Association between plant-based diets and blood pressure in the INTERMAP study

Diet to Stop Hypertension: Should Fats be Included?

PURPOSE OF REVIEW

International guidelines emphasize advice to incorporate dietary measures for the prevention and in the management of hypertension. Current data show that modest reductions in weight can have an impact on blood pressure. Reducing salt and marine oils have also shown consistent benefit in reducing blood pressure. Whether other dietary constituents, in particular the amount and type of fat that play important roles in cardiovascular prevention, influence blood pressure sufficiently to be included in the management of hypertension is less certain. In this review, we provide a summary of the most recent findings, with a focus on dietary patterns, fats and other nutrients and their impact on blood pressure and hypertension.

RECENT FINDINGS

Since reducing salt consumption is an established recommendation only corollary dietary advice is subject to the current review. Population studies that have included reliable evaluation of fat intake have indicated almost consistently blood pressure lowering with consumption of marine oils and fats. Results with vegetable oils are inconclusive. However dietary patterns that included total fat reduction and changes in the nature of vegetable fats/oils have suggested beneficial effects on blood pressure. Plant-based foods, dairy foods and yoghurt particularly, may also lower blood pressure irrespective of fat content. Total fat consumption is not directly associated with blood pressure except when it is part of a weight loss diet. Consumption of marine oils has mostly shown moderate blood pressure lowering and possibly greatest effect with docosahexaenoic acid-rich oil.

Planting the Seed for Blood Pressure Control: The Role of Plant-Based Nutrition in the Management of Hypertension

PURPOSE OF REVIEW

Hypertension results in significant morbidity, mortality, and healthcare expenditures. Fortunately, it is largely preventable and treatable by implementing dietary interventions, though these remain underutilized. Here, we aim to explore the role of healthy dietary patterns in hypertension management and describe approaches for busy clinicians to address nutrition effectively and efficiently with patients.

RECENT FINDINGS

DASH, Mediterranean, vegetarian, and vegan diets that include minimally processed, plant-based foods as core elements have consistently shown positive effects on hypertension. Recommendations that distill the most healthful components of these diets can significantly impact patient outcomes. Clinicians can harness evidence-based dietary assessment and counseling tools to implement and support behavioral changes, even during brief office visits. Healthful plant-based dietary patterns can often effectively prevent and treat hypertension. Clinicians may help improve patient outcomes by discussing evidence-based nutrition with their patients. Future work to promote infrastructural change that supports incorporating evidence-based nutrition into medical education, clinical care, and society at large can support these efforts.

Development of a novel (poly)phenol-rich diet score and its association with urinary (poly)phenol metabolites

Background: Estimating (poly)phenol intake is challenging due to inadequate dietary assessment tools and limited food content data. Currently, a priori diet scores to characterise (poly)phenol-rich diets are lacking. This study aimed to develop a novel (poly)phenol-rich diet score (PPS) and explore its relationship with circulating (poly)phenol metabolites. Methods: A total of 543 healthy free-living participants aged 18-80 years completed a food frequency questionnaire (FFQ) (EPIC-Norfolk) and provided 24 h urine samples. The PPS was developed based on the relative intake (quintiles) of 20 selected (poly)phenol-rich food items abundant in the UK diet, including tea, coffee, red wine, whole grains, chocolate and cocoa products, berries, apples and juice, pears, grapes, plums, citrus fruits and juice, potatoes and carrots, onions, peppers, garlic, green vegetables, pulses, soy and soy products, nuts, and olive oil. Foods included in the PPS were chosen based on their (poly)phenol content, main sources of (poly)phenols, and consumption frequencies in the UK population. Associations between the PPS and urinary phenolic metabolites were investigated using linear models adjusting energy intake and multiple testing (FDR adjusted p < 0.05). Result: The total PPS ranged from 25 to 88, with a mean score of 54. A total of 51 individual urinary metabolites were significantly associated with the PPS, including 39 phenolic acids, 5 flavonoids, 3 lignans, 2 resveratrol and 2 other (poly)phenol metabolites. The total (poly)phenol intake derived from FFQs also showed a positive association with PPS (stdBeta 0.32, 95% CI (0.24, 0.40), p < 0.01). Significant positive associations were observed in 24 of 27 classes and subclasses of estimated (poly)phenol intake and PPS, with stdBeta values ranging from 0.12 (0.04, 0.20) for theaflavins/thearubigins to 0.43 (0.34, 0.51) for flavonols (p < 0.01). Conclusion: High adherence to the PPS diet is associated with (poly)phenol intake and urinary biomarkers, indicating the utility of the PPS to characterise diets rich in (poly)phenols at a population level.

