The association between dietary patterns and the novel inflammatory markers platelet-activating factor and lipoprotein-associated phospholipase A2: a systematic review

Dietary patterns and colorectal cancer risk: Global Cancer Update Programme (CUP Global) systematic literature review

BACKGROUND

The 2018 World Cancer Research Fund/American Institute for Cancer Research Third Expert Report, including studies up to 2015, determined limited-no conclusion evidence on dietary patterns and colorectal cancer (CRC) risk due to insufficient data and varying pattern definitions.

OBJECTIVES

This updated review synthesized literature on dietary patterns and CRC risk/mortality.

METHODS

PubMed and Embase were searched through 31 March, 2023, for randomized controlled trials (RCTs) and prospective cohort studies on adulthood dietary patterns. Patterns were categorized by derivation method: a priori, a posteriori, or hybrid, and were then descriptively reviewed in relation to the primary outcomes: CRC risk or mortality. The Global Cancer Update Programme Expert Committee and Expert Panel independently graded the evidence on the likelihood of causality using predefined criteria.

RESULTS

Thirty-two dietary scores from 53 observational studies and 3 RCTs were reviewed. Limited-suggestive evidence was concluded for higher alignment with a priori-derived patterns: Mediterranean, healthful plant-based index, Healthy Eating Index (HEI)/alternate HEI, and Dietary Approaches to Stop Hypertension (DASH), in relation to lower CRC risk. Common features across these diets included high plant-based food intake and limited red/processed meat. Hybrid-derived patterns: the empirical dietary index for hyperinsulinemia (EDIH) and the empirical dietary inflammatory pattern (EDIP), showed strong-probable evidence for increased CRC risk. Evidence for a priori-derived low-fat dietary interventions and a posteriori-derived patterns was graded as limited-no conclusion. By cancer subsite, higher alignment with Mediterranean diet showed limited-suggestive evidence for lower rectal cancer risk, and that with HEI/alternate HEI and DASH showed limited-suggestive evidence for lower colon and rectal cancer risks. EDIH and EDIP showed strong-probable evidence for increased colon cancer risks. All exposure-mortality pairs and other pattern-outcome associations were graded as limited-no conclusion.

CONCLUSIONS

This review highlights the role of dietary patterns in CRC risk/mortality, providing insights for future research and public health strategies. This review was registered at PROSPERO as CRD42022324327 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022324327).

Post-diagnosis dietary factors, supplement use and colorectal cancer prognosis: A Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

The role of diet in colorectal cancer prognosis is not well understood and specific lifestyle recommendations are lacking. We searched for randomised controlled trials (RCTs) and longitudinal observational studies on post-diagnosis dietary factors, supplement use and colorectal cancer survival outcomes in PubMed and Embase from inception until 28th February 2022. Random-effects dose-response meta-analyses were conducted when at least three studies had sufficient information. The evidence was interpreted and graded by the CUP Global independent Expert Committee on Cancer Survivorship and Expert Panel. Five RCTs and 35 observational studies were included (30,242 cases, over 8700 all-cause and 2100 colorectal cancer deaths, 3700 progression, recurrence, or disease-free events). Meta-analyses, including 3-10 observational studies each, were conducted for: whole grains, nuts/peanuts, red and processed meat, dairy products, sugary drinks, artificially sweetened beverages, coffee, alcohol, dietary glycaemic load/index, insulin load/index, marine omega-3 polyunsaturated fatty acids, supplemental calcium, circulating 25-hydroxyvitamin D (25[OH]D) and all-cause mortality; for alcohol, supplemental calcium, circulating 25(OH)D and colorectal cancer-specific mortality; and for circulating 25(OH)D and recurrence/disease-free survival. The overall evidence was graded as 'limited'. The inverse associations between healthy dietary and/or lifestyle patterns (including diets that comprised plant-based foods), whole grains, total, caffeinated, or decaffeinated coffee and all-cause mortality and the positive associations between unhealthy dietary patterns, sugary drinks and all-cause mortality provided 'limited-suggestive' evidence. All other exposure-outcome associations provided 'limited-no conclusion' evidence. Additional, well-conducted cohort studies and carefully designed RCTs are needed to develop specific lifestyle recommendations for colorectal cancer survivors.

