Iron and vegetarian diets

Change to a Plant-Based Diet Has No Effect on Strength Performance in Trained Persons in the First 8 Weeks-A 16-Week Controlled Pilot Study

Over the past few years, the number of people who have avoided animal products has been rising steadily. A plant-based diet is associated with a healthier lifestyle and has positive effects on various diseases. More and more healthy active people and performance-orientated athletes are giving up animal products for various reasons, such as for an improved performance or faster regeneration. However, the data in this context are limited. This study aimed to obtain initial findings on the influence of a diet change to veganism on the performance of strength-trained individuals. For this study, a total of 15 omnivorous individuals were recruited. They documented their dietary food intakes over 16 weeks. Every four weeks, the strength performance was tested via a leg press and bench press. In the first 8 weeks, the participants maintained their omnivorous diet, followed by 8 weeks of a vegan dietary phase. In total, 10 subjects participated successfully, and their data were part of the statistical analyses. There was no difference in the absolute and relative strength performance for the leg and bench press after changing to a vegan diet. For the total calorie intake and carbohydrates, only a small treatment effect, but no time effect, was observed. However, for the protein intake, a time and group effect were detected. In addition, the relative protein intake decreased significantly and was lower than the current recommendations for athletes. The results demonstrate that a change to a vegan diet has no beneficial nor negative effect on the strength performance when the total calorie intake and carbohydrate content are covered in the first 8 weeks.

The nutritional profile of plant-based meat analogues available for sale in Australia

AIM

To assess the nutritional quality of plant-based meat analogues in Australia, compared to equivalent meat products, and to assess levels of micronutrient fortification in meat analogues.

METHODS

This cross-sectional study used nutrition composition data for products collected in 2021 from major supermarkets in Australia. Nutritional quality was assessed using the Health Star Rating, energy (kJ), protein (g), saturated fat (g), sodium (mg), total sugars (g), and fibre content (g) per 100 g, and level of food processing using the NOVA classification. Proportion of products fortified with iron, vitamin B₁₂ and zinc were reported. Differences in health star rating and nutrients between food categories were assessed using independent t-tests.

RESULTS

Seven hundred ninety products (n = 132 plant-based and n = 658 meat) across eight food categories were analysed. Meat analogues had a higher health star rating (mean 1.2 stars, [95% CI: 1.0-1.4 stars], p < 0.001), lower mean saturated fat (-2.4 g/100 g, [-2.9 to -1.8 g/100 g], p < 0.001) and sodium content (-132 mg/100 g, [-186 to -79 mg/100 g], p < 0.001), but higher total sugar content (0.7 g/100 g, [0.4-1.1 g/100 g], p < 0.001). Meat analogues and meat products had a similar proportion of ultra-processed products (84% and 89%, respectively). 12.1% of meat analogues were fortified with iron, vitamin B₁₂ and zinc.

CONCLUSION

Meat analogues generally had a higher health star rating compared with meat equivalents, however, the nutrient content varied. Most meat analogues were also ultra-processed and few are fortified with key micronutrients found in meat. More research is needed to understand the health impact of these foods.

Determination of vitamin D, iron and n-3 fatty acids in adolescents with different eating habits

OBJECTIVES

Proper eating habits ensure human health, so it is important to eat a balanced diet and learn the basics of proper eating from an early age. Adolescence is considered very important period for maintaining good health in terms of nutrition.

METHODS

In the study, we monitored the eating habits of 182 adolescents aged 14-19 years with different eating habits (73 vegetarians and 109 nonvegetarians) using a questionnaire on nutrition and determination of selected blood parameters - vitamin D, iron and n-3fatty acids.

RESULTS

Insufficient levels of vitamin D were determined in the whole group of adolescents, regardless of eating habits. Low iron concentrations negatively affect the biosynthesis of long-chain n-3 fatty acids, which was also reflected in our adolescents with alternative diets.

CONCLUSIONS

Based on the obtained results, it is necessary to place emphasis on the composition of the diet in adolescent age.

