Increased dietary micronutrients decrease serum homocysteine concentrations in patients at high risk of cardiovascular disease

Prevention and Treatment of Retinal Vein Occlusion: The Role of Diet-A Review

Retinal vein occlusion (RVO) is the second most common retinal disorder. In comparison to diabetic retinopathy or age-related macular degeneration, RVO is usually an unexpected event that carries a greater psychological impact. There is strong evidence to suggest that cardiovascular diseases are the most common risk factors in this pathology and it has long been known that a higher consumption of fish, nuts, fruits, and vegetables has a protective effect against these types of conditions. In the last several years, interest in plant-based diets has grown in both the general population and in the scientific community, to the point to which it has become one of the main dietary patterns adopted in Western countries. The aim of this review is to investigate the potential impact of macro- and micronutrients on retinal vein occlusion.

Folate, folic acid, and chemotherapy-induced toxicities: a systematic literature review

Folate metabolism is a target for various chemotherapeutic drugs. Folate and its synthetic variant folic acid are B-vitamins. To what extent these vitamins impact treatment tolerance in patients with cancer remains unclear. A systematic literature review was conducted on intake and status of folate and folic acid in relation to chemotherapy-induced toxicities in children and adults with cancer. A total of 6,231 publications were identified, of which 40 publications met the inclusion criteria. In 12 out of 22 studies focusing on antifolates, a deficient folate status and lower folate and folic acid intake were associated with a higher risk of toxicities. In 8 out of 14 studies focusing on fluoropyrimidine treatments, a higher folate status and intake were associated with a higher risk of toxicities. These findings might explain interindividual differences in treatment tolerance and highlight the importance of evaluating nutritional status in oncology care.

Dietary Intake of Homocysteine Metabolism-Related B-Vitamins and the Risk of Stroke: A Dose-Response Meta-Analysis of Prospective Studies

Observational studies regarding the putative associations between dietary intake of homocysteine metabolism-related B-vitamins (vitamin B-6, folate, and vitamin B-12) and stroke risk have yielded inconsistent results. Thus, we conducted a systematic meta-analysis of prospective studies in order to examine the relation between the dietary (from diet and supplements) intake of these B-vitamins and the risk of stroke. PubMed and Web of Science were searched for relevant articles published through to 25 February, 2020, and RR of stroke in relation to dietary intake of vitamin B-6, folate, and vitamin B-12 were pooled using a random-effects model. Eleven publications of 12 prospective studies comprising 389,938 participants and 10,749 cases were included in the final analysis. We found that dietary intake of vitamin B-6 and folate were associated with a reduced risk of stroke, and this inverse association remained significant in studies with >10 y of follow-up periods and among participants without a pre-existing stroke event. A dose-response analysis revealed a linear inverse association between folate and vitamin B-6 intake and the risk of stroke, with a pooled RR of 0.94 (95% CI: 0.90-0.98) and 0.94 (95% CI: 0.89-0.99) for each 100 μg/d increment in folate intake and 0.5 mg/d increment in vitamin B-6 intake, respectively. In contrast, we found no significant association between dietary vitamin B-12 intake and the risk of stroke, with an RR of 1.01 (95% CI: 0.97-1.06) per 3 μg/d increase. In conclusion, our findings suggest that increased intake of vitamin B-6 and folate is associated with a reduced risk of stroke, supporting the notion that increasing habitual folate and vitamin B-6 intake may provide a small but beneficial effect with respect to stroke.

Intake of vitamin B6, folate, and vitamin B12 and risk of coronary heart disease: a systematic review and dose-response meta-analysis of prospective cohort studies

The objective of this study was to quantify the association of B-vitamins intake with the future risk of coronary heart disease (CHD). A systematic search was performed with the use of PubMed and Scopus from inception to April 30, 2018. Prospective cohort studies evaluating the association of intake of folate, vitamin B6, and vitamin B12 with risk of CHD in the general population were included. A random-effects meta-analysis was performed. Eleven prospective cohort studies (total n = 369,746) with 5133 cases of CHD were included in the analyses. The relative risks were: 0.79 (95%CI: 0.69, 0.89; I² = 67%) for a 250 µg/d increment in folate intake; 0.87 (95%CI: 0.78, 0.96; I² = 80%) for a 0.5 mg/d increment in vitamin B6 intake; and 0.97 (95%CI: 0.80, 1.14: I² = 67%) for a 3 µg/d increment in vitamin B12 intake. The results did not change materially when the analyses were restricted only to dietary vitamins intake. A nonlinear dose-response meta-analysis demonstrated a linear inverse association between folate and vitamin B6 intake and risk of CHD. In conclusion, higher intake of folate and vitamin B6 is associated with a lower risk of CHD in the general population.

Enabling and empowering--the need for an integrated approach to address hypertension among African adults

This paper charts analytic and conceptual debates on the burden of hypertension among Africans and the interlocking role of diet and genetic factors. The discussions in this paper are about (indigenous) rather than (white) Africans. In trying to show understanding in the issues raised within this paper, the debate highlights the increasing burden of hypertension in Africans. The paper also mentions the role of adverse factors over the life course on hypertension, which is described in public health literature as a widespread burden. It also mentions that there appears to be an increasing prevalence of high blood pressure among Africans explained by widespread nutrition transitions to lipid-rich diets and a decrease in physical activity; as a result, hypertension has become a ubiquitous cause of morbidity and contributor to mortality among Africans. While these issues are acknowledged, the authors argue that it is not enough to think that persuading and encouraging poorer households to purchase 'cheap' and less fatty foods will address nutritional problems. It is one thing making food available and it is another putting the food basket on the table. Both conditions require negotiations of complex political, social, economic, cultural and environmental hurdles. What is needed is reorienting existing health care systems to meet these challenges while empowering and saturating African populations and households with systematic but intense health information, education and communication.

