Changes in predictors and status of homocysteine in young male adults after a dietary intervention with vegetables, fruits and bread

Homocysteine, hyperhomocysteinemia, and H-type hypertension

Homocysteine (Hcy) is a sulphur-containing nonessential amino acid derived from the intermediate metabolites of methionine. Methionine is obtained from dietary proteins, such as poultry, meat, eggs, seafood, and dairy products. Abnormalities in Hcy metabolic pathways, deficiencies in dietary methionine, folate, and vitamins B12, B6, and B2 and genetic defects, polymorphisms, or mutations in Hcy metabolism-related enzymes may lead to an increase in plasma Hcy levels. Generally, a plasma Hcy level higher than 10 or 15 μmol/L has been defined as hyperhomocysteinemia (HHcy). An individual with essential hypertension complicated with HHcy is considered to have H-type hypertension (HTH). Currently, HHcy is considered a novel independent risk factor for various cardiovascular diseases. To provide a useful reference for clinicians, the research progress on Hcy, HHcy, and HTH in recent years was systematically reviewed here, with a focus on the source and metabolic pathways of Hcy, plasma Hcy levels and influencing factors, detection methods for plasma Hcy levels, relationship between Hcy concentration and hypertension, pathogenesis of HTH, cardiovascular complications of HTH, and treatment of HTH.

Relationship between the methylenetetrahydrofolate reductase (MTHFR) rs1801133 SNP and serum homocysteine levels of Zhuang hypertensive patients in the central region of Guangxi

BACKGROUND

The relationship between the methylenetetrahydrofolate reductase (MTHFR) single nucleotide polymorphism (SNP) and serum homocysteine (Hcy) levels or H-type hypertension in different populations is inconsistent. This study aimed to explore the association between the MTHFR rs1801133 SNP and serum Hcy levels of Zhuang hypertensive patients in the central region of Guangxi.

METHODS

A total of 606 Zhuang inpatients with essential hypertension were recruited in our hospital from August 2016 to December 2018. The patients were divided into H-type hypertension (Hcy > 10 µmol/L, n = 528) and non-H-type hypertension (Hcy ≤ 10 µmol/L, n = 78) groups. At the same time, an age- and sex-matched group of 379 subjects with normal physical examination in our hospital were selected as the control group. Blood biochemical measurements and genotyping of the MTHFR rs1801133 SNP were performed.

RESULTS

The prevalence of H-type hypertension was 87.13%. The levels of serum Hcy in patients with hypertension were higher than those in control group (14.20 ± 5.78 μmol/L vs. 11.97 ± 5.39 μmol/L, P < 0.001), especially in patients with H-type hypertension (15.08 ± 5.65 μmol/L, P < 0.001). The frequencies of TT genotype (22.73%) and T allele (46.21%) in patients with H-type hypertension were significantly higher than those in control group (11.35% and 30.47%, respectively) and non-H-type hypertension group (10.26% and 28.85%, respectively; P < 0.001 for all). Multivariate linear regression analysis showed that serum Hcy levels were significantly correlated with creatinine, low-density lipoprotein cholesterol, endogenous creatinine clearance rate, and the MTHFR rs1801133 genotypes in control group, while serum Hcy levels were significantly correlated with creatinine, triglyceride, low-density lipoprotein cholesterol, endogenous creatinine clearance rate, glycosylated hemoglobin, and the MTHFR rs1801133 genotypes in H-type hypertension group (P < 0.05-0.001). Serum Hcy levels in the T allele carriers were higher than those in the T allele noncarriers in both H-type hypertension and control groups.

CONCLUSIONS

There was closely related between the MTHFR rs1801133 SNP and serum Hcy levels in Zhuang patients with H-type hypertension in the central region of Guangxi. The MTHFR SNP may be an important reason for the increase of serum Hcy levels in Zhuang patients with H-type hypertension in this region.

