Association between Different Types of Plant-Based Diets and Risk of Dyslipidemia: A Prospective Cohort Study

Plant-based dietary patterns and mortality from all causes, cardiovascular disease, and cancer: The Multiethnic Cohort Study

BACKGROUND & AIMS

Plant-based dietary patterns have been associated with lower risk of cardiovascular disease (CVD), some cancers, and related mortality in U.S.

POPULATIONS

However, the quality of plant foods has rarely been considered in the association between plant-based diets and mortality, especially in a population with various racial and ethnic backgrounds. We investigated whether the adherence to plant-based dietary patterns and the healthiness of plant foods are associated with mortality from all causes, CVD, and cancer and evaluated how the association varies by race and ethnicity.

METHODS

A total of 144,729 African American, Japanese American, Latino, Native Hawaiian, and White men and women who participated in the Multiethnic Cohort Study (1993-2019) were included. Cox models were used to estimate HR and 95% CI of mortality from all causes, CVD, and cancer across quintiles of three plant-based diet scores: overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI).

RESULTS

Over an average 21 years of follow-up, we identified 65,087 deaths, including 18,663 from CVD and 16,171 from cancer. Comparing the highest versus lowest quintiles, greater scores of PDI and hPDI were associated with a lower risk of all-cause mortality in both men (HR = 0.85, 95% CI: 0.82-0.89 for PDI; HR = 0.88, 95% CI: 0.85-0.91 for hPDI; both P for trend <0.0001) and women (HR = 0.89, 95% CI: 0.86-0.93 for PDI; HR = 0.86, 95% CI: 0.83-0.89 for hPDI; both P for trend <0.0001). An increased risk of all-cause mortality with uPDI was observed only in women (HR = 1.11, 95% CI: 1.07-1.15, P for trend <0.0001; P for heterogeneity by sex = 0.019). A similar trend was shown for CVD mortality with a significant increase in risk with uPDI for both men and women. PDI was associated with a lower risk of cancer mortality in men (HR = 0.86, 95% CI: 0.80-0.92, P for trend <0.0001), while neither hPDI nor uPDI was associated in either sex. Compared with the other racial and ethnic groups within each sex, the association of uPDI with all-cause mortality was stronger in White men (P for heterogeneity by race and ethnicity = 0.009) and weaker in Latino women (P for heterogeneity = 0.002).

CONCLUSION

A healthy plant-based dietary pattern emphasizing the quality of plant foods was associated with a lower risk of all-cause and CVD mortality in both men and women, although the magnitude of the associations varied across racial and ethnic groups.

Development and Validation of the Meiji Nutritional Profiling System (Meiji NPS) to Address Dietary Needs of Adults and Older Adults in Japan

This study introduces the Meiji Nutritional Profiling System (Meiji NPS), which was specifically designed to respond to age-related shifts in nutrient requirements among Japanese adults (<65 years old) and older adults (≥65 years old). Japan has one of the most aged societies in the world. The health issues of interest are malnutrition and lifestyle-related diseases among adults and frailty among older adults. Two versions of the NPS were developed based on nutrients to encourage (protein, dietary fibers, calcium, iron, and vitamin D), food groups to encourage (fruits, vegetables, nuts, legumes, and dairy), and nutrients to limit (energy, saturated fatty acids, sugars, and salt equivalents). The Meiji NPS for older adults did not include iron or saturated fatty acids. The algorithms were based on the Nutrient-Rich Foods Index (NRF). The convergent validity between the Meiji NPS and the existing NPSs for the same foods was confirmed using Spearman's correlation coefficients (NRF: r = 0.67 for adults and r = 0.60 for older adults; Health Star Rating: r = 0.64 for adults and r = 0.61 for older adults). The Meiji NPS may be useful for nutritional evaluation and reformulation of food products, tailored to adults and older adults to ameliorate health issues in Japan.

Joint association of physical activity and diet quality with dyslipidemia: a cross-sectional study in Western China

OBJECTIVE

This study aims to investigate the prevalence of dyslipidemia and assess the joint association of physical activity (PA) and diet quality on dyslipidemia risk in urban areas of Xinjiang.