Placing a Well-Designed Vegan Diet for Slovenes

Interest in vegan diets has increased globally as well as in Slovenia. The quantity of new scientific data requires a thorough synthesis of new findings and considerations about the current reserved position of the vegan diet in Slovenia. There is frequently confusion about the benefits of vegetarian diets that are often uncritically passed on to vegan diets and vice versa. This narrative review aims to serve as a framework for a well-designed vegan diet. We present advice on how to maximize the benefits and minimize the risks associated with the vegan diet and lifestyle. We highlight the proper terminology, present the health effects of a vegan diet and emphasize the nutrients of concern. In addition, we provide guidance for implementing a well-designed vegan diet in daily life. We conducted a PubMed search, up to November 2021, for studies on key nutrients (proteins, vitamin B12, vitamin D, omega-3 long chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), calcium, iron, zinc, iodine and selenium) in vegan diets. Given the limited amount of scientific evidence, we focus primarily on the general adult population. A well-designed vegan diet that includes a wide variety of plant foods and supplementation of vitamin B12, vitamin D in the winter months and potentially EPA/DHA is safe and nutritionally adequate. It has the potential to maintain and/or to improve health. For physically active adult populations, athletes or individuals with fast-paced lifestyles, there is room for further appropriate supplementation of a conventional vegan diet according to individuals' health status, needs and goals without compromising their health. A healthy vegan lifestyle, as included in government guidelines for a healthy lifestyle, includes regular physical activity, avoidance of smoking, restriction of alcohol and appropriate sleep hygiene.

The Safe and Effective Use of Plant-Based Diets with Guidelines for Health Professionals

Plant-based diets, defined here as including both vegan and lacto-ovo-vegetarian diets, are growing in popularity throughout the Western world for various reasons, including concerns for human health and the health of the planet. Plant-based diets are more environmentally sustainable than meat-based diets and have a reduced environmental impact, including producing lower levels of greenhouse gas emissions. Dietary guidelines are normally formulated to enhance the health of society, reduce the risk of chronic diseases, and prevent nutritional deficiencies. We reviewed the scientific data on plant-based diets to summarize their preventative and therapeutic role in cardiovascular disease, cancer, diabetes, obesity, and osteoporosis. Consuming plant-based diets is safe and effective for all stages of the life cycle, from pregnancy and lactation, to childhood, to old age. Plant-based diets, which are high in fiber and polyphenolics, are also associated with a diverse gut microbiota, producing metabolites that have anti-inflammatory functions that may help manage disease processes. Concerns about the adequate intake of a number of nutrients, including vitamin B12, calcium, vitamin D, iron, zinc, and omega-3 fats, are discussed. The use of fortified foods and/or supplements as well as appropriate food choices are outlined for each nutrient. Finally, guidelines are suggested for health professionals working with clients consuming plant-based diets.

Recommendations and Nutritional Considerations for Female Athletes: Health and Performance

Optimal nutrition is an important aspect of an athlete’s preparation to achieve optimal health and performance. While general concepts about micro- and macronutrients and timing of food and fluids are addressed in sports science, rarely are the specific effects of women’s physiology on energy and fluid needs highly considered in research or clinical practice. Women differ from men not only in size, but in body composition and hormonal milieu, and also differ from one another. Their monthly hormonal cycles, with fluctuations in estrogen and progesterone, have varying effects on metabolism and fluid retention. Such cycles can change from month to month, can be suppressed with exogenous hormones, and may even be manipulated to capitalize on ideal timing for performance. But before such physiology can be manipulated, its relationship with nutrition and performance must be understood. This review will address general concepts regarding substrate metabolism in women versus men, common menstrual patterns of female athletes, nutrient and hydration needs during different phases of the menstrual cycle, and health and performance issues related to menstrual cycle disruption. We will discuss up-to-date recommendations for fueling female athletes, describe areas that require further exploration, and address methodological considerations to inform future work in this important area.

