Homocysteine, circulating vascular cell adhesion molecule and carotid atherosclerosis in postmenopausal vegetarian women and omnivores

Differences in carotid to femoral pulse wave velocity and carotid intima media thickness between vegetarian and omnivorous diets in healthy subjects: a systematic review and meta-analysis

Background: Arterial stiffness and atherosclerosis are known risk factors for cardiovascular morbidity and mortality. Vegetarian diets have been associated with cardiovascular benefits, including improvements in metabolic parameters. However, the impact of a vegetarian diet on cardiovascular parameters, specifically arterial stiffness and atherosclerosis, in healthy individuals remains unclear. Thus, this study aims to analyze differences in arterial stiffness and atherosclerosis between vegetarian and omnivorous diets in healthy subjects. Methods: A systematic review and meta-analysis were conducted following established guidelines. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched for studies examining the association between vegetarian and omnivorous diets with arterial stiffness and atherosclerosis. Cross-sectional studies reporting carotid to femoral pulse wave velocity (cf-PWv) as a measure of arterial stiffness and carotid intima media thickness (c-IMT) as a measure of atherosclerosis were included. Data were synthesized using random effects models, and sensitivity analyses, meta-regressions, and assessment of publication bias were performed. Results: Ten studies were included in the systematic review, and seven studies were included in the meta-analysis. The pooled analysis demonstrated that individuals following a vegetarian diet had differences in the levels of arterial stiffness (cf-PWv) compared to those following an omnivorous diet (MD: -0.43 m s-1; 95% CI: -0.63, -0.23). Similarly, atherosclerosis (c-IMT) was found to be different in individuals adhering to a vegetarian dietary pattern (MD = -29.86 mm; 95% CI: -58.41, -1.32). Conclusions: Our findings suggest that a vegetarian diet is associated with improved arterial stiffness and reduced atherosclerosis in healthy individuals. These results support the inclusion of a well-balanced vegetarian dietary pattern in the prevention and management of cardiovascular diseases. However, further research is needed to explore the effects of a vegetarian diet on arterial health in diverse populations and to assess long-term cardiovascular outcomes.

Is It Feasible to Predict Cardiovascular Risk among Healthy Vegans, Lacto-/Ovo-Vegetarians, Pescatarians, and Omnivores under Forty?

Guidelines for cardiovascular (CV) risk assessment among young adults are uncertain. Researchers are still looking for new tools for earlier diagnosis of cardiovascular diseases (CVD), the leading cause of mortality in the modern world. This study aimed to assess whether CV risk estimation is possible in groups of healthy individuals under the age of 40 on different dietary patterns (vegans-VEGAN (n = 48), lacto-/ovo-vegetarians-VEGE (n = 49), pescatarians-PESCA (n = 23), and omnivores-OMN (n = 35)) during the pandemic period. Four metrics containing selected risk classifiers were created, and participants were assessed using them. Groups including meat consumption showed increased CV risk predictions in the metrics assessment. The next analyzes showed statistically significant relationships between the results from the created metrics and selected non-basic biomarkers for ApoA1 (OMN group, p = 0.028), IL-6 (PESCA group, p = 0.048), HCY (VEGAN group, p = 0.05), and hsCRP (OMN + PESCA groups, p = 0.025). We found that predicting CV risk among healthy people under 40 adhering to different dietary patterns, taking into account basic and non-basic laboratory assessments and created metrics, is challenging but feasible. Furthermore, the OMN group appeared to be at the highest risk of increased CV risk in the future, while risk tended to be the lowest in the VEGAN group.

Synergistic Effects of Inflammation and Atherogenic Dyslipidemia on Subclinical Carotid Atherosclerosis Assessed by Ultrasound in Patients with Familial Hypercholesterolemia and Their Family Members

Low-density lipoprotein cholesterol (LDL-C) and total to high-density lipoprotein cholesterol (TC/HDL-C) ratio are both common risk factors for atherosclerotic cardiovascular diseases (ASCVDs). However, whether high-sensitivity C-reactive protein (hsCRP) has synergistic or attenuated effects on atherogenic dyslipidemia remains unclear. We investigated subclinical carotid atherosclerosis in patients with familial hypercholesterolemia (FH) and their family members. A total of 100 families with 761 participants were prospectively studied. Participants were categorized into four groups according to atherogenic dyslipidemia and inflammatory biomarkers. The group with LDL-C ≥ 160 mg/dL (or TC/HDL-C ratio ≥ 5) combined with hsCRP ≥ 2 mg/L have a thicker carotid intima-media thickness (CIMT) in different common carotid artery (CCA) areas and a higher percentage of high plaque scores compared with other subgroups. Multivariate logistic regression analysis revealed a significantly higher adjusted odds ratio (aOR) for thicker CIMT of 3.56 (95% CI: 1.56–8.16) was noted in those with concurrent LDL-C ≥ 160 mg/dL and hsCRP ≥ 2 mg/L compared with the group with concurrent LDL-C < 160 mg/dL and hsCRP < 2 mg/L. Our results demonstrated that systemic inflammation, in terms of higher hsCRP levels ≥ 2 mg/L, synergistically contributed to atherogenic dyslipidemia of higher LDL-C or a higher TC/HDL-C ratio on subclinical atherosclerosis.

