Oily fish twice a week reduces cardiovascular risks, say researchers

09 Mar 2021 --- Consuming oily fish such as salmon at least twice per week could reduce the risk of cardiovascular disease (CVD) and death in high-risk individuals, according to a global study conducted at McMaster University, Canada.

Now published in JAMA Internal Medicine, the study analyzed the outcomes of fish consumption on over 191,000 individuals with and without vascular disease across six continents and 58 countries.

The researchers found omega 3 fatty acids to be critical, associated with a lower risk of major CVD events such as heart attacks and strokes.

The frequency of such events dropped by around 15 percent in high-risk people who ate two servings of fish rich in omega 3 every week.

“There is a significant protective benefit of fish consumption in people with cardiovascular disease,” remarks lead co-author Andrew Mente.

“This study has important implications for guidelines on fish intake globally. It indicates that increasing fish consumption and particularly oily fish in vascular patients may produce a modest cardiovascular benefit.”

Oily fish like mackerel, trout, tuna and anchovies can contain up to 30 percent oil in their fillets. 

Consuming oily fish twice a week reduced CVD events in at-risk individuals by around one sixth.Global investigation 
The study authors pooled analyses of individual participant data from four separate cohort studies. 

Firstly, the analysis investigated data collected from 147,645 individuals (139,827 without CVD and 7,818 with CVD) from 21 countries in the Prospective Urban Rural Epidemiology (PURE).  

Alongside this, data from a further 43,413 patients with vascular disease in three other prospective studies from 40 countries were used. 

Adjusted hazard ratios were calculated by multilevel Cox regression, separately within each study, and then pooled using random-effects meta-analysis. The analysis was conducted from January to June 2020.

The findings indicated that a minimal fish intake of 175 g (approximately two servings) weekly is associated with a lower risk of major CVD and mortality among patients with prior CVD but not in general populations. 

Mente notes that people at low risk for CVD can still enjoy modest protection by eating fish rich in omega 3, but the health benefits are less pronounced than for high-risk individuals.

The study authors are calling for further research on the consumption of oily fish in randomized trials of clinical outcomes among people with vascular disease.

Researching omega 3
The latest findings come amid a continued surge in consumer interest and industry research into the uses of fish for various health concerns. 

While consuming omega 3 as a supplement remains highly popular, experts believe many people are critically uninformed about using it on an individual basis. 

Last year, industry players called for greater personalization and education on how to take the right ratio of omega 3 for different maladies. 

Meanwhile, Norwegian marine oil manufacturer Epax landed nearly US$1 million to begin researching new uses for omega 3 fatty acids, particularly eye, skin and fertility. 

Currently, clinical data on omega 3 typically focus on fatty acids DHA and EPA, but there are also around 30 other lesser-known fatty acids in omega 3. 

Edited

By Louis Gore-Langton