Micronutrients and cancer

Gut microbiome-micronutrient interaction: The key to controlling the bioavailability of minerals and vitamins?

Micronutrients, namely, vitamins and minerals, are necessary for the proper functioning of the human body, and their deficiencies can have dramatic short- and long-term health consequences. Among the underlying causes, certainly a reduced dietary intake and/or poor absorption in the gastrointestinal tract play a key role in decreasing their bioavailability. Recent evidence from clinical and in vivo studies suggests an increasingly important contribution from the gut microbiome. Commensal microorganisms can in fact regulate the levels of micronutrients, both by intervening in the biosynthetic processes and by modulating their absorption. This short narrative review addresses the pivotal role of the gut microbiome in influencing the bioavailability of vitamins (such as A, B, C, D, E, and K) and minerals (calcium, iron, zinc, magnesium, and phosphorous), as well as the impact of these micronutrients on microbiome composition and functionality. Personalized microbiome-based intervention strategies could therefore constitute an innovative tool to counteract micronutrient deficiencies by modulating the gut microbiome toward an eubiotic configuration capable of satisfying the needs of our organism, while promoting general health.

Intestinal microbiota as a route for micronutrient bioavailability

The deficiency of micronutrients, including vitamins and minerals, is estimated to affect two billion people worldwide and can have devastating immediate and long-term consequences. Major causes range from inadequate micronutrient consumption mostly owing to a lack of dietary diversity, to poor nutrient absorption in the gastrointestinal tract as a result of clinical or pathological conditions. Recent studies in model organisms and humans demonstrated that intestinal microbiota plays an important role in the de novo biosynthesis and bioavailability of several micronutrients and might be a major determinant of human micronutrient status. Here, we address the importance of the gut microbiome for maintaining the balance of host vitamins and minerals and explore its potential therapeutic benefits and implications on human health.

Magnesium Supplementation: Effect on the Expression of Inflammation Genes in Erlich's Tumor

Magnesium supplementation may be beneficial for cancer patients due to its action as a modulator of cell proliferation and metabolism and its anti-inflammatory effect. Tumor metabolism can influence the bioavailability and absorption of nutrients, leading to an increase in the individual's nutritional needs. In this work, the effects of supplementing different dosages of magnesium chloride in mice with solid Ehrlich's tumors were investigated by analyzing their hematological, inflammatory and anthropometric biomarkers. Three dosages of magnesium chloride (MgCl₂) were administered for 28 consecutive days. Animal welfare was assessed according to the criteria stipulated by the National Center for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs). The inverted grid method was used to analyze muscle strength and fatigue. Difference in expression of the Tumor Necrosis Factor (TNF-α) and the Growth Transformation Factor (TGF-β1) genes was determined by the 2^-ΔCt method. The hematological evaluation consisted of the erythrogram, white blood cell and platelet counts were used for the hematological evaluation and treatment cytotoxicity. Difference in the expression of the TNF-α and TGF-β genes showed that the group that received a high dose of magnesium had a decrease in TNF-α and RNL, an improvement in well-being with a tendency to increase muscle strength and less tumor progression according to the days of treatment. The group that received a low dosage of magnesium had a smaller tumor volume and a more controlled tumor growth according to the days. The group that received an intermediate dosage presented cytotoxicity.

Exploration and forecasting of behaviours and factors relating to fruit and vegetable intake among seniors in the community

Objective

The present study investigated the current status of fruit and vegetable intake among seniors and assessed the relationship between personal background factors, social psychological factors and environmental factors of the study participants and their fruit and vegetable consumption behaviour.

Design

Research data were collected through individual interviews using a questionnaire developed by the authors. SPSS for Windows 15·0 statistical software was used to process and analyse the data.

Setting

Elderly individuals sampled from all twenty-nine administration units of Keelung City’s Renai District were interviewed.

Subjects

Study participants included 398 residents aged 65 years or older.

