Association between different types of plant-based diet and dyslipidaemia in Korean adults

A plant-based diet index to study the relation between diet and disease risk among adults: a narrative review

Plant-based diets (PBD) may offer various health benefits and contribute to a sustainable way of life, but, if not planned correctly, may also confer risks, e.g., by focusing on plant foods with low nutrient density, such as foods primarily consisting of refined carbohydrates. A plant-based diet index (PDI) differentiating between a healthful, unhealthful, and overall PBD, offers a promising approach to standardize and compare studies and integrate results. In this review we (1) summarize current evidence on the PDI and disease risk of relevance to public health, (2) discuss the methodology of the PDI and how it can be sensibly applied in further studies and (3) indicate areas with a lack of knowledge, such as vulnerable populations. In summary, our amalgamation shows, that adherence to a healthier plant-based diet is associated with an 8-68% lower risk for metabolic risk factors, diabetes, and cardiovascular disease, while adherence to an unhealthier plant-based diet is associated with a 10-63% higher risk. Although differences in calculation methods and underlying diet patterns between populations should be accounted for, the PDI can be a useful tool to assess adherence to different plant-based diet patterns and their association with health outcomes in cohort studies across cultures.

Plant-based diet indices and lipoprotein particle subclass profiles: A cross-sectional analysis of middle- to older-aged adults

BACKGROUND AND AIMS

Plant-based diets (PBDs) are associated with favourable lipid profiles and cardiometabolic outcomes. However, limited data regarding PBD indices (PDIs) and lipoprotein subclasses exist. We examined overall PDI, healthful PDI (hPDI) and unhealthful PDI (uPDI) associations with lipid and lipoprotein profiles.

METHODS

This cross-sectional analysis includes 1,986 middle- to older-aged adults from the Mitchelstown Cohort. The PDI, hPDI and uPDI scores were calculated from validated food frequency questionnaires. Higher PDI, hPDI and uPDI scores indicate a more PBD, healthful PBD and unhealthful PBD, respectively. Lipoprotein particle size and subclass concentrations were measured using nuclear magnetic resonance spectroscopy. Relationships between PDIs and lipid and lipoprotein profiles were examined via correlation and regression analyses adjusted for covariates.

RESULTS

In fully adjusted regression analyses, higher PDI scores were associated with lower high-density lipoprotein (HDL) cholesterol concentrations and more triglyceride-rich lipoprotein and small very low-density lipoprotein (VLDL) particles. Higher hPDI scores were negatively associated with non-HDL cholesterol concentrations, large VLDL and small HDL particles, the Lipoprotein Insulin Resistance Index (LP-IR) score and VLDL particle size. Higher uPDI scores were associated with lower HDL cholesterol and greater triglyceride concentrations and more medium and large VLDL, total LDL, small LDL and total non-HDL particles, less large LDL and large HDL particles, a greater LP-IR score, greater VLDL particle size and smaller LDL and HDL particle size.

CONCLUSIONS

This study provides novel evidence regarding associations between PBD quality and lipoprotein subclasses. A more unhealthful PBD was robustly associated with a more pro-atherogenic lipoprotein profile.

Scoping review of the association of plant-based diet quality with health outcomes

Introduction

The association of plant-based dietary patterns with health outcomes has traditionally been assessed without considering nutritional value. The plant-based dietary index (PDI), first published in 2016, overcomes this limitation with both a healthful PDI (hPDI) and an unhealthful PDI (uPDI), based on the quality of plant foods consumed plus the frequency of animal foods. We sought to summarize the breadth of research using the hPDI and uPDI to gain insight into how the quality of plant-based dietary patterns might be associated with health outcomes.

Methods

Scoping review of studies that used the PDI, hPDI, or uPDI to report associations with health outcomes. Multiple databases were searched from 2010 through April 2023 with 2 authors independently assessing eligibility and extracting data. In addition to assessing the association of the indices to health outcomes, we determined the frequency of concordant or discordant findings for hPDI versus PDI and for hPDI versus uPDI.

