Fish oil, an abundant source of long chain omega-3 fatty acids, has become popular in the UK and other developed countries. However, despite recent studies, there have been significant gaps in identifying the proven cardiovascular health benefits of fish oil, and some studies have shown conflicting results.
The study included a total of 427,678 men and women between the ages of 40 and 69 who had not been diagnosed with CVD or cancer between 2006 and 2010 and until the end of 2018 at the start of the study.
Participants were assessed using a questionnaire asking about their habits using various dietary supplements, including fish oil. The questionnaire also had participants respond to socio-demographic questions such as age, gender, rating center, ethnicity, and household income. socio-economic status questions using the Townsend Deprivation Index; Questions about lifestyle such as smoking status, alcohol consumption, BMI, physical activity, diet; and, if necessary, questions about their comorbidities.
Analysis of the questionnaire data found that 133,438 (31.2%) of the participants habitually take fish oil supplements. Those who were supplemented with fish oil were older and more likely to be female, non-smokers, physically active, and had lower rates of diabetes. The results also showed that fish oil consumers ate oily fish more often than those who did not consume fish oil and had higher rates of high blood pressure and long-standing illness than non-consumers. Those who supplemented with fish oil were also more likely to take antihypertensive drugs, aspirin, vitamin supplements, and mineral and other dietary supplements.
Overall, the results indicated that habitual fish oil supplementation was associated with a 13% lower risk of all-cause mortality, a 16% lower risk of CVD mortality, and a 7% lower risk of CVD events in the general population.
The study’s results are in line with several other previous studies claiming the benefits of fish oil supplements in lowering the risk of CVD events. According to the study’s authors, possible explanations for the conflicting results of previous studies may be due to insufficient sample sizes, events, and dosages of fish oil.
There is not yet enough evidence as to which component of omega-3 fatty acids (docosahexaenoic acid, eicosapentaenoic acid, or docosahexaenoic acid and eicosapentaenoic acid) provides benefits for CVD events or all-cause mortality, and the UK biobank has identified that future studies are needed.
1. Li Z, Zhong W., Liu S. et al. Associations of habitual fish oil supplementation with cardiovascular outcomes and all cause mortality: evidence from a large population-based cohort study. BMJ. 2020; 368. doi https://doi.org/10.1136/bmj.m456.