Abstract
Cardiovascular disease (CVD) is a major economic burden in the United States. CVD risk factors, particularly hypertension and hypercholesterolemia, are typically treated with drug therapy. Five-year efficacy of such drugs to prevent CVD is estimated to be 5%. Plant-based diets have emerged as effective mitigators of these risk factors.
Generated Summary
This study investigates the effectiveness of a defined, plant-based diet in an outpatient cardiovascular clinic setting. The research involved a 4-week intervention where participants followed a plant-based diet. The study aimed to assess the diet’s impact on hypercholesterolemia, hypertension, and medication usage. The methodology included weekly office visits to monitor participants, assess medication needs, and collect data. The analysis involved paired-samples t-tests and 1-way repeated-measures ANOVA to evaluate changes in various clinical parameters and biochemical markers. The study’s scope encompassed new patients registered at a cardiovascular center, and the intervention was conducted in an outpatient clinical setting.
Key Findings & Statistics
- Cardiovascular disease (CVD) is a major economic burden in the United States, with 17% of all healthcare expenditures going toward CVD care.
- Projections estimate that 40.5% of the US population may have some form of CVD by 2030, leading to a near tripling in medical care costs, from $273 billion to $818 billion.
- The standard of clinical care in the primary prevention of CVD is to reduce CVD risk factors, particularly through lipid-lowering and antihypertensive drug therapy.
- Nearly 40% of the population has high serum low-density lipoprotein cholesterol (LDL-C).
- Approximately one-third of individuals age 40 to 59 years are estimated to be hypertensive.
- Of those with hypertension (HTN), 76% are on medications to reduce blood pressure, but only 52% achieve blood-pressure control.
- High-risk patients have a < 5% chance of benefiting from cardioprotective drugs within the next 5 years.
- Participants consumed a plant-based diet consisting of raw fruits, vegetables, seeds, and avocado; all animal products were excluded.
- Significant reductions were observed for systolic (-16.6 mmHg) and diastolic (-9.1 mmHg) blood pressure (P < 0.0005), serum lipids (P ≤ 0.008), and total medication usage (P < 0.0005).
- Other CVD risk factors, including weight (P < 0.0005), waist circumference (P < 0.0005), heart rate (P = 0.018), insulin (P < 0.0005), glycated hemoglobin (P = 0.002), and high-sensitivity C-reactive protein (P = 0.001) were also reduced.
- Baseline characteristics of the patients are shown in Table 1. All participants were age 32 to 69 years with HTN, elevated LDL-C, and excess body weight. HTN was defined as systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg. Elevated LDL-C was considered to be a serum LDL-C concentration ≥ 100 mg/dL, and excess body weight was defined as a body mass index ≥25 kg/m².
- Participants, n = 31
- Mean age, y : 53.4 (32-69)
- F: 10 (33)
- Race/ethnicity African American: 21 (67)
- Hispanic: 3 (10)
- White: 3 (10)
- BMI, kg/m²: 37.5 ± 8.3
- 25-29.9 (overweight): 6 (19)
- 30-34.9 (obese class 1): 6 (19)
- 35-39.9 (obese class 2): 10 (33)
- ≥40: 9 (29)
- CAD: 10 (33)
- T2DM: 8 (27)
- Arthritis: 7 (23)
- Prediabetes: 5 (17)
- Medications, n : 49
- ACEI: 5
- Central antiadrenergic: 1
- Cardioselective (B1)-blocker: 6
- Noncardioselective (B1)-blocker: 2
- CCB: 9
- Potassium-sparing diuretic: 1
- Thiazide diuretic: 14
- Other prescription drugs, total: 33
- Biguanide: 2
- Sulfonylurea: 3
- Dipeptidylpeptidase-4 inhibitor: 1
- Insulin: 2
- NSAID: 1
- Biologic immune suppressant: 1
- Statin: 2
- Bronchodilator/steroid inhaler: 5
- Thyroid drugs: 3
- Xanthine oxidase inhibitor: 2
- PPI: 1
- Antianginal: 2
- Digitalis glycoside: 1
- Vasodilator: 1
- Other: 5
- Total medications: 82
- Nutrient intake of participants on the defined, plant-based diet significantly changed after 4 weeks (Table 3).