Differences in Mexican American and Non-Hispanic White veterans' homocysteine levels

PURPOSE

To compare homocysteine (Hcy) levels and possible modulatory factors, such as nutrient or supplement intake, between Mexican American and Non-Hispanic White (NHW) male military veterans scoring at high- versus low-risk for stroke.

DESIGN

A cross-sectional survey with a high and low stroke risk biomarkers substudy.

METHODS

Voluntary participants were Mexican American (n=109) and NHW (n=120) veteran outpatients 54 to 85 years of age at a Southwestern Veterans Administration (VA) medical center. Measures included food frequency, health history, and stroke risk scale derived from the Framingham Study. Biomarker subgroups, 30 Mexican American and 30 NHW, half of each group scoring high or low on stroke risk, who were tested for morning fasting blood levels of Hcy, B12, and folate.

FINDINGS

In the cross-sectional study (n=229), nutrient intake was comparable between ethnic groups. In the substudy, Mexican Americans (n=30) with high or low stroke risk scores and NHW (n=30) with high stroke risk scores had elevated Hcy levels (12.5; 11.9; 11.4 micromol/L respectively) compared to NHW veterans with low stroke risk scores (7.8 micromol/L) even after controlling for age, education, folate, diabetes, and smoking pack-years (p=.001). Mexican Americans compared to NHW were significantly more likely to be in the preclinical (17% versus 3% >10 micromol/L) and clinical ranges (69% versus 35% >15 micromol/L) for Hcy.

CONCLUSIONS

Mexican Americans showed higher levels of Hcy whether they scored high or low for stroke, and greater representation in clinical and preclinical Hcy ranges compared to NHW veterans. The Framingham-derived, predominantly NHW population-based stroke risk measure might require ethnically relevant stroke risk factors for Mexican Americans.

Dietary and weight changes after treatments for lymphoma

To estimate the current prevalence of overweight and any associations with self-reported changes in dietary patterns, we surveyed 141 patients who had completed treatments for lymphoma at The M. D. Anderson Cancer Center. We hypothesized that those who perceived that they were currently eating more fruits, vegetables, or whole grains would be more likely to be in a normal weight as body mass index (BMI) category. Usual food choices during the past year were assessed through the previously validated Block Dietary Data Systems Food Frequency Questionnaire (FFQ). Perceived increases in fruits, vegetables, or whole grains after treatment were assessed through supplementary questions. Height, weight, and medications were recorded from a retrospective record review. A majority of subjects were overweight or obese before treatment, and this proportion had increased when assessed a median of 20 mo after treatment. Patients perceiving that they currently consumed more fruits, vegetables, or whole grains were not more likely to be in a normal BMI category even after controlling for medications associated with weight gain as indicated by pharmaceutical company information. However, a majority of subjects consumed 40% or more of energy from fat and ate less than the recommended minimum of 5-a-day fruits and vegetables.

Availability of essential elements in nutrient supplements used as antidiabetic herbal formulations

Five brands of antidiabetic herbal formulations as tablets, Diabetex, Divya Madhu Nashini, Jambrushila, Diabeticin, and Madhumeh Nashini, from different pharmacies were analyzed for six minor (Na, K, Ca, Cl, Mg, and P) and 20 trace (As, Ba, Br, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V, and Zn) elements by thermal neutron irradiation followed by high-resolution gamma ray spectrometry. Further Ni, Cd, and Pb were determined by atomic absorption spectrophotometry. Most elements vary in a narrow range by a factor of 2-4 while a few others vary in a wide range, e.g., Na (0.05-0.67 mg/g), Mn (26.7-250 microg/g), and V (0.26-2.50 microg/g). All the five brands contain K, Cl, Mg, P, and Ca as minor constituents along with mean trace amounts of Cr (2.11 +/- 0.67 microg/g), Cu (15.7 +/- 7.11 microg/g), Fe (459 +/- 171 microg/g), Mn (143 +/- 23 microg/g), Se (238 +/- 112 ng/g), and V (0.99 +/- 0.93 microg/g). Jambrushila is enriched in Na, Ca, Mg, Cl, Fe, Cu, Se, and Zn, essential nutrients responsible for curing diabetes. Dietary intake of Mn, Fe, and Cu are greater than 10% of the recommended dietary allowance, whereas that for Zn and Se is less than 2%. Mean contents of toxic elements (As, Cd, Hg, and Pb) were found below permissible limits except in Jambrushila. Cr and Zn were inversely correlated with r = -0.81, whereas Rb and Cs exhibit linear correlation (r = 0.93) in five brands. C, H, N analysis showed C approximately 55%, H approximately 12%, and N approximately 2% with a total of approximately 70% organic matter. However, thermal decomposition studies at 700 degrees C suggest less than 5% nonvolatile metal oxides. Herbal formulations contain minor and trace elements in bioavailable forms that favorably influence glucose tolerance and possibly increase the body's ability to ameliorate development of diabetes.

