Zinc status in athletes, in relation to diet and exercise

Zinc Status In Athletes:

Purpose: The purpose of this study was to examine the status of zinc in endurance athletes, based on the knowledge that they have significantly increased requirements.

Methods: Dietary tendencies of endurance athletes was followed.

Results: It was established that endurance athletes consume high carbohydrate diets; these are often low in zinc. Affects of low zinc in athletes can include osteoporosis, anorexia, increased fatigue and decreased appetite, however it can be difficult to detect mild zinc deficiency, which is what most athletes are likely subject to.

Michelletti, A., Ruggero, R., & Rufini, S. (2001). Zinc status in athletes relation to diet and exercise. Sports Med, 31(8), 577-582. Retrieved from http://people.umass.edu/kin380/Zinc and Athletes.pdf

Supplement Options: What to look for on the shelf

1. Chelated Zinc

True to its name, this type of zinc has undergone chellation, which is a process molecues undergo that gives them an electrical charge allowing them to positively attract a charged mineral, in this case zinc. It reates a temporary increase in thei complecity and concetration of the mineral within the molecule.

2. Zinc Orotate

This type of zinc is most easily absorbed by the human cellular membranes. It has been chellated to orotic acid, it is more neutrally charged, allows them to pass through membranes of cells easity and offered highest amounts of accompanying mineral atoms into cells leading to higher tissue concentrations. It is arguably the best form of zinc on the market today.

3. Zinc Picolinate:

Has been chelated to picolinic amino acids.

4) Zinc Gluconate:

While popular on the market, this is a chemical substitute for zinc, it is essentially fermented glucose, and therefore not the best option. The body does not absorb much of this chemical, and it does not have the benefits of actual zinc.

5) Zinc Acetate:

This is another chemically altered form of zinc, which is slightly more bio available than gluconates. It contains copper

This form of zinc, also known as zinc salt dihydrate and zinc diacetate, is created by adding acetic acid to zinc carbonate or zinc metal. It has been known to have immune effects similar to actual zinc, but negative affects from toxic quantities of copper.

6) Zinc Oxide:

This form is common in topical creams, and has decent but not great absorption rates.

7) Zinc Sulfate:

Water-soluble and non-chelated, this is an inorganic form of zinc. Studies show mixed results on the body’s ability to absorb and metabolize this form of zinc.

This information was taken directly from

http://www.globalhealingcenter.com/natural-health/types-of-zinc/

How to Best Absorb Zinc

Marginal zinc deficiency and sub optimal zinc levels have been found in people all over the world, in both developed and 3^rd world nations. There are several potential causes of this, including the form of zinc ingested. Phytate, which is present in many fortified grainy foods, inhibits zinc absorption. Forms of phosphates that particularly affect zinc absorption include inositol, hexaphosphates and pentaphosphates, where as lower phytates are not so influential. One solution to this problem includes the removal or reduction of phytates by enzyme (phytase) germination or fermentation. The ingestion of iron and cadmium at the same time as zinc significantly inhibit absorption as well. The quantity of protein in a given meal has been shown to have a positive affect on zinc absorption, but is somewhat dependent on the type of protein. For example, casein has a modest inhibitory effect on zinc absorption, compared to amino acids including histidine and methionine as well as other low molecular weight ions, which have a positive effect on zinc absorption.

Comments: knowledge about factors that inhibit or encourage zinc absorption are crucial when trying to increase serum zinc levels, as in true for any vitamin or mineral absorption.

Lonnerdal, B. (2000). Dietary factors influencing zinc absorption. Journal of Nutrition, 30(5), 1378-1383. Retrieved from http://jn.nutrition.org/content/130/5/1378S.full

TOP 10 FOODS CONTAINING ZINC

Health-Alicious-Ness Provides a list of top 10 foods High in Zinc.

#1: Oysters

Depending on type and variety oysters provide 16-182mg of zinc per 100g serving. This accounts for 110%-1200% of the DV for zinc. The food highest in zinc is The Steamed Wild Eastern Oyster which provides 182 mg of zinc per 100g serving, or 76mg (509% DV) in 6 oysters, and 154mg (1029% DV) in a 3 ounce serving.
Click to see complete nutrition facts.

