Hypertension: The Role of Healthy Eating and Lifestyle Habits

Hypertension, commonly known as high blood pressure, affects almost 1 in 4 Canadians.1 Healthy eating and exercise habits are recommended to help prevent and manage hypertension.2 Hypertension Canada recommends Dietary Approaches to Stop Hypertension (DASH) - a healthy diet that emphasizes fruits, vegetables, and milk products.2-5 

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Understanding the risk

High blood pressure can damage arteries and reduce blood flow throughout the body. This increases the risk of other health issues, including cardiovascular diseases such as stroke, heart attack, and heart failure, as well as kidney disease and kidney failure, and dementia.6 Preventing and managing hypertension can help limit damage to the arteries to protect health.

Regular blood pressure monitoring is important, since there are no obvious warning signs, aside from elevated blood pressure numbers. While the risk of hypertension tends to increase with age and people with a family history of hypertension are more prone to develop high blood pressure, a number of healthy lifestyle habits can help with both prevention and management.2,6 When needed, several types of medications may also be prescribed to help treat hypertension.

In practice

Hypertension Canada guidelines recommend a number of healthy eating and lifestyle habits to help prevent and manage high blood pressure in at risk individuals. These include:

  • Following the DASH diet, that emphasizes fruits, vegetables, milk products, whole-grain foods, and legumes, nuts and seeds;
  • Considering a reduction in sodium towards 2000 mg per day, or salt to 5 g per day;
  • Accumulating 30-60 minutes of moderate-intensity dynamic exercise (e.g. walking, jogging, cycling or swimming) 4-7 days per week;
  • Achieving and maintaining a healthy weight;
  • Abstaining from or reducing alcohol consumption to two or less drinks per day;
  • Managing stress.

Healthy lifestyle habits

Fortunately, research shows that adopting a healthy diet, being physically active, reducing alcohol intake, and achieving a healthy weight can all contribute to lowering blood pressure.7 Managing risk factors such as diet and exercise can help to offset, at least to some extent, a genetic predisposition towards high blood pressure and its cardiovascular complications.8

An analysis of data from the Canadian Health Measures Survey (including 13,407 respondents) showed that our lifestyle habits matter for healthy blood pressure control.7 Being overweight contributed to 24% of all cases of hypertension. Eating vegetables and fruits fewer than five times per day and engaging in less than 150 minutes of moderate-to-vigorous physical activity a week were also associated with an increased risk of hypertension. As was having diabetes and having chronic kidney disease.

The DASH diet and dairy foods

Research also shows a healthy DASH diet that includes enough vegetables, fruit and milk products is associated with better blood pressure control.3-5 The landmark DASH diet study examined the impact of eating patterns on blood pressure. This trial found that eating about 3 servings of milk products plus 8 to 10 servings of fruits and vegetables daily as part of the DASH diet was associated with the greatest benefit in terms of blood pressure reduction.

The mechanisms by which milk products may influence blood pressure remain to be fully understood. However, researchers have identified some key nutrients that may play a role.

Calcium is thought to be one of the main nutrients involved. Research indicates that higher dietary calcium intakes are associated with a lower risk of developing high blood pressure.9

Vitamin D appears to play a role given its importance in calcium absorption. Research shows low vitamin D status is linked with blood vessel constriction, and sodium and water retention.10

Magnesium contributes to normal muscle function, thus may help blood vessel walls to relax. Evidence suggests low dietary magnesium is associated with a higher risk of hypertension.11  

Potassium and sodium balance also appears to play a key role in blood vessel relaxation.

Studies indicate that high potassium intakes are associated with lower blood pressure.12

Learn more about the DASH diet here.

Milk Products and Hypertension: Summary of Evidence

View the evidence

A large body of evidence indicates that milk products can have a favourable effect on blood pressure. Many studies, such as systematic reviews and randomized-controlled trials including the landmark DASH diet study, have demonstrated a beneficial association between milk product consumption and the prevention and management of hypertension. Hypertension Canada recommends the DASH diet (which emphasizes fruits, vegetables, and milk products) as an important strategy to help prevent and manage high blood pressure.

