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Apr-17-2014

Iron Supplements Boost Performance

 

There's been a lot of controversy about taking iron supplements with most of the controversy being polarized into two groups, those that insist iron supplements are necessary and those that insist that they're not. Of course and as usual the truth lies somewhere in between. In some cases they're beneficial and in others they may actually be harmful.

 

The main objection to iron supplementation is that it can increase iron stores and lead to increased oxidative stress and inflammation in the body which in turn may increase the incidence of cardiovascular problems, diabetes and cancer (see abstracts below). Another objection is that iron supplements are necessary as you can get all the iron you need from your diet. And finally there are those that feel that there are no definitive studies that show that iron supplementation increases athletic performance.

 

Even though these can be valid objections, studies have shown that many serious athletes are iron deficient and thus would benefit from iron supplementation (see abstract below re: deficiency in professional athletes). A new study (see abstract below re: iron supplementation benerits physical performance), the first to confirm the effects of iron supplements on performance, has found that iron supplementation in women results in an improvement in exercise performance both in terms or efficiency and highest level of exertion. The study was a systematic review and analysis of iron supplementation’s effects on exercise performance in pre-menopausal women.

 

As far as potential toxicity from iron overload there are ways to make sure that doesn't happen. First of all blood tests, ranging from a simple hemoglobin and blood analysis, to more sophisticated testing involving the determinations of iron in the body, can be done if iron overload is suspected. As well, there have been several studies showing that manipulating the diet can mitigate the toxic effects of iron overload, including milk proteins (see abstracts below). The mitigating effects of milk proteins is important since many athletes and those into fitness and improving body composition take protein supplements.

 

The bottom line is that iron, up to a point, is beneficial for both men and women, and especially so for those that are iron deficient (but not necessarily anemic). But iron overload can cause problems even though these problems can be lessened by various methods including increasing dietary protein and

 

As such, this is the rationale I followed with my MVM, multi vitamin and mineral plus supplement. Enough iron to correct any deficiencies and maximize the beneficial effects but not enough to cause iron overload. As well, all of my protein supplements, including Power Drink, Myosin Protein, and MRP LoCarb contain various milk proteins.

 

However, having said that there are a very small subset of people that shouldn’t take supplemental iron – for example those with preexisting or a tendency to iron overload including the two most common causes, hereditary haemochromatosis and iron overload resulting from repeated blood transfusion.

 

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Abstracts:

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J Nutr. 2014 Apr 9. [Epub ahead of print]

 

Iron Supplementation Benefits Physical Performance in Women of Reproductive Age: A Systematic Review and Meta-Analysis.

 

Pasricha SR1, Low M, Thompson J, Farrell A, De-Regil LM.

 

Abstract

 

Animal and human observational studies suggest that iron deficiency impairs physical exercise performance, but findings from randomized trials on the effects of iron are equivocal. Iron deficiency and anemia are especially common in women of reproductive age (WRA). Clear evidence of benefit from iron supplementation would inform clinical and public health guidelines. Therefore, we performed a systematic review and meta-analysis to determine the effect of iron supplementation compared with control on exercise performance in WRA. We searched the Cochrane Central Register of Clinical Trials, MEDLINE, Scopus (comprising Embase and MEDLINE), WHO regional databases, and other sources in July 2013. Randomized controlled trials that measured exercise outcomes in WRA randomized to daily oral iron supplementation vs. control were eligible. Random-effects meta-analysis was used to calculate mean differences (MDs) and standardized MDs (SMDs). Risk of bias was assessed using the Cochrane risk-of-bias tool. Of 6757 titles screened, 24 eligible studies were identified, 22 of which contained extractable data. Only 3 studies were at overall low risk of bias. Iron supplementation improved both maximal exercise performance, demonstrated by an increase in maximal oxygen consumption (VO2 max) [for relative VO2 max, MD: 2.35 mL/(kg min; 95% CI: 0.82, 3.88; P = 0.003, 18 studies; for absolute VO2 max, MD: 0.11 L/min; 95% CI: 0.03, 0.20; P = 0.01, 9 studies; for overall VO2 max, SMD: 0.37; 95% CI: 0.11, 0.62; P = 0.005, 20 studies], and submaximal exercise performance, demonstrated by a lower heart rate (MD: -4.05 beats per minute; 95% CI: -7.25, -0.85; P = 0.01, 6 studies) and proportion of VO2 max (MD: -2.68%; 95% CI: -4.94, -0.41; P = 0.02, 6 studies) required to achieve defined workloads. Daily iron supplementation significantly improves maximal and submaximal exercise performance in WRA, providing a rationale to prevent and treat iron deficiency in this group. This trial was registered with PROSPERO (http://www.crd.york.ac.uk/PROSPERO/prospero.asp) as CRD42013005166.

 

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J Nutr Sci Vitaminol (Tokyo). 2013;59(3):198-205.

 

Whey protein inhibits iron overload-induced oxidative stress in rats.

