seven things to eat or avoid to lower your risk of hypertension

by clare collins, tracy burrows, and tracy schumacher, university of newcastle

high blood pressure is called the silent killer . that’s because it has no symptoms . having high blood pressure (hypertension) increases your risk of heart disease, stroke, heart failure and kidney disease.

nearly 15 million canadians live with, or are a dangerously high risk of high blood pressure – 140/90 millimetres of mercury (mmhg) or more – or take medications for it.

no wonder heart disease and stroke directly cost the canadian economy $20.9 billion a year .

optimal blood pressure is 120 mmhg or less over 80 mmhg or less. lowering it by 1-2 mmhg can have a big impact on reducing your risk of heart disease and stroke, and the nation’s health care costs.

what to eat to lower your blood pressure

a review with five research trials included tested the impact of oats on systolic blood pressure (the first blood pressure number, which is the pressure at which the heart pumps blood) and diastolic blood pressure (the second number, which is when the heart relaxes) in about 400 healthy adults.

this quantity of oats or oat bran contains around four grams of a type of fibre called beta-glucan .

while some of fibre’s effect is due to weight loss, soluble fibres produce bioactive products when they’re fermented in the large bowel. these work directly to lower blood pressure.recommended minimum daily adult fibre intakes are 30 grams for men and 25 grams for women.

a review of 16 trials of mostly healthy young men found drinking beetroot juice was associated with a 4.4 mmhg reduction in systolic blood pressure. but it found no change in diastolic blood pressure.

however a recent trial in 68 adults who already had high blood pressure found beetroot juice reduced systolic and diastolic blood pressure.

vitamin c, or ascorbic acid , is found in fresh vegetables and fruit. an average serve contains 10-40mg of vitamin c.

in a review of 29 short-term trials of vitamin c supplements , people were given 500 mg of vitamin c per day for about eight weeks.

however, those at risk of kidney stones need to be cautious about taking vitamin c supplements. excess vitamin c is excreted via the kidneys and can contribute to the formation of kidney stones.when only those with existing high blood pressure were considered, the drop in systolic blood pressure was 4.85 mmhg.

one advantage of getting more vitamin c from eating more vegetables and fruit is that you boost your potassium intake, which helps counter the effects of sodium from salt.

what to avoid to lower your blood pressure

salt or sodium chloride has been used to preserve foods and as a flavour enhancer for centuries.

high salt intakes are associated with higher blood pressure .

but canadians eat about 3400 mg of sodium a day—more than double the amount recommended. adults should aim for 1500 mg of sodium a day, without going over 2300 mg a day.

a review of studies involving 3,230 people showed that reducing salt intakes by 4.4 grams a day could reduce systolic blood pressure by about 4.2 mmhg and diastolic by 2.1 mmhg.

consuming one or more alcoholic drink a day is associated with systolic blood pressure that is about 2.7 mmhg and diastolic blood pressure 1.4 mmhg higher than non-drinkers.

a rise in blood pressure after drinking alcohol is more likely to happen when you’re awake , rather during sleep.

the bad news is that larger amounts of alcohol increase your risk of high blood pressure, especially in men , but also to a lesser extent in women .

high blood pressure due to eating black liquorice is rare, but case reports have occurred .

most liquorice candy sold currently contains very little true liquorice root and therefore, little glycyrrhizic acid (gza), the active ingredient.

occasionally, liquorice candy does contain gza in large amounts. gza causes sodium retention and potassium loss , which contributes to high blood pressure.

so check liquorice food labels. take care if it contains liquorice root.

high intakes of caffeine from coffee increase blood pressure in the short term.

in a review of five trials , people given one to two cups of strong coffee had an increase in their systolic blood pressure of 8.1 mmhg and 5.7 mmhg for diastolic blood pressure, up to about three hours after drinking it.

but three studies that lasted two weeks found drinking coffee did not increase blood pressure compared with decaffeinated coffee or avoiding caffeine. so you need to monitor your individual response to caffeine.