METHODS

Conducted from July 2019 to September 2021 in Xinjiang, China, this cross-sectional study involved 11,855 participants (mean age 47.1 ± 9.4 years, 53.1% male). Standard methods were used to measure plasma cholesterol levels, and validated questionnaires were employed to evaluate dietary habits and PA. The definition of dyslipidemia is based on 2023 Chinese guidelines for lipid management. PA was divided into guideline-recommended moderate-to-vigorous physical activity (MVPA) and non-MVPA, following World Health Organization guidelines. The Food Frequency Questionnaire was used to obtain the intake frequency of each dietary term. Each item was scored based on consumption frequency and divided into three groups (good, intermediate, and poor) based on total dietary score. Multivariate logistic regression analysis was performed to identify dyslipidemia risk factors, as well as the joint association of PA and diet quality.

RESULTS

Dyslipidemia prevalence among urban adults in Xinjiang was 39.3%, with notable sex disparities (52.6% in males vs. 24.3% in females, P < 0.001). Among participants with dyslipidemia, the awareness, treatment and control rates were 6.9%, 3.1%, and 1.9%, respectively. A significant multiplicative interaction between PA and diet quality is associated with dyslipidemia (P for interaction < 0.05). Less PA and poor diet quality were associated with an increased odds of dyslipidemia. Even individuals with poor (OR = 1.464, 95% CI: 1.106-1.939) or intermediate (OR = 1.229, 95% CI: 1.003-1.505) diet quality but adhering to recommended MVPA had lower odds of dyslipidemia compared to those with good diet quality but inadequate MVPA (OR = 1.510, 95% CI: 1.252-1.821).

CONCLUSIONS

Dyslipidemia prevalence was 39.3% in urban adults in Xinjiang, with limited awareness, treatment, and control. Following guideline-recommended MVPA and maintaining good diet quality were protective against dyslipidemia. Low levels of PA associated with a higher prevalence of dyslipidemia, even in individuals with good diet quality.

Emerging Perspectives on the Set of Conditions That Lead to the Emergence of Metabolic Syndrome

Metabolic syndrome, as a medical condition, presents multifactorial complexity that is characterized by the resulting damage from genetic, environmental, and lifestyle factors (presence or absence of physical activity, food choices). Thus, metabolic syndrome qualifies unequivocally as a medical condition in which there are, simultaneously, several independent metabolic risk factors, namely, abdominal obesity, high triglyceride level, low HDL cholesterol level, arterial hypertension, and high glycemic level. Although age, sex, socio-economic status, and the precise definition of metabolic syndrome all influence the prevalence and risk of developing the condition, clinical and epidemiological studies clearly show that central obesity, as measured by an increased abdominal circumference, is the main risk factor. Thus, due to the growing global incidence of obesity, there has been an increase in the incidence of metabolic syndrome. Starting with obesity, all other metabolic risk factors are influenced: for example, as a result of insulin resistance with hyperglycemia, diabetes is linked to an increased risk of cardiovascular disease due to increased abdominal circumference. Through this review, we aimed to highlight the latest research studies and dietary nutritional interventions useful in the prevention of this disease but also implementation strategies for primary prevention among the healthy population.

Plant-based dietary patterns and fasting insulin: a cross-sectional study from NHANES 2017-2018

BACKGROUND

Previous studies have created plant-based diet indices to assess the health effects of specific dietary patterns.

OBJECTIVE

To examine the association between the plant-based content of diet and fasting insulin in adults from the NHANES 2017-2018 database.

METHODS

Demographic, dietary, lab and clinical data and fasting insulin were obtained from the NHANES 2017-2018 database. From two 24-h dietary recalls, we created a plant-based diet index (PDI) and a healthy plant-based diet index (hPDI). A high PDI score indicated more plants were consumed versus animal foods. A high hPDI score indicated healthier, plant materials (whole grains, whole fruits, vegetables, legumes, vegetable oils, seeds and nuts) were consumed. The relationships between the natural log of fasting insulin, PDI, and hPDI were analyzed using multiple linear regression adjusting for body mass index (BMI) and alanine aminotransferase (ALT).