Results

We included 95 articles (54% longitudinal, 37% cross-sectional, and 9% case-control) with a median sample size of 3,646. Higher hPDI levels were associated with favorable health outcomes in 36% of comparisons (most often for obesity, mortality, diabetes, cardiovascular disease, and psychiatric disorders), compared to 25% for the PDI and only 2% for the uPDI. Conversely, higher levels of the uPDI were associated with unfavorable health outcomes in 33% of comparisons, in contrast to under 1% for the hPDI and 2% for the PDI. When the hPDI association to an outcome was discordant with the uPDI or PDI, the significance and directionality always favored the hPDI over the uPDI, and nearly always favored the hPDI over the PDI.

Discussion

Dietary indices that account for the quality of plant foods can show health benefits that might be missed by a generic plant-based index. A greater focus on the quality of plant foods could improve nutrition guidelines, raise awareness about the benefits of adding unrefined plant foods to the diet, and empower consumers to make incremental additions of such foods to displace unhealthy foods. We anticipate increasing use of indices that address food quality in future research.

Plant-based diets could ameliorate the risk factors of cardiovascular diseases in adults with chronic diseases

Adherence to plant-based diets is recommended to prevent and control chronic diseases. However, not all plant-based foods are healthy for this purpose. This study investigated the relationship between plant-based diets and risk factors for cardiovascular diseases (CVDs) in adults with chronic diseases. This cross-sectional study was performed on 3678 males and females (age range: 40-70 years) with chronic diseases who participated in the Kharameh cohort study. A validated semiquantitative food-frequency questionnaire was used to calculate the plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Lipid profile, fasting blood sugar (FBS), blood pressure, and anthropometric indices were measured. Multivariable-adjusted logistic regression analysis was performed to determine the association between plant-based diets and CVDs risk factors. Higher adherence to the PDI was inversely associated with the level of FBS (odds ratio [OR] = 0.42; 95% confidence interval [CI]: 0.33-0.53; p < .001). A significant decrease was observed for total cholesterol in those with higher adherence to hPDI (OR = 0.80; 95% CI: 0.65-0.98; p = .035). Additionally, the score of uPDI was positively related to FBS (OR = 1.23; 95% CI: 1.00-1.53; p = .01), total cholesterol (OR = 1.23; 95% CI: 1.01-1.49; p = .061), and low-density lipoprotein (OR = 1.39; 95% CI: 1.13-1.71; p = .009). It was concluded that adherence to PDI and hPDI was related to a lower level of FBS and total cholesterol, respectively. Moreover, the findings suggested that regular intake of the uPDI was correlated with some risk factors for CVDs in adults with chronic diseases.

Association between Unhealthful Plant-Based Diets and Possible Risk of Dyslipidemia

The relationship between the various types of diets derived from plants and vulnerability of dyslipidemia has rarely been investigated, and limited data exist in Asians whose dietary pattern is fairly different from that of the Western population. We aim to analyze the relationship between three plant-based diet indices (PDI) and the risk of dyslipidemia. Participants included 173,209 Korean adults who were aged ≥40 years from the Korean Genome and Epidemiology Study_Health Examination (2004–2013). A food frequency questionnaire (FFQ) was used to assess dietary intake. Three PDI were quantified for the study: overall PDI, healthful PDI (hPDI), and unhealthful PDI (uPDI). Among the 147,945 included, 48,166 (32.6%) of participants had dyslipidemia. Great adherence to uPDI was related with 15% greater odds of having dyslipidemia (OR: 1.15; 95% CI: 1.11–1.20, p-trend < 0.0001). No significant association was observed between PDI, hPDI, and dyslipidemia. The association between uPDI and dyslipidemia was significantly stronger among participants aged ≥55 years when compared to participants aged <55 years (p-value for interaction = 0.001). The quality of plant foods is vital in preventing dyslipidemia among people consuming high plant-based food diets.