Regularly eating a diet supplemented with flaxseed oil may lower blood pressure and reduce risk of cardiovascular disease, according to a new study. The small trial showed that subjects who were on a diet fortified with flaxseed oil with high omega-3 alpha-linolenic acid ( ALA) significantly lowered their blood pressure.
The trial involved 59 men with an average age 53 who had high blood lipid concentrations. In the trial, two groups of participants were randomly assigned a diet either with flaxseed oil or a placebo (safflower oil). The study diet contained eight grams per day of omega-3 ALA rich flaxseed oil whereas the control diet contained omega-6, linoleic acid-rich safflower oil. The ratio of omega-6 to omega 3 fatty acids was 1.3 to 1in the ALA supplemented diet and 13.2 to 1 in the safflower diet.
High ratios of omega-6 to omega 3 have been known to be a risk for cardiovascular disease. The ratio in Americans can be up to 20, meaning that their diet contains way too much omega-6 fatty acids, which are abundantly present in vegetable oils.
After 12 weeks of supplementation, the researchers found those who were on the flaxseed oil diet experienced a significant drop in both systolic and diastolic blood pressures.
"Our results indicate that increased ALA intake can bring about a significant decrease in SBP (systolic blood pressure) and DBP (diastolic blood pressure) by approximately 5 mmHg or three to 6 percent,” lead author George Paschos and colleagues write in their report. "The magnitude of the hypertensive effect (5 mmHG or 3-6 per cent) is certainly clinically relevant, and is expected to considerably reduce the overall CVD risk in these patients,” the authors say.
Those who were on the safflower oil diet did not experience any significant decrease in blood pressure. The authors say the mechanism by which the flaxseed oil affects the blood pressure remains unknown. In addition, the amount of flaxseed oil used in the trial is beyond what the consumer normally has access to.
"However, several products like cooking oil, margarine, salad dressing, and mayonnaise fortified with ALA can be produced by the industry, and inclusion of these foods in the diet has been shown to substantially increase dietary ALA intake to levels exceeding those used in the present study,” the authors write.
Title: "Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients”: European Journal of Clinical Nutrition: Advance online publication; doi: 10.1038/sj.ejcn.1602631