Relationship Between Dietary Patterns and Carotid Atherosclerosis Among People Aged 50 Years or Older: A Population-Based Study in China

Background: The relationship between dietary patterns and atherosclerosis is inconclusive. Usually, diets vary greatly among different regions due to cultural differences and lifestyles. Few studies to date based on a Chinese population have investigated the relationship between dietary patterns and the formation of atherosclerosis in carotid arteries. We aimed to investigate whether dietary patterns were related to carotid atherosclerosis among an adult population in Tianjin, China. Methods: This cross-sectional study included a total of 2,346 participants aged 50 years or older (mean: 59.7 ± 6.29 years). Dietary intakes were assessed using a validated 81-item semiquantitative food frequency questionnaire, and factor analysis was used to identify dietary patterns. Carotid atherosclerosis was defined as a common carotid artery intima-media thickness ≥1.0 mm or plaques, or a carotid bifurcation intima-media thickness ≥1.2 mm. Multiple logistic regression models were used to explore the relationship between dietary patterns and carotid atherosclerosis. Results: Three factors were determined: "health" dietary pattern (factor 1), "traditional Tianjin" dietary pattern (factor 2), and "sweets" dietary pattern (factor 3). The multivariable-adjusted odds ratios (95% CI) of carotid atherosclerosis for the increasing quartiles of the sweets dietary pattern scores in women were as follows: 1.00 (reference), 1.33 (0.91, 1.97), 1.21 (0.82, 1.79), 1.64 (1.08, 2.51) (p for trend <0.05). No significant difference was found between any dietary pattern and carotid atherosclerosis in men. Conclusion: Greater adherence to "sweets" dietary patterns was positively related to a higher prevalence of carotid atherosclerosis in women aged 50 or older. No relationship was found between any dietary pattern and carotid atherosclerosis in men. Further prospective studies are warranted to test this finding in other populations.

Inflammatory, oxidative and DNA damage status in vegetarians: is the future of human diet green?

The health benefit of a vegetarian diet is still under debate as it may result in a higher intake of some beneficial micronutrients, while others may be reduced, thus influencing various metabolic pathways and health-related biomarkers. This scoping review discusses inflammatory, oxidative and DNA damage status in vegetarians and vegans compared to omnivores. Most of the reviewed studies indicated favorable effects of a vegetarian diet on oxidative status compared to omnivores but did not clearly associate particular dietary habits to genome damage. The evidence on the effect of vegetarian diet on the inflammatory and immunological biomarkers is poor, which could at least partly be explained by methodological constraints such as small sample size, short duration of vegetarianism and inconsistent definitions of the omnivorous diet. The only inflammatory biomarker that seems to be associated with the vegetarian diet was inflammatory mediator C-reactive protein, which in several studies showed lower values in vegetarians as compared to omnivores. There were very few studies on immunological markers and the results on the difference between vegetarians and omnivores were inconclusive. Although several biomarkers involved in oxidative stress and inflammation showed a beneficial association with the vegetarian diet, further research in well-defined and sufficiently sized cohorts is needed to provide more evidence.

Association between Vitamin D Deficiency and High Serum Levels of Small Dense LDL in Middle-Aged Adults

Recent studies suggested a potential link between vitamin D deficiency and cardiovascular risk factors, including dyslipidemia. This study aimed to investigate the association between serum 25(OH)D levels and atherogenic lipid profiles, specifically, that of small dense low-density lipoprotein-cholesterol (sdLDL-C). From 2009 to 2011, a total of 715 individuals aged 35-65 without evident cardiovascular disease (CVD) were enrolled. Their levels of serum 25(OH)D and lipid profiles were measured. Vitamin D deficiency was found to be more common in females, smokers, alcohol drinkers, individuals at a younger age, and those who do not exercise regularly. The analysis of lipid profiles revealed that high sdLDL-C levels were associated with low serum vitamin D levels and were more common among cigarette smokers; alcohol drinkers; individuals with hypertension; individuals with high BMI; and those with high levels of fasting blood glucose, triglycerides, LDL-C, and VLDL-C. The use of multivariate logistic regression verified a strong negative correlation between low vitamin D status (serum 25(OH)D < 15 ng/mL) and the three identified biomarkers of atherogenic dyslipidemia: high serum levels of sdLDL-C, triglycerides, and VLDL-C. This study provides strong evidence that vitamin D deficiency is associated with atherogenic dyslipidemia, and in particular, high sdLDL-C levels in middle-aged adults without CVD.

Association of Trimethylamine N-Oxide and Its Precursor With Cerebral Small Vessel Imaging Markers

Background: High plasma levels of trimethylamine N-oxide (TMAO) and its precursor choline have been linked to stroke; however, their association with cerebral small vessel disease remains unclear. Here we evaluated the association of plasma levels of TMAO and choline with imaging markers of cerebral small vessel disease, including white matter hyperintensities, lacunes, and cerebral microbleeds.