Results

On average, study participants ate five daily servings of fruits and vegetables on 2·86 d/week. The important variables influencing fruit and vegetable consumption were education level, outcome expectancy, social support, self-efficacy, frequency of dining out and role modelling. Educated participants consumed more fruits and vegetables than those without education. Outcome expectancy, social support, self-efficacy and role modelling had positive impacts on fruit and vegetable intake, but frequency of dining out had a negative impact on fruit and vegetable intake. The significant predictors of fruit and vegetable intake behaviour were education level, outcome expectancy, social support and frequency of dining out. Among those variables, social support was the most influential factor.

Conclusions

Our findings supported the conclusion that health education strategies to increase fruit and vegetable intake among seniors should include the variables of social support and outcome expectancy.

Dietary, endocrine, and metabolic factors in the development of colorectal cancer

INTRODUCTION

Colorectal cancer is the third cause of death in industrialized countries. Genetic susceptibility and diet are determinant of cancer risk and tumor behavior. Variation in cancer incidence among and within populations with similar dietary patterns suggests that an individual response may reflect interactions with genetic factors, which may modify gene, protein, and metabolite expression patterns. Nutrigenomics, defined as the interaction between nutrition and an individual genome, will likely provide important clues about responders and non-responders to nutritional intervention.

DISCUSSION

Epidemiological and experimental studies suggest a protective role of some normal components of daily diet (fish oil, milk, and vegetables), estrogens, and phytoestrogens in colorectal cancer. The effect of estrogen seems to be mediated by their binding to estrogen receptor beta (ER-β), one of the two estrogen receptors with high affinity for these hormones. Very recently, the demonstration of an involvement of ER-β in the development of adenomatous polyps of the colon has also been documented, suggesting the use of selective ER-β agonists in primary colorectal cancer prevention. Phytoestrogens are plant-derived compounds that structurally and functionally act as estrogen agonists in mammals. They are characterized by a higher binding affinity to ER-β as compared to estrogen receptor alpha (ER-α), the other estrogen receptor subtype. These biological characteristics explain why the administration of phytoestrogens does not produce the classical side effects associated to estrogen administration (cerebro- and cardiovascular accidents, higher incidence of endometrial and breast cancer) and makes these substances potential candidates for colorectal cancer prevention.

Recent advances in understanding the role of diet and obesity in the development of colorectal cancer

Colorectal cancer (CRC) is a major cause of premature death in the UK and many developed countries. However, the risk of developing CRC is well recognised to be associated not only with diet but also with obesity and lack of exercise. While epidemiological evidence shows an association with factors such as high red meat intake and low intake of vegetables, fibre and fish, the mechanisms underlying these effects are only now being elucidated. CRC develops over many years and is typically characterised by an accumulation of mutations, which may arise as a consequence of inherited polymorphisms in key genes, but more commonly as a result of spontaneously arising mutations affecting genes controlling cell proliferation, differentiation, apoptosis and DNA repair. Epigenetic changes are observed throughout the progress from normal morphology through formation of adenoma, and the subsequent development of carcinoma. The reasons why this accumulation of loss of homoeostatic controls arises are unclear but chronic inflammation has been proposed to play a central role. Obesity is associated with increased plasma levels of chemokines and adipokines characteristic of chronic systemic inflammation, and dietary factors such as fish oils and phytochemicals have been shown to have anti-inflammatory properties as well as modulating established risk factors such as apoptosis and cell proliferation. There is also some evidence that diet can modify epigenetic changes. This paper briefly reviews the current state of knowledge in relation to CRC development and considers evidence for potential mechanisms by which diet may modify risk.

Longitudinal assessment of micronutrient intake among African-American and white girls: The National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVE

Low intakes of micronutrients among adolescents may be linked to long-term health risks, especially in African-American girls. This report describes intake of key micronutrients relative to the Dietary Reference Intakes in a sample of African-American and white girls.

DESIGN

Longitudinal analyses used data from 3-day food records collected in the National Heart, Lung, and Blood Institute Growth and Health Study.