Hyperhomocysteinemia decreases circulating high-density lipoprotein by inhibiting apolipoprotein A-I Protein synthesis and enhancing HDL cholesterol clearance

We previously reported that hyperhomocysteinemia (HHcy), an independent risk factor of coronary artery disease (CAD), is associated with increased atherosclerosis and decreased plasma high-density lipoprotein cholesterol (HDL-C) in cystathionine beta-synthase-/apolipoprotein E-deficient (CBS(-/-)/apoE(-/-)) mice. We observed that plasma homocysteine (Hcy) concentrations are negatively correlated with HDL-C and apolipoprotein A1 (apoA-I) in patients with CAD. We found the loss of large HDL particles, increased HDL-free cholesterol, and decreased HDL protein in CBS(-/-)/apoE(-/-) mice, and attenuated cholesterol efflux from cholesterol-loaded macrophages to plasma in CBS(-/-)/apoE(-/-) mice. ApoA-I protein was reduced in the plasma and liver, but hepatic apoA-I mRNA was unchanged in CBS(-/-)/apoE(-/-) mice. Moreover, Hcy (0.5 to 2 mmol/L) reduced the levels of apoA-I protein but not mRNA and inhibited apoA-1 protein synthesis in mouse primary hepatocytes. Further, plasma lecithin:cholesterol acyltransferase (LCAT) substrate reactivity was decreased, LCAT specific activity increased, and plasma LCAT protein levels unchanged in apoE(-/-)/CBS(-/-) mice. Finally, the clearance of plasma HDL cholesteryl ester, but not HDL protein, was faster in CBS(-/-)/apoE(-/-) mice, correlated with increased scavenger receptor B1, and unchanged ATP-binding cassette transporter A1 protein expression in the liver. These findings indicate that HHcy inhibits reverse cholesterol transport by reducing circulating HDL via inhibiting apoA-I protein synthesis and enhancing HDL-C clearance.

Nutritional determinants of plasma total homocysteine distribution in the Canary Islands

OBJECTIVE

We sought to define plasma homocysteine reference values in healthy individuals in the Canary Islands and to determine its relations to folate and vitamin B12 intakes and concentrations.

DESIGN

Cross-sectional study.

SETTING

Population-based representative sample of 557 participants, aged 18-65 years, from the Canary Islands Nutrition Survey (ENCA).

SUBJECTS

All participants completed two 24-h dietary recalls and a general questionnaire collecting socio-demographic and health-related lifestyle information.

INTERVENTIONS

Plasma homocysteine and serum vitamin B12 levels were measured by immunoassay, whereas folate levels through an automated ionic capturing method.

RESULTS

Median plasma homocysteine was 11.9 micromol/l, higher in men (13.1 micromol/l) than in women (10.9 micromol/l) (P<0.001) and positively associated with age in both sexes (P<0.001). The prevalence of hyperhomocysteinaemia (> or = 15 micromol/l), 21.4%, was also greater in men (32.2%) than in women (13.4%). There were significant negative correlations between plasma homocysteine and serum (r=-0.32, P<0.001) and erythrocyte (r=-0.26, P<0.001) folate, as well as serum vitamin B12 (r=-0.28, P<0.001) concentrations. When divided in quartiles of vitamin intakes or concentrations, men with the lowest vitamin B12 and folate serum values had significantly higher plasma homocysteine concentrations than those in the other three quartiles. In women, hyperhomocysteinaemia was higher in the lowest quartiles of folate intake and serum and erythrocyte folate concentrations.

CONCLUSIONS

These data provide further evidence that hyperhomocysteinaemia is a sensitive marker of inadequate folate and vitamin B12 status, allowing for the identification of those with greatest need for nutritional interventions.

Responsiveness of homocysteine concentrations to food and supplemental folate intakes in smokers and never‐smokers enrolled in a diet intervention trial

We investigated circulating homocysteine concentrations in relation to smoking, folate intake (from food and supplements), serum folate concentrations, and other dietary variables. The present study is part of a parent trial assessing the effects of increasing vegetable, fruit, and fiber intakes and reducing the percentage of energy obtained from fat on breast cancer recurrence in 3,088 women previously diagnosed with breast cancer. Of the 121 smokers enrolled in the parent trial, 85 were available at baseline for the present study and were randomly matched to 85 never-smokers on baseline folate intake, age, and intervention status. Follow-up data were available on 53 smokers (22 intervention and 31 comparison) and 56 never-smokers (24 intervention and 32 comparison). No significant differences in circulating homocysteine and folate concentrations were observed between smokers and never-smokers at baseline. For smokers, significant decreases in circulating homocysteine and significant increases in folate concentrations (p < .05) from baseline to 12 months were observed in the comparison group. For never-smokers, significant decreases in circulating homocysteine and significant increases in folate concentrations were observed in the intervention and comparison groups (p < .05). In the multivariate analysis, changes in serum folate concentration and supplemental folic acid were significantly associated with change in plasma homocysteine concentrations (p < .05). These findings show that increasing supplemental folic acid can reduce homocysteine concentrations, which may have implications for lowering cardiovascular disease risk for smokers and never-smokers.