Methods: We performed a baseline cross-sectional analysis of a multicenter hospital-based cohort study from 2015 to 2018. The data were collected from 30 hospitals in China and included 1,098 patients with ischemic stroke/transient ischemic attack aged ≥18 years. White matter hyperintensities, lacunes, and cerebral microbleeds were evaluated with the patients' demographic, clinical, and laboratory information removed. White matter hyperintensities were rated using the Fazekas visual grading scale, while the degree of severity of the lacunes and cerebral microbleeds was defined by the number of lesions.

Results: Increased TMAO levels were associated with severe white matter hyperintensities [adjusted odds ratio (aOR) for the highest vs. lowest quartile, 1.5; 95% confidence interval (CI), 1.0–2.1, p = 0.04]. High TMAO levels were more strongly associated with severe periventricular white matter hyperintensities (aOR for the highest vs. lowest quartile, 1.6; 95% CI, 1.1–2.3, p = 0.009) than deep white matter hyperintensities (aOR for the highest vs. lowest quartile, 1.3; 95% CI, 0.9–1.9, p = 0.16). No significant association was observed between TMAO and lacunes or cerebral microbleeds. Choline showed trends similar to that of TMAO in the association with cerebral small vessel disease.

Conclusions: In patients with ischemic stroke or transient ischemic attack, TMAO and choline appear to be associated with white matter hyperintensities, but not with lacunes or cerebral microbleeds; TMAO and choline were associated with increased risk of a greater periventricular, rather than deep, white matter hyperintensities burden.

Determination of Major Endogenous FAHFAs in Healthy Human Circulation: The Correlations with Several Circulating Cardiovascular-Related Biomarkers and Anti-Inflammatory Effects on RAW 264.7 Cells

Fatty acid esters of hydroxy fatty acids (FAHFAs) are newly discovered long-chain fatty acids. However, the major endogenous FAHFAs in healthy human circulation, their correlation with cardiovascular (CV) biomarkers, and their anti-inflammatory effects have not been investigated and remain unclear. In the present study, a total of 57 healthy subjects were recruited. Liquid chromatography–mass spectrometry (LC-MS) was developed for the simultaneous determination of seven FAHFAs, four long-chain fatty acids, and four non-traditional circulating CV-related biomarkers. We found two major types of FAHFAs in healthy human circulation, palmitoleic acid ester of 9-hydroxystearic acid (9-POHSA), and oleic acid ester of 9-hydroxystearic acid (9-OAHSA). Both 9-POHSA and 9-OAHSA had a strong positive correlation with each other and were negatively correlated with fasting blood glucose, S-adenosyl-l-homocysteine (SAH), and trimethylamine N-oxide (TMAO), but not with l-homocysteine. 9-POHSA was also positively correlated with l-carnitine. Moreover, we confirmed that both 9-POHSA and 9-OAHSA exhibited an anti-inflammatory effect by suppressing LPS stimulated cytokines, including IL-1β and IL-6 in RAW 264.7 cells. In addition, palmitoleic acid also had a positive correlation with 9-POHSA and 9-OAHSA. As far as we know, this is the first report showing the major endogenous FAHFAs in healthy subjects and their CV protection potential which might be correlated with SAH and TMAO reduction, l-Carnitine elevation, and their anti-inflammatory effects.

The association of dietary patterns and carotid intima-media thickness: A synthesis of current evidence

AIMS

Dietary pattern (DP) analysis has emerged as a holistic method to understand the effects of food intake on health outcomes. Though dietary intake has been associated with cardiovascular disease, the association of DPs and carotid intima-media thickness (CIMT), a robust early marker of cardiovascular disease progression has not been comprehensively investigated. This study systematically explores the association of a posteriori and a priori DPs and CIMT.

DATA SYNTHESIS

Through a systematic search of MEDLINE, CINAHL, and Web of Science, twenty studies that derived DPs using a posteriori or a priori methods with CIMT as an outcome were included. Four cross-sectional studies and 1 cohort paper reported a statistically significant association between increased consumption of 'unhealthy' foods (i.e processed meat, soda drinks and refined grain) and increased CIMT. While four cross-sectional studies reported a statistically significant association of DPs characterized by increased consumption of 'healthy' foods (i.e fruit and vegetables, fish) and decreased CIMT. DPs derived from each study varied depending on derivation method, study design and use of dietary data collection method.

CONCLUSION

Findings from this review are generally supportive of a trend between DPs with higher consumption of 'healthy' foods and lower consumption of 'unhealthy' foods and decreased CIMT; however, the association was largely not statistically significant. Evidence was overwhelmingly heterogeneous due to differences seen in DPs based on location and culture, sample characteristics and adjustment for confounders. Long-term prospective observational and interventional studies with standardized sample selection and dietary data collection are needed to significantly establish the role of DPs on CIMT.