Associations between healthy food groups and platelet-activating factor, lipoprotein-associated phospholipase A2 and C-reactive protein: a cross-sectional study

PURPOSE

To investigate the association between pro-inflammatory markers platelet-activating factor (PAF), lipoprotein-associated phospholipase A2 (Lp-PLA2), hsCRP, and intake of core food groups including fruit, cruciferous and other vegetables, grains, meat and poultry, fish and seafood, nuts and legumes, and dairy.

METHODS

A cross-sectional study was conducted. 100 adults (49 ± 13 years, 31% male) with variable cardiovascular disease risk were recruited. Data were collected in 2021 and 2022. Fasting PAF, Lp-PLA2 activity, hsCRP and usual dietary intake (via a validated food frequency questionnaire) were measured. Intake of foods were converted into serves and classified into food groups. Correlations and multiple regressions were performed with adjustment for confounders.

RESULTS

A one-serve increase in cruciferous vegetables per day was associated with 20-24% lower PAF levels. An increase of one serve per day of nuts and legumes was associated with 40% lower hsCRP levels. There were small correlations with PAF and Lp-PLA2 and cheese, however, these were not significant at the Bonferroni-adjusted P < 0.005 level.

CONCLUSION

The lack of associations between PAF and Lp-PLA2 and other healthy foods may be due to confounding by COVID-19 infection and vaccination programs which prevents any firm conclusion on the relationship between PAF, Lp-PLA2 and food groups. Future research should aim to examine the relationship with these novel markers and healthy food groups in a non-pandemic setting.

Associations of phase angle with platelet-activating factor metabolism and related dietary factors in healthy volunteers

Introduction

Phase angle (PA) is derived from bioelectrical impedance analysis (BIA). It reflects cell membrane function and decreases in disease. It is affected by inflammation, oxidative stress, and diet. Platelet-activating factor (PAF) is a potent inflammatory lipid mediator. Its levels, along with the activity of its metabolic enzymes, including CDP-choline:1-alkyl-2-acetyl-sn-glycerol-cholinephosphotransferase, acetyl-CoA:lyso-PAF-acetyltransferases, and PAF-AH/Lp-PLA2 are also related to dietary factors, such as the dietary antioxidant capacity (DAC). The aim of the study was to estimate whether the PAF metabolic circuit and related dietary factors are associated with PA in healthy volunteers.

Methods

In healthy subjects, PAF, its metabolic enzyme activity, and erythrocyte fatty acids were measured, while desaturases were estimated. Food-frequency questionnaires and recalls were used, and food groups, macronutrient intake, MedDietScore, and DAC were assessed. Lifestyle and biochemical variables were collected. DXA and BIA measurements were performed.

Results

Lp-PLA2 activity was positively associated with PA (rho = 0.651, p < 0.001, total population; rho = 0.780, p < 0.001, women), while PAF levels were negatively associated with PA only in men (partial rho = -0.627, p = 0.012) and inversely related to DAC. Estimated desaturase 6 was inversely associated with PA (rho = -0.404, p = 0.01, total sample). Moreover, the DAC correlated positively with PA (rho = 0.513, p = 0.03, women). All correlations were adjusted for age, body mass index, and sex (if applicable).

Conclusion

PA is associated with PAF levels and Lp-PLA2 activity in a gender-dependent fashion, indicating the involvement of PAF in cell membrane impairment. The relationship of PA with DAC suggests a protective effect of antioxidants on cellular health, considering that antioxidants may inhibit PAF generation.

Exploring the mechanism of atherosclerosis and the intervention of traditional Chinese medicine combined with mesenchymal stem cells based on inflammatory targets