Antioxidant nutrient intake and supplements as potential moderators of cognitive decline and cardiovascular disease in obstructive sleep apnea

Cognitive deficits and cardiovascular disease (CVD) are comorbid conditions frequently associated with obstructive sleep apnea (OSA). Oxygen free radical release and its differential regulation of cytokine synthesis and immune modulation resulting from OSA-related hypoxic events have been hypothesized as the underlying mechanism(s) for the cognitive deficits and CVD in OSA. A number of studies have suggested that increased levels of oxidative stress and/or antioxidant deficiencies may also be risk factors in cognitive decline and CVD. The influence of antioxidant nutrients and supplements, such as Vitamins B6, B12, C, E, folic acid, alpha-lipoic acid and Coenzyme Q(10) on cognitive decline and CVD have been investigated. The influence of antioxidant nutrients or supplements on OSA remains to be investigated. Even if dietary or supplemental antioxidants do not prove to be effective therapies for OSA, dietary assessment and prescription to increase dietary intake of neuro- and cardio-protective nutrients may make it possible to reduce some of the cognitive and cardiovascular sequelae associated with OSA.

Frequent consumption of milk, yogurt, cold breakfast cereals, peppers, and cruciferous vegetables and intakes of dietary folate and riboflavin but not vitamins B-12 and B-6 are inversely associated with serum total homocysteine concentrations in the US population

BACKGROUND

Elevated circulating total homocysteine (tHcy) is an independent risk factor for vascular diseases.

OBJECTIVE

We investigated the relation between dietary intakes and serum tHcy in the US population.

DESIGN

Data from the third National Health and Nutrition Examination Survey (1988-1994) were used to investigate the associations between food consumption frequency and dietary B vitamin intakes and serum tHcy in 5996 persons.

RESULTS

Multivariate-adjusted tHcy concentrations were approximately 15.2% higher in subjects who never consumed milk than in those who consumed milk >30 times/mo, approximately 6.4% higher in subjects who never consumed yogurt than in those who consumed yogurt >15 times/mo, approximately 7.4% higher in subjects who never consumed cold breakfast cereals than in those who consumed cold breakfast cereals >30 times/mo, approximately 6.3% higher in subjects who never consumed peppers (includes red, yellow, green, and hot chili peppers) than in those who consumed peppers >30 times/mo, and approximately 16.5% higher in subjects who never consumed cruciferous vegetables than in those who consumed cruciferous vegetables >30 times/mo. Consumption of citrus fruit and juices, cheese, meats, coffee, or tea had no significant association with tHcy. Folate (beta=-0.0017, P for trend=0.004) and riboflavin (beta=-0.2851, P for trend=0.027), but not vitamin B-6 (beta=0.0505, P for trend=0.70) and cobalamin (beta=-0.0035, P for trend=0.58), were inversely related to serum tHcy after adjustment for confounders.

CONCLUSIONS

In this population-based study, milk, yogurt, cold breakfast cereals, peppers, and cruciferous vegetables were inversely related to serum tHcy. This association may be explained by increased intakes of folate and riboflavin.

Folate and cobalamin synergistically decrease the risk of high plasma homocysteine in a nonsupplemented elderly institutionalized population

OBJECTIVE

Total plasma homocysteine (tHcy) has been associated with an increased risk of cardiovascular disease in the general population and elderly subjects are at high risk of elevated homocysteine because of an impaired vitamin status. The aim of the present study was to determine the independent and interactive association of adequate folate and cobalamin (intake and serum levels) with tHcy in elderly subjects who were not taking vitamin supplementation.

DESIGN AND METHODS

Cross-sectional analysis of a sample of 140 elderly recruited from seven nursing homes in Asturias (Northern Spain). Dietary intake was assessed by a food frequency questionnaire, and serum folate, cobalamin, and tHcy were determined in fasting blood samples.

RESULTS

Mean tHcy concentration was 13.3 micromol/L (upper quartile of tHcy >16.0 micromol/L) and was inversely correlated with serum folate. Subjects with an adequate intake or serum levels of both folate and B12 were at a reduced risk of being in the highest quartile of tHcy. In both cases, the reduction of high tHcy (upper quartile) risk was found to be greater than expected when subjects with high levels of both vitamins were considered together.

CONCLUSIONS

Adequate folate and cobalamin (both intake and serum levels) act synergistically to decrease the risk of high total plasma homocysteine levels in this elderly population.

Micronutrient Deficiencies as Predisposing Factors for Hypertension in Lacto-Vegetarian Indian Adults

OBJECTIVE

With the increasing knowledge about the antioxidant potential of many micronutrients such as zinc and vitamin C, their roles in oxidative stress related health disorders have been postulated. This study therefore investigated low micronutrient status as a predisposing factor for hypertension in a traditionally lacto-vegetarian population like Indians.

METHODS

Micronutrient profile was assessed in 109 hypertensives with age-gender-socio-economic status matched 115 healthy normotensives (30-58 years of age). Food intakes were estimated through a semi-quantitative food frequency questionnaire. Nutrient intakes were then evaluated by previous estimates of cooked foods from our laboratory. Systolic and diastolic blood pressure (SBP, DBP), age, weight, height, waist and hip circumference, occupation, physical activity, smoking habits were recorded. Fasting blood samples were analyzed for hemoglobin, serum level of glucose, triglycerides, total cholesterol, HDL, ceruloplasmin, plasma level of ascorbic acid, folic acid, retinol, erythrocyte glutathione reductase activity coefficient (EGRAC) and erythrocyte membrane zinc.

