Mastering Cardiovascular Health: Evidence-Based Lifestyle Interventions for Blood Pressure, Lipids, and Overall Risk Reduction

Introduction to Cardiovascular Risk and Lifestyle Interventions

This blog post is based on the comprehensive "Lifestyle Interventions to Reduce Cardiovascular Risk: Systematic Evidence Review From the Lifestyle Work Group, 2013" published by the U.S. Department of Health and Human Services, National Institutes of Health, National Heart, Lung, and Blood Institute (NHLBI). This pivotal report evaluates the role of specific dietary patterns, nutrient intake, and physical activity in reducing cardiovascular disease (CVD) risk factors like high blood pressure and abnormal lipids.

Cardiovascular disease remains the leading cause of morbidity and mortality in Americans. The majority of adults in the United States have at least one CVD risk factor; the frequency of these risk factors increases with age. These risk factors include elevated low-density lipoprotein cholesterol (LDL-C) (33.5%), hypertension (31%) and prehypertension (29.7%), and diabetes (11.3%).

Recognizing the immense impact of lifestyle on CVD, the NHLBI convened expert panels and work groups to rigorously update clinical guidelines. This systematic evidence review summarizes the findings of the Lifestyle Work Group, aiming to inform primary care providers and ultimately help reduce CVD risk factors in America.

The report addresses critical questions (CQs) regarding the effects of dietary patterns, macronutrients, sodium, potassium, and physical activity on CVD risk factors and outcomes.

Section 1: Dietary Patterns and Macronutrients: Impact on Blood Pressure and Lipids

Research consistently highlights the importance of nutrition in modifying CVD risk. Historically, focus was on individual dietary components, but more recently, studies emphasize the role of overall dietary patterns.

CQ1: Among adults, what is the effect of dietary patterns and/or macronutrient composition on CVD risk factors, when compared to no treatment or to other types of interventions?

This question specifically examined the impact on blood pressure (systolic and diastolic BP) and lipid-related measurements (LDL-C, HDL-C, triglycerides (TG), non-HDL-C, etc.).

Mediterranean-Style Dietary Pattern

Studies on the Mediterranean (MED) dietary pattern show its common features include: higher in fruits (particularly fresh), vegetables (emphasizing root and green varieties), whole grains (cereals, breads, rice, or pasta), and fatty fish (rich in omega-3 fatty acids); lower in red meat (and emphasizing lean meats); substituted lower fat or fat-free dairy products for higher fat dairy foods; and used oils (olive or canola), nuts (walnuts, almonds, or hazelnuts) or margarines blended with rapeseed or flaxseed oils in lieu of butter and other fats. The MED dietary patterns in these studies tended to be moderate in total fat (32-35 percent of total calories), lower in saturated fat (9-10 percent of total calories), high in fiber (27-37 g/day) and increased in PUFAs, particularly omega-3s.

Evidence Statement 1 (ES1): Blood Pressure

Counseling to eat a MED dietary pattern, compared with minimal advice to consume a low-fat dietary pattern, in free-living middle-aged or older adults (with type 2 diabetes or at least three CVD risk factors), reduces BP by 6-7/2-3 mmHg. In an observational study of healthy younger adults, adherence to a MED dietary pattern is associated with lower BP (2-3/1-2 mmHg).

Strength of evidence: Low.

Evidence Statement 2 (ES2): Lipids

Counseling to eat a MED dietary pattern, compared with minimal or no dietary advice, in free-living middle-aged or older adults (with or without CVD or at high risk for CVD) results in no consistent effect on LDL-C, HDL-C, and plasma TG, in part because of substantial differences and limitations in the studies.

Strength of evidence: Low.

DASH Dietary Pattern

The DASH (Dietary Approaches to Stop Hypertension) dietary pattern is high in vegetables, fruits, and low-fat dairy products, whole grains, poultry, fish, and nuts and low in sweets, sugar-sweetened beverages, and red meats. Regarding macronutrients, the DASH dietary pattern is low in saturated fat, total fat, and cholesterol and rich in potassium, magnesium, and calcium, as well as protein and fiber.

Evidence Statement 3 (ES3): DASH and Blood Pressure

When all food is supplied to adults with BP 120-159/80-95 mmHg and both body weight and sodium intake are kept stable, the DASH dietary pattern, when compared with a typical American diet of the 1990s, lowers BP by 5-6/3 mmHg.

Strength of evidence: High.