Highlights

  • Milk products including milk, cheese and yogurt are associated with a reduced risk of developing hypertension;
  • Overall, studies indicate higher intakes of milk products (including milk, cheese and yogurt) can help with better blood pressure control;
  • The DASH diet is a recommended dietary pattern for controlling blood pressure that emphasizes fruits, vegetables, and milk products (milk, cheese and yogurt);
  • A DASH diet with high-fat dairy foods (milk, cheese and yogurt) is as beneficial for controlling blood pressure, and has favourable effects on some blood lipid markers, compared to a DASH diet with low-fat dairy foods;
  • Hypertension Canada recommends the DASH diet for the prevention and management of high blood pressure in at-risk individuals.

The evidence

Systematic reviews and meta-analyses

A 2021 systematic review and dose-response meta-analysis by Heidari et al. examined the relationship between the consumption of dairy products and the risk of hypertension.1 A total of 353,303 participants from 16 prospective cohort studies published between 2002 and 2020 were included in the analyses. Overall, the authors concluded that higher dairy product consumption was associated with a reduced risk of hypertension:

  • Total dairy products, low-fat dairy products, milk and fermented dairy products were each associated with a reduced risk of hypertension;
  • For total dairy products, dose-response analysis indicated intakes of up to 30 servings per week continued to further reduce the risk of hypertension;
  • Low-fat dairy products were associated with a lower risk of hypertension with increasing intakes, whereas no association was observed with high-fat dairy products.

In 2019, Liu et al. examined the association of food sources of fructose‐containing sugars with the development of hypertension.2 Their systematic review and dose-response meta-analysis including 26 reports from 15 prospective cohorts, concluded that:

  • Sugar-sweetened beverages were associated with an increased risk of incident hypertension;
  • Yogurt showed a protective association against the development of hypertension (5% reduced risk per 125 g), as did fruit;
  • 100% fruit juice showed a protective association only at moderate intakes;
  • No association was observed for dairy desserts, fruit drinks and sweet snacks.

A 2017 systematic review and dose-response meta-analysis of prospective cohort studies by Schwingshackl et al. summarized the evidence on food group intakes and risk of hypertension.3 They included 28 reports, examining a total of 12 food groups including whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages. Comparing the highest with the lowest intake categories, linear dose-response meta-analysis showed that:

  • Dairy foods (200 g/day), fruits (100 g/day), nuts (28 g/day) and whole grains (30 g/day) were each associated with a reduced risk of hypertension;
  • Red meat (100 g/day), processed meat (50 g/day) and sugar-sweetened beverages (250 mL/day) were each associated with an increased risk of hypertension.

A 2016 systematic review of meta-analyses of prospective cohort studies by Drouin-Chartier et al. examined and rated the evidence regarding the relationship between the consumption of dairy products and the risk of cardiometabolic outcomes including hypertension.4 The findings were as follows:

  • Total dairy consumption is associated with a reduced risk of hypertension, based on high-quality evidence;
  • Milk and low-fat dairy consumption are associated with a reduced risk of hypertension, based on moderate-quality evidence;
  • Consumption of regular-fat dairy and high-fat dairy, cheese, yogurt, and fermented dairy is not associated with hypertension, based on high- to moderate-quality evidence.

Randomized controlled trials

A randomized, controlled cross-over trial by Rancourt-Bouchard et al. 2020 examined the effect of low-fat milk and regular-fat cheese consumption on ambulatory blood pressure in 55 healthy men and women with “high-normal” blood pressure.5 It is important to note that the dairy free control diet in this study was lower in sodium than the experimental diets that included dairy. This study reported:

  • Diets with 3 daily servings of 1% milk or 1 daily 50 g serving of regular-fat cheddar cheese (enriched with GABA) had an overall neutral effect on ambulatory blood pressure after 6 weeks when compared to a dairy-free control diet that was lower in sodium;
  • Exploratory analysis revealed that a daily serving of cheese decreased systolic blood pressure in men; and, 3 daily servings of 1% milk lowered ambulatory diastolic blood pressure in men and women.

Rietsema et al. 2019 investigated the effect of high compared with low dairy consumption on blood pressure in 52 overweight middle-aged adults, in a randomized cross-over study.6 Participants followed a low-dairy diet (with ≤1 daily serving of dairy) and a high dairy diet (with 5 daily servings of dairy for women and 6 for men) for a period of 6 weeks. This study found that:

  • Consumption of a high-dairy diet as compared to a low-dairy diet reduced both systolic and diastolic blood pressure (by an average of 4.6 mm Hg and 3.0 mm Hg, respectively);
  • Further analyses suggest that this blood pressure benefit was largely related to the increase in dietary calcium that naturally occurs with a high-dairy diet.