Homocysteine, Cognitive Functions, and Degenerative Dementias: State of the Art

There is strong evidence that homocysteine is a risk factor not only for cerebrovascular diseases but also for degenerative dementias. A recent consensus statement renewed the importance and the role of high levels of homocysteine in cognitive decline in several forms of degenerative dementia, such as Alzheimer's disease. Although the molecular mechanisms by which homocysteine causes cell dysfunction are known, both the impact of homocysteine on specific cognitive functions and the relationship between homocysteine level and non-Alzheimer dementias have been poorly investigated. Most of the studies addressing the impact of hyperhomocysteinemia on dementias have not examined the profile of performance across different cognitive domains, and have only relied on screening tests, which provide a very general and coarse-grained picture of the cognitive status of the patients. Yet, trying to understand whether hyperhomocysteinemia is associated with the impairment of specific cognitive functions would be crucial, as it would be, in parallel, learning whether some brain circuits are particularly susceptible to the damage caused by hyperhomocysteinemia. These steps would allow one to (i) understand the actual role of homocysteine in the pathogenesis of cognitive decline and (ii) improve the diagnostic accuracy, differential diagnosis and prognostic implications. This review is aimed at exploring and revising the state of the art of these two strictly related domains. Suggestions for future research are provided.

Effects of Oral Carotenoids on Oxidative Stress: A Systematic Review and Meta-Analysis of Studies in the Recent 20 Years

Carotenoids protect organs, tissues, and cells from the damaging action of singlet oxygen, oxygen radicals, and lipid peroxides. This systematic review was sought to evaluate the influence of oral carotenoids on antioxidant/oxidative markers, blood carotenoids levels, and lipid/lipoprotein parameters in human subjects. A comprehensive review of relevant literature was conducted in PubMed, Web of Sciences, and the Cochrane library, from 2000 to December 2020. Randomized controlled trials, case-controlled trials, or controlled trials were identified. A total of eighteen trials were included, with the target populations being healthy subjects in 16 studies, athletes in 1 study, and pregnant women in 1 study. The meta-analysis results showed that carotenoids complex supplementation significantly increased the levels of antioxidative parameters ferric-reducing ability of plasma (FRAP) and oxygen radical absorbance capacity (ORAC) [standardized mean difference (SMD) = 0.468; 95% CI: 0.159-0.776, p = 0.003; SMD = 0.568; 95% CI: 0.190-0.947, p = 0.003] and decreased the blood triglyceride (TG) level (SMD = -0.410, 95% CI: -0.698 to -0.122, p = 0.005). Oral carotenoids supplement significantly increased the blood levels of β-carotene (SMD = 0.490, 95% CI: 0.123-0.858, p = 0.009), α-tocopherol (SMD = 0.752, 95%CI: 0.020-1.485, p = 0.044), and the intaking durations were 8 weeks. The levels of antioxidative enzymes and other lipid/lipoprotein parameters were not different between subjects receiving carotenoids and controls (p > 0.05). In conclusion, our systematic review showed that the carotenoids complex is beneficial for alleviating potential oxidative stress via interacting with free radicals or decreasing blood TG levels. The intaking duration of carotenoids should be 8 weeks to reach enough concentration for function.

Prevalence and risk factors for hyperhomocysteinemia: a population-based cross-sectional study from Hunan, China

OBJECTIVES

Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. We aimed to investigate the prevalence and risk factors for hyperhomocysteinemia, especially modifiable lifestyle factors, such as smoking behaviour and dietary factors.

DESIGN

Population-based cross-sectional study.

SETTING

Hunan Province, China PARTICIPANTS: A total of 4012 participants completed the study, between July 2013 and March 2014. The median age is 55 (interquartile range: 45-63) years, with 1644 males (41%) and 2368 females (59%).

MAIN OUTCOME MEASURES

Homocysteine level were measured by the microplate enzyme immunoassay method. Hyperthomocysteinemia was defined as ≥15 µmol/L. Questionnaire was used to investigate potential risk factors of hyperhomocysteinemia. Crude odd ratio (OR) or adjusted OR with 95% CI were determined by using univariable or multivariable logistic regression models.