Atherosclerosis (AS) is a chronic inflammatory vascular disease, which is the common pathological basis of cardiovascular and cerebrovascular diseases. The immune inflammatory response throughout the course of AS has been evidenced by studies, in which a large number of immune cells and inflammatory factors play a crucial role in the pathogenesis of AS. The inflammation related to AS is mainly mediated by inflammatory cytokines (IL-1β, IL-6, IL-18, TNF-α, hs-CRP, SAA), inflammatory enzymes (Lp-PLA2, sPLA2-IIA, MMPs), and inflammatory signaling pathways (P38 MAPK signaling pathway, NF-κB signaling pathway, TLR2/4 signaling pathway). It is involved in the pathophysiological process of AS, and the degree of inflammation measured by it can be used to evaluate the risk of progression of AS plaque instability. In recent years, traditional Chinese medicine (TCM) has shown the advantage of minimal side effects in immune regulation and has made some progress in the prevention and treatment of AS. Mesenchymal stem cells (MSCs), as self-renewal, highly differentiated, and pluripotent stem cells with anti-inflammatory properties and immune regulation, have been widely used for AS treatment. They also play an important inflammation-immune regulatory function in AS. Notably, in terms of regulating immune cells and inflammatory factors, compared with TCM and its compound, the combination therapy has obvious anti-inflammatory advantages over the use of MSCs alone. It is an important means to further improve the efficacy of AS and provides a new way for the prevention and treatment of AS.

Cardiovascular Diseases and Marine Oils: A Focus on Omega-3 Polyunsaturated Fatty Acids and Polar Lipids

Cardiovascular diseases (CVD) remain the leading cause of death across the globe, hence, establishing strategies to counteract CVD are imperative to reduce mortality and the burden on health systems. Dietary modification is an effective primary prevention strategy against CVD. Research regarding dietary supplementation has become increasingly popular. This review focuses on the current in vivo, in vitro, and epidemiological studies associated with that of omega-3 polyunsaturated fatty acids (n-3 PUFAs) and polar lipids (PLs) and how they play a role against CVD. Furthermore, this review focuses on the results of several major clinical trials examining n-3 PUFAs regarding both primary and secondary prevention of CVD. Notably, we place a lens on the REDUCE-IT and STRENGTH trials. Finally, supplementation of PLs has recently been suggested as a potential alternative avenue for the reduction of CVD incidence versus neutral forms of n-3 PUFAs. However, the clinical evidence for this argument is currently rather limited. Therefore, we draw on the current literature to suggest future clinical trials for PL supplementation. We conclude that despite conflicting evidence, future human trials must be completed to confirm whether PL supplementation may be more effective than n-3 PUFA supplementation to reduce cardiovascular risk.

The association between dietary quality scores with C-reactive protein and novel biomarkers of inflammation platelet-activating factor and lipoprotein-associated phospholipase A2: a cross-sectional study

Healthy dietary patterns are associated with lower inflammation and cardiovascular disease (CVD) risk and adherence can be measured using diet quality scores. Inflammation is traditionally measured with C-reactive protein (hsCRP), however there is interest in novel pro-inflammatory markers platelet-activating factor (PAF) and lipoprotein-associated phospholipase A2 (Lp-PLA2) that are specifically involved in endothelial dysfunction and inflammation. This cross-sectional study investigated the association between PAF, Lp-PLA2, hsCRP, and six diet scores. One hundred adults (49 ± 13 years, 31% male) with variable CVD risk were recruited. Fasting PAF, Lp-PLA2 and hsCRP and usual dietary intake were measured. Adherence to Dietary Approaches to Stop Hypertension (DASH), Dairy-adjusted DASH, Vegetarian Lifestyle Index, Healthy Eating Index for Australians (HEIFA), Mediterranean Diet Adherence Screener (MEDAS) and PREDIMED-Plus (erMedDiet) scores were calculated. Correlations and multiple regressions were performed. hsCRP, but not PAF, independently correlated with several diet scores. Lp-PLA2 independently correlated with Vegetarian Lifestyle Index only in unadjusted models. A one-point increase in adherence to the DASH Index, the Dairy-adjusted DASH Index and the Vegetarian Lifestyle Index was associated with a 30%, 30%, and 33% reduction in hsCRP levels, respectively. Smaller effects were seen with the other diet scores with a one-point increase in adherence resulting in a 19%, 22% and 16% reduction in hsCRP with HEIFA, MEDAS, erMedDiet scores, respectively. The lack of stronger associations between the novel markers of inflammation and diet scores may be due to confounding by COVID-19 infection and vaccination programs, which prevents any firm conclusion on the relationship between PAF, Lp-PLA2 and healthy dietary patterns. Future research should aim to examine the relationship with these novel markers and healthy dietary patterns in a non-pandemic setting.