 

Kim J1, Paik HD, Yoon YC, Park E.

 

Abstract

 

In this study, we evaluated the effects of whey protein on oxidative stress in rats that were subjected to oxidative stress induced by iron overload. Thirty male rats were assigned to 3 groups: the control group (regular [50 mg/kg diet] dose of iron+20% casein), iron overload group (high [2,000 mg/kg] dose of iron+20% casein, IO), and whey protein group (high dose of iron+10% casein+10% whey protein, IO+whey). After 6 wk, the IO group showed a reduction in the plasma total radical trapping antioxidant parameter and the activity of erythrocyte superoxide dismutase and an increase in lipid peroxidation (determined from the proportion of conjugated dienes). However, whey protein ameliorated the oxidative changes induced by iron overload. The concentration of erythrocyte glutathione was significantly higher in the IO+whey group than in the IO group. In addition, whey protein supplementation fully inhibited iron overload-induced DNA damage in leukocytes and colonocytes. A highly significant positive correlation was observed between plasma iron levels and DNA damage in leukocytes and colonocytes. These results show the antioxidative and antigenotoxic effects of whey protein in an in vivo model of iron overload-induced oxidative stress.

 

Full text available at: https://www.jstage.jst.go.jp/article/jnsv/59/3/59_198/_pdf.

 

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Free Radic Res. 2006 May;40(5):535-42.

 

Iron and exercise induced alterations in antioxidant status. Protection by dietary milk proteins.

 

Zunquin G1, Rouleau V, Bouhallab S, Bureau F, Theunynck D, Rousselot P, Arhan P, Bougle D.

 

Abstract

 

Lipid peroxidation stress induced by iron supplementation can contribute to the induction of gut lesions. Intensive sports lead to ischemia reperfusion, which increases free radical production. Athletes frequently use heavy iron supplementation, whose effects are unknown. On the other hand, milk proteins have in vitro antioxidant properties, which could counteract these potential side effects. The main aims of the study were: (1) to demonstrate the effects of combined exercise training (ET) and iron overload on antioxidant status; (2) to assess the protective properties of casein in vivo; (3) to study the mechanisms involved in an in vitro model. Antioxidant status was assessed by measuring the activity of antioxidant enzymes (superoxide dismutase (SOD); glutathione peroxidase (GSH-Px)), and on the onset of aberrant crypts (AC) in colon, which can be induced by lipid peroxidation. At day 30, all ET animals showed an increase in the activity of antioxidant enzymes, in iron concentration in colon mucosa and liver and in the number of AC compared to untrained rats. It was found that Casein's milk protein supplementation significantly reduced these parameters. Additional information on protective effect of casein was provided by measuring the extent of TBARS formation during iron/ascorbate-induced oxidation of liposomes. Free casein and casein bound to iron were found to significantly reduce iron-induced lipid peroxidation. The results of the overall study suggest that Iron supplementation during intensive sport training would decrease anti-oxidant status. Dietary milk protein supplementation could at least partly prevent occurrence of deleterious effects to tissue induced by iron overload.

 

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Int J Cardiol. 2012 Apr 19;156(2):186-91. doi: 10.1016/j.ijcard.2010.10.139. Epub 2010 Dec 9.

 

Absolute and functional iron deficiency in professional athletes during training and recovery.

 

Reinke S1, Taylor WR, Duda GN, von Haehling S, Reinke P, Volk HD, Anker SD, Doehner W.

 

Abstract

 

BACKGROUND:

 

Iron deficiency (ID) is one of the most important metabolic dysfunctions. Athletic performance depends on oxygen transport and mitochondrial efficiency, thus on optimal iron balance. We hypothesised that physical extremes result in ID in elite athletes and that the short recovery period may be insufficient to allow a lasting replenishment of iron reserves.

 

METHODS:

 

Iron metabolism was examined in 20 elite rowing athletes and 10 professional soccer players at the end of a competitive season, after recuperation and during pre-season training. Absolute ID values were defined as ferritin <30 μg/L, functional ID as ferritin 30-99 μg/L or 100-299 μg/L+transferrin saturation <20%.

 

RESULTS:

 

At the end of season, 27% of all athletes had absolute ID and 70% showed functional ID. Absolute iron depletion was not generally restored after recuperation and observed at all time points in 14% of the athletes. Although athletes with initially low ferritin levels showed a slight increase during recuperation (p<0.09), these increases remained within borderline levels. Furthermore, 10% showed borderline haemoglobin levels, suggestive of mild anaemia, as defined by the World Health Organisation.

 

CONCLUSION:

 

A significant proportion of professional athletes have ID, independent of the training mode. Although recuperation seems to allow a certain recovery of iron storage, particularly in athletes with initially low ferritin levels, this retrieval was insufficient to fully normalise reduced iron levels. Therefore, iron status should be carefully monitored during the various training and competitive periods in elite athletes. An adequate iron supplementation may be needed to maintain balanced iron stores.

 

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J Nutr Sci Vitaminol (Tokyo). 2013;59(3):198-205.