Iodine Excretion and Intake in Women of Reproductive Age in South Australia Eating Plant-Based and Omnivore Diets: A Pilot Study

Women consuming a strictly vegan/plant-based diet may be at increased risk of low iodine intake due to avoidance of animal products containing iodine. The aim of this pilot study was to determine the iodine excretion and intake in women consuming vegan/plant based diets compared with women consuming omnivore diets. Fifty-seven women (n = 31 plant-based, n = 26 omnivores), provided two spot urine samples to assess urinary iodine concentration (UIC). Two days of dietary intake were also recorded by participants. As the data were not normally distributed results are reported as median (IQR). UIC was significantly different between groups, 44 (26-66) µg/L in the vegan/plant-based group versus 64 (40-88) µg/L in omnivores (p < 0.05). UIC did not meet the >100 µg/L level recommended by the World Health Organization. Iodine intake was also significantly different, 78 (62-91) µg/day in the vegan/plant-based group and 125 (86-175) µg/day in the omnivores (p = 0.000). Iodine intake and bread intake were correlated with iodine excretion (CC 0.410-4.11, p = 0.003). These data indicate iodine insufficiency in both groups of women as the median values were below the minimum WHO recommendation. A larger study assessing iodine excretion in the Australian women of reproductive age who are not pregnant or breastfeeding is needed to confirm these findings.

Iron-Enriched Nutritional Supplements for the 2030 Pharmacy Shelves

Iron deficiency (ID) affects people of all ages in many countries. Due to intestinal blood loss and reduced iron absorption, ID is a threat to IBD patients, women, and children the most. Current therapies can efficiently recover normal serum transferrin saturation and hemoglobin concentration but may cause several side effects, including intestinal inflammation. ID patients may benefit from innovative nutritional supplements that may satisfy iron needs without side effects. There is a growing interest in new iron-rich superfoods, like algae and mushrooms, which combine antioxidant and anti-inflammatory properties with iron richness.

Dietary Intake, Body Composition and Iron Status in Experienced and Elite Climbers

Climbing has developed into a popular recreational and elite sport, evidenced by a growing number of licenced competition athletes, and the acceptance into the Olympic calendar for Tokyo 2020. A nutritional assessment, including the evaluation of anthropometric and biochemical data, has not been previously reported in climbing athletes. Therefore, the aim of this study was to assess the dietary intake, body composition, and iron status in experienced climbers, across a range of performance levels. Forty climbers (n = 20 male, n = 20 female; 8.8 ± 6.6 years' experience; BMI 21.6 ± 1.7) aged 18–46 (30.3 ± 6.7 years) participated in the study. Dietary intake was recorded in a 3-days diet diary. Body composition was assessed using a skinfold profile and iron status via blood markers. Mean energy intake was 2154.6 ± 450 kcal·day⁻¹, with 30% of male climbers and 5% of female climbers failing to meet predicted resting metabolic rate. Furthermore, 77.5% of participants failed to meet a predicted energy requirement to support a “moderate” training programme. There were no significant correlations between daily energy intake and exercise volume. Mean intake of carbohydrate, protein and fat was 3.7 ± 0.9 g·kg⁻¹·day⁻¹, 1.6 ± 0.5 g·kg⁻¹·day⁻¹, and 1.4 ± 0.4 g·kg⁻¹·day⁻¹, respectively, with no significant difference between genders. Approximately 17% of males (n =3) and 45% of females (n = 9) had a sub-optimal iron status. Thirty percent of females met the classification criteria for iron deficiency. Mean serum ferritin was significantly greater in males, compared to females (102.7 ± 54.9 vs. 51.4 ± 24.2 μg·L⁻¹; p ≤ 0.01) and significantly lower in vegan/vegetarians vs. omnivores, in female climbers only (33.2 ± 14.8 vs. 57.5 ± 24 μg·L⁻¹; p = 0.05). No significant differences were observed between climbing ability groups (intermediate-advanced/elite-higher elite) for body composition, dietary intake, or iron status, for males or females. These findings suggest that experienced climbers are at risk of energy restriction and iron deficiency, therefore, routine assessment of nutritional status is warranted. Future research should consider iron status in relation to energy availability and investigate additional factors which may predispose this population to iron deficiency, as well as the risk of relative energy deficiency in sport (RED-S).