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.

Popular fad diets: An evidence-based perspective

Despite the emergence of stronger nutritional science over the past two decades, fad diets remain highly popular. However, growing medical evidence has led to the endorsement of healthy eating patterns by medical societies. This thus allows fad diets to be compared to the emerging scientific evidence as to which diets promote or damage health. In this narrative review, the most popular current fad diets are critically analyzed, including low-fat diets, vegan and vegetarian diets, low-carbohydrate diets, ketogenic diets, Paleolithic diets, and intermittent fasting. Each of these diets has some scientific merit, but each has potential deficiencies relative to the findings of nutritional science. This article also presents the common themes that emerge among the dietary guidance of leading health organizations, such as the American Heart Association and the American College of Lifestyle Medicine. While there are important distinctions between dietary recommendations emanating from various medical societies, each recommends eating more unrefined, plant-based foods, while eating fewer highly processed foods and added sugars, and avoiding excessive calorie consumption as an important nutritional strategy for the prevention and management of chronic conditions and promotion of overall health.

Effect of salt reduction interventions in lowering blood pressure: A comprehensive systematic review and meta-analysis of controlled clinical trials

BACKGROUND

Excessive salt intake results in hypertension (HTN), which is a major risk factor for cardiovascular disease (CVD). This review and meta-analysis aimed to evaluate the effect of salt reduction interventions on systolic blood pressure (SBP) and diastolic blood pressure (DBP).

METHODS

Studies were identified via systematic searches of the databases, including PubMed, Embase, Scopus, and Web of Science. All the studies examining the effectiveness of salt reduction interventions on blood pressure (BP), regardless of age, sex, and HTN status, were included in the systematic review, and eligible studies were used in the meta-analysis. A random-effect model was applied for quantitative data synthesis.

RESULTS

A total of 50 trials extracted from 40 articles (21 trials on nutrition education,10 on self-help materials,17 on salt substitutes, and 2 on food reformulation) were included in the systematic review. The pooled results of 44 eligible trials showed that salt substitution and nutrition education interventions had significant effects on both SBP (WMD: -7.44 mmHg, P<0.001 and WMD: -2.75 mmHg, P<0.001, respectively), and DBP (WMD: -3.77 mmHg, P<0.001 and WMD: -2.11 mmHg, P<0.001, respectively). Furthermore, using self-help materials led to a significant reduction in SBP among subjects aged 25-60 years (WMD: -2.60 mmHg, P = 0.008); it also decreased both SBP and DBP among those who were hypertensive (WMD: -3.87 mmHg, P = 0.003 and WMD: -2.91 mmHg, P<0.001, respectively).

CONCLUSION

Our results supported that salt substitution and nutrition education are effective nutrition strategies to lower BP. It seems that multi-component approaches could be more effective in improving BP status. However, further trials are required.

Low dietary sodium potentially mediates COVID-19 prevention associated with whole-food plant-based diets

Compared with an omnivorous Western diet, plant-based diets containing mostly fruits, vegetables, grains, legumes, nuts and seeds, with restricted amounts of foods of animal origin, are associated with reduced risk and severity of COVID-19. Additionally, inflammatory immune responses and severe acute respiratory symptoms of COVID-19, including pulmonary oedema, shortness of breath, fever and nasopharyngeal infections, are associated with Na toxicity from excessive dietary Na. High dietary Na is also associated with increased risks of diseases and conditions that are co-morbid with COVID-19, including chronic kidney disease, hypertension, stroke, diabetes and obesity. This article presents evidence that low dietary Na potentially mediates the association of plant-based diets with COVID-19 prevention. Processed meats and poultry injected with sodium chloride contribute considerable amounts of dietary Na in the Western diet, and the avoidance or reduction of these and other processed foods in whole-food plant-based (WFPB) diets could help lower overall dietary Na intake. Moreover, high amounts of K in plant-based diets increase urinary Na excretion, and preagricultural diets high in plant-based foods were estimated to contain much lower ratios of dietary Na to K compared with modern diets. Further research should investigate low Na in WFPB diets for protection against COVID-19 and co-morbid conditions.

