How much can diet and exercise alone lower blood pressure?

From the Guidelines

Diet and exercise can significantly lower blood pressure, often reducing systolic blood pressure by 5-10 mmHg and diastolic by 2-8 mmHg, with the most recent evidence suggesting reductions of up to -7 mmHg in systolic and -5 mmHg in diastolic blood pressure through long-term exercise training intervention 1. To achieve optimal results, it is recommended to aim for 150 minutes of moderate aerobic exercise weekly, such as brisk walking, swimming, or cycling, plus strength training twice weekly. Some key dietary changes include:

• Adopting the DASH diet, which is rich in fruits, vegetables, whole grains, and low-fat dairy
• Reducing sodium intake to less than 2,300 mg daily, with some guidelines suggesting a reduction to less than 1,500 mg/d 1
• Limiting alcohol intake to 1-2 drinks per day
• Maintaining a healthy weight, with a target of losing at least 1 kg if overweight or obese 1 These lifestyle modifications work by improving blood vessel flexibility, reducing fluid volume, decreasing vascular resistance, and helping maintain healthy body weight. The full effect typically develops over 2-4 weeks of consistent practice. While these changes can be sufficient for those with mild hypertension, people with moderate to severe hypertension may need medication in addition to lifestyle modifications. For best results, it is essential to track blood pressure regularly and make these changes permanent rather than temporary fixes. Additionally, a Mediterranean-type diet, which is rich in vegetables, fruits, and low-fat dairy products, has been shown to have a cardiovascular protective effect and can be a good alternative to the DASH diet 1.

From the Research

Effects of Diet and Exercise on Blood Pressure

• The Dietary Approaches to Stop Hypertension (DASH) diet has been shown to lower blood pressure in several studies. For example, a study published in 1997 found that the DASH diet reduced systolic and diastolic blood pressure by 5.5 and 3.0 mm Hg, respectively, compared to a control diet 2.
• Exercise alone has also been associated with reductions in blood pressure. A study published in 2004 found that exercise alone was associated with reductions of approximately 3.5 and 2.0 mm Hg in systolic and diastolic blood pressure, respectively 3.
• Weight loss has also been shown to lower blood pressure. A study published in 2004 found that reductions of approximately 8.5 mm Hg in systolic blood pressure and 6.5 mm Hg in diastolic blood pressure accompanied weight loss of 8 kg 3.
• Combining diet and exercise has been shown to have an even greater effect on blood pressure. A study published in 2018 found that a home-based lifestyle modification intervention that included both diet and exercise was effective in lowering blood pressure, with significant reductions in daytime ambulatory systolic blood pressure compared to a control group 4.
• Reducing sodium intake has also been shown to lower blood pressure. A study published in 2001 found that reducing sodium intake from high to low levels reduced systolic blood pressure by 6.7 mm Hg in participants with hypertension, and by 3.7 mm Hg in participants without hypertension 5.

Subgroup Analysis

• The DASH diet has been shown to be effective in lowering blood pressure in various subgroups, including African Americans, whites, men, women, and individuals with and without hypertension 6.
• A study published in 1999 found that the DASH combination diet lowered systolic blood pressure significantly more in African Americans (6.8 mm Hg) than in whites (3.0 mm Hg), and in hypertensive subjects (11.4 mm Hg) than in nonhypertensive subjects (3.4 mm Hg) 6.

Overall Effects

• The overall effect of diet and exercise on blood pressure can be significant. A study published in 2004 found that a combined exercise and weight-loss intervention decreased systolic and diastolic blood pressure by 12.5 and 7.9 mm Hg, respectively, in overweight hypertensive patients 3.
• The DASH diet, with or without sodium reduction or weight loss, has been shown to lower blood pressure in virtually all subgroups examined, and may be an effective strategy for preventing and treating hypertension in a broad cross section of the population 2, 6.