RESULTS

Analyses were based on 1,714 participants, 897 women and 817 men with a median age of 52 years. In this sample, 610 (35.6%) were white, 407 (23.8%) were black, 231 (13.5%) were Mexican, 207 (12.1%) were Asian, 157 (9.2%) were other Hispanic, and 102 (6%) were other or mixed race. Median fasting insulin was 9.74 μU/mL (IQR: 6.2, 15.56). For every 1 unit increase in PDI, the natural log of fasting insulin decreased 0.0068 ± 0.003 μU/mL (CI: -0.00097, -0.013) (p = 0.02). After adjusting for BMI and ALT, the PDI did not significantly predict fasting insulin as the association was not robust due to multicollinearity. The hPDI was inversely and significantly associated with the natural log of fasting insulin (-0.0027 ± 0.00134, CI: -0.000087, -0.0053) (p = 0.043) in a multivariable model including BMI and ALT.

CONCLUSION

A healthy plant-based diet is associated with a decrease in fasting insulin levels. Healthfulness of the diet is an important factor when considering the benefit of a plant-based diet.

Plant-Based Dietary Indices in Relation to Nutrient and Food Group Intakes in Preschool-Aged Children

Dietary guidance promotes plant-based foods, yet minimal research has examined intake in children. This study examined plant-based food intake in preschool-aged children using plant-based dietary index (PDI) metrics and related these metrics to nutrient and food group intakes. Dietary data were collected from preschool-aged children (n = 283, 3.45 ± 1.22 years) from the Guelph Family Health Study at baseline using the Automated Self-Administered 24-Hour Dietary Assessment Tool. Food intake servings were assigned to 16 food groups for calculation of overall PDI (oPDI), healthful PDI (hPDI), and less healthful (lhPDI) scores and summarized into tertiles for energy-adjusted comparisons. For oPDI, participants in the highest vs. lowest tertile had higher intakes of nutrients and food groups to encourage (e.g., dietary fiber, fruits) as well as lower intakes of nutrients to encourage (e.g., calcium, vitamin D). For hPDI, participants in the highest vs. lowest tertile had higher intakes of nutrients and food groups to encourage and lower intakes of those to limit (e.g., saturated fat, sweets and desserts). For lhPDI, participants in the highest vs. lowest tertile had higher intakes of nutrients and food groups to limit and lower intakes of those to encourage. These results can inform dietetic practice for dietary guidance that promotes plant-based foods in children.

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 Nutrition: Exploring Health Benefits for Atherosclerosis, Chronic Diseases, and Metabolic Syndrome-A Comprehensive Review

Atherosclerosis, chronic non-communicable diseases, and metabolic syndrome are highly interconnected and collectively contribute to global health concerns that reduce life expectancy and quality of life. These conditions arise from multiple risk factors, including inflammation, insulin resistance, impaired blood lipid profile, endothelial dysfunction, and increased cardiovascular risk. Adopting a plant-based diet has gained popularity as a viable alternative to promote health and mitigate the incidence of, and risk factors associated with, these three health conditions. Understanding the potential benefits of a plant-based diet for human health is crucial, particularly in the face of the rising prevalence of chronic diseases like diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. Thus, this review focused on the plausible advantages of consuming a type of food pattern for the prevention and/or treatment of chronic diseases, emphasizing the dietary aspects that contribute to these conditions and the evidence supporting the benefits of a plant-based diet for human health. To facilitate a more in-depth analysis, we present separate evidence for each of these three concepts, acknowledging their intrinsic connection while providing a specific focus on each one. This review underscores the potential of a plant-based diet to target the underlying causes of these chronic diseases and enhance health outcomes for individuals and populations.

