Serum concentration and dietary intake of vitamins A and E in low-income South African elderly

Vitamin E and cardiovascular diseases: an interest to public health?

Cardiovascular diseases (CVD) are the leading cause of death worldwide. From this perspective, the role of vitamin E and its metabolites in preventing CVD has been studied, being supported by the findings that low vitamin E concentrations are associated with an increased risk of cardiovascular events. Despite this, no studies have analysed the co-existence of vitamin E deficiency (VED) and CVD on the basis of population studies. Facing that, this study summarises information on the relationship between vitamin E status and CVD, providing a basis for understanding the determining and protective factors for its development. VED may be a public health problem since it has been observed to vary from 0·6% to 55·5% worldwide, with higher percentages in Asia and Europe, where CVD mortality rates stand out. Intervention studies with α-tocopherol supplementation do not confirm cardioprotective action of vitamin E, which may reflect that α-tocopherol alone does not provide cardiovascular protection to individuals, but the consumption of all isomers found in food. Considering that low concentrations of α-tocopherol can lead to a higher susceptibility to diseases involving oxidative stress in the population, in addition to the high and growing prevalence of CVD and VED, it is essential to investigate or reinterpret the mechanisms of action of vitamin E and its metabolites in the cardiovascular process to better understand the co-existence of CVD and VED. It is also important to implement public health policies and programmes aimed at promoting the consumption of natural food sources of vitamin E and healthy fats.

Prevalence of vitamin E inadequacy, dietary intake and sources of alpha-tocopherol, and predictors of alpha- and gamma-tocopherol status in adolescent girls in Central Mozambique

An adequate alpha-tocopherol status is important for females at reproductive age. We studied the dietary intake and sources of alpha-tocopherol and alpha- and gamma-tocopherol status indicators in 14-19-year-old girls in Central Mozambique. We also explored factors associated with alpha- and gamma-tocopherol status. The participants (n 508) were from the cross-sectional ZANE Study that was conducted in 2010. We recruited two separate samples, one in January-February and the other in May-June. We collected venous blood samples and conducted 24 h dietary recall interviews. At the time of blood sampling, 11 % of participants were pregnant and 10 % were lactating. In the total sample, both seasons combined, the median intake of alpha-tocopherol was 6⋅7 mg/d, the mean plasma alpha- and gamma-tocopherol concentrations were 13⋅5 and 0⋅75 μmol/l, respectively, and the prevalence of vitamin E inadequacy (alpha-tocopherol <12 μmol/l) was 36⋅7 % (95 % CI: 31⋅9-42⋅0 %). Season and lactation status were significant predictors of alpha-tocopherol status regardless of which the three indicators (plasma concentration, alpha-tocopherol:total cholesterol ratio, gamma-tocopherol:alpha-tocopherol ratio) were used. Being a lactating mother was negatively associated and having a blood sample taken in January-February, when the main sources of alpha-tocopherol were mango and dark green leafy vegetables, was positively associated with alpha-tocopherol status. In conclusion, vitamin E inadequacy was common in Central Mozambique, and the status may fluctuate due to seasonal changes in the diet. We suggest that lactating mothers are specifically at risk of poor alpha-tocopherol status in resource-poor settings.

The low prevalence rate of vitamin E deficiency in urban adults of Wuhan from central China: findings from a single-center, cross-sectional study

Background

Vitamin E is an essential nutrient in human body famous for its antioxidant and non-antioxidant functions. However, little is known about vitamin E deficiency status in urban adults of Wuhan from central China. Our aim is to describe the distribution of both circulating and lipid-adjusted serum vitamin E concentration in urban adults of Wuhan.

Methods

We hypothesized that the prevalence rate of vitamin E deficiency would be low in Wuhan in consideration of the Chinese food composition. A cross-sectional study with 846 adults was performed in a single-center. Concentrations of vitamin E were measured by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS).

Results

The median (interquartile range, IQR) of serum vitamin E concentration was 27.40 (22.89–33.20) μmol/L while that of serum vitamin E concentration adjusted by total cholesterol or the sum of cholesterol (TC) and triglyceride (TG) (the sum of cholesterol and triglyceride, TLs) were 6.20 (5.30–7.48) and 4.86 (4.10–5.65) mmol/mol, respectively. No significant difference of the circulating and TC-adjusted vitamin E concentration was found between male and female except for vitamin E/TLs. However, concentrations of vitamin E increased significantly (r = 0.137, P < 0.001) with age, but lipid-adjusted concentrations of vitamin E did not. On analysis of risk factors, the subjects characterized by hypercholesterolemia are more likely to exhibit higher circulating but lower lipid-adjusted vitamin E level due to adequacy of the serum carriers for delivery of vitamin E. Only 0.47% of the population were below 12 μmol/L of vitamin E defined as functional deficiency.

Conclusion

The prevalence rate of vitamin E deficiency in urban adults of Wuhan is low, which is important and useful to clinicians for clinical decision-making in public health practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-023-01103-9.