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.

Plant-based diets and risk of frailty in community-dwelling older adults: the Seniors-ENRICA-1 cohort

Frailty is a geriatric syndrome that leads to increased risk of hospitalization, disability, and death. The effect of plant-based diets defined by the quality of their plant foods is unclear. Our objective is to study the association between two plant-based diet indices and the occurrence of frailty among community-dwelling older adults in Spain. We analyzed data from 1880 individuals aged ≥ 60 years from the Spanish Seniors ENRICA-1 cohort. We used a validated diet history to build two indices: (a) the healthful Plant-based Diet Index (hPDI) where healthy plant foods received positive scores, whereas less-healthy plant foods and animal foods received reverse scores; and (b) the unhealthful Plant-based Diet Index (uPDI), with positive scores to less-healthy plant foods and reverse scores to animal and healthy plant foods. Incident frailty was defined with the Fried phenotype. Study associations were summarized with odds ratios (OR) and 95% confidence intervals (CI) obtained from multivariable logistic models. After 3.3 years of follow-up, 136 incident frailty cases were ascertained. Comparing the highest vs. the lowest tertile of adherence, the OR [95% CI] for frailty was 0.43 (0.25-0.74; p-trend = .003) for the hPDI, and 2.89 (1.73-4.84; p-trend < .001) for the uPDI. Higher consumption of healthy plant foods was inversely associated with frailty (0.39 [0.23-0.66; p-trend < 0.001]); higher consumption of unhealthy plant foods was associated with higher frailty risk (2.40 [1.23-4.71; p-trend = .01]). In older adults, the hPDI was associated with lower risk of frailty, while the opposite was found for the uPDI.

Associations Among Plant-Based Dietary Indexes, the Dietary Inflammatory Index, and Inflammatory Potential in Female College Students In Saudi Arabia: A Cross-Sectional Study

BACKGROUND

Saudi Arabian diets are transitioning to more Western dietary patterns that have been associated with higher levels of inflammation. Emerging evidence suggests plant-based diets are related to lower levels of inflammation; however, the definition of plant-based diets varies.

OBJECTIVE

The purpose of this study was to identify the extent to which an overall Plant-Based Diet Index (PDI), Healthy-PDI (hPDI), and Unhealthy-PDI (uPDI) vs Energy-Adjusted Dietary Inflammatory Index correlate with high-sensitivity C-reactive protein (hs-CRP) level.

DESIGN

This was a cross-sectional study carried out at King Saud University. Data on dietary intake, anthropometrics, and hs-CRP were collected.

PARTICIPANTS/SETTING

Female students aged 19 to 35 years (n = 401) were recruited from King Saud University, Riyadh, Saudi Arabia, between February and May 2019.

MAIN OUTCOME MEASURES

The main outcome was hs-CRP level.

STATISTICAL ANALYSES PERFORMED

Pearson correlation and multivariate linear regression analyses were used to examine the associations between hs-CRP, each PDI, and Energy-Adjusted Dietary Inflammatory Index (E-DII).

RESULTS

E-DII and uPDI scores had a moderate and a small positive correlation with hs-CRP levels (r = 0.46 and 0.22, respectively), whereas PDI and hPDI scores had a small and a moderate inverse correlation with hs-CRP levels (r = -0.13 and -0.31, respectively). A 1-standard deviation higher E-DII score was directly associated with a 1.05 mg/L higher hs-CRP level (95% confidence interval 0.72 to 1.38; P < 0.0001) after adjusting for body mass index. Overall PDI score was not associated with hs-CRP levels. A 6-point higher hPDI and uPDI score were associated with a 0.13 mg/L lower hs-CRP (95% confidence interval -0.08 to -0.28) and a 0.15 mg/L higher hs-CRP (95% confidence interval 0.03 to 0.31), respectively, after adjusting for lifestyle and dietary factors; however, results attenuated and were no longer statistically significant after body mass index adjustment.

CONCLUSIONS

Although all indexes had a small or moderate correlation with hs-CRP, only E-DII score was positively associated with hs-CRP level. Future research can examine PDI-based interventions for lowering inflammation.