#2: Toasted Wheat Germ

Packed in jars and sold toasted, wheat germ is great to sprinkle on top of any food. Try it on salads, rice, or steamed vegetables. Toasted wheat germ provides 17mg (112% DV) of zinc per 100g serving, which is 19mg (126% DV) per cup, and 1.2mg (8% DV) in a single tablespoon. Crude (untoasted) wheat germ provides 12mg (82% DV) of zinc per 100g serving, 14mg (94% DV) per cup, and 1mg (6% DV) per tablespoon. Click to see complete nutrition facts. Buy Wheat Germ from Amazon.com

#3: Veal Liver

The liver of any animal is packed with vitamins and minerals and most commonly served as pâté or liverwurst. Veal liver has the most zinc with 12mg per 100g serving accounting for 81% of the DV, that is 8.98mg of zinc (60% DV) in a cooked slice of liver (80g). Liver is best prepared steamed or fried with onions and herbs. 
Click to see complete nutrition facts.

#4: Low Fat Roast Beef

Low fat beef shoulder, shank, and chuck all contain about 10mg (70% DV) of zinc per 100g serving, 18mg (119% DV) per pound, and 9mg (59% DV) in a 3 oz serving. If you buy pre-processed roast beef be sure to consult the nutrition facts about the cut and nutrients. Not all nutrition labels report zinc, so don't worry if you don't see it. 
Click to see complete nutrition facts.

#5: Roasted Pumpkin and Squash Seeds

A popular food in the Middle East and East Asia pumpkin and squash seeds contain about 10mg (70% DV) of zinc per 100g serving, 6.6mg (59% DV) per cup, and 3mg (19% DV) per ounce (~85 seeds). If you can't find these in your local supermarket you will surely find them in Middle Eastern or East Asian specialty stores. Alternatively, you can also save any pumpkin and squash seeds you have and roast them in your oven. The seeds are typically eaten by cracking the outer shell and eating the seed inside. 
Click to see complete nutrition facts. Seeds and Nuts with the Fewest Calories.

#6: Dried Watermelon Seeds

Much like the pumpkin and squash, watermelon seeds are popular in the Middle East and East Asia and they should be in specialty stores catering to those cultures. It is also possible to just eat the seeds raw with the watermelon. You can shell them, or just chew them up whole. Dried watermelon seeds provide 10mg (70% DV) of zinc per 100g serving, 11mg (74 %DV) per cup, and 3mg (19% DV) per ounce. 
Click to see complete nutrition facts.

#7: Dark Chocolate and Cocoa Powder

Chocolate is showing more and more health benefits and dark chocolate is coming into vogue. Unsweetened baking chocolate provides 9.6mg (64% DV) of zinc per 100g serving (most bars are 50-100 grams). Cocoa powder will provide 6.8mg (45% DV) per 100g, or 5.4mg (39% DV) per cup, 0.3mg (2% DV) per tablespoon. Most milk chocolates provide around 2.3mg (15% DV) per 100g serving or 1mg (7% DV) per bar. Click to see complete nutrition facts. Buy Dark Chocolate from Amazon.com

#8: Lamb (Mutton)

Lamb is a common meat in the Middle East, Mediterranean, and most of Europe, but is increasing in popularity in the Americas. Lamb provides between 4.2-8.7mg of zinc per 100g serving (28%-58% DV) depending on cut. That is up to 7.4mg (49% DV) in a 3 ounce serving (85 grams). 
Click to see complete nutrition facts.

#9: Peanuts

Peanuts are a great source of zinc, 100 grams of oil roasted peanuts will provide 6.6mg (44% DV) of zinc, or 8.8mg (59% DV) in 1 cup chopped, 1.9mg (12% DV) per oz (~39 peanuts). Dry roasted peanuts will provide half as much zinc at 3.3mg (22% DV) per 100 gram serving, or 4.8mg (32% DV) per cup, and 1mg (6% DV) per oz. 
Click to see complete nutrition facts. Buy Peanuts from Amazon.com

#10: Crab

Almost any kind of crab will be a great source of zinc. Alaksa King crab in particular provides 7.6mg (51% DV) of zinc per 100 gram serving, which is 10.2mg (68% DV) in an average crab leg, and 6.5mg (43% DV) in a 3 ounce serving. Click to see complete nutrition facts.