A randomized controlled cross-over study conducted by Roy et al. 2019 explored the addition of whole-fat dairy foods to the habitual diet of adults with high systolic blood pressure (120-159/<99 mm Hg).7 The 60 adults who participated in this study followed two different diets for a period of 4 weeks. The high-dairy intervention involved adding 4 daily servings of full-fat dairy (milk, cheese and yogurt) to the participant’s regular diet. For the no-dairy control diet, participants were asked to eliminate all dairy from their regular diet. This study found that:

  • The addition of 4 servings per day of full-fat dairy products did not have an impact on blood pressure in adults with high systolic blood pressure.

A randomized, controlled cross-over study by Drouin-Chartier et al. investigated how dairy products impact blood pressure in 89 men and women with mild to moderate hypertension.8 Consumption of 3 daily servings of dairy products (milk, cheese and yogurt) had beneficial effects on daytime systolic ambulatory blood pressure in men, compared to a heart-healthy, dairy-free control diet. The lack of difference in blood pressure observed in women on the higher dairy vs. control diet may be due to the lower sodium, higher fruit and vegetable intake and weight loss with the control diet.

  • Consuming 3 daily servings of dairy products reduced mean daytime ambulatory systolic blood pressure (-2 mm Hg) in men.
  • Dairy consumption significantly improved endothelial function in both men and women.

Prospective cohort studies

In 2018, Buendia et al. found that the long-term consumption of dairy foods is associated with a lower risk of developing high blood pressure.9 This study evaluated the relationship between the consumption of total dairy, and milk, cheese and yogurt and high blood pressure in three large prospective cohorts. Participants in The Nurses Health Study I and II and The Health Professionals Follow-Up Study were followed for periods of 20-30 years. This study found that:

  • Higher consumption of total dairy foods (3-6 servings vs. <0.5 servings per day) and yogurt in particular (5 or more servings per week vs. less than 1 serving per month) were both associated with a 16% lower risk of developing high blood pressure;
  • Higher compared to low intakes of milk and cheese were also associated with a 12%, and 6% lower risk of high blood pressure, respectively.

Another 2018 study by Buendia et al. evaluated regular yogurt intake and cardiovascular disease risk in hypertensive adults.10 In participants from the Nurses Health Study and Health Professionals Follow-up Study cohorts, this study found that hypertensive adults who consumed ≥2 servings of yogurt a week had a lower risk of heart attack and stroke:

  • Consuming ≥2 servings of yogurt per week was associated with a 17% lower risk of cardiovascular disease in women and a 21% lower risk in men (compared to those who consumed <1 serving per month);
  • Regular yogurt consumers with higher adherence to the DASH diet reduced their cardiovascular disease risk by 16% and 30% (in women and men respectively).

The DASH diet

The impact of dietary patterns on blood pressure was examined in the original landmark randomized controlled trial, Dietary Approaches to Stop Hypertension (DASH) diet study.11 After following a control diet for 3 weeks, 459 adults were randomized to 1 of 3 diets, which differed primarily in their content of fruit and vegetables and milk products, as follows:11,12

  • Control diet (typical of most Americans): 0.5 servings/day of milk products and 2.6 servings/day of fruit and vegetables;
  • Fruit and vegetable diet: 8 to 10 servings/day of fruit and vegetables and only 0.3 servings/day of milk products;
  • Combination (DASH) diet: ~3 servings/day of milk products, in addition to 8 to 10 servings/day of fruit and vegetables;
    • The milk products in the combination (DASH) diet included ~30 g of regular-fat cheese;
    • Sodium was constant for all diets at ~3,000 mg/d.