Trends in research on dietary behavior and cardiovascular disease from 2002 to 2022: a bibliometric analysis

Background

Dietary behaviors and cardiovascular disease are two major health issues that have attracted a lot of attention from researchers worldwide. In this study, we aimed to provide a comprehensive analysis of the publication trends, authorship patterns, institutional affiliations, country/region contributions, journal outlets, highly cited documents, and keyword clusters in the field of dietary behaviors and cardiovascular disease research over the past two decades.

Methods

We conducted a systematic literature review of peer-reviewed articles published from 2002 to 2022 in the Web of Science Core Collection database. We extracted and analyzed data on the annual publication volume, authorship patterns, institutional affiliations, country/region contributions, journal outlets, highly cited documents, and keyword clusters using bibliometric methods and visualization tools.

Results

Our study analyzed 3,904 articles, including 702 reviews and 3,202 research articles. The results revealed a continuous increase in the number of publications in this field over the past two decades. The top 10 authors, institutions, and countries/regions with the highest publication output were identified, indicating the leading contributors to this field. Moreover, the most frequently cited documents and highly clustered keywords were identified, providing insights into the research themes and topics in this field.

Conclusion

Our study provides a comprehensive analysis of the publication trends, authorship patterns, institutional affiliations, country/region contributions, journal outlets, highly cited documents, and keyword clusters in the field of dietary behaviors and cardiovascular disease research over the past two decades. The findings provide valuable information for researchers, policymakers, and stakeholders to understand the research landscape, identify research gaps, and develop future research directions in this field.

The healthful plant-based diet index as a tool for obesity prevention-The healthy lifestyle community program cohort 3 study

Background

World-wide the prevalence of obesity is high, and promoting a shift toward more healthful and more plant-based dietary patterns appears to be one promising strategy to address this issue. A dietary score to assess adherence to a healthy plant-based diet is the healthful plant-based diet index. While there is evidence from cohort studies that an increased healthful plant-based diet index is associated with improved risk markers, evidence from intervention studies is still lacking.

Methods

A lifestyle intervention was conducted with mostly middle-aged and elderly participants from the general population (n = 115). The intervention consisted of a 16-month lifestyle program focusing on a healthy plant-based diet, physical activity, stress management, and community support.

Results

After 10 weeks, significant improvements were seen in dietary quality, body weight, body mass index, waist circumference, total cholesterol, measured and calculated low-density lipoprotein (LDL) cholesterol, oxidized LDL particles, non-high-density lipoprotein cholesterol, remnant cholesterol, glucose, insulin, blood pressure, and pulse pressure. After 16 months, significant decreases were seen in body weight (-1.8 kg), body mass index (-0.6 kg/m2), and measured LDL cholesterol (-12 mg/dl). Increases in the healthful plant-based diet index were associated with risk marker improvements.

Conclusions

The recommendation of moving toward a plant-based diet appears acceptable and actionable and may improve body weight. The healthful plant-based diet index can be a useful parameter for intervention studies.

Protective Effect of Olive Oil Microconstituents in Atherosclerosis: Emphasis on PAF Implicated Atherosclerosis Theory

Atherosclerosis is a progressive vascular multifactorial process. The mechanisms underlining the initiating event of atheromatous plaque formation are inflammation and oxidation. Among the modifiable risk factors for cardiovascular diseases, diet and especially the Mediterranean diet (MedDiet), has been widely recognized as one of the healthiest dietary patterns. Olive oil (OO), the main source of the fatty components of the MedDiet is superior to the other "Mono-unsaturated fatty acids containing oils" due to the existence of specific microconstituents. In this review, the effects of OO microconstituents in atherosclerosis, based on data from in vitro and in vivo studies with special attention on their inhibitory activity against PAF (Platelet-Activating Factor) actions, are presented and critically discussed. In conclusion, we propose that the anti-atherogenic effect of OO is attributed to the synergistic action of its microconstituents, mainly polar lipids that act as PAF inhibitors, specific polyphenols and α-tocopherol that also exert anti-PAF activity. This beneficial effect, also mediated through anti-PAF action, can occur from microconstituents extracted from olive pomace, a toxic by-product of the OO production process that constitutes a significant ecological problem. Daily intake of moderate amounts of OO consumed in the context of a balanced diet is significant for healthy adults.