RESULTS

There were no significant differences between protein, fat intakes of normal and hypertensive individuals, though intakes of men were higher than those of women (p < 0.05). Intakes of omega-6 fatty acids were higher (p = 0.08) and omega-3 fatty acids were lower in hypertensive men than normotensive men (p = 0.04). Gender differences were also significant for micronutrient intakes except vitamin C and beta-carotene. Intakes of potassium, copper, folic acid and vitamin C were significantly lower in hypertensive individuals than in normotenisves. No significant association was found between occupation or activity level and hypertension (p > 0.2) in these subjects. Conditional logistic regression analysis indicated that intakes of vitamin C, folic acid and zinc were associated with 18% (OR = 1.18, 95% CI:1.08, 1.26), 51% (OR = 1.51, 95% CI 0.94, 2.1) higher odds for hypertension, and 3% lower odds for hypertension (OR = 0.97, 95% CI 0.92, 1.01), respectively. Mean plasma vitamin C and folic acid were significantly higher (p < 0.01), and serum ceruloplasmin and erythrocyte membrane zinc were marginally higher (p = 0.07) in normal than hypertensive subjects. In multivariate linear regression analyses, plasma vitamin C, serum ceruloplasmin and erythrocyte membrane zinc were negatively associated with SBP (p = 0.00001) and plasma vitamin C was negatively associated with DBP (p = 0.0001).

CONCLUSION

Low dietary intakes of vitamin C, folic acid and zinc emerged as the possible risk factors for hypertension. Further, lower levels of plasma vitamin C, erythrocyte membrane zinc and ceruloplasmin were found to be the putative intermediary biomarkers in pathogenesis of hypertension.

The Role of Antioxidant Micronutrients in the Prevention of Diabetic Complications

Diabetes mellitus is associated with an increased production of reactive oxygen species and a reduction in antioxidant defenses. This leads to oxidative stress, which is partly responsible for diabetic complications. Tight glycemic control is the most effective way of preventing or decreasing these complications. Nevertheless, antioxidant micronutrients can be proposed as adjunctive therapy in patients with diabetes. Indeed, some minerals and vitamins are able to indirectly participate in the reduction of oxidative stress in diabetic patients by improving glycemic control and/or are able to exert antioxidant activity. This article reviews the use of minerals (vanadium, chromium, magnesium, zinc, selenium, copper) and vitamins or cofactors (tocopherol [vitamin E], ascorbic acid [vitamin C], ubidecarenone [ubiquinone; coenzyme Q], nicotinamide, riboflavin, thioctic acid [lipoic acid], flavonoids) in diabetes, with a particular focus on the prevention of diabetic complications. Results show that dietary supplementation with micronutrients may be a complement to classical therapies for preventing and treating diabetic complications. Supplementation is expected to be more effective when a deficiency in these micronutrients exists. Nevertheless, many clinical studies have reported beneficial effects in individuals without deficiencies, although several of these studies were short term and had small sample sizes. However, a randomized, double-blind, placebo-controlled, multicenter trial showed that thioctic acid at an oral dosage of 800 mg/day for 4 months significantly improved cardiac autonomic neuropathy in type 2 diabetic patients. Above all, individuals with diabetes should be educated about the importance of consuming adequate amounts of vitamins and minerals from natural food sources, within the constraints of recommended sugar and carbohydrate intake.

Meta-analysis of plasma homocysteine, serum folate, serum vitamin B12, and thermolabile MTHFR genotype as risk factors for retinal vascular occlusive disease

PURPOSE

To assess the role of plasma total homocysteine (tHcy) levels, serum folate and vitamin B(12)levels, and homozygosity for the thermolabile methylenetetrahydrofolate reductase genotype (TT) as risk factors for retinal vascular occlusive disease.

DESIGN

Meta-analysis of literature.

METHODS

A MEDLINE search was performed to identify all published case-control studies of plasma tHcy levels, serum folate and vitamin B(12) levels, and TT genotype in persons with retinal vascular occlusive disease. Main outcome measures included calculation of plasma tHcy, serum folate, and serum vitamin B(12) standard differences and odds ratios (OR) of TT genotype between cases and controls.

RESULTS

In total, 614 patients with all types of retinal vein occlusion had higher plasma tHcy levels than 762 control subjects (standard difference, 0.867; 95% confidence interval [CI] = 0.735, 0.999; P <.001). Plasma tHcy levels were also higher in 154 patients with retinal artery occlusion compared with 358 control subjects (standard difference 1.174; 95% CI = 0.947, 1.402; P <.001). Serum folates, but not vitamin B(12) levels, were lower in 287 patients with retinal vascular occlusion than in the same number of control subjects (standard difference, 0.508; 95% CI = 0.340, 0.675; P <.001; and -0.060; 95% CI = -0.024, 0.104; P =.474, respectively). Similar proportions of 690 patients with retinal vein occlusion and 2754 control subjects demonstrated the TT genotype (OR = 1.332; 95% CI = 0.995, 1.783; P =.054) as did 152 patients with retinal artery occlusions and 435 control subjects (OR = 1.716; 95% CI = 0.977, 3.014; P =.060).