RESULTS

The prevalence of hyperhomocysteinemia is 35.4% (45.4% vs 28.5% for men, women, respectively). One-year increase in age is significantly associated with 2% higher risk of hyperhomocysteinemia (OR=1.02, 95% CI: 1.01 to 1.03). One unit increase of BMI is associated with 5% higher risk of hyperhomocysteinemia (OR=1.05, 95% CI: 1.03 to 1.07). Compared with the non-smoker, smoking participants have a 24% higher risk of hyperhomocysteinemia (OR=1.24, 95% CI: 1.006 to 1.53), while the risk for those quitting smoking are not significantly different (OR=1.14, 95% CI: 0.85 to 1.54). compared with those consuming fruit and vegetable at least once every day, those consuming less than once every day had a significantly higher risk of hyperhomocysteinemia (OR=1.29, 95% CI:1.11 to 1.50). In addition, we found there were significant sex interaction with education level or alcohol drinking on the risk of hyperhomocysteinemia (p_interaction <0.05).

CONCLUSIONS

Higher BMI and older age are potential risk factors for hyperhomocysteinemia. Current smoking but not quitting smoking is associated with higher risk of hyperhomocysteinemia. Fruit and vegetable consumption may have protective effect against hyperhomocysteinemia. Alcohol consumption or education level might interact to influence the risk of hyperhomocysteinemia.

Homocysteine in Neurology: A Possible Contributing Factor to Small Vessel Disease

Homocysteine (Hcy) is a sulfur-containing amino acid generated during methionine metabolism, accumulation of which may be caused by genetic defects or the deficit of vitamin B12 and folate. A serum level greater than 15 micro-mols/L is defined as hyperhomocysteinemia (HHcy). Hcy has many roles, the most important being the active participation in the transmethylation reactions, fundamental for the brain. Many studies focused on the role of homocysteine accumulation in vascular or degenerative neurological diseases, but the results are still undefined. More is known in cardiovascular disease. HHcy is a determinant for the development and progression of inflammation, atherosclerotic plaque formation, endothelium, arteriolar damage, smooth muscle cell proliferation, and altered-oxidative stress response. Conversely, few studies focused on the relationship between HHcy and small vessel disease (SVD), despite the evidence that mice with HHcy showed a significant end-feet disruption of astrocytes with a diffuse SVD. A severe reduction of vascular aquaporin-4-water channels, lower levels of high-functioning potassium channels, and higher metalloproteinases are also observed. HHcy modulates the N-homocysteinylation process, promoting a pro-coagulative state and damage of the cellular protein integrity. This altered process could be directly involved in the altered endothelium activation, typical of SVD and protein quality, inhibiting the ubiquitin-proteasome system control. HHcy also promotes a constant enhancement of microglia activation, inducing the sustained pro-inflammatory status observed in SVD. This review article addresses the possible role of HHcy in small-vessel disease and understands its pathogenic impact.

Recommended Consumption of Fruits and Vegetables Increases the Intake of Polyphenols and Flavonoids in Brazilian Adults

Background:

Adequate consumption of fruits and vegetables (FV) is associated with reduced risks of various diseases, especially due to their nutrient, fiber, and bioactive compound content. Polyphenols are included in this last class. In Brazil, as in several other regions of the world, consumption of FV is low. Data on the importance of the recommended intake of FV for the ingestion of these compounds and subclasses are scarce.

Objective:

To estimate the intake of polyphenols by Brazilian adults and to verify the impact of the recommended consumption of FV for this intake.

Methods:

Data from 21,959 adults were obtained from the Brazilian Dairy Survey of the Household Budget Survey (POF 2008-2009). Food intake was estimated from a single food register. Polyphenol intake was calculated using the Phenol-Explorer database. To evaluate the impact of FV on the consumption of polyphenols, the population was divided into two groups according to the FV intake as recommended by the World Health Organization.

