A, Weber T, Walker JJ, Gluud C for the FOTIP Team. Randomised controlled trials of fish oil supplementation in high risk pregnancies. A multicentre study in 7 European countries. British Journal of Obstetrics and Gynaecology 2000; 107: 382-395.
Joensen F, Olsen SF, Holm T, Joensen HD. Perinatal deaths in the Faroe Islands 1986-1995. Acta Obstetricia et Gynecologica Scandinavica 2000; 79: 834-838.
Olsen SF, Beck DN, Kollslíð R, Rasmussen RW. High birth weights in prewar Faroe Islands. Journal of Epidemiology and Community Health 2001; 55: 215. (Short Report.)
Olsen SF, Secher NJ. Low consumption of seafood in early pregnancy as a risk factor for preterm delivery: prospective cohort study. BMJ 2002 Feb 23; 324 (7335): 447-450. (The longer electronic version of the article can be seen here http://www.bmj.com.ezp-prod1.hul.harvard.edu/content/324/7335/447# )
Olsen SF, Secher SF, Bjornsson S, Weber T, Atke A. The potential benefits of using fish oil in relation to preterm labor: The case for a randomized controlled trial? Acta Obstetricia et Gynecologica Scandinavica 2003; 82: 978-82.
Olsen SF. Is supplementation with marine omega-3 fatty acids during pregnancy a useful tool in the prevention of preterm birth? Clinical Obstetrics and Gynecology 2004; 47: 768-74.
Olsen SF. The People’s League of Health trial. Journal of the Royal Society of Medicine 2006; 99: 44-45.
Makrides M, Duley L, Olsen SF. Impact of intake of n-3 fatty acids, and of other eicosanoid precursor fatty acids, on pregnancy complications. Cochrane Review 2006 Jul 19;3:CD003402.
Olsen SF, Østerdal ML, Salvig JD, Kesmodel U, Henriksen TB, Hedegaard M, Secher NJ. Duration of pregnancy in relation to seafood intake during early and mid pregnancy: prospective cohort.European Journal of Epidemiology 2006; 21: 749-58.
Olsen SF, TB Mikkelsen, VK Knudsen, I Orozova-Bekkevold, Th I Halldórsson, M Strøm, and ML Østerdal.Data collected on maternal dietary exposures in the Danish National Birth Cohort. Paediatric and Perinatal Epidemiology 2007; 21: 76-86.
Olsen SF, Halldorsson ThI, Willett WC, Knudsen VK, Gillman MW, Mikkelsen TB, Olsen J and The NUTRIX Consortium. Milk consumption during pregnancy is associated with increased infant size at birth: prospective cohort study. American Journal of Clinical Nutrition 2007; 86: 1104-10.
Olsen SF, Østerdal ML, Salvig JD, Mortensen LM, Rytter D, Secher NJ, Henriksen TB. Fish oil intake compared with olive oil intake in late pregnancy and asthma in the offspring: 16 y of registry-based follow-up from a randomized controlled trial. American Journal of Clinical Nutrition 2008; 88: 167-75.
Rytter D, Bech BH, Christensen JH, Schmidt EB, Henriksen TB, Olsen SF. Intake of fish oil during pregnancy and adipocity in 19-y-old offspring: follow-up on a randomized controlled trial.American Journal of Clinical Nutrition 2011 Sep;94(3):701-8.
Rytter D, Bech BH, Christensen JH, Schmidt EB, Henriksen TB, Olsen SF. The effect of maternal fish oil supplementation during the last trimester of pregnancy on blood pressure, heart rate and heart rate variability in the 19-year-old offspring. British Journal of Nutrition 2012; 108:1475-83.
Halldorsson TI, Rytter D, Haug LS, Bech BH, Danielsen I, Becher G, Henriksen TB, Olsen SF. Prenatal Exposure to Perfluorooctanoate and Risk of Overweight at 20 Years of Age: A Prospective Cohort Study. Environmental Health Perspectives 2012; 120: 668-73.
Maslova E, Granstrøm C, Hansen S, Pedersen SB, Strøm M, Willett W, Olsen SF. Peanut and tree nut consumption during pregnancy and child allergic disease – should mothers decrease their intake? Longitudinal evidence from the Danish National Birth Cohort. Journal of Allergy and Clinical Immunology 2012; 130:724-32.
Center for Fetal Programming
Nordic Nutritional Recommendation home page
EU project EARNEST
Danish Nutrition Council, Report on maternal nutrition
PPTs from talk given in Milano in May 2012 on ‘Impact of marine n-3 fatty acids consumed in pregnancy on mother and child health, with particular focus on the prevention of preterm birth’http://www.fondazionegiorgiopardi.it/wp-content/uploads/2012/05/Olsen-FONDAZIONE-GIORGIO-PARDI-4-May-2012.pdf