Plant-based diets for children as a means of improving adult cardiometabolic health

Cardiovascular disease (CVD) is the largest contributor to global mortality, and this trend is expected to continue. Although mortality rates have been falling, adverse developments in obesity and diabetes threaten to reverse this. It has been estimated that the only viable strategy to reduce the epidemic is to focus on population-wide risk factor reduction. Primordial prevention, a strategy aimed at avoiding the development of risk factors before the disease onset, has been shown to reduce the CVD epidemic substantially. Plant-based diets appear beneficial for prevention of cardiometabolic diseases, with adult vegetarians and vegans having lower CVD risk than omnivores. Atherosclerosis starts in childhood and progresses in relation to classical CVD risk factors, which, along with dietary habits, track to adulthood. Based on this evidence, it is proposed that plant-based diets in childhood could promote cardiometabolic health in adults and thereby reduce CVD and promote longevity and health. However, the need for additional research to establish the safety of predominantly or exclusively plant-based diets in children is noted.

Effect of vegetarian diets on the presentation of metabolic syndrome or its components: A systematic review and meta-analysis

BACKGROUND & AIMS

Several studies have examined the effect of vegetarian diets (VD) on metabolic syndrome (MetS) or its components, but findings have been inconsistent. The aim of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies to assess the association between VD and MetS or its components (systolic blood pressure [SBP], diastolic blood pressure [DBP], fasting glucose triglycerides, waist circumference [WC], HDL-cholesterol (HDL-C)) in adults.

METHODS

The Cochrane Library, EMBASE, PubMed, Web of Science, and Scopus were searched. RCTs, cohort studies and cross-sectional studies evaluating the effects of VD on MetS or its components in adults, with omnivore diet as control group, were included. Random effects meta-analyses stratified by study design were employed to calculate pooled estimates.

RESULTS

A total of 71 studies (n = 103 008) met the inclusion criteria (6 RCTs, 2 cohorts, 63 cross-sectional). VD were not associated with MetS in comparison to omnivorous diet (OR 0.96, 95% CI 0.50-1.85, p = 0.9) according to meta-analysis of five cross-sectional studies. Likewise, meta-analysis of RCTs and cohort studies indicated that consumption of VD were not associated with MetS components. Meta-analysis of cross-sectional studies demonstrated that VD were significantly associated with lower levels of SBP (mean difference [MD] -4.18 mmHg, 95%CI -5.57 to -2.80, p < 0.00001), DBP (MD -3.03 mmHg, 95% CI -4.93 to -1.13, p = 0.002), fasting glucose (MD -0.26 mmol/L, 95% CI -0.35to -0.17, p < 0.00001), WC (MD -1.63 cm, 95% CI -3.13 to -0.13, p = 0.03), and HDL-C (MD -0.05 mmol/L, 95% CI -0.07 to -0.03, p < 0.0001) in comparison to omnivorous diet. Heterogeneity of effects among cross-sectional studies was high. About, one-half of the included studies had high risk of bias.

CONCLUSIONS

VD in comparison with omnivorous diet is not associated with a lower risk of MetS based on results of meta-analysis of cross-sectional studies. The association between VD and lower levels of SBP, DBP, HDL-C, and fasting glucose is uncertain due to high heterogeneity across the cross-sectional studies. Larger and controlled studies are needed to evaluate the association between VD and MetS and its components.

Position paper on vegetarian diets from the working group of the Italian Society of Human Nutrition

BACKGROUND

Interest in vegetarian diets is growing in Italy and elsewhere, as government agencies and health/nutrition organizations are emphasizing that regular consumption of plant foods may provide health benefits and help prevent certain diseases.

METHODS AND RESULTS

We conducted a Pubmed search, up to September, 2015, for studies on key nutrients (proteins, vitamin B12, iron, zinc, calcium, vitamin D, and n-3 fatty acids) in vegetarian diets. From 295 eligible publications the following emerged: Vegetarians should be encouraged to supplement their diets with a reliable source of vitamin B12 (vitamin-fortified foods or supplements). Since the plant protein digestibility is lower than that of animal proteins it may be appropriate for vegetarians to consume more proteins than recommended for the general population. Vegetarians should also be encouraged to habitually consume good sources of calcium, iron and zinc - particularly vegetables that are low in oxalate and phytate (e.g. Brassicaceae), nuts and seeds, and calcium-rich mineral water. Calcium, iron, and zinc bioavailability can be improved by soaking, germination, and sour-dough leavening that lower the phytate content of pulses and cereals. Vegetarians can ensure good n-3 fatty acid status by habitually consuming good sources of a-linolenic acid (walnuts, flaxseeds, chia seeds, and their oils) and limiting linoleic acid intake (corn and sunflower oils).

CONCLUSIONS

Well-planned vegetarian diets that include a wide variety of plant foods, and a reliable source of vitamin B12, provide adequate nutrient intake. Government agencies and health/nutrition organizations should provide more educational resources to help Italians consume nutritionally adequate vegetarian diets.