Food Pattern Modeling as an Alternative Assessment Method to Multiday Dietary Recalls for Iron-Related Nutrients: A Proof-of-Concept Study

There are barriers to in-depth memory-based dietary assessment techniques in community-based research. Food pattern modeling may be an alternative method to traditional assessment techniques. The objective of this study was to pilot a comparison of food pattern modeling to 24 h diet recalls for predicting hematological outcomes of iron status. Data from 3-24 h dietary recalls in 27 women were analyzed by two methods: mean dietary intake estimates or food pattern modeling. Food pattern modeling was used to determine the total inventory of foods consumed with iron, phytate, or ascorbic acid or iron-phytate ratios. Each variable was analyzed for its relationship to hemoglobin, ferritin, and acute iron absorption from a meal challenge study by creating receiver operating characteristic (ROC) curves. There were no differences in ROC curves or diagnostic accuracies between food pattern modeling or mean dietary intake estimates for iron, vitamin C, phytate, or phytate-iron ratios for estimating hemoglobin or ferritin values (p > 0.05). Food pattern modeling was inferior to mean dietary estimates for acute iron absorption, suggesting that more detailed methods may be necessary for studies with sensitive or acute dietary measurement outcomes. Food pattern modeling for total iron, vitamin C, phytate, and phytate-iron ratios may be comparable to detailed memory-based recalls for larger studies assessing the impact of foods on iron status.

Altered nutrient status reprograms host inflammation and metabolic health via gut microbiota

The metabolism of macro- and micronutrients is a complex and highly regulated biological process. An imbalance in the metabolites and their signaling networks can lead to nonresolving inflammation and consequently to the development of chronic inflammatory-associated diseases. Therefore, identifying the accumulated metabolites and altered pathways during inflammatory disorders would not only serve as "real-time" markers but also help in the development of nutritional therapeutics. In this review, we explore recent research that has delved into elucidating the effects of carbohydrate/calorie restriction, protein malnutrition, lipid emulsions and micronutrient deficiencies on metabolic health and inflammation. Moreover, we describe the integrated stress response in terms of amino acid starvation and lipemia and how this modulates new age diseases such as inflammatory bowel disease and atherosclerosis. Lastly, we explain the latest research on metaflammation and inflammaging. This review focuses on multiple signaling pathways, including, but not limited to, the FGF21-β-hydroxybutryate-NLRP3 axis, the GCN2-eIF2α-ATF4 pathway, the von Hippel-Lindau/hypoxia-inducible transcription factor pathway and the TMAO-PERK-FoxO1 axis. Additionally, throughout the review, we explain how the gut microbiota responds to altered nutrient status and also how antimicrobial peptides generated from nutrient-based signaling pathways can modulate the gut microbiota. Collectively, it must be emphasized that metabolic starvation and inflammation are strongly regulated by both environmental (i.e., nutrition, gut microbiome) and nonenvironmental (i.e., genetics) factors, which can influence the susceptibility to inflammatory disorders.

Analysis of Heme and Non-Heme Iron Intake and Iron Dietary Sources in Adolescent Menstruating Females in a National Polish Sample

Iron intake and heme/non-heme iron proportions are crucial for iron deficiency anemia prevention. Women of childbearing age are indicated by World Health Organization as the primary target group, but maintaining iron balance is particularly challenging for adolescents. The aim of the presented study was to analyze heme and non-heme iron intake and dietary sources in adolescent menstruating females in a national Polish sample. The study was conducted in a representative sample of adolescents (aged 15-20) who were recruited from all regions of Poland based on secondary school sampling (random quota sampling), with 1385 female adolescents being included in the sample. The iron intake was assessed using the previously validated IRONIC-FFQ (IRON Intake Calculation-Food Frequency Questionnaire). The intakes of iron, heme iron, non-heme iron, and iron from food product groups were assessed and compared with those of male adolescents (n = 1025) who were recruited from the same schools, as well as between sub-groups stratified by age, body mass index, anemia history, following vegetarian diet, applying iron supplementation and school type. Compared with male individuals, females were characterized by a lower intake of all forms of iron. It was stated that non-heme iron intake was highest in younger ones, overweight ones, vegetarian ones, and comprehensive school students. Female adolescents with anemia history were characterized by similar iron intake as others. For the target group, there is inadequate nutritional education and a necessity to broaden the knowledge about specific sources of iron.