Association between plant-based diets and metabolic syndrome in obese adults from Iran: a cross-sectional study

BACKGROUND

Metabolic syndrome (MetS) is a common chronic disease with several complications. Given that, studies on the association of plant-based diet indices (PDIs) with risk of MetS among adults with obesity, are limited, we aimed to examine the association between PDIs (including overall PDI, healthy PDI (hPDI), unhealthy PDI (uPDI)) and MetS in Iranian adults with obesity.

METHODS

In Tabriz, Iran, a total of 347 adults between the ages of 20 and 50 participated in this cross-sectional research study. We created an overall PDI, hPDI, and uPDI from validated semi-quantitative food-frequency questionnaire (FFQ) data. To investigate the association between hPDI, overall PDI, uPDI, and MetS and its components, a binary logistic regression analysis was performed.

RESULTS

The average age was 40.78 ± 9.23 years, and the average body mass index was 32.62 ± 4.80 kg/m². There was no significant association between overall PDI (OR: 0.87; 95% CI: 0.54-1.47), hPDI (OR: 0.82; 95% CI: 0.48-1.40), and uPDI (OR: 0.83; 95% CI: 0.87-2.46) with MetS, even after adjustment for confounders. Moreover, our findings showed that participants with the highest adherence to uPDI had a higher chance of hyperglycemia (OR: 2.50; 95% CI: 1.13-5.52). Also, this association was significant in the first (OR: 2.51; 95% CI: 1.04-6.04) and second (OR: 2.58; 95% CI: 1.05-6.33) models, after controlling for covariates. However, in both adjusted and crude models, we did not find a significant association between hPDI and PDI scores and MetS components such as high triglyceride, high waist circumference, low High-density lipoprotein cholesterol, raised blood pressure, and hyperglycemia. Moreover, those in the top tertile of uPDI had higher fasting blood sugar and insulin levels when compared with those in the first tertile, and subjects in the last tertile of hPDI compared with participants in the first tertile had lower weight, waist-to-hip ratio, and fat-free mass.

CONCLUSION

We found a direct significant association between uPDI and odds of hyperglycemia in the whole population of study. Future large-scale, prospective studies on PDIs and the MetS are necessary to confirm these findings.

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 Different Types of Plant-Based Diets and Dyslipidemia in Middle-Aged and Elderly Chinese Participants

Plant-based dietary patterns may reduce the risk of dyslipidemia. However, not all plant-based foods are beneficial, and limited data exist for the Chinese population. We investigated the association between different plant-based dietary indices and the risk of dyslipidemia in a Chinese middle-aged and elderly population. The study participants (n = 4096) consisted of adults between 35 and 74 years of age from Xinjiang, China. Dietary consumption of the study participants was evaluated using a semi-quantitative food-frequency questionnaire (FFQ). Three different plant-based dietary indices were calculated using data from dietary surveys, including overall plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Based on these indices, we created an adjusted plant-based diet index (aPDI) based on the Xinjiang population actual dietary behavior and health effects of food. We measured the levels of total cholesterol, triglyceride, LDL-C, and HDL-C in the blood of the study participants. We used multivariable logistic regression and restricted cubic spline to analyze the relationship between plant-based diets and dyslipidemia. The findings showed that 36.6% of the participants had dyslipidemia. Higher PDI adherence was related to lower odds of dyslipidemia (Q3 vs. Q1, OR: 0.780, 95% CI: 0.641-0.949; Q4 vs. Q1, OR: 0.799, 95% CI: 0.659-0.970). High aPDI was related to lower odds of dyslipidemia (Q4 vs. Q1, OR: 0.770, 95% CI: 0.628-0.945; Q5 vs. Q1, OR: 0.748, 95% CI: 0.607-0.921). High scores for PDI, hPDI, and aPDI were all related to a reduced risk of low HDL-C (OR: 0.638, 95% CI: 0.491-0.823; OR: 0.661, 95% CI: 0.502-0.870; OR: 0.580, 95% CI: 0.443-0.758). Conversely, a high uPDI score was associated with an increased risk of low HDL-C (OR: 1.349, 95% CI: 1.046-1.740). There was no non-linear relationship between PDI, hPDI, uPDI, and aPDI and the risk of different types of dyslipidemia. Plant-based dietary indices are related to specific types of dyslipidemia risk. Appropriately increasing the consumption of plant-based foods while improving the quality of plant-based dietary patterns is critical for the prevention of dyslipidemia, especially low HDL-C, in the population.