Vegetarian diets and gut microbiota: important shifts in markers of metabolism and cardiovascular disease

Vegetarian diets have been associated with a lower incidence of several chronic diseases. The benefits of plant-based diets are related mainly to the improvement of metabolic parameters that can indicate risk for such diseases. Some metabolic factors, such as oxidative balance, lipid profile, and glucose homeostasis, can be improved directly by diet, but paradoxically, some characteristics of vegetarian diets may promote a negative scenario that increases the risk of certain chronic diseases. Additionally, many benefits of a vegetarian diet are mediated by the gut microbiota, members of which not only have taxonomic and functional differences but also produce diverse, specific metabolites that vary according to whether the host consumes an omnivorous or a vegetarian diet. This review examines the modulation of human metabolism and gut microbiota by vegetarian and omnivorous dietary patterns and explores how this modulation may affect the risk of cardiovascular disease.

Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians?

The goal of this paper is to describe the role of vitamin B12 deficiency in cardiovascular disease development among vegetarians. Vegetarians have a high prevalence of vitamin B12 deficiency. Deficiency of this vitamin is associated with a variety of atherogenic processes that are mainly, but not exclusively, due to vitamin B12 deficiency-induced hyperhomocysteinemia. Each 5-μmol/L increase above 10 μmol/L of serum homocysteine is associated with a 20% increased risk of circulatory health problems. Mean homocysteine concentration >10 μmol/L among vegetarians was reported in 32 of 34 reports. Macrocytosis associated with vitamin B12 deficiency is also associated with fatal and non-fatal coronary disease, myocardial infarction, stroke, and other circulatory health problems. Compared with non-vegetarians, vegetarians have an improved profile of the traditional cardiovascular disease risk factors, including serum lipids, blood pressure, serum glucose concentration, and weight status. However, not all studies that assessed cardiovascular disease incidence among vegetarians reported a protective effect. Among studies that did show a lower prevalence of circulatory health problems, the effect was not as pronounced as expected, which may be a result of poor vitamin B12 status due to a vegetarian diet. Vitamin B12 deficiency may negate the cardiovascular disease prevention benefits of vegetarian diets. In order to further reduce the risk of cardiovascular disease, vegetarians should be advised to use vitamin B12 supplements.

Vegan diet, subnormal vitamin B-12 status and cardiovascular health

Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products). Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80%) in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases.

Vegan diet and blood lipid profiles: a cross-sectional study of pre and postmenopausal women

Background

Vegan diet has been associated with lower risk of cardiovascular diseases and mortality, partly due to its effects on serum lipid profiles. Lipid profiles [high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C) and triglycerides (TG)] have not been fully elucidated either in pre and postmenopausal vegans or in ovo-lacto vegetarians. This study aimed to compare lipid profiles among vegans, ovo-lacto vegetarians and omnivores.

Methods

Demographic data and lipid profiles were obtained from the 2002 Taiwanese Survey on Hypertension, Hyperglycemia and Hyperlipidemia. Multivariate linear regression analysis was used to examine factors significantly and independently associated with different categories of veganism and to estimate the β value of lipid profiles in the dietary types.

Results

A total of 2397 premenopausal and 1154 postmenopausal participants who did not receive lipid lowering drugs were enrolled. Premenopausal vegans had significantly lower HDL-C and higher TG, LDL-C/HDL-C, total cholesterol (TC)/HDL-C and TG/HDL-C compared with omnivores. For postmenopausal women, vegans had lower TC while ovo-lacto vegetarians were observed with low HDL-C when compared with omnivores. Multivariate linear regression analyses showed that vegan and ovo-lacto vegetarian diets decreased HDL-C levels in premenopausal women (β = -7.63, p = 0.001 and β = -4.87, p = 0.001, respectively). There were significant associations between lower LDL-C and ovo-lacto vegetarian diets (β = -7.14, p = 0.008) and also between TG and vegan diet (β = 23.37, p = 0.008), compared with omnivorous diet. Post-menopausal women reported to have consumed either a vegan or an ovo-lacto vegetarian diet were at the risk of having low HDL-C unlike those that consumed omnivorous diets (β = -4.88, p = 0.015 and β = -4.48, p = 0.047). There were no significant changes in LDL-C in both pre and postmenopausal vegans.

Conclusions

Vegan diet was associated with reduced HDL-C level. Because of its effects on lowering HDL-C and LDL-C, ovo-lacto vegetarian diet may be more appropriate for premenopausal women.

Plasma total homocysteine status of vegetarians compared with omnivores: a systematic review and meta-analysis

There is strong evidence indicating that elevated plasma total homocysteine (tHcy) levels are a major independent biomarker and/or a contributor to chronic conditions, such as CVD. A deficiency of vitamin B12can elevate homocysteine. Vegetarians are a group of the population who are potentially at greater risk of vitamin B12deficiency than omnivores. This is the first systematic review and meta-analysis to appraise a range of studies that compared the homocysteine and vitamin B12levels of vegetarians and omnivores. The search methods employed identified 443 entries, from which, by screening using set inclusion and exclusion criteria, six eligible cohort case studies and eleven cross-sectional studies from 1999 to 2010 were revealed, which compared concentrations of plasma tHcy and serum vitamin B12of omnivores, lactovegetarians or lacto-ovovegetarians and vegans. Of the identified seventeen studies (3230 participants), only two studies reported that vegan concentrations of plasma tHcy and serum vitamin B12did not differ from omnivores. The present study confirmed that an inverse relationship exists between plasma tHcy and serum vitamin B12, from which it can be concluded that the usual dietary source of vitamin B12is animal products and those who choose to omit or restrict these products are destined to become vitamin B12deficient. At present, the available supplement, which is usually used for fortification of food, is the unreliable cyanocobalamin. A well-designed study is needed to investigate a reliable and suitable supplement to normalise the elevated plasma tHcy of a high majority of vegetarians. This would fill the gaps in the present nutritional scientific knowledge.

