Omega-3 Fatty Acids: MI Risk in Diabetic, Non-Diabetic Patients with CAD Interview wit:
Elin Strand

Researcher, Department of Clinical Science
University of Bergen, Norway What are the main findings of this study?

Answer: The main findings in this prospective observational cohort study among patients with established coronary artery disease were that a very high intake of omega-3 fatty acids was associated with a reduced risk of acute myocardial infarction in patients with diabetes, but with an increased risk of fatal acute myocardial infarction and with lower glycosylated hemoglobin in those without impaired glucose metabolism. Were any of the findings unexpected?

Answer: A beneficial effect among patients with diabetes was in accordance with our research hypothesis. However, the association between a very high omega-3 intake and increased risk of fatal acute myocardial infarction in patients without diabetes with normal glucose metabolism was somewhat surprising, although this was in accordance with a more speculative hypothesis. This hypothesis was based on results from prior studies showing that subjects with particular low glycosylated hemoglobin may have higher mortality. We thus speculate that this could be due to excess mortality from myocardial infarction and promoted by excess omega-3 intake. We did not expect to observe an effect of this extent on glucose metabolism, such as the adverse effect of the very high omega-3 associated with significantly lower levels of glycosylated hemoglobin. What should clinicians and patients take away from your report?

Answer: This and previous studies on omega-3 effects altogether suggests that there is no simple answer to what recommendations should be made in relation to omega-3 intake in a large heterogeneous population. A good lifestyle with a well-balanced diet that includes a few fish meals per week, will probably meet the need for omega-3 in most people. In such cases, additional use of omega-3 supplements is probably in general not necessary. However, a high intake may be beneficial for certain sub-groups, but may have adverse effects in other sub-groups. What recommendations do you have for future research as a result of this study?

Answer: These findings need confirmation, and we hope that prior conducted studies could be reanalysed to investigate whether patients with normal glucose tolerance are particular vulnerable to a very high intake of these fatty acids. Future randomized studies should investigate whether patients with diabetes may benefit from having a high intake of omega-3.

Since a high intake of omega-3 may be disadvantageous in certain patients as indicated here, we believe it would not be ethical to perform a randomized clinical study targeting this specific sub-group. Instead, it would be very interesting to study if the current results could be reproduced by dividing previous larger prospective cohorts or randomized trials into similar sub-groups and by investigating the effects using animal models.

A randomized trial in diabetes patients would be appropriate, although the recent Origin study in dysglycemic patients did not reveal an effect. In our opinion, the population represented by the Origin study clearly differed from our diabetes patients as thoroughly discussed in the manuscript. Thus, it would be interesting to study the effects through a randomized trial in a diabetic population more similar to the diabetes group in our study, not so aggressively treated by diabetic medication.


Dietary intake of n-3 long-chain polyunsaturated fatty acids and risk of myocardial infarction in coronary artery disease patients with or without diabetes mellitus: a prospective cohort study.

Strand E, Pedersen ER, Svingen GF, Schartum-Hansen H, Rebnord EW, Bjørndal B, Seifert R, Bohov P, Meyer K, Hiltunen JK, Nordrehaug JE, Nilsen DW, Berge RK, Nygård O.

BMC Med. 2013 Oct 8;11(1):216. [Epub ahead of print]



Last Updated on October 22, 2013 by Marie Benz MD FAAD