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High blood pressure (also known as hypertension) affects one in three American adults. It is a significant contributor to heart disease, stroke and premature mortality worldwide. By forcing the heart to work harder, high blood pressure damages the heart muscle and impairs its ability to relax. High blood pressure also damages blood vessels, increasing the risk of stroke and heart attack.

Exercise, eating a healthy diet and lowering alcohol consumption are effective ways to reduce elevated blood pressure. These lifestyle changes are arguably more demanding than taking a daily pill, but they are a great first-line treatment and do not come with the side effects of many common medications.

There are five evidence-based lifestyle changes you can make to reduce mildly elevated blood pressure. Mild elevation is defined as a blood pressure of 140-159/<90 mm Hg. Blood pressure higher than this, or in people with an otherwise increased risk of heart disease - those who have had a prior heart attack, or diabetes for example, should begin a more intensive treatment regime that includes medication as well as the following recommendations.

1.Adopting the DASH diet (Dietary Approaches to Stop Hypertension)

The DASH diet is rich in fruit, vegetables, and low fat dairy. The diet emphasises consumption of whole grains, poultry, fish, and nuts and a reduction in fats, red meat, sweets, and sugar-containing beverages. The diet is low in saturated fat and cholesterol and high in potassium, calcium, magnesium, dietary fibre, and protein.

Studies have tried to figure out the mechanisms through which the diet reduces blood pressure. The exact answer remains elusive, but hypotheses include the increased magnesium and potassium encourage the kidneys to reduce blood pressure, and the diet increases nitric oxide - a chemical that dilates blood vessels. The effects of the diet appear to be independent of any weight loss that may also occur with the reduced fat and sugar consumption.

Adherence to the DASH diet reduces systolic blood pressure (the higher number in the reading) by approximately 8-14 mmHg. This effect was seen as early as 2 months into adopting the diet. The effects have been shown to last as long as 18 months in patients adhering to the diet. Partial dietary changes have also been shown to reduce pressure, albeit to a lesser degree.

2. 30-60 minutes of regular exercise

The European Society of Hypertension guidelines recommend 30 minutes of moderate exercise 5-7 days a week to reduce blood pressure. Regular exercise can reduce blood pressure by approximately 4-9 mmHg. This is at the higher end of recommendations and studies have also suggested that as little as 30-60 minutes of exercise per week can lower blood pressure. Importantly, evidence suggests that modest exercise has a dose-dependent effect that seems to plateau at 90 minutes per week². So while groups exercising for 30-60 minutes per week saw a reduction in blood pressure, this was greater in those exercising for 60-90 minutes per week with no further reduction past that.

3.Reduced salt intake

On average people consume 10g of of salt a day - the equivalent to 2 teaspoons. Halving this can lower your blood pressure by approximately 5 mm Hg. Like exercise, there is a dose-response relationship between salt intake and blood pressure and while recommendations suggest halving salt intake, even greater reductions can lead to lower blood pressure.

4.Reduction of alcohol intake

Drinking 3 standard drinks per day is associated with an 5-10 mm Hg increase in blood pressure over time. This may seem counterintuitive because in small amounts alcohol reduces blood pressure. You might be familiar with the experience of drinking wine on a warm day and feeling woozy on standing up suddenly because the alcohol has lowered your blood pressure. Overtime regular drinking has the opposite effect and raises blood pressure.

The Canadian Hypertension Education Program recommends limiting alcohol consumption to ≤ 2 drinks/day in healthy people - not exceeding 14 standard drinks per week for men and 9 standard drinks per week for women. Reducing alcohol intake to these levels can reduce blood pressure between 2 - 4 mm Hg.

5.Weight loss if warranted

If warranted, weight loss can help to reduce blood pressure. The recommendations are to aim for a BMI of <25 kg/m2 and a waist circumference measurement of <102 cm for men and <88 cm in women. Studies have shown a 3 mm Hg drop on average per 4-8% bodyweight reduction.

References:

1. He, Feng J, Jiafu Li, and Graham A MacGregor. "Effect Of Longer-Term Modest Salt Reduction On Blood Pressure". Cochrane Database of Systematic Reviews (2013): n. pag. Web. 14 Feb. 2017.

2. Ishikawa-Takata, K. "How Much Exercise Is Required To Reduce Blood Pressure In Essential Hypertensives: A Dose–Response Study". American Journal of Hypertension 16.8 (2003): 629-633. Web.

3. Moore, T. J. et al. "DASH (Dietary Approaches To Stop Hypertension) Diet Is Effective Treatment For Stage 1 Isolated Systolic Hypertension". Hypertension 38.2 (2001): 155-158. Web. 14 Feb. 2017.

4. Viera, Anthony J and Emily M Hawes. "Management Of Mild Hypertension In Adults". BMJ (2016): i5719. Web. 14 Feb. 2017.