Last updated on March 18th, 2018
Zinc (Zn) is an essential micronutrient that is lost through perspiration.
It helps optimize levels of testosterone for highly active people and/or those who sweat a lot, making supplementation a virtual must for athletes and serious gym members.
It helps strengthen the immune system, reduce depression and has potent antioxidant properties.
Zinc Key Points and Benefits
- It is an Essential Micronutrient
- Testosterone Booster (for those with deficiency related low testosterone)
- Immune Booster
- Synergistic with Green Tea Catechins
- Daily average dose is about 10mg
- Higher dosage to treat deficiency is about 30-35mg per day
- Upper tolerable limit is about 40mg per day
- Impairs Iron absorption if both Iron and Zinc are above 10mg and taken on empty stomach
Zinc is an essential micronutrient. It is involved in enzyme regulation, the immune system and the endocrine (hormones) system.
It can be found in different food groups, including meat, egg, pulses and other legumes. Oysters are famous for their aphrodisiac properties; a results of their high Zn content.
In the case of a deficiency, supplementing can optimize testosterone levels, boost the immune system, act as a powerful antioxidant and protect the prostate. It also helps repair innermost layer of the intestinal tract; the mucosa.
Editor’s Note: Zinc can be a very important supplement for athletes and indeed anybody who sweats a lot. This is because it is lost from our bodies via perspiration.
It’s difficult to replenish the amount required from diet alone, especially if you are quite active/sweat excessively. Supplementation provides an easy way to keep many essential functions ticking over at optimal rates – testosterone production, immunity to illness included.
Furthermore, testosterone is also depleted from heavy activity (such as weight training) so including zinc will be even more important to those looking to take advantage of their main anabolic hormone and grow some muscle.
Zn is moderately well researched for its effects on humans and is understood to a very reliable degree with respect to dosage limits and interactions with other substances.
Different Types of Zinc
There are different forms of Zn compounds, which contain different quantities of the molecule:
- Zinc Sulphate (22% elemental zinc)
- Zinc Citrate (34%)
- Zinc Gluconate (13%)
- Zinc Monomethionine (21%)
NOTE: there is usually no need to worry about this as most supplements simply include the dosage of the elemental Zinc itself.
Scientific Support for Zinc
Below are examples of scientific studies which have investigated the various benefits of supplementation:
2006 Study with Wrestlers
This study showed that 3mg zinc per kg of bodyweight could optimize testosterone levels in elite wrestlers. The testosterone in the placebo group declined in comparison due to the high workload of the training.
Kilic M et al. The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc. 2006. [http://www.ncbi.nlm.nih.gov/pubmed/16648789]
2007 Study with Cycling
This time sedentary men were subjected to a cycling exercise. The same dose of zinc – 3mg/kg – prevented the decrease in testosterone and thyroid hormones.
Kilic M. Effect of fatiguing bicycle exercise on thyroid hormone and testosterone levels in sedentary males supplemented with oral zinc. 2007. [http://www.ncbi.nlm.nih.gov/pubmed/17984944]
There are several other studies which have supported the use of zinc to optimize testosterone levels – or put another way – prevent the reduction of it due to activity or other causes.
2010 Study with young Women
Young women were given a multivitamin or a multivitamin plus zinc. The MV and zinc group showed a significant reduction in anger/hostility and depression.
Sawada T, Yokoi K. Effect of zinc supplementation on mood states in young women: a pilot study. 2010 [http://www.ncbi.nlm.nih.gov/pubmed/20087376]
2015 Study with Obese or Overweight Subjects with Depressive Symptoms
In this study, obese people took 30mg zinc per day for 12 weeks and experienced a significant reduction in depression.
Zinc monotherapy increases serum brain-derived neurotrophic factor (BDNF) levels and decreases depressive symptoms in overweight or obese subjects: a double-blind, randomized, placebo-controlled trial. 2015. [http://www.ncbi.nlm.nih.gov/pubmed/24621065]
Again there are more studies to support the anti-depressive qualities of zinc.
Other Scientifically Proven Effects
- Reduction of Acne
- Heightened Cognitive Function
- Weight Reduction
- Increase in IGF-1 (growth factor associated with anabolic muscle and bone growth)
- Decrease in LDL-C (“bad cholesterol”)
- Improvement in Insulin Sensitivity
- Improved Subjective Well-Being
- Reduced Aggression
- Increased T4 Thyroid Hormone (after exercise induced depletion)
- Reduced Infection Risk
- Prevention of Viral Warts
- Improved Reaction Time
- Reduction of Psoriasis
- Therapeutic Reduction of Liver Cirrhosis
- Improved Dental Health
- Improved Sperm Count
- Increased Fertility in Men
- Increased Luteinizing Hormone (leading to increased testosterone)
NOTE: It is worth noting that most of the above effects are noticed only in people deficient OR those who lead particularly active lives where they lose a lot through perspiration.
Usage and Dosage Guidelines
The average daily dose which can be used as a daily “top-up” is around the 10mg mark.
Higher dosages, in the 30-40mg range are usually more appropriate for treating deficiencies.
Even higher dosages up to 100mg per day have been used, but not for periods longer than 8 to 16 weeks as it is nonetheless higher than the 40mg advised upper limit.
Is Zinc Safe – Are There Side Effects?
It is safe at recommended dosages. It is an essential micronutrient for the proper functioning on the human body.
For supplemental dosages; long term periods of over 30mg per day have been noted to be safe, though every day maintenance dosing should be about 10mg.
If both Iron and Zinc are ingested at more than 10mg each on an empty stomach, the Iron absorption may be limited.
Conclusion and Recommendations
Anybody deficient should supplement between 30 and 40mg per day until their doctor advises otherwise from regular blood tests.
The effects of being deficient are profoundly unpleasant as they can lead on to many knock-on effects, such as a low testosterone state, increased depression and a poor immune system.
People who naturally sweat a lot or exercise enough to have the same result may suffer from low levels because it is lost from the body via perspiration.
Zinc is available in the diet, but replenishment of optimal levels may be difficult if there is a lot of fluid loss through physical exertion on a daily basis.
Supplementation is the easiest way to maintain optimum levels of zinc, and in-turn, optimal levels of health.