Prevalence and Factors Associated with Food Insecurity among Older Adults in Sub-Saharan Africa: A Systematic Review

Food insecurity has been undermining the health and well-being of a growing number of older adults in Sub-Saharan Africa. This review aimed to examine the prevalence of food insecurity and the related contributing factors of food insecurity among older adults in Sub-Saharan Africa. We used PubMed, Scopus, ScienceDirect, and Web of Science Core Collection as our search engines and included 22 articles for data extraction. Prevalence of severe and moderate food insecurity in households with older adults ranged from 6.0 to 87.3% and from 8.3 to 48.5%, respectively. Various socio-economic (e.g., low education level, being widowed, low income, lower wealth position of households, living in a rental house, living in rural areas, lack of social grants or pensions), demographic (e.g., female, Black racial group, larger family size), and health and nutrition status-related (e.g., self-reported poor health status, having a functional and mobility-related disability, psychological disorders) factors influence food insecurity in older adults in Sub-Saharan Africa. The findings of this review can help stakeholders to prioritize the issue of food insecurity, design and implement policies and programs to improve food security among older adults in Sub-Saharan Africa.

Association of physical activity, vitamin E levels, and total antioxidant capacity with academic performance and executive functions of adolescents

BACKGROUND

Although various studies have shown the effect of vigorous physical activity on academic achievements, no studies have investigated the effect of vitamin E levels on academic performance. The present study aimed to assess the association between physical activity, vitamin E levels and total antioxidant capacity on the academic performance and executive functions of adolescents aged 15-18 years.

METHODS

The physical activity of participants was assessed according to the time spent engaging in moderate and intense exercise programs. Participants were classified into three groups representing mild, moderate, and high activity. Serum total antioxidant capacity was measured using a colorimetric assay kit. Vitamin E was estimated by the α- and γ-tocopherol levels in fasting serum samples using high-performance liquid chromatography paired with a diode array detector. School grades (ranging from 1.0, very poor; to 10.0, outstanding) were obtained at the end of the academic year to evaluate academic performance and executive functions.

RESULTS

A total of 120 school students (mean age 16.36 ± 0.77 years; 70 boys, 50 girls) participated in the study. Academic performance was higher for students classified as moderately or highly active compared with those in the mild activity group. Serum levels of vitamin E, total antioxidant capacity, and leisure-time physical activity were also higher in the moderate and high activity groups. There was a significant correlation between age, gender, body mind index, α- and γ-tocopherol, total antioxidant capacity, leisure-time physical activity and academic performance.

CONCLUSIONS

The academic performance and executive function scores were found to be positively correlated with age, gender, α- and γ-tocopherol, total antioxidant capacity, and physical activity; and were negatively correlated with body mind index. Our findings indicate that physical activity should be promoted during and after school hours, along with a healthy balanced diet including vitamin E.

How dietary intake has been assessed in African countries? A systematic review

BACKGROUND

Dietary patterns are often considered as one of the main causes of non-communicable diseases worldwide. It is of utmost importance to study dietary habits in developing countries since this work is scarce.

OBJECTIVE

To summarize the most recent research conducted in this field in African countries, namely the most used methodologies and tools.

METHODS

A systematic review was conducted on MEDLINE®/PubMed, aiming to identify scientific publications focused on studies of dietary intake of different African populations, in a ten-year period. Papers not written in English/Portuguese/Spanish, studies developed among African people but not developed in African countries, studies aiming to assess a particular nutrient/specific food/food toxin and studies that assessed dietary intake among children were excluded.

FINDINGS

Out of 99 included studies, the 24-hour recall and the food-frequency questionnaire were the most used dietary intake assessment tools, used to assess diet at an individual level. It was also observed that often country-unspecific food composition databases are used, and the methodologies employed are poorly validated and standardized.

CONCLUSIONS

There is an emergent need to improve the existing food databases by updating food data and to develop suitable country-specific databases for those that do not have their own food composition table.

A preliminary study on the effects of star fruit consumption on antioxidant and lipid status in elderly Thai individuals

OBJECTIVE

The aims of this preliminary study were to evaluate the antioxidant and lipid status before and after star fruit juice consumption in healthy elderly subjects, and the vitamins in star fruit extracts.

METHODS

A preliminary designated protocol was performed in 27 elderly individuals with a mean (±SD) age of 69.5±5.3 years, by planning a 2-week control period before 4 weeks of consumption of star fruit twice daily. Oxidative stress parameters such as total antioxidant capacity, glutathione, malondialdehyde, protein hydroperoxide, multivitamins such as l-ascorbic acid (Vit C), retinoic acid (Vit A), and tocopherol (Vit E), and the lipid profile parameters such as cholesterol, triglyceride, high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C) were analyzed. Moreover, Vit C, Vit A, and Vit E levels were evaluated in the star fruit extracts during the 4-week period.

RESULTS

In the 2-week control period, all parameters showed no statistically significant difference; after 4 weeks of consumption, significant improvement in the antioxidant status was observed with increased total antioxidant capacity and reduced malondialdehyde and protein hydroperoxide levels, as well as significantly increased levels of Vit C and Vit A, when compared to the two-time evaluation during the baseline periods. However, glutathione and Vit E showed no statistical difference. In addition, the HDL-C level was higher and the LDL-C level was significantly lower when compared to both baseline periods. But the levels of triglyceride and cholesterol showed no difference. Vit C and Vit A were identified in small quantities in the star fruit extract.