 

Whey protein inhibits iron overload-induced oxidative stress in rats.

 

Kim J1, Paik HD, Yoon YC, Park E.

 

Abstract

 

In this study, we evaluated the effects of whey protein on oxidative stress in rats that were subjected to oxidative stress induced by iron overload. Thirty male rats were assigned to 3 groups: the control group (regular [50 mg/kg diet] dose of iron+20% casein), iron overload group (high [2,000 mg/kg] dose of iron+20% casein, IO), and whey protein group (high dose of iron+10% casein+10% whey protein, IO+whey). After 6 wk, the IO group showed a reduction in the plasma total radical trapping antioxidant parameter and the activity of erythrocyte superoxide dismutase and an increase in lipid peroxidation (determined from the proportion of conjugated dienes). However, whey protein ameliorated the oxidative changes induced by iron overload. The concentration of erythrocyte glutathione was significantly higher in the IO+whey group than in the IO group. In addition, whey protein supplementation fully inhibited iron overload-induced DNA damage in leukocytes and colonocytes. A highly significant positive correlation was observed between plasma iron levels and DNA damage in leukocytes and colonocytes. These results show the antioxidative and antigenotoxic effects of whey protein in an in vivo model of iron overload-induced oxidative stress.

 

-----------------------------------

 

Free Radic Res. 2006 May;40(5):535-42.

 

Iron and exercise induced alterations in antioxidant status. Protection by dietary milk proteins.

 

Zunquin G1, Rouleau V, Bouhallab S, Bureau F, Theunynck D, Rousselot P, Arhan P, Bougle D.

 

Abstract

 

Lipid peroxidation stress induced by iron supplementation can contribute to the induction of gut lesions. Intensive sports lead to ischemia reperfusion, which increases free radical production. Athletes frequently use heavy iron supplementation, whose effects are unknown. On the other hand, milk proteins have in vitro antioxidant properties, which could counteract these potential side effects. The main aims of the study were: (1) to demonstrate the effects of combined exercise training (ET) and iron overload on antioxidant status; (2) to assess the protective properties of casein in vivo; (3) to study the mechanisms involved in an in vitro model. Antioxidant status was assessed by measuring the activity of antioxidant enzymes (superoxide dismutase (SOD); glutathione peroxidase (GSH-Px)), and on the onset of aberrant crypts (AC) in colon, which can be induced by lipid peroxidation. At day 30, all ET animals showed an increase in the activity of antioxidant enzymes, in iron concentration in colon mucosa and liver and in the number of AC compared to untrained rats. It was found that Casein's milk protein supplementation significantly reduced these parameters. Additional information on protective effect of casein was provided by measuring the extent of TBARS formation during iron/ascorbate-induced oxidation of liposomes. Free casein and casein bound to iron were found to significantly reduce iron-induced lipid peroxidation. The results of the overall study suggest that Iron supplementation during intensive sport training would decrease anti-oxidant status. Dietary milk protein supplementation could at least partly prevent occurrence of deleterious effects to tissue induced by iron overload.

 

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Toxicol Appl Pharmacol. 2005 Jan 15;202(2):199-211.

 

Iron metabolism and toxicity.

 

Papanikolaou G1, Pantopoulos K.

 

Abstract

 

Iron is an essential nutrient with limited bioavailability. When present in excess, iron poses a threat to cells and tissues, and therefore iron homeostasis has to be tightly controlled. Iron's toxicity is largely based on its ability to catalyze the generation of radicals, which attack and damage cellular macromolecules and promote cell death and tissue injury. This is lucidly illustrated in diseases of iron overload, such as hereditary hemochromatosis or transfusional siderosis, where excessive iron accumulation results in tissue damage and organ failure. Pathological iron accumulation in the liver has also been linked to the development of hepatocellular cancer. Here we provide a background on the biology and toxicity of iron and the basic concepts of iron homeostasis at the cellular and systemic level. In addition, we provide an overview of the various disorders of iron overload, which are directly linked to iron's toxicity. Finally, we discuss the potential role of iron in malignant transformation and cancer.

 

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Crit Rev Clin Lab Sci. 2008;45(1):1-23. doi: 10.1080/10408360701713104 .

 

Oxidative stress and iron homeostasis: mechanistic and health aspects.

 

Galaris D1, Pantopoulos K.

 

Abstract

 

Iron is an essential cofactor for important biological activities and biochemical reactions, including the transport of oxygen via red blood cells and its reduction to water during respiration. While iron's bioavailability is generally limited, pathological accumulation of the metal within tissues aggravates the generation of reactive oxygen species (ROS) and elicits toxic effects, which are mainly related to oxidative stress. Here, we describe the role of iron in ROS-induced toxicity and discuss molecular mechanisms and physiological aspects of ROS- and iron-mediated signaling. In addition, we review our current understanding of the regulation of iron homeostasis at the cellular and systemic levels, and focus on the pathogenesis and management of iron overload disorders.

 

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