Results:

The average consumption of phenolic compounds was 441.04 mg among individuals consuming less than 400 g of FV daily, and 651.86 mg those consuming equal or more than 400 g daily. In addition, individuals consuming 400 g or more FV per day consumed approximately 12 times more phenolic from FV, especially flavonoids and the anthocyanin and flavanone subclasses.

Conclusions:

The high consumption of FV is essential for a higher dietary intake and diversity of polyphenols and flavonoids compounds by the Brazilian population.

The Controversial Role of Homocysteine in Neurology: From Labs to Clinical Practice

Homocysteine (Hcy) is a sulfur-containing amino acid that is generated during methionine metabolism. Physiologic Hcy levels are determined primarily by dietary intake and vitamin status. Elevated plasma levels of Hcy can be caused by deficiency of either vitamin B12 or folate. Hyperhomocysteinemia (HHcy) can be responsible of different systemic and neurological disease. Actually, HHcy has been considered as a risk factor for systemic atherosclerosis and cardiovascular disease (CVD) and HHcy has been reported in many neurologic disorders including cognitive impairment and stroke, independent of long-recognized factors such as hyperlipidemia, hypertension, diabetes mellitus, and smoking. HHcy is typically defined as levels >15 micromol/L. Treatment of hyperhomocysteinemia with folic acid and B vitamins seems to be effective in the prevention of the development of atherosclerosis, CVD, and strokes. However, data from literature show controversial results regarding the significance of homocysteine as a risk factor for CVD and stroke and whether patients should be routinely screened for homocysteine. HHcy-induced oxidative stress, endothelial dysfunction, inflammation, smooth muscle cell proliferation, and endoplasmic reticulum (ER) stress have been considered to play an important role in the pathogenesis of several diseases including atherosclerosis and stroke. The aim of our research is to review the possible role of HHcy in neurodegenerative disease and stroke and to understand its pathogenesis.

Effect of increasing fruit and vegetable intake by dietary intervention on nutritional biomarkers and attitudes to dietary change: a randomised trial

PURPOSE

Low fruit and vegetable consumption is linked with an increased risk of death from vascular disease and cancer. The benefit of eating fruits and vegetables is attributed in part to antioxidants, vitamins and phytochemicals. Whether increasing intake impacts on markers of disease remains to be established. This study investigates whether increasing daily intake of fruits, vegetables and juices from low (approx. 3 portions), to high intakes (approx. 8 portions) impacts on nutritional and clinical biomarkers. Barriers to achieving the recommended fruit and vegetable intakes are also investigated.

METHOD

In a randomised clinical trial, the participants [19 men and 26 women (39-58 years)] with low reported fruit, juice and vegetable intake (<3 portions/day) were randomised to consume either their usual diet or a diet supplemented with an additional 480 g of fruit and vegetables and fruit juice (300 ml) daily for 12 weeks. Nutritional biomarkers (vitamin C, carotenoids, B vitamins), antioxidant capacity and genomic stability were measured pre-intervention, at 4-, 8- and 12 weeks throughout the intervention. Samples were also taken post-intervention after a 6-week washout period. Glucose, homocysteine, lipids, blood pressure, weight and arterial stiffness were also measured. Intake of fruit, fruit juice and vegetables was reassessed 12 months after conducting the study and a questionnaire was developed to identify barriers to healthy eating.

RESULTS

Intake increased significantly in the intervention group compared to controls, achieving 8.4 portions/day after 12 weeks. Plasma vitamin C (35%), folate (15%) and certain carotenoids [α-carotene (50%) and β-carotene (70%) and lutein/zeaxanthin (70%)] were significantly increased (P < 0.05) in the intervention group. There were no significant changes in antioxidant capacity, DNA damage and markers of vascular health. Barriers to achieving recommended intakes of fruits and vegetables measured 12 months after the intervention period were amount, inconvenience and cost.