CONCLUSION

This preliminary study suggested that consumption of star fruit juice twice daily for 1 month improved the elderly people's antioxidant status and vitamins, as well as improved the lipoproteins related to Vit C and Vit A in the star fruit extract.

Genome-wide association study and pathway-level analysis of tocochromanol levels in maize grain

Tocopherols and tocotrienols, collectively known as tocochromanols, are the major lipid-soluble antioxidants in maize (Zea mays L.) grain. Given that individual tocochromanols differ in their degree of vitamin E activity, variation for tocochromanol composition and content in grain from among diverse maize inbred lines has important nutritional and health implications for enhancing the vitamin E and antioxidant contents of maize-derived foods through plant breeding. Toward this end, we conducted a genome-wide association study of six tocochromanol compounds and 14 of their sums, ratios, and proportions with a 281 maize inbred association panel that was genotyped for 591,822 SNP markers. In addition to providing further insight into the association between ZmVTE4 (γ-tocopherol methyltransferase) haplotypes and α-tocopherol content, we also detected a novel association between ZmVTE1 (tocopherol cyclase) and tocotrienol composition. In a pathway-level analysis, we assessed the genetic contribution of 60 a priori candidate genes encoding the core tocochromanol pathway (VTE genes) and reactions for pathways supplying the isoprenoid tail and aromatic head group of tocochromanols. This analysis identified two additional genes, ZmHGGT1 (homogentisate geranylgeranyltransferase) and one prephenate dehydratase parolog (of four in the genome) that also modestly contribute to tocotrienol variation in the panel. Collectively, our results provide the most favorable ZmVTE4 haplotype and suggest three new gene targets for increasing vitamin E and antioxidant levels through marker-assisted selection.

Nutritional vulnerability of older persons living in urban areas of Lake Victoria Basin in East Africa: a cross sectional survey

The aim of this study was to (1) determine the prevalence of malnutrition and (2) investigate factors affecting nutritional status of older persons living in urban areas of Lake Victoria Basin. The prevalence of underweight was 16.5%, with men (24.1%) being significantly more likely to be underweight (P < 0.05) than women (12.3%). Overall, 61.2% had normal body mass indices, 13.2% were overweight, and 9.1% were obese. Energy intake was low (1596.3-1630.5 Kcal), with only 22% and 38% of men and women, respectively, meeting their daily requirements. Protein intake was adequate in more than half of men and women. Vitamin A, iron, and zinc intakes were moderate, while calcium intake was low (P < 0.05). Inadequate food access, poor health, living arrangements, and poor eating patterns were the main nutritional risk factors. There is a need to plan nutrition programs that can improve living conditions, health, and nutritional status of older adults in these urban areas of the Lake Victoria Basin.

Genome-wide association studies identified three independent polymorphisms associated with α-tocopherol content in maize kernels

Tocopherols are a class of four natural compounds that can provide nutrition and function as antioxidant in both plants and animals. Maize kernels have low α-tocopherol content, the compound with the highest vitamin E activity, thus, raising the risk of vitamin E deficiency in human populations relying on maize as their primary vitamin E source. In this study, two insertion/deletions (InDels) within a gene encoding γ-tocopherol methyltransferase, Zea mays VTE4 (ZmVTE4), and a single nucleotide polymorphism (SNP) located ~85 kb upstream of ZmVTE4 were identified to be significantly associated with α-tocopherol levels in maize kernels by conducting an association study with a panel of ~500 diverse inbred lines. Linkage analysis in three populations that segregated at either one of these three polymorphisms but not at the other two suggested that the three polymorphisms could affect α-tocopherol content independently. Furthermore, we found that haplotypes of the two InDels could explain ∼33% of α-tocopherol variation in the association panel, suggesting ZmVTE4 is a major gene involved in natural phenotypic variation of α-tocopherol. One of the two InDels is located within the promoter region and associates with ZmVTE4 transcript level. This information can not only help in understanding the underlying mechanism of natural tocopherol variations in maize kernels, but also provide valuable markers for marker-assisted breeding of α-tocopherol content in maize kernels, which will then facilitate the improvement of maize as a better source of daily vitamin E nutrition.

Vitamin E deficiency in developing countries

In addition to its role as a potent antioxidant, vitamin E is involved in a wide range of physiological processes, ranging from immune function and control of inflammation to regulation of gene expression and cognitive performance. Results from multiple studies suggest that poor nutritional status and higher prevalence of other oxidative stressors such as malaria and HIV infection predispose populations in developing countries for vitamin E deficiency. Although direct comparison between study outcomes is complicated by varied definitions of vitamin E deficiency, data trends indicate that children and the elderly are more vulnerable age groups and that men may be at higher risk for deficiency than women. Public health initiatives aimed at improving the vitamin E status of high-risk populations in developing countries would be prudent to counteract oxidative stress, improve immune function, and protect against neurologic and cognitive deficits. Additional research is needed to establish dose-response relationships of various interventions and to develop cost-effective, culturally-appropriate, and targeted programs.