Chinese lacto-vegetarian diet exerts favorable effects on metabolic parameters, intima-media thickness, and cardiovascular risks in healthy men

BACKGROUND

To investigate whether the Chinese lacto-vegetarian diet has protective effects on metabolic and cardiovascular disease (CVD).

METHODS

One hundred sixty-nine healthy Chinese lacto-vegetarians and 126 healthy omnivore men aged 21-76 years were enrolled. Anthropometric indexes, lipid profile, insulin sensitivity, pancreatic β cell function, and intima-media thickness (IMT) of carotid arteries were assessed and compared. Cardiovascular risk points and probability of developing CVD in 5-10 years in participants aged 24-55 years were calculated.

RESULTS

Compared with omnivores, lacto-vegetarians had remarkably lower body mass index, systolic and diastolic blood pressure, and serum levels of triglyceride, total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, γ-glutamyl transferase, serum creatinine, uric acid, fasting blood glucose, as well as lower total cholesterol/high-density lipoprotein cholesterol ratio. Vegetarians also had higher homeostasis model assessment β cell function and insulin secretion index and thinner carotid IMT than the omnivores did. These results corresponded with lower cardiovascular risk points and probability of developing CVD in 5-10 years in vegetarians 24-55 years old.

CONCLUSIONS

In healthy Chinese men, the lacto-vegetarian diet seems to exert protective effects on blood pressure, lipid profiles, and metabolic parameters and results in significantly lower carotid IMT. Lower CVD risks found in vegetarians also reflect the beneficial effect of the Chinese lacto-vegetarian diet.

Arterial function of carotid and brachial arteries in postmenopausal vegetarians

Background:

Vegetarianism is associated with a lower risk of cardiovascular disease. However, studies of arterial function in vegetarians are limited.

Methods:

This study investigated arterial function in vegetarianism by comparing 49 healthy postmenopausal vegetarians with 41 age-matched omnivores. The arterial function of the common carotid artery was assessed by carotid duplex, while the pulse dynamics method was used to measure brachial artery distensibility (BAD), compliance (BAC), and resistance (BAR). Fasting blood levels of glucose, lipids, lipoprotein (a), high-sensitivity C-reactive protein, homocysteine, and vitamin B12 were also measured.

Results:

Vegetarians had significantly lower serum cholesterol, high-density and low-density lipoprotein, and glucose compared with omnivores. They also had lower vitamin B12 but higher homocysteine levels. Serum levels of lipoprotein (a) and high-sensitivity C-reactive protein were no different between the two groups. There were no significant differences in carotid beta stiffness index, BAC, and BAD between the two groups even after adjustment for associated covariates. However, BAR was significantly lower in vegetarians than in omnivores. Multiple linear regression analysis revealed that age and pulse pressure were two important determinants of carotid beta stiffness index and BAD. Vegetarianism is not associated with better arterial elasticity.

Conclusion:

Apparently healthy postmenopausal vegetarians are not significantly better in terms of carotid beta stiffness index, BAC, and BAD, but have significantly decreased BAR than omnivores. Prevention of vitamin B12 deficiency might be beneficial for cardiovascular health in vegetarians.

Segment-specific association between plasma homocysteine level and carotid artery intima-media thickness in the Framingham Offspring Study

Elevated plasma total homocysteine (tHcy) level is an established risk factor for cardiovascular disease. The relationship between tHcy and carotid artery intima-media thickness (IMT) at the internal carotid artery (ICA)/bulb-IMT and common carotid artery (CCA)-IMT had not been systematically studied, however. Because the ICA/bulb segment is more prone to plaque formation than the CCA segment, differential associations with tHcy at these sites might suggest mechanisms of tHcy action. We examined the cross-sectional segment-specific relationships of tHcy to ICA/bulb-IMT and CCA-IMT in 2499 participants from the Framingham Offspring Study who were free of cardiovascular disease. In multivariate linear regression analysis, ICA/bulb-IMT was significantly higher in the fourth tHcy quartile category compared with the other quartile categories, in both the age- and sex-adjusted and the multivariate-adjusted models (P for trend <.0001 and <.01, respectively). We observed a significant age-by-tHcy interaction for ICA/bulb-IMT (P=.03) and thus stratified the analyses by median age (58 years). A significant positive trend between tHcy and ICA/bulb-IMT was seen in individuals age ≥58 years (P for trend <.01), but not in younger individuals (P for trend=.24) in multivariate-adjusted models. For CCA-IMT, no significant trends were observed in any of the analyses. The segment-specific association between elevated tHcy level and ICA/bulb-IMT suggests an association between tHcy and plaque formation.

