Flaxseed may lower high blood pressure
EATING a bit of flaxseed daily could help to lower high blood pressure, a new study suggests.
Researchers said it is still too early to swop blood-pressure medication for the fibre-filled seeds. But if future studies confirm the new results, flax could offer a cheap way to treat high blood pressure, they added.
Flaxseed is well-known as a plant source of omega-3 fatty acids, fibre and lignans, a type of antioxidant. But so far, its effect on high blood pressure - or hypertension - has been better studied in animals than humans.
"This is the first demonstration of the cardiovascular effects of dietary flaxseed in a hypertensive population," Dr Grant Pierce told Reuters Health via e-mail.
He is the senior author of the study and executive director of research at St Boniface Hospital in Winnipeg, Manitoba, Canada.
His team's findings were published in the journal Hypertension. The trial included 110 people who had been diagnosed with peripheral artery disease, in which plaque builds up in arteries in the leg. Patients with the condition often have high blood pressure.
The participants were randomly assigned to either a flaxseed or comparison group.
People in the flaxseed group ate a variety of foods - like bagels, muffins and pasta - which contained 30g of milled flaxseed every day for six months.
Those in the comparison group were given foods that tasted similar, but did not contain any flaxseed.
People who had an initial systolic blood pressure - the top number in a blood-pressure reading - of at least 140 mm Hg saw that figure drop by 15 mm Hg, on average, after six months of taking flaxseed.
Their diastolic blood pressure - the bottom number - also fell by 7 mm Hg. Blood pressure did not change among people with hypertension in the comparison group.
"These decreases in (blood pressure) are among the most potent dietary interventions observed and comparable to current medication," Dr Pierce said.
However, there was no flaxseed-related benefit for people with normal blood pressure.
The new study was partially funded by the Flax Council of Canada. It was not originally designed to study blood pressure, which means the results have to be interpreted with more caution.