Iron considerations for the athlete: a narrative review

Iron plays a significant role in the body, and is specifically important to athletes, since it is a dominant feature in processes such as oxygen transport and energy metabolism. Despite its importance, athlete populations, especially females and endurance athletes, are commonly diagnosed with iron deficiency, suggesting an association between sport performance and iron regulation. Although iron deficiency is most common in female athletes (~ 15-35% athlete cohorts deficient), approximately 5-11% of male athlete cohorts also present with this issue. Furthermore, interest has grown in the mechanisms that influence iron absorption in athletes over the last decade, with the link between iron regulation and exercise becoming a research focus. Specifically, exercise-induced increases in the master iron regulatory hormone, hepcidin, has been highlighted as a contributing factor towards altered iron metabolism in athletes. To date, a plethora of research has been conducted, including investigation into the impact that sex hormones, diet (e.g. macronutrient manipulation), training and environmental stress (e.g. hypoxia due to altitude training) have on an athlete's iron status, with numerous recommendations proposed for consideration. This review summarises the current state of research with respect to the aforementioned factors, drawing conclusions and recommendations for future work.

Iron Status of Vegetarian Adults: A Review of Literature

The goal of this study was to review published data on iron status among vegetarian adults. Thirteen original articles met the inclusion criteria. Among female vegetarians, the percentage of the sample with ferritin <12 µg/L or <12 ng/mL ranged from 12% to 79%. An inadequate hemoglobin concentration ranged from 6% to 30.3%. Among males, the range of ferritin <12 µg/L across studies was from 1.7% to 29%. The prevalence of hemoglobin below deficiency cutoff ranged from 0% to 15.3%. A higher percentage of vegetarian females, compared to nonvegetarian participants, had ferritin below deficiency cutoff in all but one study (34% vs 0%, 47% vs 42%, 18% vs 13%, 27.8% vs 6.5% among Catholic nuns and 19.4% among college students, 79% Indian, and 56% Caucasian vegetarian vs 27% of nonvegetarian). Serum ferritin was lower in male vegetarians than male nonvegetarians in each study (11% among vegans and 21% among vegetarians compared to 6% and 7% among high and moderate meat consumers, 3% of vegetarians, and 25% vegans vs 0% of nonvegetarians, 29% vs 7%, 9% vs 0%). Vegetarians have a high prevalence of depleted iron stores. A higher proportion of vegetarians, compared to nonvegetarians, had iron deficiency anemia. This is especially true for premenopausal vegetarian women.

Risk factors and birth outcomes of anaemia in early pregnancy in a nulliparous cohort

BACKGROUND

Anaemia in pregnancy is a major public health and economic problem worldwide, that contributes to both maternal and fetal morbidity and mortality.

OBJECTIVE

The aim of the study was to calculate the prevalence of anaemia in early pregnancy in a cohort of 'low risk' women participating in a large international multicentre prospective study (n = 5 609), to identify the modifiable risk factors for anaemia in pregnancy in this cohort, and to compare the birth outcomes between pregnancies with and without anaemia in early gestation.

METHODS

The study is an analysis of data that were collected prospectively during the Screening for Pregnancy Endpoints study. Anaemia was defined according to the World Health Organization's definition of anaemia in pregnancy (haemoglobin < 11g/dL). Binary logistic regression with adjustment for potential confounders (country, maternal age, having a marital partner, ethnic origin, years of schooling, and having paid work) was the main method of analysis.

RESULTS

The hallmark findings were the low prevalence of anaemia (2.2%), that having no marital partner was an independent risk factor for having anaemia (OR 1.34, 95% CI 1.01-1.78), and that there was no statistically significant effect of anaemia on adverse pregnancy outcomes (small for gestational age, pre-tem birth, mode of delivery, low birth weight, APGAR score < 7 at one and five minutes). Adverse pregnancy outcomes were however more common in those with anaemia than in those without.

CONCLUSION

In this low risk healthy pregnant population we found a low anaemia rate. The absence of a marital partner was a non-modifiable factor, albeit one which may reflect a variety of confounding factors, that should be considered for addition to anaemia's conceptual framework of determinants. Although not statistically significant, clinically, a trend towards a higher risk of adverse pregnancy outcomes was observed in women that were anaemic in early pregnancy.