CONCLUSION

While increasing fruit, juice and vegetable consumption increases circulating level of beneficial nutrients in healthy subjects, a 12-week intervention was not associated with effects on antioxidant status or lymphocyte DNA damage.

TRIAL REGISTRATION

This trial was registered at Controlled-Trials.com; registration ISRCTN71368072.

Validation of the Brazilian Healthy Eating Index-Revised Using Biomarkers in Children and Adolescents

The Brazilian Healthy Eating Index-Revised (BHEI-R) can be used to determine overall dietary patterns. We assessed the BHEI-R scores in children and adolescents, aged from 9 to 13 years old, and associated its component scores with biomarkers of health and dietary exposure. Three 24-h recalls were used to generate BHEI-R. Biomarkers were analyzed in plasma and red blood cells. Correlation tests, agreement, and covariance analyses were used to associate BHEI-R components with biomarkers. Data from 167 subjects were used. The strongest correlations were between fruits, vegetables and legumes with omega-6 and omega-3 fatty acids, and β-carotene intakes. Milk and dairy correlated with plasma retinol and pyridoxine. All components rich in vegetable and animal protein sources correlated with plasma creatine. Total BHEI-R scores were positively associated with intakes of omega-6, omega-3, fiber and vitamin C, and inversely associated with energy and saturated fat intakes of individuals. Plasma β-carotene and riboflavin biomarkers were positively associated with total BHEI-R. An inadequate food consumption pattern was captured by both biomarkers of health and dietary exposure. BHEI-R was validated for the above dietary components and can be associated with metabolomics and nutritional epidemiological data in future pediatric studies.

Influence of food groups on plasma total homocysteine for specific MTHFR C677T genotypes in Chinese population

Scope

It has been demonstrated that a mutation of MTHFR C677T increases plasma total homocysteine (Hcy) concentration and decreases folate. Natural foods can improve Hcy levels, but the effect of certain foods remains undetermined. The aim of this study was to investigate the association between food groups and Hcy, and to explore the correlations between Hcy and dietary folate/vitamin (Vit) B12 for genotype‐specific population.

Methods and results

A total of 4507 adults were enrolled in this study, all of whom underwent physical examinations and genotyping. A dietary recall questionnaire, which assessed the frequency (F) and quantity (Q) of food consumption, was completed by all. For the male CC group, after adjustment for age and BMI, fish (F) was negatively correlated with Hcy; for the male CT group, fish (F) and eggs (F) were negatively associated with Hcy, whereas cereal/wheat (Q) were positively correlated with Hcy; for the male TT group, fish (F), meat (Q), milk (F), and fruits/vegetables (Q) were negatively associated with Hcy, whereas sugar (Q) and salt (Q) were positively associated with Hcy. For the female CC group, fruits/vegetables (Q), eggs (F) and meat (F) were negatively correlated with Hcy, but soy (F) was positively correlated with Hcy; for the female CT group, eggs (F) and meat (Q) were negatively correlated with Hcy, whereas soy (F), fried foods (F) and salt (Q) were positively correlated with Hcy; for the female TT group, fish(F), eggs (F), and fruits/vegetables (F) were negatively associated with Hcy. Furthermore, we found that Hcy was more closely correlated with folate than with Vit B12 for males (CC, CT and TT) and female TT genotype. However, the correlation between Hcy and Vit B12 was stronger for the female CT/CC groups.

Conclusion

Hcy levels were influenced by food groups to varying degrees, which were based on gender and MTHFR C677T genotypes. Hcy levels were more closely correlated with folate for males (CC, CT and TT) and the female TT group, but it was more closely correlated with Vit B12 for the female CT/CC groups.