Evidence Statement 4 (ES4): DASH and Lipids

When food is supplied to adults with a total cholesterol level <260 mg/dL and an LDL-C level <160 mg/dL and when body weight is kept stable, the DASH dietary pattern, when compared with a typical American diet of the 1990s, lowers LDL-C by 11 mg/dL, lowers HDL-C by 4 mg/dL and has no effect on TG.

Strength of evidence: High.

The DASH diet has shown similar BP-lowering effects across various subpopulations including women and men, African American and non-African American adults, older and younger adults, and hypertensive and nonhypertensive adults.

• Strength of evidence (for BP effect across subpopulations): High.

Dietary Fat and Cholesterol

Saturated Fat

• ES11: When food was supplied to adults in a dietary pattern that achieved a macronutrient composition of 5-6 percent saturated fat (compared with a control diet of 14-15 percent saturated fat), LDL-C was lowered 11-13 mg/dL in two studies and 11 percent in one study.
  • Strength of evidence: High.
• ES12: In controlled feeding trials among adults, for every 1 percent of energy from SFA that is replaced by 1 percent of energy from carbohydrate, MUFA, or PUFA: LDL-C decreases by an estimated 1.2, 1.3, and 1.8 mg/dL, respectively; and HDL-C decreases by an estimated 0.4, 1.2, and 0.2 mg/dL, respectively.
  • Strength of evidence: Moderate.

Trans Fat

• ES14: In controlled feeding trials among adults, for every 1 percent of energy from trans MUFAs replaced with 1 percent of energy from MUFA or PUFA, LDL-C decreases by 1.5 mg/dL and 2.0 mg/dL, respectively.
  • Strength of evidence: Moderate.
• ES15: In controlled feeding trials among adults, the replacement of 1 percent of energy as trans MUFAs with carbohydrates decreases LDL-C levels by 1.5 mg/dL but has no effect on HDL-C and TG levels.
  • Strength of evidence: Moderate.

Dietary Cholesterol

• ES16: Evidence is not sufficient to determine whether lowering dietary cholesterol reduces LDL-C.

Section 2: Sodium and Potassium: Impact on Blood Pressure and CVD Outcomes

This section examines the individual effects of sodium and potassium, which are associated with CVD risk factors and outcomes.

CQ2: Among adults, what is the effect of dietary intake of sodium and potassium on CVD risk factors and outcomes, when compared to no treatment or to other types of interventions?

Sodium and Blood Pressure

• ES1: In adults, 25-80 years of age with BP 120-159/80-95 mmHg, reducing sodium intake lowers BP.
  • Strength of evidence: High.
• ES2: In adults, 25-75 years of age with BP 120-159/80-95 mmHg, reducing sodium intake that achieves a mean 24-hour urinary sodium excretion of approximately **2,400 mg/day**, relative to approximately 3,300 mg/day, lowers BP by **2/1 mmHg**, and reducing sodium intake that achieves a mean 24-hour urinary sodium excretion of approximately **1,500 mg/day** lowers BP by **7/3 mmHg**.
  • Strength of evidence: Moderate.
• ES3: In adults, 30-80 years of age with or without hypertension, counseling to reduce sodium intake by an average of **1,150 mg/day** reduces BP by **3-4/1-2 mmHg**.
  • Strength of evidence: High.

Effect in Subpopulations:

• ES4: In adults with prehypertension or hypertension, reducing sodium intake lowers BP in women and men, African American and non-African American adults, and older and younger adults.
  • Strength of evidence: High.
• ES5: Reducing sodium intake lowers BP in adults with either prehypertension or hypertension when eating either the typical American diet or the DASH dietary pattern. The effect is greater in those with hypertension.
  • Strength of evidence: High.

Sodium in the context of Dietary Pattern Changes:

• ES6: In adults, 25-80 years of age with BP 120-159/80-95 mmHg, the combination of reducing sodium intake and eating the DASH dietary pattern lowers BP more than reducing sodium intake alone.
  • Strength of evidence: Moderate.

Sodium and other minerals:

• ES7: Evidence from RCTs is not sufficient to determine whether reducing sodium intake and changing dietary intake of any other single mineral (e.g., increasing potassium, calcium, or magnesium) lowers BP more than reducing sodium intake alone.

Sodium and CHD/CVD Outcomes

• ES8: A reduction in sodium intake by approximately **1,000 mg/day** reduces CVD events by about **30 percent**.
  • Strength of evidence: Low.
• ES9: Higher dietary sodium intake is associated with a greater risk for fatal and nonfatal stroke and CVD.
  • Strength of evidence: Low.