- Energy, Kcal: -33 (-683 ± 808) P <0.0005
- Fat, % of energy: -48 (-17.3 ± 12.8) P <0.0005
- Saturated fat, % of energy: -67 (-7.7 ± 5.5) P <0.0005
- Monounsaturated fat, % of energy: -47 (-6.2 ± 5.4) P <0.0005
- Polyunsaturated fat, % of energy: -36 (-3.0 ± 3.5) P <0.0005
- Omega-6, g: -67 (-12.4 ± 10.6) P <0.0005
- Omega-3, g: 1 (0.03 ± 2.16) 0.92
- Trans fat, g: -99 (-2.21 ± 2.00) P <0.0005
- Cholesterol, mg: -96 (-283.2 ± 214.8) P <0.0005
- Carbohydrate, % of energy: 57 (26.3 ± 17.0) P <0.0005
- Protein, % of energy: -54% (-9.0 ± 6.1) P <0.0005
- Total fiber, g: 150 (30.6 ± 17.8) P <0.0005
- Total vitamin A activity, IU: 303 (25 121 ± 21 876) P <0.0005
- Vitamin D, IU: -92 (-146.8 ± 161.8) P <0.0005
- Vitamin E, mg: 6 (0.6 ± 6.4) 0.60
- Vitamin C, mg: 370 (325.0 ± 197.3) P <0.0005
- Vitamin B12, µg: -92 (-3.6 ± 2.3) P <0.0005
- Folate, µg: 115 (343 ± 329) P <0.0005
- Iron, mg: -1 (-0.1 ± 9.9) 0.97
- Calcium, mg: -29 (-229 ± 527) 0.024
- Sodium, mg: -76 (-2891 ± 1776) P <0.0005
- Magnesium, mg: 69 (200.0 ± 178.0) P <0.0005
- Zinc, mg: -76 (-4.4 ± 7.0) 0.002
- Potassium, mg: 90 (2410 ± 1764) P <0.0005
- Weight, kg, mean ± SE: 108.1 ± 5.1 105.4 ± 4.8 103.9 ± 4.8 102.6 ± 4.7 101.4 ± 4.7 P <0.0005
- BMI, kg/m²: 37.5 ± 1.4 36.5 ± 1.4 36.0 ± 1.4 35.6 ± 1.4 35.2 ± 1.4 P <0.0005
- WC, cm: 111.9 ± 2.5 109.2 ± 2.5 107.6 ± 2.5 106.3 ± 2.5 105.3 ± 2.5 P <0.0005
- SBP, mm Hg: 146.6 ± 2.8 131.9 ± 2.8 127.0 ± 2.4 129.5 ± 1.9 130.0 ± 2.3 P <0.0005
- DBP, mm Hg: 91.2 ± 1.3 81.5 ± 1.4 79.0 ± 1.3 82.1 ± 1.2 82.1 ± 1.2 P <0.0005
- BP medications: 1.6 ± 1.1 1.6 ± 1.0 1.4 ± 1.0 1.1 ± 1.0 1.0 ± 0.1 P <0.0005
- Other prescription drugs: 1.0 ± 1.4 1.0 ± 1.4 0.9 ± 1.5 0.6 ± 0.9 0.5 ± 0.9 0.008
- Total medications: 2.6 ± 2.0 2.7 ± 2.0 2.3 ± 2.0 1.8 ± 1.6 1.6 ± 1.3 <0.0005
- During screening, a total of 65 patients showed interest in participating in the study; however, 30 patients did not meet inclusion criteria or were excluded.
- The average body mass index was 37.5 kg/m² ± 8.3 kg/m², and approximately 81% of the participants were obese.
- The reduction in blood pressure was accompanied with a decreased use of blood pressure medications (decreased 33% by week 4).
- Those taking hypoglycemic drugs, including insulin, reduced medication usage by 87%.
- Overall, total medication usage decreased 40% by week 4.
- HbA1c was significantly reduced (P = 0.002).
- The average HbA1c of this sample was 5.9%.
Other Important Findings
- The study found that participants lost an average of 6.7 kg (14.7 lbs.) after four weeks on the defined plant-based diet.
- Significant reductions were also observed for other CVD risk factors, including weight, heart rate, waist circumference, insulin, HbA1c, and hs-CRP.
- The reduction in blood pressure by this nutritional intervention was due to a variety of contributing factors, which may include a reduction in hs-CRP (-2.4 ± 3.7 mg/L) and increased consumption of nitrates, potassium, and magnesium.
- Increased dietary fiber, phytosterols, and polyphenols also likely contributed to reduced serum lipids in addition to the exclusion of animal-based foods.
Limitations Noted in the Document
- The study’s limitations include a small sample size, the absence of a control group, and the short duration of follow-up.
- The study’s short duration.
- Further research is needed to determine whether medications, serum lipids, and blood pressure would continue to decrease if the diet were consumed for an extended period of time.
- Extended trials are needed to assess long-term adherence to the diet.
- Inclusion of periodic postprandial glucose testing during the intervention may help establish a potential relationship between postprandial glucose fluctuations and reduced HbA1c.
Conclusion
The study demonstrates that a defined, plant-based diet can be an effective therapeutic approach in the clinical setting to treat hypertension, hypercholesterolemia, and other cardiovascular risk factors. The intervention resulted in clinically significant reductions in systolic and diastolic blood pressure, along with decreased medication usage and improved serum lipid profiles. The findings suggest that patients may find this dietary approach preferable to conventional and costly drug therapy. The study’s results highlight the potential of dietary interventions in managing cardiovascular health. The observed improvements in multiple CVD risk factors, including body weight, heart rate, and waist circumference, further support the efficacy of the plant-based diet. The study also notes that participants’ blood pressure was better even when discontinuing medications, which may indicate superiority of the dietary intervention over drug therapy. The conclusion underscores the need for further replication trials with larger sample sizes, control groups, and other dietary comparison groups to validate these findings and explore the long-term effects of the plant-based diet on cardiovascular health. The study’s findings have real-world applicability in the clinical setting.