Interrelationships among platelet-activating factor and lipoprotein-associated phospholipase A2 activity and traditional cardiovascular risk factors

Traditionally cardiovascular disease (CVD) risk has been assessed through blood lipids and inflammatory marker C-reactive protein (hsCRP). Recent clinical interest in novel pro-inflammatory markers platelet-activating factor (PAF) and lipoprotein-associated phospholipase A₂ (Lp-PLA₂ ) recognizes that vascular damage can exist in the absence of traditional risk factors. This cross-sectional study investigated the potential relationship between circulating PAF, Lp-PLA₂ , hsCRP, and traditional risk factors for CVD. One hundred adults (49 ± 13 years, 31% male) with variable CVD risk were recruited. Fasting inflammatory markers PAF, Lp-PLA₂ and hsCRP and total, high-density lipoprotein (HDL), low-density lipoprotein (LDL) cholesterol, and triglycerides were measured. Blood pressure, body mass index, and waist circumference were measured. Medical and physical activity data were self-reported. Linear and multiple regressions were performed. PAF, Lp-PLA₂ , and hsCRP independently correlated with several CVD risk factors. PAF was correlated significantly with risk factors in an unexpected way; there was a medium positive correlation between PAF and HDL cholesterol (r = 0.394, p < 0.001) and medium negative correlations with Total:HDL cholesterol; (r = -0.436, p < 0.001) systolic blood pressure; (r = -0.307, p = 0.001); BMI (r = -0.381, p < 0.001); and waist circumference (r = -0.404, p < 0.001). There were large positive correlations between Lp-PLA₂ and LDL (r = 0.525, p < 0.001) and non-HDL cholesterol (r = 0.508, p < 0.001). There were large positive correlations between hsCRP and Total:HDL cholesterol (r = 0.524, p < 0.001); BMI (r = 0.668, p < 0.001); and waist circumference (r = 0.676, p < 0.001). PAF, Lp-PLA₂ , and hsCRP are implicated in the pathophysiology of inflammation in CVD; however, the relationships between each marker and traditional risk factors were different suggesting they may be involved in different atherogenic pathways.

The anti-inflammatory effects of a Mediterranean diet: a review

PURPOSE OF REVIEW

Chronic noncommunicable diseases remain the leading cause of morbidity and mortality worldwide and the majority are preventable with a healthy diet and lifestyle, but controversy remains as to the best approach. Greater adherence to a traditional Mediterranean diet has consistently been associated with lower morbidity and mortality from cardiovascular disease, diabetes and many cancers, and lower all-cause mortality. Despite the well known benefits on chronic disease risk there remains some scepticism as to the effects of this dietary pattern across populations outside the Mediterranean and the mechanisms of action of this traditional plant-based dietary pattern.This narrative review aims to summarize the latest evidence on the health protective effects of a traditional Mediterranean diet on chronic noncommunicable diseases, specifically focussing on the anti-inflammatory effects of this highly published dietary pattern.

RECENT FINDINGS

Recent high-quality evidence now supports a Mediterranean diet in secondary prevention of cardiovascular disease with impacts on atherosclerosis progression, likely through reduction of systemic inflammation and irrespective of changes in cholesterol or weight. The Mediterranean diet has a low Dietary Inflammatory Index illustrating its anti-inflammatory potential. This dietary pattern beneficially modulates the gut microbiota and immune system, including emerging evidence for efficacy against severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019). Emerging evidence shows clinicians are not routinely recommending a Mediterranean diet despite well known evidence due to barriers such as lack of training, patient materials and concerns about potential patient adherence.

SUMMARY

The physiological mechanisms of action of this healthy diet pattern are becoming better understood to be multisystem and involving the gut. Larger controlled trials investigating mechanistic effects in broader non-Mediterranean populations are warranted. Although reflected in therapeutic guidelines for chronic disease management worldwide there are individual, clinical practice and health system barriers to its implementation that need a multisectoral approach to address.