Special notes:

-animal sources provide zinc that is more easily absorbed than plant sources.

http://www.healthaliciousness.com/articles/zinc.php

SEX DRIVE

Vitamins for Libito Enhancement for Women.

Livestrong provides excellent information on zinc and its many benefits for the human body in all stages of life.

One interesting section discusses the importance of zinc on hormone production, including the synthesis of testosterone. While many people do not associate testosterone with women, they create and use it just as men do, only they have significantly smaller quantities. Female athletes that have higher serum testosterone levels tend to perform at a higher level than females with lower serum testosterone. Testosterone also plays a role in libido and sex drive for men and women, so ladies if you are in a funk, consider your diet. A small amount of zinc can provide a little extra “drive” according to LiveStrong.com.

http://www.livestrong.com/article/97313-vitamins-libido-enhancement-women/

What Runner's World Says

Article Review:

Supplements Made Simple: Zinc

According to Runner’s World, “a little zinc goes a long way”.  The body may only contain about 2mg of zinc, but it cooperates with over 100 different enzymes to help with metabolism, immune system, muscle growth and recovery, wound healing and male sexual function.

            Not only do runners sweat out minute amounts of zinc, but the amount secreted in urine is increased after a run of at least 6 miles, according to this article. This article also states that up to 40% of athletes are under normal levels of zinc, signs for this including easily contracting colds or bronchitits. Aside from increased zinc secretion, athletes often shy away from zinc rich foods because they are high in fat.

Some low fat high zinc options include wheat germ, fortified grains, and black eyed peas. These commonly contain 25-100% of daily zinc recommendations. Zinc is best absorbed from meat however, options including sea food, poultry, beef and pork.

My 2 cents.

We have established that runners are at an elevated risk for zinc deficiency, and while the author of this article recommends supplementation, I cannot help but insert that a quick chat with the doctor could do nothing but good before anyone, runner or not, begins to take supplements regularly. The toxic effects of zinc are serious, and no one is safe from them.

Original Article by Liz Applegate, 2000.

http://www.runnersworld.co.uk/nutrition/supplements-made-simple---zinc/282.html

Zinc Supplementation and Growth

Zinc Supplementation and Growth

Purpose: The purpose of this study was to further determine the effects of zinc supplementation on the growth of infants and young children, as well as maternal supplementation.

Methods: 2 of 12 studies completed showed significant weight increases and 1 showed positive height increases in control group consuming zinc supplements. Two studies simultaneously showed that the affects of zinc were not seen when supplemented with iron.

Conclusions: Zinc did not induce growth or weight gain on healthy, non zinc deficient, non stunted subjects. It did, however, provide positive affects on health and weight to people who did not meet current health standards. There were conflicting results from studies done on maternal supplementation.

Comments: This furthers the notion that zinc supplementation should be closely monitored, especially during periods of significant growth and development including pregnancy, infancy and young childhood. Zinc can have significant positive or negative effects, which are seriously influenced by dosage.

Ruz, M. (2006). Zinc supplementation and growth.Current Opinion in Clinical Nutrition & Metabolic Care, 9(6), 757-762. doi: 10.1097/01.mco.0000247479.87402.5b

What Happens When There's Not Enough

Zinc Deficiency: Serious Business

While it is unlikely for a person living in the US today to become zinc deficient, about 2 billion people world wide suffer from a lack of this mineral. The impact of zinc deficiency was discovered about 49 years ago, and the world is forever improved because of it. Zinc deficiency can cause many negative effects on the human body including but not limited to growth retardation, hypergonadism, immune dysfunction as well as cognitive impairment. Zinc has been shown to be an intracellular signaling molecule in monocytes, dendritic cells and macrophages and it plays an important role in cell-mediated immune functions and oxidative stress. Zinc supplementation has proven an affective treatment for diarrhea in children, blindness in the elderly, various infections. It also decreased oxidative stress and decreased the generation of inflammatory cytokines. Clinical zinc supplementation was found to help in treatment of neurological disease, atherosclerosis, and several malignancies.

These represent some of the more serious effects of zinc deficiency. It is not something to be taken lightly, but it is important to note that zinc deficiency is not a common occurrence among people living in the developed world. Fortified foods ensure this, although athletes, vegetarians, and people pregnant or lactating are at an elevated risk for zinc deficiency. The above conditions result from long periods of time, or times of growth without zinc, and not a temporary imbalanced diet.

