Athletes, Endurance Performance, Hemoglobin, Intestinal Health, Iron, Microbiota
Conditions
Keywords
oxidative stress, football
Brief summary
The aim of the study is to characterize the diet and iron status of young female elite football players and examine the relationship between iron intake, iron status, hemoglobin levels, intestinal health and sports performance. In addition, the effects of low-dose iron supplements on iron stores will be investigated and whether such supplementation affects intestinal health, microbiota composition and biomarkers for oxidative stress.
Detailed description
Iron deficiency can lead to fatigue and anemia. Because iron is necessary for the formation of new blood cells (hematopoiesis), it is an extensive practice internationally among athletes to take iron supplements in the belief that this will improve endurance performance and oxygen transport capacity by increasing red blood cell production. Although iron intake in menstruating women has shown to reduce the prevalence of anemia and iron deficiency as well as increasing hemoglobin values and iron stores. However iron supplementation increases the risk of iron excess and can result in undesirable effects such as constipation and abdominal pain as well as negative impact on intestinal epithelial permeability and increase in oxidative stress. Because iron is important for the replication and survival of almost all bacteria, with few exceptions, the intake of iron also affect the composition of the intestinal bacteria. Not surprisingly, both high and low iron levels affect the composition of the microbiota in the gut. It is not known if young menstruating Norwegian female athletes cover their need for iron via the diet or whether extra intake in the form of a low-dose supplement could be beneficial in terms of hemoglobin levels and sports performance. Because iron preparations are not prescription and are sold in pharmacies, health food stores and larger grocery stores, this can lead to uncritical intake of iron. Since the use of iron preparations has been documented to be widespread in foreign sports environments, it is important to both characterize the iron status of Norwegian athletes and at the same time examine the beneficial value of iron supplements on sports performance as well as monitoring effects on microbiota composition and intestinal health. The aim of the study is therefore to characterize the diet and iron status of young female elite football players and examine the relationship between iron intake, iron status, hemoglobin levels, intestinal health and sports performance. In addition, the effects of low-dose iron supplements will be investigated in relation to iron stores, hemoglobin levels and sports performance and whether such supplementation affects intestinal health, microbiota composition and biomarkers for oxidative stress.
Interventions
DIETARY_SUPPLEMENTIron supplement (27mg)
The participants will be randomized to an intervention group or a control group. The intervention group will ingest 27mg iron daily for three months.
Sponsors
Norwegian University of Life Sciences
Norwegian School of Sport Sciences
University of Oslo
Norwegian Olympic Sports Centre
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Masking description
The assessor of outcomes are blinded to group allocation.
Intervention model description
The intervention group will ingest 27 mg iron supplement per day for three months while the control group will not ingest iron supplements.
Eligibility
Sex/Gender
FEMALE
Age
16 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
\- Female elite football players from two selected football clubs
Exclusion criteria
* Pregnancy * Medical conditions that are worsened by taking iron supplements * Already taking iron supplements
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diet composition | 3 months | Diet composition will be assessed using digital 7 day dietary records. |
| Iron intake | 3 months | Iron intake will be calculated based on average daily intake of iron according to the digital 7 day dietary recordings. |
| Serum Iron | 3 months | Iron status will be assessed by analyzing serum iron (µmol/L) |
| Serum transferrin | 3 months | Iron status will be assessed by analyzing serum transferrin (µmol/L) |
| Serum ferritin | 3 months | Iron status will be assessed by analyzing serum ferritin (µg/L) |
| Hemoglobin levels | 3 months | hemoglobin (Hb) (g/dl) will be analyzed in whole blood (EDTA) using an automated hematology analyzer. |
| LPS binding protein | 3 months | -Intestinal health will be measured using biomarkers of intestinal leakage in serum and feces such as sLPS binding protein (LBP) (ug/ml) |
| Neutrophil gelatinase-associated lipocalin | 3 months | -Intestinal health will be measured using biomarkers of intestinal leakage in serum and feces such as fecal neutrophil gelatinase-associated lipocalin (NGAL) (ng/g feces) |
| Serum cytokines | 3 months | -Intestinal health will be measured using serum biomarkers of systemic inflammation (e.g. serum cytokines such as IL-1, IL-6, and TNF-α pg/ml). |
| Sports performance | 3 months | Sports performance specific for football will be be measured using the Yo-Yo Intermittent Recovery Test (YYIR1). |
| Differential counts | 3 months | Differential counts (% of WBC) will be analyzed in whole blood (EDTA) using an automated hematology analyzer. |
| Ferric reducing ability of plasma | 3 months | -Oxidative stress will be assessed measuring the ferric reducing ability of plasma (FRAP) |
| Diacron reactive oxygen metabolites | 3 months | -Oxidative stress will be assessed measuring biomarkers of total oksidativ stress e.g. diacron reactive oxygen metabolites (dROM). |
| Microbiota composition | 3 months | -Microbiota composition will be analyzed mainly using 16S rRNA gene sequencing. The main effect of the intervention on the microbiota will be tested based on crude alpha and beta diversity indices but we will also apply advanced multivariate methods. |
Countries
Norway
Outcome results
None listed