Plant-Based Diets and Lipid, Lipoprotein, and Inflammatory Biomarkers of Cardiovascular Disease: A Review of Observational and Interventional Studies

Plant-based diets (PBDs) are becoming increasingly popular. Thus far, the literature has focused on their association with lipid profiles, with less investigation of lipoprotein and inflammatory profiles. Because pro-atherogenic lipid, lipoprotein, and inflammatory processes may facilitate the development of atherosclerosis, understanding the relation between PBDs and these processes is important to inform risk mitigation strategies. Therefore, the objective of this paper was to review the literature on PBDs and lipid, lipoprotein, and inflammatory biomarkers of cardiovascular disease (CVD). A structured literature search was performed, retrieving 752 records, of which 43 articles were included. Plant-based diets generally associated with favourable lipid and lipoprotein profiles, characterised by decreased total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B concentrations, and less low-grade inflammation, characterised by decreased C-reactive protein concentrations. Effect sizes from PBD interventions were greatest compared to habitual dietary patterns, and for non-low-fat vegan and tightly controlled dietary interventions. Associations between PBD indices and the reviewed biomarkers were less consistent. Findings are discussed with reference to the literature on PBDs and PBD indices and CVD risk, the associations between specific plant food groups and CVD outcomes and the reviewed biomarker outcomes, and the potential mechanisms underpinning associations between PBDs and reduced CVD risk.

Lifestyle elements and risk of metabolic syndrome in adults

Background

The aim of the study was to investigate which elements of lifestyle are associated with metabolic health in adults, defined as the absence of components of metabolic syndrome (MetS) based on the International Diabetes Federation criteria.

Methods

Data from 10,277 individuals aged 40–65 years constituted the material of this study. Univariate and multivariate analyses with backward stepwise selection were carried out to identify the factors associated with the absence of metabolic disorders.

Results

No family history of cardiovascular disease increased the odds of being metabolically healthy 1.5-2-fold. Furthermore, the following factors were associated with higher odds of being metabolically healthy in men: abstinence from alcohol (healthy individuals vs. those with ≥3 [OR = 5.49 (2.23–13.52); p<0.001], ≥2 [OR = 4.52 (1.87–10.91); p = 0.001], and ≥1 components of MetS [OR = 3.04 (1.41–6.56); p = 0.005]), moderate alcohol use (healthy individuals vs. those with ≥3 [OR = 3.36 (1.54–7.32); p = 0.002], ≥2 [OR = 3.28 (1.52–7.10); p = 0.002], and ≥1 components of MetS [OR = 3.93 (1.64–9.42); p = 0.002]), moderate-to-vigorous physical activity (MVPA) >2 hours/day and sitting time of 3–6 hours/day. Drinking >2 cups of coffee per day (healthy vs. those with ≥3 [OR = 2.00 (1.47–2.71)], ≥2 [OR = 1.84 (1.38–2.45)], and ≥1 components of MetS [OR = 1.72 (1.30–2.28); all p<0.001]), limiting animal fats to <2 servings/day, MVPA >2 hours/day, and 7–8 hours of sleep per day were associated with higher odds of being metabolically healthy in women.

Conclusions

A healthy lifestyle increased the odds of being metabolically healthy. Some lifestyle modifications may appear effective in prevention of not only MetS, but also single metabolic risk factors.

Healthy and unhealthy plant-based diets in relation to the incidence of colorectal cancer overall and by molecular subtypes

BACKGROUND

Plant-based foods have been recommended for health. However, not all plant foods are healthy, and little is known about the association between plant-based diets and specific molecular subtypes of colorectal cancer (CRC). We examined the associations of healthy and unhealthy plant-based diets with the incidence of CRC and its molecular subtypes.