CONCLUSIONS

Retinal vascular occlusion is associated with elevated plasma tHcy levels and low serum folate levels, but not serum vitamin B(12) levels and TT genotype. Until a prospective multicenter trial is undertaken, plasma tHcy levels and serum folate levels should be determined in patients with retinal vascular occlusions, and dietary supplementation with low doses of folate and vitamin B(12) should be considered for affected persons.

Nutritional supplementation with Chlorella pyrenoidosa for mild to moderate hypertension

Pharmacological treatment of hypertension reduces the risk of cardiovascular disease; however, randomized, controlled clinical trials and population studies have also shown that abnormally high blood pressure (BP) can be lowered with diet modification and exercise. The objective of this pilot study was to determine whether daily dietary supplementation with 10 g Chlorella tablets and 100 ml Chlorella extract for 2 months would reduce BP in subjects with a mean sitting diastolic BP (SiDBP) between 90 and 115 mm Hg. Thirty-three people were enrolled and underwent a 4-week washout period from all antihypertensive medications, during which they consumed placebo. At completion of this washout/placebo period, 24 subjects were considered evaluable (i.e., had a SiDBP between 90 and 115 mm Hg) and were continued in the study. After 1 or 2 months of dietary Chlorella supplementation, the average heart rate, sitting systolic BP, and SiDBP changed only slightly; after 2 months of Chlorella consumption, the group's mean SiDBP was 96.5 +/- 6.6. However, a heterogenous response pattern to Chlorella existed, with 25% (6/24) of the subjects achieving their BP goal (SiDBP less than 90 mm Hg). Furthermore, the BP of nonresponders did not increase significantly above washout values. Quality-of-life questionnaires indicated an overall perception that health had significantly improved in conjunction with Chlorella consumption. The results indicate that, for some subjects with mild to moderate hypertension, a daily dietary supplement of Chlorella reduced or kept stable their SiDBP.

Dietary risk markers that contribute to the aetiology of hypertension in black South African children: the THUSA BANA study

Although clinical hypertension occurs less frequently in children than in adults, ample evidence supports the concept that the roots of essential hypertension extend back to childhood. Since little is available in the literature on causal dietary factors of hypertension in children, this study hypothesised that certain dietary factors can be identified as risk markers that might contribute to the aetiology of hypertension in black children. Children aged 10-15 years were randomly selected from 30 schools in the North West Province from 2000 to 2001. These children comprised 321 black males and 373 females from rural to urbanised communities, of which 40 male and 79 female subjects were identified with high-normal to hypertensive blood pressure. Blood pressure was measured with a Finapres apparatus and data were analysed with the Fast Modelflo software program to provide systolic, diastolic and mean blood pressure. A 24-h dietary recall questionnaire and weight and height measurements were taken. In a stepwise regression analysis, the following variables were significantly associated (P < or = 0.05) with blood pressure parameters of hypertensive males: biotin, folic acid, pantothenic acid, zinc and magnesium. Energy, biotin and vitamin A intakes were significantly associated with blood pressure parameters of hypertensive females. No significant dietary markers were indicated for any of the normotensive groups. Dietary intakes of all of these nutrients were well below the dietary reference intakes. In conclusion, the dietary results coupled with the cardiovascular parameters of this study identified folic acid and biotin as risk markers that could contribute to the aetiology of hypertension in black persons. The low intakes of these nutrients, among others, is a matter of serious concern, as is the increasing tendency towards urbanisation.

Connective tissue: Vascular and hematological (blood) support

Connective Tissue (CT) is a ubiquitous component of all major tissues and structures of the body (50% of all body protein is CT), including that of the blood, vascular, muscle, tendon, ligament, fascia, bone, joint, IVD's (intervertebral discs) and skin. Because of its ubiquitous nature, CT is an often overlooked component of any essential nutritional program that may address the structure, and/or function of these tissues. The central role of CT in the health of a virtually all cells, tissues, organs, and organ systems, is discussed. General nutritional CT support strategies, as well as specific CT support strategies that focus on blood, vascular, structural system (eg, muscles, tendons, ligaments, fascia, bone, and joints), integument (skin) and inflammatory and immune mediation will be discussed here and will deal with connective tissue dynamics and dysfunction. An overview of the current scientific understanding and possible options for naturally enhancing the structure and function of CT through the application of these concepts will be discussed in this article, with specific attention on the vascular and hematological systems.

Diet and exercise habits of patients with diabetes, dyslipidemia, cardiovascular disease or hypertension

OBJECTIVE

The objective of this study was to determine whether free-living individuals diagnosed with diabetes, dyslipidemia, cardiovascular disease or hypertension follow standard dietary recommendations for treatment of these diet-modifiable disorders.

METHODS

Data are from 1,782 adult men and women who completed an annual clinic visit as part of a large study of diet and health. Usual dietary intake over the previous month was assessed with a self-administered food frequency questionnaire. Trained staff obtained a detailed medical history and information on health and exercise habits, measured height and weight, and collected a fasting blood specimen to measure total serum cholesterol, triglycerides and carotenoids. Multivariate linear regression was used to test associations of diet-modifiable chronic diseases with diet and exercise habits.

