Abstract
Lipoprotein(a) [Lp(a)] is a highly atherogenic lipoprotein and is minimally effected by lifestyle changes. While some drugs can reduce Lp(a), diet has not consistently shown definitive reduction of this biomarker. The effect of consuming a plant-based diet on serum Lp(a) concentrations have not been previously evaluated. Hypothesis: Consumption of a defined, plant-based for 4 weeks reduces Lp(a). Methods: Secondary analysis of a previous trial was conducted, in which overweight and obese individuals (n = 31) with low-density lipoprotein cholesterol concentrations >100 mg/dL consumed a defined, plant-based diet for 4 weeks. Baseline and 4-week labs were collected. Data were analyzed using a paired samples t-test. Results: Significant reductions were observed for serum Lp(a) (-32.0 ± 52.3 nmol/L, P = 0.003), apolipoprotein B (-13.2 ± 18.3 mg/dL, P < 0.0005), low-density lipoprotein (LDL) particles (-304.8 ± 363.0 nmol/L, P < 0.0005) and small-dense LDL cholesterol (-10.0 ± 9.2 mg/dL, P < 0.0005). Additionally, serum interleukin-6 (IL-6), total white blood cells, lipoprotein-associated phospholipase A2 (Lp-PLA2), high-sensitivity c-reactive protein (hs-CRP), and fibrinogen were significantly reduced (P ≤ 0.004). Conclusions: A defined, plant-based diet has a favorable impact on Lp(a), inflammatory indicators, and other atherogenic lipoproteins and particles. Lp(a) concentration was previously thought to be only minimally altered by dietary interventions. In this protocol however, a defined plant-based diet was shown to substantially reduce this biomarker. Further investigation is required to elucidate the specific mechanisms that contribute to the reductions in Lp(a) concentrations, which may include alterations in gene expression.
Generated Summary
This study investigated the impact of a defined, plant-based diet on lipoprotein(a) [Lp(a)], inflammation, and other atherogenic lipoproteins and particles in overweight and obese individuals with elevated low-density lipoprotein cholesterol (LDL-C) concentrations. The research employed a secondary analysis of a previous trial, involving 31 participants who consumed a defined, plant-based diet for four weeks. The methodology included collecting baseline and four-week labs to analyze changes in various biomarkers. The study’s focus was to evaluate whether a plant-based diet could significantly reduce Lp(a) concentrations, which are minimally affected by lifestyle changes, and to identify potential mechanisms behind these reductions.
Key Findings & Statistics
- Demographics: The study included 31 participants; 81% were obese, with two-thirds being women and 80% African American.
- Dietary Changes: Significant changes were observed in food group consumption.
- Fruits: Total fruit consumption increased by 808% (from 1.3 ± 2.0 servings to 11.8 ± 10.4 servings, P < 0.0005).
- Vegetables: Total vegetable consumption increased by 493% (from 2.7 ± 2.0 servings to 16.0 ± 9.2 servings, P < 0.0005).
- Animal Products: Total animal product consumption decreased by 95% (from 7.9 ± 4.7 servings to 0.4 ± 1.4 servings, P = 0.001).
- Biomarker Reductions: The plant-based diet led to significant reductions in various biomarkers.
- Lp(a): Serum Lp(a) was significantly reduced (-32.0 ± 52.3 nmol/L, P = 0.003).
- Apolipoprotein B: Apolipoprotein B decreased (-13.2 ± 18.3 mg/dL, P < 0.0005).
- LDL Particles: Low-density lipoprotein (LDL) particles decreased (-304.8 ± 363.0 nmol/L, P < 0.0005).
- Small-dense LDL Cholesterol: Small-dense LDL cholesterol decreased (-10.0 ± 9.2 mg/dL, P < 0.0005).
- Inflammation Markers: Inflammatory indicators also showed significant reductions.
- hs-CRP: High-sensitivity c-reactive protein (hs-CRP) decreased significantly (P ≤ 0.004).
- IL-6: Interleukin-6 (IL-6) also significantly decreased (P ≤ 0.004).
- Other Significant Reductions: Further significant reductions were observed.
- Total Cholesterol: Total cholesterol was reduced (P < 0.0005).
- LDL-C: LDL-C was reduced (P < 0.0005).
- Triglycerides: Triglycerides were reduced (P = 0.008).
- HDL-C: High-density lipoprotein cholesterol (HDL-C) was reduced (P < 0.0005).
- sdLDL-C: Small dense LDL-C was reduced by 30%.
- hs-CRP reduction: hs-CRP was reduced by 30.7%.
- Food group changes: notable increases in fruit (808%) and vegetable (493%) consumption, and a 95% decrease in animal product consumption.
Other Important Findings
- The study found that a defined, plant-based diet has a favorable impact on Lp(a), inflammatory indicators, and other atherogenic lipoproteins and particles.
- The reduction in Lp(a) was rapid, occurring within four weeks.
- The study also observed reductions in LDL-P, sdLDL-C, Apo-B, HDL2-C, and Apo A-1.
- Inflammatory markers such as hs-CRP, IL-6, Lp-PLA2, and fibrinogen were significantly decreased.
- Decreased consumption of white potatoes, fried potatoes, total grains, refined grains, whole grains, added oils, added animal fat, red meat, white meat, eggs, and dairy were also observed (P ≤ 0.027).
- The consumption of sweets and nuts/seeds did not significantly change between baseline and 4 weeks.
- The study’s dietary intervention led to significant reductions in body weight, BMI, total cholesterol, LDL-C, HDL-C, and triglycerides.
- The magnitude of Lp(a) change was comparable to other leading medical therapies, such as niacin and PCSK9 inhibitors.
- The study observed no statistically significant changes for endothelin-1, TNF-α, myeloperoxidase, troponin-I, or NT-proBNP between baseline and 4 weeks.
Limitations Noted in the Document
- The study lacked a control group, which limits the ability to establish a causal relationship definitively.
- The sample size was relatively small (n=31), which may limit the generalizability of the findings.
- The study was conducted in an outpatient cardiovascular clinic, limiting the control over other lifestyle factors.
- The study’s focus on a specific population (overweight and obese individuals with elevated LDL-C) may limit the applicability of the findings to other populations.
Conclusion
The study’s findings strongly support the efficacy of a defined, plant-based diet in reducing Lp(a), along with other atherogenic lipoproteins and inflammatory markers, within a short period. This is particularly significant because Lp(a) has been historically resistant to lifestyle interventions. The 16% reduction in Lp(a) achieved in this study within four weeks is a notable outcome. The study’s success can be attributed to the elimination of animal products, processed foods, and the increased intake of fruits and vegetables. The significant reductions in hs-CRP, IL-6, and other inflammatory markers highlight the anti-inflammatory effects of the diet, which may contribute to the reduction in Lp(a) levels. The study’s methodology, with the high dietary adherence and provision of all food, strengthens the conclusion that the intervention directly caused the observed biochemical changes. The study’s results suggest that this dietary intervention may be an appropriate tool for treating complex patients with a myriad of elevated CVD-related biomarkers. The research supports a shift towards a diet that emphasizes whole, unprocessed plant foods, which can offer considerable improvements in cardiovascular health.