SUBJECTS/SETTING

Subjects included 1,166 white and 1,213 African-American girls (aged 9 to 18 years).

MAIN OUTCOME MEASURES

Estimated usual daily intakes of vitamins A, E, C, D, B-6, B-12, magnesium, folate, calcium, and zinc were compared to the Adequate Intake (for vitamin D and calcium) or the Estimated Average Requirement (EAR) (all other micronutrients).

STATISTICAL ANALYSES PERFORMED

Usual daily intake of each micronutrient was estimated. For nutrients with an EAR, the EAR cut-point method was used to assess the prevalence of low nutrient intakes. Mixed models were used to identify age and racial differences in usual daily intake of each nutrient.

RESULTS

African-American girls consumed less vitamin A and D, calcium, and magnesium compared to white girls. Regardless of race, a substantial percentage of girls had intakes below the EAR: vitamin E (81.2% to 99.0%), magnesium (24.0% to 94.5%), folate (46.0% to 87.3%). Intakes of vitamins A, D, and C; calcium; and magnesium decreased across years. As girls aged, there was an increasing proportion with intakes below the EAR for vitamins A, C, B-6, and B-12.

CONCLUSIONS

Food and nutrition professionals should continue to educate adolescent girls, especially those who are African American, about the importance of a nutrient-dense diet for optimum health.

The Influence of Sociodemographic Factors on Patterns of Fruit and Vegetable Consumption in Canadian Adolescents

BACKGROUND

Poor dietary habits may increase risk for obesity and chronic diseases among Canadian adolescents.

OBJECTIVES

The aims of the present study were to: (a) establish the patterns of fruit and vegetable intake by Canadian adolescents, and (b) identify the impact of sociodemographic factors-including age, household income, household education, ethnicity, living arrangement, and location-on the pattern of fruit and vegetable intake in this population.

DESIGN

This is a cross-sectional study using the data from the Canadian Community Health Survey, Cycle 2.1, Public Use File. The survey used questions similar to a food frequency questionnaire.

METHODS

Total fruit and vegetable intake of 18,524 Canadian adolescents (12 to 19 years old) was cross-tabulated between two age groups (12 to 14 years old [n=7,410] and 15 to 19 years old [n=11,114]) by sex, level of household education, total household income, ethnicity, living arrangement, and geographical location.

RESULTS

The data revealed that a 38.3% of Canadian adolescents in this study consumed fruits and vegetables five to 10 times per day; fewer older adolescents (15- to 19-year-olds) reported eating fruits and vegetables at that frequency as compared with the younger subgroup (12- to 14-year-olds) (P<0.001). Household education and income independently had a significant (P<0.001) positive impact on fruit and vegetable consumption. Females reported a significantly (P<0.05) higher frequency of intake than did males. Adolescents living in homes with only one parent reported a significantly (P<0.005) lower frequency of intake, as compared with adolescents living with two parents.

CONCLUSIONS

These results may help to identify adolescent groups at risk for poor eating habits and support the implementation of programs to encourage higher fruit and vegetable intakes.

Folate, vitamin B12 and total homocysteine levels in neonates from Brazil

OBJECTIVE

To determine folates, vitamin B12 and total homocysteine levels among neonates from mothers of low or high socioeconomic status.

DESIGN

We carried out a cross-sectional transversal study comprising 143 neonates from two maternity hospitals in the city of Salvador, Northeast of Brazil. Cord blood samples were obtained at the time of delivery from newborns from low (group 1, n=77) or high (group 2, n=66) socioeconomic status. The vitamin B12 and folates were analyzed by electrochemiluminescence immunoassay and by a competitive test using a natural folate-binding protein (FBP), respectively. Total homocyteine levels were measured by fluorescence polarization immunoassay. Maternal environmental risk factors for pregnancy complications were obtained from all mothers.