RESULTS

42% of the study sample reported at least one diet-modifiable disease or risk factor for disease. These individuals had higher total serum cholesterol (p < 0.001) and triglycerides (p < 0.001) compared to those without these conditions. Diabetics consumed a greater percent of energy from fat (p < 0.01), and men with hypertension consumed a greater percent energy from saturated fat (p < 0.05) compared to those without these conditions. There were few other differences in dietary intake between diseased and healthy individuals, and on average, all participants had diets that were not consistent with recommended guidelines for prevention or treatment of these diet-modifiable disorders. Forty-six percent of all participants were overweight or obese, and BMI was significantly higher among participants with at least one diet-modifiable disorder (p < 0.001). Healthy and diseased participants exercised about 17 minutes per day, and compared to non-diabetics, persons with diabetes exercised with 25% less intensity (p < 0.05).

CONCLUSION

Participants in this sample with diet-modifiable disorders reported that they are motivated to eat less fat, but most are still overweight or obese, consume a diet high in fat and low in fruits and vegetables and engage in very little physical exercise. New strategies are needed to help patients adopt and maintain healthful dietary practices that will reduce their risk.

Hyperhomocysteinemia and thrombosis

Homocysteine (Hcy) is a sulfhydryl amino acid derived from the metabolic conversion of methionine, which is dependent on vitamins (folic acid, B12, and B6) as cofactors or cosubstrates. In 1969, McCully first reported the presence of severe atherosclerotic lesions in patients with severe hyperhomocysteinemia and hypothesized the existence of a pathogenic link between hyperhomocysteinemia and atherogenesis. Several case-control and cross-sectional studies were consistent with the initial hypothesis of McCully, showing that moderate hyperhomocysteinemia is also associated with heightened risk of occlusive arterial disease. Less consistent results have been reported by prospective cohort studies of subjects who were healthy at the time of their enrollment, whereas prospective cohort studies of patients with overt coronary artery disease or other conditions at risk consistently confirmed the association between moderate hyperhomocysteinemia and cardiovascular morbidity and mortality. More recently, an association between moderate hyperhomocysteinemia and heightened risk of venous thromboembolism has been documented, suggesting that hyperhomocysteinemia might be involved not only in atherogenesis, but also in thrombogenesis. The mechanisms by which hyperhomocysteinemia might contribute to atherogenesis and thrombogenesis are incompletely understood. The mainstay of treatment of hyperhomocysteinemia is folic acid, alone or in combination with vitamin B12 and vitamin B6. Although it is quite clear that vitamins effectively reduce the plasma levels of total homocysteine (tHcy), we do not yet know whether they will decrease the risk of vascular disease. The results of ongoing randomized, placebo-controlled, double-blind trials of the effects of vitamins on the thrombotic risk will help in defining whether the relationship between hyperhomocysteinemia and thrombosis is causal, and will potentially have a dramatic effect in the prevention of thromboembolic events.

Treatment approaches: food first for weight management and health

Many genetic, environmental, behavioral, and cultural factors affect health. Diet is as vital as any of them for preventing disease and promoting well-being. We know that what we eat can lead to premature disability and mortality: to obesity, coronary heart disease, type 2 diabetes, degenerative arthritis, sleep apnea, and other illnesses. Now scientific evidence points to links between dietary patterns and illness. The study of these links is a new approach to understanding the role that diet plays in chronic disease. Initial studies include those on eating patterns and risk of colon cancer. More recently, researchers have investigated all-cause mortality and leading causes of chronic disease. Novel epidemiological approaches include factorial analysis to evaluate dietary patterns and cluster analysis to examine nutrient intake, gender, and weight status across food-pattern clusters. These methods work best within groups to identify major dietary patterns, but not necessarily ideal diets. They may also differ across population groups. The success of the Dietary Approaches to Stop Hypertension and Lyon Diet Heart studies supports the value of dietary pattern analysis. At the same time, the relative failure of single-nutrient studies underscores the need for new methodologies and directions in research.

Reducing cardiovascular disease risk with diet

OBJECTIVE

Past research efforts to determine the influence of the diet on cardiovascular (CV) health have focused on the individual roles of specific dietary components with debatable success. Awareness of the impact and complexity of nutrient interactions has expanded in recent years to include assessment of dietary patterns as they contribute to lower CV disease risk.

RESEARCH METHODS AND PROCEDURES

In a series of multicenter studies, we compared a comprehensive, prepared meal plan, formulated to meet recommended intake levels of macro- and micronutrients, with a self-selected diet based on the exchange system. The three studies comprised adult participants with hypertension, hyperlipidemia, and type 2 diabetes (n = 560, 251, and 330, respectively). The first two studies (10 weeks) varied by the amount of contact with study personnel, and the third study assessed long-term effects over 52 weeks. Outcome measures included: blood pressure, lipid and lipoprotein levels, glycemic control, homocysteine, compliance, quality of life, and weight.

RESULTS

The first study demonstrated significant improvements in all measures, with greater improvements with the prepared meal plan compared with the self-selected diet. The second study, designed to parallel the contact frequency that would occur in a real world clinical setting, also produced significant improvements in multiple CV risk factors. In the long-term study, in addition to sustained improvements in risk factors, significant weight loss was achieved and maintained over the 52 weeks.

DISCUSSION

These trials demonstrate that regular consumption of a nutritionally complete diet offers multiple, concurrent clinical benefits for reducing CV disease risk and body weight.