Vitamin B-12 and homocysteine status among vegetarians: a global perspective

Evidence exists that well-planned vegetarian diets provide numerous health benefits and are appropriate for all stages of the life cycle. It is also known that animal foods provide micronutrients that are nonexistent or available only in limited amounts in plant foods. Restriction or exclusion of all animal foods may therefore result in low intake of certain micronutrients such as vitamin B-12, thereby affecting vitamin B-12 status and elevating plasma homocysteine concentrations. Overall, the studies we reviewed showed reduced mean vitamin B-12 status and elevated mean homocysteine concentrations in vegetarians, particularly among vegans. Low vitamin B-12 intake may lead to decreased bioavailability and functional deficiency of cobalamin. Although early noticeable symptoms of vitamin B-12 deficiency are nonspecific (unusual fatigue, digestion problems, frequent upper respiratory infections), the best-known clinical manifestations of cobalamin malabsorption are hematologic (pernicious anemia) and neurologic symptoms. Hyperhomocysteinemia is associated with an increased risk of atherosclerosis and cardiovascular disease. Given these health concerns, vegetarians, particularly vegans, must be advised to carefully plan their diets, to monitor their plasma vitamin B-12 on a regular basis to facilitate early detection of low cobalamin status, and to use vitamin B-12-fortified foods or take vitamin B-12 supplements if necessary.

The relationships among serum glucose, albumin concentrations and carotid atherosclerosis in men with spinal cord injury

Limited information is available that examines the interrelationships between glucose tolerance, serum albumin, subclinical inflammation, and carotid atherosclerosis (CA) in patients with spinal cord injury (SCI). We prospectively recruited 110 male patients with traumatic SCI, 57 with SCI at thoracic level 6 or above (SCI-T6) and 53 with SCI at T7 or below (SCI-T7), and 62 age-matched able-bodied controls from the National Taiwan University Hospital. The associations among glucose levels after oral glucose tolerance tests (OGTT), serum albumin, high-sensitivity C-reactive protein (hs-CRP), and CA in terms of the extracranial carotid artery (ECCA) plaque score and common carotid artery (CCA) intima-media thickness (IMT) were examined. Results showed significantly higher post-challenge glucose levels and carotid plaque scores and lower serum albumin in the SCI-T6 patients. In addition, serum albumin was negatively associated with CA and post-challenge glucose levels. The higher post-challenge glucose levels at 120min (Glu120) were associated with higher serum hs-CRP levels and lower serum albumin levels. In addition, lower serum albumin levels were associated with a thicker CCA IMT and a higher prevalence of ECCA plaque. Mixed models revealed that body mass index, age, LDL-cholesterol, Glu120, homeostasis model assessment for insulin resistance (HOMA-IR), lower serum albumin and smoking habits were positively associated with CCA IMT. Age, HOMA-IR, LDL-cholesterol, and lower serum albumin were identified as the important factors for the presence of carotid plaque by multiple linear regression analyses. In conclusion, post-challenge hyperglycemia and serum albumin levels are important indicators of CV health in men with SCI.

Carotid intima-media thickness and markers of inflammation, endothelial damage and hemostasis

BACKGROUND

Different soluble molecules involved in inflammation, endothelial damage, or hemostasis are recognized as potential cardiovascular risk markers. Studies to assess the role of these markers in the atherosclerotic process by evaluating their relationship to carotid intima-media thickness (C-IMT) tend to provide contrasting results.

PURPOSE

To perform a review of studies addressing the association between C-IMT and soluble markers and to investigate whether the observed inconsistencies could be explained by the characteristics of the patients included in different studies, for example prevalence of atherosclerotic disease (atherosclerotic burden), gender, age, or occurrence of specific vascular risk factors (VRFs).

DATA SOURCES

PubMed and Embase (January 1990 to March 2006).

STUDY SELECTION

Articles in English reporting original cross-sectional studies.

DATA EXTRACTION

Two authors independently extracted data on study design, population, sample size, ultrasonic methodology, and statistical approach.

DATA SYNTHESIS

Despite the marked heterogeneity of results presented in the literature, meta-analysis established that studies showing positive associations between C-IMT and plasma levels of C-reactive protein (CRP) or fibrinogen are in the majority. Funnel plot analyses suggested the absence of an important publication bias. Data on the relationships between C-IMT and other soluble markers are by contrast scanty, contradictory, or unconfirmed by multivariate (as opposed to univariate) analyses, and the freedom from publication bias here cannot be vouched for. The degree of atherosclerotic burden in the population studied does not account for the heterogeneity of findings reported. Gender, noninsulin-dependent diabetes mellitus (NIDDM) and hypercholesterolemia influence the association between C-IMT and CRP. Blood pressure and hypercholesterolemia influence the association between C-IMT and fibrinogen. For all the other soluble markers considered, the number of groups was too small for this kind of statistical considerations.

LIMITATIONS

Heterogeneity in ultrasound methodologies and in statistical approach limited comparability between studies. For most soluble markers, publication bias of positive results cannot be excluded.