Estimate of consumption of phenolic compounds by Brazilian population

OBJECTIVE: Estimate the intake of phenolic compounds by the Brazilian population. METHODS: To estimate the average per capita food consumption, micro data from the National Dietary Survey and from the Household Budget Survey from 2008 to 2009 was analyzed. The phenolic content in food was estimated from the base of Phenol-Explorer. It was chosen according to compatibility and variety of food items and usual method of preparation. RESULTS: The Brazilian population consumed, on average, 460.15 mg/day of total phenolic compounds, derived mainly from beverages (48.9%), especially coffee and legumes (19.5%). Since this analysis of classes of phenolics it was possible to observe an intake of 314 mg/day of phenolic acids, 138.92 mg/day of flavonoids and 7.16 mg/ day of other kinds of phenolics. Regarding the variables studied this present study shows that those men who live in the countryside and in the northeastern region of the country had a higher consumption of phenolic compounds. Besides, consumption was higher by adults and the elderly, the medium income classes, the population with incomplete and complete primary education and those with adequate nutrition and also overweight status. CONCLUSION: The intake of phenolic compounds can be considered low, especially where consumption of fruit and vegetables is insufficient. We can conclude that coffee and black beans were the best contributors to phenolic intake.

Hyperhomocysteinemia and neurologic disorders: a review

Homocysteine (Hcy) is a sulfur-containing amino acid that is generated during methionine metabolism. It has a physiologic role in DNA metabolism via methylation, a process governed by the presentation of folate, and vitamins B6 and B12. Physiologic Hcy levels are determined primarily by dietary intake and vitamin status. Elevated plasma levels of Hcy (eHcy) can be caused by deficiency of either vitamin B12 or folate, or a combination thereof. Certain genetic factors also cause eHcy, such as C667T substitution of the gene encoding methylenetetrahydrofolate reductase. eHcy has been observed in several medical conditions, such as cardiovascular disorders, atherosclerosis, myocardial infarction, stroke, minimal cognitive impairment, dementia, Parkinson's disease, multiple sclerosis, epilepsy, and eclampsia. There is evidence from laboratory and clinical studies that Hcy, and especially eHcy, exerts direct toxic effects on both the vascular and nervous systems. This article provides a review of the current literature on the possible roles of eHcy relevant to various neurologic disorders.

Are plasma homocysteine concentrations in Brazilian adolescents influenced by the intake of the main food sources of natural folate?

BACKGROUND

Folate, a B vitamin, has been associated with a reduced concentration of plasma homocysteine (phcy), a marker of cardiovascular disease. The contribution of fruits and vegetables (FV) and other natural folate-rich foods to folate intake and folate status in Brazilian adolescents has hardly been determined.

OBJECTIVES

To investigate the intake of FV and beans and its association with the concentration of phcy in adolescents.

METHODS

This was a cross-sectional population-based study with a complex sample survey, with 198 adolescents who completed two 24-hour dietary recalls, a food frequency questionnaire, and a fasting blood draw. Usual dietary intake estimates were derived applying the Multiple Source Method. Three different generalized linear models with a gamma distribution were developed for each sex to evaluate the relationship between phcy and tertiles of FV intake as well as to evaluate the relationship between phcy and tertiles of FV and bean intake.

RESULTS

No association was found between phcy concentration and FV intake or between phcy and FV and beans. Serum folate and female sex were inversely related to phcy.

CONCLUSION

Phcy was not related to FV or FV and beans; this may be attributable to a low intake of these food groups.

[Determinants and relationship of homocysteinemia with cardiometabolic risk factors. A study in Benin, West Africa]

INTRODUCTION

Elevated circulating homocysteine (Hcy) is considered as an independent cardiovascular disease risk factor. Hyperhomocysteinaemia (HHcy) is influenced by nutritional, genetic, and environmental factors. The purpose of the study was to assess HHcy prevalence in Benin, its association with intakes of B-vitamins (B2, B6, B9, B12), alcohol intake, and socio-economic status (SES), and its links with other factors of cardio-metabolic risk.

