A new study finds that Omega-3s lower diastolic blood pressure in young people, and shows even greater effects for people who don’t consider themselves fish eaters.
High blood pressure is defined by a systolic (that’s the top number) reading greater than 140 and a diastolic (the bottom one) reading greater than 90 mmHg. If you have high blood pressure, you may be at a higher risk for developing cardiovascular disease (CVD).
However, high blood pressure is not the only likely cause of CVD. No, it seems that diet plays a pretty crucial role, too. Too many saturated fats, sugars, processed foods and a diet lacking adequate amounts of fruits and vegetables all appear to be risk factors as well.
While many countries have seen increases in cardiovascular disease in recent years, it is responsible for half of the deaths in Europe, and kills more Americans every year than cancer.
Omega-3 has already been shown to have a positive effect on blood pressure and cardiovascular risk. One meta-analysis, or a review of previously published scientific research revealed consistent finding showing significant reductions in both systolic and diastolic measures.
What’s more, consuming small daily doses seems to have the greatest effect.
The new study was conducted by Professor Inga Thorsdottir, from the University of Iceland. Together with her colleagues, they recruited 324 overweight young adults (20-40 y of age) to take part in an 8-week long study to see if an omega-3 diet would have any effect on diastolic blood pressure.
The participants were randomly assigned to one of four groups: salmon, cod, fish oil supplements, or a control group which received only sunflower oil and no fish.
The salmon diet contained 2.1 g of omega-3 LC-PUFAs per day. The cod diet averaged a daily dose of 0.3 g of omega-3 LC-PUFAs per day, and the fish oil diet consisted of 1.3 g of omega-3 LC-PUFAs per day.
After eight weeks, the participants lost an average of 11.5 pounds, and experienced reductions in blood pressure (SBP (-4.4+/-8.6 mmHg) and DBP (-4.1+/-7.4 mmHg).
Researchers were shocked to discover the greatest reductions in blood pressure were found among people who did not regularly consume fish prior to the study. The researcher noted that “A lower DHA content in erythrocyte membrane at baseline, which might identify infrequent fish eaters, is associated with a greater DBP reduction in the course of an eight-week dietary intervention providing fatty seafood“. Given this study’s relatively short duration, this is exciting news!
Moreover, the researchers were perplexed that there was no significant difference between the fish oil, the salmon, and the control. Considering the cod and the control groups were fairly similar in that “both diets provided no or only small amounts of u-3 LC-PUFAs“, one might assume that the findings would be nearly identical. Yet, because significant differences were only seen among the fish oil, salmon, and cod groups one wonders about “a certain placebo effect” or even if there is a larger mystery to be understood regarding lower DHA levels.