CONCLUSIONS

Only CRP and fibrinogen seem to be unequivocally related to C-IMT. For all the other soluble markers considered, no clear-cut conclusions can be drawn.

[Vegetarian nutrition: Preventive potential and possible risks. Part 1: Plant foods]

Today vegetarian nutrition is more accepted and widespread in Europe than in former years. For a long time scientific research on vegetarian diets has focused mostly on malnutrition, whereas nowadays research centers increasingly on the preventive potential of plant-based diets. We followed a nutritive and a metabolic-epidemiological approach to obtain dietary recommendations. A MEDLINE research was performed for all plant food groups relevant for a vegetarian diet (key words: all relevant food groups, "vegetarian diet", "chronic disease", "cancer", "cardiovascular disease", "diabetes mellitus", "osteoporosis"). All relevant food groups were characterized regarding their nutrient content and rated with respect to the available metabolic-epidemiological evidence. Based on the evidence criteria of the WHO/FAO, cancer risk reduction by a high intake of vegetables and fruits is assessed as probable or possible, while a lowered risk of cardiovascular disease is convincing and a lowered risk of osteoporosis is probable. The evidence of a risk reducing effect of whole grain relating to colorectal cancer is assessed as possible, whereas it is probable relating to cardiovascular disease and diabetes mellitus type 2. There is an insufficient risk-reducing effect of legumes like soja relating to epithelial tumours and cardiovascular disease. The evidence of a risk-reducing effect of nuts to cardiovascular disease is assessed as probable, and in relation to cholelithiasis and diabetes mellitus type 2 as possible and insufficient, respectively. In conclusion, high consumption of fruits, vegetables, whole grains and nuts can lower the risk for several chronic diseases.

Total cardiovascular risk profile of Taiwanese vegetarians

BACKGROUND

Although the health benefits of vegetarian diets have been well documented among Western population, there are geographic differences of vegetarian diets and the health benefits of the Taiwanese vegetarian diet have not been studied extensively. In addition to conventional risk factors, homocysteine and high-sensitivity C-reactive protein (hs-CRP) levels have been found to predict first atherothrombotic events. We undertook this study to examine the total risk profile of Taiwanese vegetarians.

METHODS

A total of 198 healthy subjects (99 vegetarians and 99 omnivores) were recruited. Fasting blood samples were analyzed for glucose, cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), white blood cell count, hs-CRP and homocysteine.

RESULTS

There was no significant difference in age, body mass index, blood glucose, white blood cell count, triglyceride and HDL-C between the two groups. The vegetarian group had significantly more females (65.7 vs 46.5%); lower body weight (58.66+/-11.13 vs 62.88+/-12.24 kg); shorter height (159.14+/-7.88 vs 162.53 +/-8.14 cm); lower total cholesterol (184.74+/-33.23 vs 202.01+/-41.05 mg/dl); and lower LDL-C (119.63+/-31.59 vs 135.89+/-39.50 mg/dl). Hs-CRP was significantly lower (0.14+/-0.23 vs 0.23+/-0.44 mg/dl, P=0.025), whereas homocysteine was significantly higher (10.97+/-6.69 vs 8.44+/-2.50 micromol/l, P=0.001) in vegetarians than omnivores.

CONCLUSIONS

Taiwanese vegetarians have lower total cholesterol, LDL-C and hs-CRP levels, and higher homocysteine levels than omnivores. Owing to different predictive value of each risk factor, the Taiwanese vegetarians had a better cardiovascular risk profile than omnivores. Whether the Taiwanese vegetarian diet should be supplemented with vitamin B(12) to lower serum homocysteine level remains to be addressed.

Hepatitis B virus seropositivity is not associated with increased risk of carotid atherosclerosis in Taiwanese

BACKGROUND

Chronic infection has been proposed to increase the risk of atherosclerosis in several experimental and epidemiological studies. However, the relationship of chronic hepatitis B virus (HBV) infection and atherosclerosis remains controversial. We conducted this cross-sectional study to evaluate the association of carotid atherosclerosis with hepatitis B seropositivity.

METHODS AND RESULTS

In this cross-sectional study, we collected data from subjects undergoing health examination, including B-mode carotid ultrasonography, hepatitis B surface antigen (HBsAg) status and assessment of traditional cardiovascular risk factors, at our institutes in Taiwan between 2002 and 2003. Cases with chronic hepatitis C had been excluded. Of the 508 eligible subjects, 87 (17.1%) were positive for HBsAg and only six of them were positive for HBeAg. Compared with HBsAg negative subjects, the ORs (and 95% CIs) for the subjects with chronic hepatitis B to have carotid atherosclerosis were 1.24 (0.73-2.10) indexed by the presence of carotid atherosclerotic plaque (Intima-media thickness, IMT>or=1.3mm), 0.74 (0.38-1.42) by maximal common carotid artery IMT>or=75th percentile, and 1.09 (0.62-1.90) by extracranial carotid artery atherosclerotic score>or=2, with the use of multivariate logistic regression analyses.

CONCLUSION

Hepatitis B virus seropositivity was not associated with an increased severity of carotid atherosclerosis in Taiwanese.