High prevalence of hyperhomocysteinemia in chronic alcoholism: the importance of the thermolabile form of the enzyme methylenetetrahydrofolate reductase (MTHFR)

Alcoholism is related to malnutrition and low levels of several vitamins that take part in the metabolism of homocysteine. The objective of the study was to analyze the prevalence of hyperhomocysteinemia in patients with heavy alcohol intake and the factors on which it depends. Included in the study were 103 hospitalized heavy drinkers (i.e., patients with an intake of alcohol greater than 80 g per day). Serum homocysteine, folate, and vitamin B(12) levels, plasma vitamin B(6) levels, and CT677 polymorphisms of methylenetetrahydrofolate reductase (MTHFR) were determined. We also recorded the intensity of alcoholism, the status of nutrition, and the existence of liver cirrhosis. Determination of biochemical data was repeated after 15 days of withdrawal. Serum homocysteine levels were found to be significantly elevated, whereas serum folate and plasma B(6) levels were significantly decreased. Serum homocysteine levels were significantly higher in those heavy drinkers who showed the TT polymorphism of MTHFR, with a prevalence of hyperhomocysteinemia of 84.2% in the homozygote TT, 54.3% in the heterozygote CT, and 31.6% in the normal CC genotype. Serum homocysteine inversely correlated with serum folate, serum B(12), and plasma B(6) levels. We did not find any relation between serum homocysteine and intensity of alcoholism, nutritional status, or liver cirrhosis. Serum folate levels were significantly decreased in heavy drinkers, mainly depending on irregular feeding and malnutrition. After 15 days of withdrawal, serum homocysteine levels significantly decreased, whereas folate, B(12), and B(6) levels significantly increased. The conclusion is that heavy drinkers show a high prevalence of hyperhomocysteinemia related to low levels of folate, B(6), and B(12) and to the TT polymorphism of MTHFR.

Inadequate nutrient intakes are common and are associated with low diet variety in rural, community-dwelling elderly

Poor dietary habits and inadequate nutrient intakes are of concern in the elderly. The nutritional characteristics of those who survive to become the oldest are not well defined. Our goal was to describe dietary habits, nutrient intakes and nutritional risk of community-dwelling, rural Iowans, 79 y of age and older. Subjects were interviewed (n = 420) using a standardized format on one occasion in their homes and instructed to complete 3-d diet records (n = 261) after the in-home interview. Standardized interviews assessed demographic information, cognitive function and dietary habits (Nutrition Screening Initiative Checklist). Adequate nutrient intake was defined as consumption of the nutrient's estimated average requirement, 67% adequate intake or 67% recommended dietary allowance. Mean age was 85.2 y, 57% lived alone and 58% were widowed. Subjects completing 3-d diet records were younger, more cognitively intact and less likely to be at nutritional risk than subjects not completing diet records. The percentage of subjects with inadequate intakes of selected nutrients was 75% for folate, 83% for vitamin D and 63% for calcium. Eighty percent of subjects reported inadequate intakes of four or more nutrients. Diet variety was positively associated with the number of nutrients consumed at adequate intakes (r = 0.498), total energy (r = 0.522) and dietary fiber (r = 0.421). Our results suggest that rural, community-dwelling old have inadequate intakes of several nutrients. Recommendations to increase diet variety and consume a nutrient supplement may be necessary for elderly people to achieve adequate nutrient intakes.

Plasmatic homocysteine response to vitamin supplementation in elderly people

Homocysteine (Hcy) increase is now widely accepted as a risk factor for vascular disease. The effects of folic acid (FA) and vitamins B12 and B6 in lowering Hcy have been extensively studied, but there is still little data on the response to FA dietary administration. Our purpose was to evaluate the impact of the diet and the degree of response to different doses of pharmacological FA supplementation. In a prospective, randomized, and simple blind study, 50 elderly subjects were given a 400-microg/day FA diet and were randomly assigned to one of the following treatments: Group I = placebo tablet; Group II = tablet containing 1-mg folic acid, 1-mg B12, and 25-mg B6; and Group III = tablet containing 2.5-mg folic acid and same B6 and B12 doses as Group II. Forty-four subjects completed the study, and their plasmas were evaluated. Hcy concentration significantly decreased even in patients with normal basal values, and there were no differences in the response between individuals receiving diet plus placebo and those receiving diet plus pharmacological supplementation. After the treatment, the mean decrease of plasmatic Hcy levels was 10.8 (9.4, 12.5) micromol/l, geometric mean [95% confidence interval (95% CI)], and particularly, the values for Group I were 10.6 (7.4, 14.8) micromol/l. In 31% of the subjects, the post-treatment Hcy levels were less than or = 5 micromol/l. These results show that a special diet, with or without pharmacological FA and B12 and B6 supplementation, significantly decreases the Hcy levels in elderly people. Therefore, a diet with high contents of FA might have an enormous impact on the morbidity and mortality of atherothrombosis.

The power of food to improve multiple cardiovascular risk factors

Past research efforts to determine the influence of the diet on cardiovascular health have focused on the individual roles of specific dietary components, and have done so with debatable success. Awareness of the impact and complexity of nutrient interactions has expanded in recent years to include assessment of overall dietary patterns as they contribute to lower cardiovascular disease risk. Several large-scale studies have now demonstrated that whereas manipulations of single nutrients may influence some people with selected conditions, it is improving the total dietary profile that will consistently and beneficially effect multiple cardiovascular risk factors including high blood pressure, plasma lipids, hemoglobin A1c, homocysteine, and weight.