The dairy-enriched combination diet (DASH diet) had twice the impact as the fruit and vegetable diet, reducing systolic blood pressure by 5.5 mm Hg and diastolic blood pressure by 3.0 mm Hg more than the control diet.11 About 50% of the magnitude in these reductions could be ascribed to the milk products per se in the diet.13

A 2016 randomized controlled crossover trial by Chiu et al. examined the effects of substituting full-fat for low-fat dairy foods in the DASH diet.14 In total, 36 hypertensive subjects followed a control diet, a standard DASH diet, and a higher-fat lower-carbohydrate modification of the DASH diet (High Fat-DASH) for 3 weeks each. The High Fat-DASH diet was similar to the standard DASH diet, except that non-fat and low-fat dairy was substituted with full-fat milk, cheese, and yogurt, increasing saturated fat from 8% to 14%, and sugars were reduced (mostly from fruit juices) by 12% of the total energy intake. This study provides strong evidence that consuming full-fat dairy, as part of a modified DASH diet, reduces blood pressure and has favourable effects on some blood lipid markers compared to a standard DASH diet.

  • Systolic and diastolic blood pressures were comparably reduced in the DASH and High Fat-DASH groups (reduction of ~2.8-3.4 mm Hg compared to control).
  • Favourable effects on some blood lipid markers, including reduced plasma triglycerides and VLDL concentrations and increased LDL particle size, were also observed in the High Fat-DASH group compared to the standard DASH group.

Hypertension Canada recommends the DASH diet for normotensive individuals at increased risk of developing hypertension as well as those with hypertension.15 

To learn more about the DASH diet watch this webinar with Dr. Sally Chiu from Touro University and read The Dash diet: A look at the research.

Potential mechanisms

Although the mechanisms by which milk products may modulate blood pressure remain to be fully elucidated, calcium is thought to be one of the main nutrients responsible for the impact of milk products on blood pressure control.13 Research indicates that other components of dairy foods including vitamin D, magnesium, potassium, phosphorus, milk proteins and bioactive peptides may also play a role.

Calcium

A 2019 dose-response meta-analysis of large, high-quality prospective cohort studies found an association between higher dietary calcium intake and a reduced risk of developing high blood pressure.16 Subgroup analysis showed this association only with dairy calcium intake, but not with non-dairy calcium. The beneficial effect of dietary calcium persisted in studies that controlled for intakes of sodium, potassium and magnesium. A number of mechanisms have been proposed. Higher dietary calcium intakes decrease calcium influx into vascular smooth muscle cells, suppressing contractions and may also decrease plasma renin activity. In addition, calcium increases adipocyte lipolysis, decreases lipogenesis and plays a regulatory role in energy metabolism and may contribute to weight management. Higher dietary calcium intake is also associated with reduced insulin resistance, another underlying cause of hypertension.

Vitamin D 

Vitamin D, because of its importance in calcium absorption, may also play a role in the management of blood pressure. Additionally, low vitamin D status has been shown to increase blood pressure by activating the renin-angiotensin-aldosterone system, which leads to vasoconstriction and sodium and water retention.17

Potassium 

Potassium intake appears to be involved in blood pressure regulation. An increase of 750 to 1,000 mg/d of potassium can decrease blood pressure by 2 to 3 mm Hg, based on several observational studies.18

Milk proteins 

A 2017 meta-analysis of randomized controlled trials also provides evidence that milk proteins lower both systolic and diastolic blood pressure.19 The mechanism involves bioactive peptides. Bioactive peptides are formed by either the digestion of casein and whey protein (the main proteins in milk products) or the lactobacilli fermentation of milk (for instance during cheese making). In fact, antihypertensive peptides have been found in various types of cheese.20

Bioactive peptides have been shown to have an angiotensin-1-converting enzyme (ACE) inhibitory effect, a key process in blood pressure control.13 They may also have antioxidant properties and may increase nitric oxide production, both of which may help reduce blood pressure.21 Other studies have found that certain milk-derived peptide combinations also have hypotensive effects via the modulation of endothelin-1 released by endothelial cells.22 A meta-analysis of milk tripeptides on blood pressure indicated that milk-derived tripeptides have hypotensive effects in individuals with prehypertension and hypertension.23

Conclusion

A large body of evidence supports a beneficial relationship between milk product consumption and blood pressure control.

The evidence indicates that a higher intake of milk products is associated with a reduced risk of developing hypertension. The DASH diet, which emphasizes fruits and vegetables and milk products (milk, yogurt, cheese), is recommended for the prevention and management of hypertension.

More studies, including randomized controlled trials, are needed to better understand the effects of higher-fat milk products on blood pressure and the mechanisms by which milk products exert their beneficial effect on blood pressure.

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