METHODS

While 123 773 participants of the Nurses' Health Study and the Health Professionals Follow-up Study had been followed up (3 143 158 person-years), 3077 of them had developed CRC. Healthy and unhealthy plant-based diet indices (hPDI and uPDI, respectively) were calculated using repeated food frequency questionnaire data. We determined the tumoural status of microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and BRAF and KRAS mutations.

RESULTS

Higher hPDI was associated with lower CRC incidence (multivariable hazard ratio [HR] comparing extreme quartiles, 0.86, 95% confidence interval [CI]: 0.77, 0.96; P-trend = .04), whereas higher uPDI was associated with higher CRC incidence (multivariable HR comparing extreme quartiles, 1.16, 95% CI: 1.04, 1.29; P-trend = .005). The association of hPDI significantly differed by KRAS status (P-heterogeneity = .003) but not by other tumour markers. The hPDI was associated with lower incidence of KRAS-wildtype CRC (multivariable HR comparing extreme quartiles, 0.74, 95% CI: 0.57, 0.96; P-trend = .004) but not KRAS-mutant CRC (P-trend = .22).

CONCLUSIONS

While unhealthy plant-based diet enriched with refined grains and sugar is associated with higher CRC incidence, healthy plant-based diet rich in whole grains, fruits and vegetables is associated with lower incidence of CRC, especially KRAS-wildtype CRC.

Healthful Plant-Based Diet and Incidence of Type 2 Diabetes in Asian Population

Plant-based diets have been suggested to be beneficial for type 2 diabetes (T2D). However, studies investigating the association between the healthiness of a plant-based diet and T2D risk are limited. This study explored the prospective association between scores from three different plant-based diet indices and risk of T2D and investigated whether associations differ by demographic and lifestyle factors in the Korean population. Data were derived from the Korean Genome and Epidemiology Study (KoGES), a prospective cohort study initiated between 2001 and 2002. Dietary intakes were assessed using a validated food frequency questionnaire. Scores for three plant-based diet indices (overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI)) were measured. A total of 7363 Korean adults aged 40–69 years without T2D and related chronic diseases at baseline were included. Incident T2D was defined as elevated plasma glucose (≥126 mg/dL), self-report of a doctor’s diagnosis of T2D, or use of oral hypoglycemic drug. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs for T2D risk. During a follow-up period of 14 years, 977 participants developed T2D. A 10-point higher score in hPDI was associated with a 14% lower risk of T2D (HR: 0.86, 95% CI, 0.77–0.95), adjusting for potential confounders. In subgroup analysis, inverse associations between hPDI and T2D risk were stronger in participants with a family history of T2D (HR: 0.58, 95% CI, 0.44 0.76) or history of hypertension (HR: 0.73, 95% CI, 0.60 0.89) than those without a family history of T2D (p interaction = 0.01) or history of hypertension (p interaction = 0.04). Considering the quality of the plant foods may be important for the prevention of T2D in the Korean population, which habitually consumes diets rich in plant foods.

Update on Plant-Based Diets and Cardiometabolic Risk

PURPOSE OF REVIEW

The number of published studies on the health effects of plant-based diets has increased dramatically in the last decade. The purpose of this narrative review is to update the most recent evidence from large prospective cohort studies and meta-analyses on the effects of plant-based dietary patterns on cardiovascular outcomes and risk factors and total mortality.

RECENT FINDINGS

Most new data from large prospective cohort studies carried out in the USA, Europe, and Asia continue to show inverse associations between plant-based diets and the incidence of ischemic heart disease and stroke, while less data exist for heart failure incidence. New analyses suggest that only some components of plant-based diets are associated with cardiovascular benefit. Recent meta-analyses show inverse associations between plant-protein intake and all-cause mortality, although heterogeneity exists, and small mortality risks from some animal proteins, notably processed meats. New studies continue to demonstrate small but favorable effects of plant-based diets on traditional risk factors and suggest other emerging mechanisms by which plant-based diets exert cardiovascular benefits. The recommendation to consume a plant-based diet to reduce cardiovascular risk remains an evidence-based strategy based on observational studies. New data highlight the importance of ensuring that these diets are nutrient-rich and low in plant foods associated with signals of harm. For this reason, assessment of diet quality is important even in patients who report adherence to plant-based diets. Large randomized trials with hard cardiovascular endpoints might strengthen this evidence-base, but feasibility is limited.