METHODS

The cross-sectional study included 541 apparently healthy subjects, aged 25 to 65 years, from three sites: the main city, a small city and a rural area. Hcy was measured with an ELISA test kit. The HHcy cut-off was 12 μmol/L. Dietary intake was assessed with three 24-hour recalls. We used a structured questionnaire to assess alcohol consumption, demographics, and SES according to education and an amenity score as income proxy. Criteria for obesity, hypertension, dyslipidemia and hyperglycemia were primarily those of World Health Organization (WHO) and the International Diabetes Federation.

RESULTS

Mean age was 38.1 ± 10.1 years. The prevalence of HHcy was 52.2% in men and 24.7% in women. In multiple linear regression models, Hcy in men was positively associated with alcohol intake, but only alcohol in beer. In women, Hcy was negatively related to vitamin B12 intake. According to multivariate models of cardio-metabolic risk factors, HHcy was associated in women with more than twice the odds of hypertension and with high TC/HDL-c ratio. In men, Hcy was positively and independently associated with diastolic blood pressure and with LDL-cholesterol and total cholesterol in linear regression models.

DISCUSSION

The prevalence of HHcy is high in Benin, when compared with other studies, and it was as expected higher in men than in women. Elevated Hcy was associated with inadequate intake of vitamin B12 in women, whereas alcohol consumption and its negative correlation with B12 intake was also involved in men. Although HHcy was independently associated with hypertension (in women) and more adverse cholesterol profile, no inference can be made because of the cross-sectional design of the study.

Fruit and vegetable consumption and proinflammatory gene expression from peripheral blood mononuclear cells in young adults: a translational study

BACKGROUND

Fruits and vegetables are important sources of fiber and nutrients with a recognized antioxidant capacity, which could have beneficial effects on the proinflammatory status as well as some metabolic syndrome and cardiovascular disease features. The current study assessed the potential relationships of fruit and vegetable consumption with the plasma concentrations and mRNA expression values of some proinflammatory markers in young adults.

METHODS

One-hundred and twenty healthy subjects (50 men/70 women; 20.8 +/- 2.6 y; 22.3 +/- 2.8 kg/m2) were enrolled. Experimental determinations included anthropometry, blood pressure and lifestyle features as well as blood biochemical and inflammatory measurements. The mRNA was isolated from peripheral blood mononuclear cells (PBMC) and the gene expression concerning selected inflammatory markers was assessed by quantitative real-time PCR. Nutritional intakes were estimated by a validated semi-quantitative food-frequency questionnaire.

RESULTS

The highest tertile of energy-adjusted fruit and vegetable consumption (>660 g/d) was associated with lower plasma concentrations of C-reactive protein (CRP) and homocysteine and with lower ICAM1, IL1R1, IL6, TNFalpha and NFkappaB1 gene expression in PBMC (P for trend < 0.05), independently of gender, age, energy intake, physical activity, smoking, body mass index, systolic blood pressure and circulating non-esterified fatty acids. In addition, plasma CRP, homocysteine and TNFalpha concentrations and ICAM1, TNFalpha and NFkappaB1 gene expression in PBMC showed a descending trend as increased fiber intake (>19.5 g/d) from fruits and vegetables (P for trend < 0.05). Furthermore, the participants within the higher tertile (>11.8 mmol/d) of dietary total antioxidant capacity showed lower plasma CRP and mRNA values of ICAM1, IL1R1, IL6, TNFalpha and NFkappaB1 genes (P for trend < 0.05). The inverse association between fruit and vegetable consumption and study proinflammatory markers followed the same trend and remained statistically significant, after the inclusion of other foods/nutrients in the linear regression models.

CONCLUSION

A higher fruit and vegetable consumption was independently associated not only with reduced CRP and homocysteine concentrations but also with a lower mRNA expression in PBMC of some relevant proinflammatory markers in healthy young adults.