RESULTS

Only 2% of women from group 1 received prenatal care/vitamin supplementation, whereas almost all mothers from group 2 (96%) were properly followed. Anemia and/or infections pre- or during pregnancy was more prevalent among mothers of babies from group 1. Folate levels among newborns from group 1 and 2 were 7.38+/-2.71 and 8.83+/-4.06 ng/ml, respectively. No difference in the vitamin B12 levels was determined between groups. In addition, tHcy serum levels were higher among newborns from group 1 compared to those from group 2 (8.54+/-4.06 vs 6.35+/-1.33 micromol/l, respectively; P=0.005).

CONCLUSION

These results demonstrate that unprivileged young woman has limited accesses to prenatal care, present high-risk factors that hamper both maternal and newborn health. Maternal and newborn health status could be improved by simply reinforcing the use of folate-enriched diet. The work presented illustrates the challenges that developing countries have to face in order to provide preventive adequate health care to the population at large.

Awareness and Use of Folic Acid Among Women in the Lower Mississippi Delta

CONTEXT

National and state efforts to increase folic acid awareness and use may not be reaching large segments of the population.

PURPOSE

This study examines folic acid awareness and use among women of childbearing age in a representative, economically at-risk rural sample and identifies factors that influence awareness and use.

METHODS

A cross-sectional random digit dialing telephone survey was completed with a representative sample of 646 women aged 14-45 years in 36 counties of the lower Mississippi Delta. Folic acid awareness and supplement use were estimated by percentages weighted to reflect the 36-county population. Pregnancy intentions and the ability to become pregnant were used to predict awareness and use among a subsample of sexually active women.

FINDINGS

Compared to national samples, Delta women were less likely to have heard of folic acid (75% vs 64%) or to take a regular (5-7 days/wk) folic acid supplement (34% vs 22%). The proportion of women who took regular folic acid supplements was very low among some subgroups: African Americans (14%), those 14-19 years of age (12%), and those with low incomes (13%) and low educational levels (14%). Of the women who reported being sexually active, the ability to become pregnant more than doubled their likelihood of regular supplement use.

CONCLUSIONS

The national folic acid campaign has not reached many women in the rural Mississippi Delta. A new mode of folic acid education is needed that is focused on low-income and young women and women not planning pregnancies. In the Delta and similar geographic regions, health care providers, black church leaders, and youth group leaders could be valuable advocates for folic acid.

Dietary approaches that delay age-related diseases

Reducing food intake in lower animals such as the rat decreases body weight, retards many aging processes, delays the onset of most diseases of old age, and prolongs life. A number of clinical trials of food restriction in healthy adult human subjects running over 2-15 years show significant reductions in body weight, blood cholesterol, blood glucose, and blood pressure, which are risk factors for the development of cardiovascular disease and diabetes. Lifestyle interventions that lower energy balance by reducing body weight such as physical exercise can also delay the development of diabetes and cardiovascular disease. In general, clinical trials are suggesting that diets high in calories or fat along with overweight are associated with increased risk for cardiovascular disease, type 2 diabetes, some cancers, and dementia. There is a growing literature indicating that specific dietary constituents are able to influence the development of age-related diseases, including certain fats (trans fatty acids, saturated, and polyunsaturated fats) and cholesterol for cardiovascular disease, glycemic index and fiber for diabetes, fruits and vegetables for cardiovascular disease, and calcium and vitamin D for osteoporosis and bone fracture. In addition, there are dietary compounds from different functional foods, herbs, and neutraceuticals such as ginseng, nuts, grains, and polyphenols that may affect the development of age-related diseases. Long-term prospective clinical trials will be needed to confirm these diet-disease relationships. On the basis of current research, the best diet to delay age-related disease onset is one low in calories and saturated fat and high in wholegrain cereals, legumes, fruits and vegetables, and which maintains a lean body weight. Such a diet should become a key component of healthy aging, delaying age-related diseases and perhaps intervening in the aging process itself. Furthermore, there are studies suggesting that nutrition in childhood and even in the fetus may influence the later development of aging diseases and lifespan.