The Relationship between Plant-Based Diet Index and Semen Parameters of Men with Infertility: A Cross-Sectional Study

BACKGROUND

Infertility is a major clinical problem that affects people psychologically and medically. For the past 40 years, studies have linked nearly 50% of childlessness to male infertility. It is worth noting that unlike other factors contributing to infertility, diet is a tunable factor and can be applied in counseling infertile men. The goal of this study was to determine the relationship between plant diet index (PDI) and semen parameters in Iranian infertile men.

MATERIALS AND METHODS

In this cross-sectional study, dietary intake was determined by a valid 168-item questionnaire (FFQ). In this study, four dependent semen parameters, including total sperm motility (TSM), sperm concentration (SC), normal sperm morphology (NSM), and semen volume (SV) were measured.

RESULTS

Results of this study stated that greater adherence to the healthful plant-based diet index (hPDI), can significantly increase sperm density and motility in men, as well as greater adherence to the PDI dietary pattern is related to a lower risk of sperm volume deficiency, and ultimately more adherence to the unhealthful plant-based diet index (uPDI), can reduce the risk of sperm motility.

CONCLUSION

In this study, for the first time, the relationship between PDI, hPDI, uPDI and male infertility was evaluated. Altogether, this study demonstrated that nutrition has an impact on semen quality and fertility of men.

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.

The Association of Plant-Based Diet With Cardiovascular Disease and Mortality: A Meta-Analysis and Systematic Review of Prospect Cohort Studies

Background: The association between plant-based diets and cardiovascular disease (CVD) remains poorly characterized. Given that diet represents an important and a modifiable risk factor, this study aimed to assess (1) the relationships between the impact of adherence to plant-based diets on cardiovascular mortality, incident CVD, and stroke; (2) if associations differed by adherence to healthful and less healthful plant-based diets.

Methods and Findings: MEDLINE and EMBASE databases were searched up to May 2021. Studies assessing CVD outcomes with relation to plant-based dietary patterns or according to plant-based dietary indices (PDI) were included. A meta-analysis of hazard ratios (HR) was conducted using DerSimonian and Laird random effects model. Thirteen studies involving 410,085 participants were included. Greater adherence to an overall plant-based dietary pattern was significantly associated with a lower risk of cardiovascular mortality (pooled HR: 0.92, 95% CI: 0.86–0.99 p = 0.0193, I² = 88.5%, N = 124,501) and a lower risk of CVD incidence (pooled HR: 0.90, 95% CI: 0.82–0.98, p = 0.0173, I² = 87.2%, N = 323,854). Among the studies that used PDI, unhealthful plant-based diets were associated with increased risk of cardiovascular mortality (pooled HR: 1.05, 95% CI: 1.01–1.09, p = 0.0123, I² = 0.00%, N = 18,966), but not CVD incidence. Conversely, healthful plant-based diets were associated with decreased CVD incidence (pooled HR: 0.87, 95% CI: 0.80–0.95, p = 0.0011, I² = 57.5%, N = 71,301), but not mortality. Vegetarians also had significantly lower CVD incidence (HR: 0.81, 95% CI: 0.72–0.91, p = 0.0004, I² = 22.2%, N = 16,254), but similar CVD mortality or stroke risk when compared to the meat-eaters.

Conclusion: To date, this comprehensive study examines the effects of a plant-based diet on major clinical endpoints using more holistic PDIs. These findings highlight the favorable role of healthful plant-based foods in reducing cardiovascular mortality and CVD.