Potassium and Blood Pressure and CHD/CVD Outcomes

• ES12: Evidence is not sufficient to determine whether increasing dietary potassium intake lowers BP.
• ES13: In observational studies with appropriate adjustments (e.g., BP, sodium intake, etc.), higher dietary potassium intake is associated with lower risk for stroke.
  • Strength of evidence: Low.
• ES14: Evidence is not sufficient to determine an association between dietary potassium intake and CHD, heart failure, and cardiovascular mortality.

Section 3: Physical Activity: Impact on Lipids and Blood Pressure

Data from a large body of observational studies show an association between higher levels of physical activity and lower rates of many chronic diseases, including CVD, and enhanced longevity.

CQ3: Among adults, what is the effect of physical activity on blood pressure and lipids, when compared to no treatment, or to other types of interventions?

Aerobic Exercise Training and Lipids

• ES1: Among adults, aerobic physical activity, as compared to control interventions, reduces LDL-C by 2.5 mg/dL on average to 6.0 mg/dL.
  • Strength of evidence: Moderate.
• ES2: Among adults, aerobic physical activity alone, as compared to control interventions, reduces non-HDL-C 6 mg/dL on average.
  • Strength of evidence: Moderate.
• ES3: Among adults, aerobic physical activity alone, as compared to control interventions, has no consistent effect on TG.
  • Strength of evidence: Moderate.
• ES4: Among adults, aerobic physical activity alone, as compared to control interventions, has no consistent effect on HDL-C.
  • Strength of evidence: Moderate.

Resistance Exercise Training and Lipids

• ES5: Among adults, resistance training, as compared to control interventions, reduces LDL-C, TG, and non-HDL-C by 6 to 9 mg/dL on average and has no effect on HDL-C. Typical interventions shown to reduce LDL-C, TG, and non-HDL-C and have no effect on HDL-C include resistance physical activity programs that average 24 weeks in duration and include >3 days per week, 9 exercises performed for 3 sets and 11 repetitions at an average intensity of 70 percent of one maximal repetition.
  • Strength of evidence: Low.

Physical Activity and Blood Pressure

• ES6: Among adult men and women at all BP levels, including hypertensive individuals, aerobic physical activity decreases systolic and diastolic BP, on average, by 2-5 mmHg and 1-4 mmHg, respectively. Typical interventions shown to be effective for lowering BP include aerobic physical activity of, on average, at least 12 weeks duration, 3 to 4 sessions per week, lasting on average 40 minutes per session, and involving moderate- to vigorous intensity physical activity.
  • Strength of evidence: High.

Resistance Exercise Training and Blood Pressure:

• The review did not provide consistent evidence that resistance exercise training alone reduces BP.

Combination of Aerobic and Resistance Exercise:

• No meta-analyses or reviews have been published that specifically examine the effect of a combined regimen of aerobic exercise and resistance training on BP.

Key Takeaways for Managing Cardiovascular Risk Factors

This comprehensive review highlights several critical lifestyle interventions for managing high blood pressure, abnormal lipids, and overall cardiovascular risk:

• Dietary Patterns are Key: Adopting healthy eating patterns like DASH or Mediterranean diets is highly effective. These diets emphasize fruits, vegetables, whole grains, lean protein, and healthy fats, while limiting saturated/trans fats, cholesterol, sodium, and sweets.
• Sodium Reduction is Crucial: Lowering sodium intake significantly reduces blood pressure, especially in individuals with prehypertension or hypertension. Combining sodium reduction with a DASH diet yields even greater benefits.
• Physical Activity Matters: Regular aerobic exercise consistently improves LDL-C and non-HDL-C and substantially lowers both systolic and diastolic blood pressure across various adult populations. Resistance training also shows benefits for lipids.
• Integrated Approach: Effective management of cardiovascular risk factors involves a synergistic approach combining healthy dietary choices and regular physical activity.

Gaps in Evidence and Future Research Needs

The report identifies several areas needing further research, including:

• Interaction between dietary modifications and statin treatment.
• Relative effects of different fatty acids on lipids, inflammation, and emerging CVD risk factors.
• The effects of dietary cholesterol within current dietary fat intake ranges.
• Effects of physical activity in adults taking BP and/or lipid-lowering medications.
• Optimal exercise patterns (dose-response) and the effects of combined aerobic and resistance training on BP.

Disclaimer: This information is derived from a scientific evidence review published in 2013. Always consult with a healthcare professional for personalized medical advice and treatment plans.

Data Source: U.S. Department of Health and Human Services, National Institutes of Health, National Heart, Lung, and Blood Institute.