Prasad A.S. Impact of the discovery of human zinc deficiency on health. Journal of American College of Nutrition.2009;28:257–265.

Zinc On the Brain

Effect of zinc supplementation on mood states in young women: a pilot study.

Purpose: This study was done to see the connection between zinc supplementation and brain development and function, as well as mood states in young women.

Methods: This study utilized a standardized, double blind, placebo controlled procedure. Major outcomes include psychological measures, somatic symptoms and serum zinc levels. The study consisted or 30 women randomly placed in one of two groups.

Results: Women in the group consuming a zinc containing multi vitamin for 10 weeks showed decreased anger, aggression and better concentration at the end of the study, compared to their placebo consuming counter parts.

Comments: Zinc supports cell division and DNA synthesis, it seems that by the same means that it creates strong and healthy muscles, it supports brain activity as well.

Sawada , T., & Yokoi, K. (2010). Effect of zinc supplementation on mood states in young women: a pilot study. European Journal of Clinical Nutrition, (64), 331-333. doi: 10.1038/ejcn.2009.158

Calling All Endurance Athletes!

Article Review:Why Zinc is Important

Article Review:

 

Zinc has a myriad of benefits for the human body, when consumed within a healthy range for individuals based on gender, age, and athletic tendencies. This article published in Star Weekend Magazine in 2006 discusses these.

Zinc plays a major role in cell division and DNA replication, which means a stronger immune system via the addition of more immune cells. It also improves senses of smell and taste, through DNA replication, as well as improving appetite and mood.

Zinc Deficiency and Zinc Toxicity

Both have serious negative health implications, and endurance athletes are at an increased risk for both. Endurance athletes commonly consume a diet that is high in carbohydrates, which happen to be low in zinc. This can ultimately be detrimental to the health and athletic success of individuals because of zinc’s direct influence on appetite, taste bud development, and the facts that insufficient zinc intake can result in difficulty digesting protein, menstrual irregularities, amenorrhea, and or osteoporosis. It can also lead to weight loss, decreased endurance, and fatigue. Endurance athletes are at this increased disadvantage because of increased sweat loss, and the redistribution of zinc between plasma and red blood cells.

With that being said, zinc supplementation should be closely monitored. Too much zinc has been known to cause abdominal cramping, diarrhea and vomiting. It may also lead to disproportionate absorption of iron, nickel, calcium, selenium, phosphorus, copper, and vitamins A, B1 and C.

The Food and Nutrition Board of The Institute of Medicine states that upper level limits of zinc is 40mg per day, and that Zinc intake that exceeds 80 mg per day has the potential to decrease HDL-C levels (good cholesterol) and even white blood cells.

Moral of this story: take your zinc- but not too much.

See original article. 

http://www.thedailystar.net/magazine/2006/12/02/health.htm

Zinc and Women

 Zinc is an important mineral for all people, and has many benefits that particularly pertain to women. It is aids in bone and muscle development, as well as immune functions of the body. It also plays a role in DNA synthesis, protein synthesis and cell division.

While zinc is particularly important during pregnancy and times of lactation, toxic effects of too much zinc are of magnified importance during these periods as well, so physicians should be consulted before supplements are consumed.

Zinc and Menstruation:

Research shows that zinc helps regulate the body’s secretion of progesterone, which leads to the onset of PMS. Therefore, sufficient zinc consumption can ease symptoms of PMS, as well as menstrual dysmenorrhea and cramps.

Zinc and Pregnancy:

According to LiveStrong.com, the Linus Pauling Institute at Oregon State University estimates that 82% of women around the world are at risk for zinc deficiency, likely because of the increased daily recommendation for zinc during pregnancy.  Sufficient zinc consumption during pregnancy can prevent low birth weight, premature birth, congenital abnormalities and delivery complications.

Elderly Women: Zinc and Calcium

As women age, plasma zinc levels increase. This may be partially caused by increased quantity of calcium women ingest in order to prevent osteoporosis, and the fact that zinc and calcium compete for absorption. Thus, increased calcium intake may mean less of the zinc ingested is actually absorbed, and causing older women to need to ingest higher quantities of zinc in order to keep up.

http://www.livestrong.com/article/492749-what-are-the-benefits-of-zinc-for-women/#ixzz2BIG9rwRi