Genetics of homocysteine metabolism and associated disorders

Homocysteine is a sulfur-containing amino acid derived from the metabolism of methionine, an essential amino acid, and is metabolized by one of two pathways: remethylation or transsulfuration. Abnormalities of these pathways lead to hyperhomocysteinemia. Hyperhomocysteinemia is observed in approximately 5% of the general population and is associated with an increased risk for many disorders, including vascular and neurodegenerative diseases, autoimmune disorders, birth defects, diabetes, renal disease, osteoporosis, neuropsychiatric disorders, and cancer. We review here the correlation between homocysteine metabolism and the disorders described above with genetic variants on genes coding for enzymes of homocysteine metabolism relevant to clinical practice, especially common variants of the MTHFR gene, 677C>T and 1298A>C. We also discuss the management of hyperhomocysteinemia with folic acid supplementation and fortification of folic acid and the impact of a decrease in the prevalence of congenital anomalies and a decline in the incidence of stroke mortality.

Effect of 2 pieces of nutritional advice on folate status in Swedish women: a randomized controlled trial

BACKGROUND

Ten years after the introduction of mandatory folic acid fortification in the United States, Canada, and Costa Rica, the issue is still under debate in several countries, and Sweden recently decided against mandatory fortification.

OBJECTIVE

The objective was to determine the folate status of women after an intervention involving 2 Swedish dietary recommendations: a food recommendation (bread) and a complete meal recommendation (breakfast).

DESIGN

Fifty-one free-living women with normal folate status participated in a 12-wk controlled intervention trial. Subjects were randomly assigned to one of the following interventions: apple juice (control group; n = 17), a breakfast providing 125 microg folate (breakfast group; n = 17), or 5 slices of whole-meal bread to be eaten over the course of the day, which provided 70 microg folate (bread group; n = 17). Folate status was assessed on the basis of concentrations of erythrocyte folate, serum folate, and plasma total homocysteine (tHcy) at baseline and at weeks 8 and 12 of the trial.

RESULTS

In the breakfast group, initial median concentrations of erythrocyte folate (805 nmol/L) increased by 172 nmol/L (95% CI: 24, 293; P = 0.02) relative to the control. The relative increase in initial serum folate (2 nmol/L, 95% CI: 0, 5; P = 0.06) was nonsignificant. The initial tHcy concentration (8.7 micromol/L) decreased by 2.3 micromol/L (95% CI: -1, -3.4; P < 0.01). In the bread group, the initial tHcy concentration (9.1 micromol/L) decreased nonsignificantly by 1.4 micromol/L (95% CI: 0, -2.8; P = 0.08) relative to the control group, whereas other outcomes were stable.

CONCLUSIONS

The folate status of the subjects improved after regular consumption of the breakfast meal. The additional folate intake from the bread maintained the folate status but was not sufficient to improve it.

Association between folate intake from different food sources in Norway and homocysteine status in a dietary intervention among young male adults

The aim of the present investigation was to study the effect of a dietary intervention which combined nutrition information with increased availability of vegetables, fruits and wholegrain bread. The effect of the intervention was determined by changes in the intake of vegetables, fruits, wholegrain bread and estimated nutrients. Furthermore, the study investigated whether changes in relative contribution from different food sources of folate were related to changes in the concentration of plasma total homocysteine (p-tHcy). The 5-month intervention study included 376 male recruits from the Norwegian National Guard, Vaernes (intervention group) and 105 male recruits from the Norwegian National Guard, Heggelia (control group). The study resulted in an increase in the total consumption of vegetables, fruits, berries and juice (P < 0·001) and of wholegrain bread (P < 0·001). The participants in the intervention group showed a higher increase in the intake of dietary fibre (P < 0·001) and folate (P < 0·001) compared with the control group. The relative contribution of folate intake from fruits, vegetables and wholegrain bread was higher in the intervention group compared with the control group (P < 0·001 for all). The increased intake of folate from wholegrain bread was inversely associated with a reduced concentration of p-tHcy (P = 0·017). In summary, the dietary intervention resulted in an increased intake of vegetables, fruits and wholegrain bread and a subsequent increase in folate intake from these food components. Reduction in the concentration of p-tHcy was significantly related to an increased folate intake due to an increased consumption of wholegrain bread.