Ever since the novel coronavirus brought the disease it causes, COVID-19, into global every day discourse, zinc has often been mentioned in health-related write-ups.
Zinc is a trace element that is necessary for a healthy immune system. A lack of zinc can make a person more susceptible to disease and illness.
It is responsible for a number of functions in the human body, and it helps stimulate the activity of at least 100 different enzymes. Only a small intake of zinc is necessary to reap the benefits.
Currently, the recommended dietary allowance (RDA) for zinc is 8 milligrams (mg) a day for women and 11 mg a day for men. The element is naturally found in many different foods, but it is also available as a dietary supplement.
Zinc is vital for a healthy immune system, correctly synthesizing DNA, promoting healthy growth during childhood, and healing wounds. The following are some of the health benefits of zinc:
1) Regulating immune function
The human body needs zinc to activate T lymphocytes (T cells). T cells help the body in two ways: to control and regulate immune responses as well as attacking infected or cancerous cells.
Zinc deficiency can severely impair immune system function. According to a study published in the American Journal of Clinical Nutrition, “zinc-deficient persons experience increased susceptibility to a variety of pathogens.”
2) Treatment of diarrhea
Diarrhea kills an astonishing 1.6 million children who are under five years, annually. Zinc pills may help reduce diarrhea. A PLoS Medicine study, which “followed a nationwide public health campaign to increase zinc use for childhood diarrhea in Bangladesh,” confirmed that a 10-day course of zinc tablets is effective at treating diarrhea and also helps prevent future bouts of the condition.
3) Affects learning and memory
Research conducted at the University of Toronto and published in the journal Neuron suggested that zinc has a crucial role in regulating how neurons communicate with one another, affecting how memories are formed and how we learn.
4) Treatment of the common cold
Zinc lozenges were found to shorten the duration of common cold episodes by up to 40 percent in a study published in the Open Respiratory Medicine Journal. In addition, a Cochrane review concluded that taking “zinc (lozenges or syrup) is beneficial in reducing the duration and severity of the common cold in healthy people, when taken within 24 hours of onset of symptoms.”
5) Role in wound healing
Zinc plays a role in maintaining skin integrity and structure. Patients experiencing chronic wounds or ulcers often have deficient zinc metabolism and lower serum zinc levels. Zinc is often used in skin creams for treating diaper rash or other skin irritations.
A Swedish study that analysed zinc in wound healing concluded that “topical zinc may stimulate leg ulcer healing by enhancing re-epithelialization, decreasing inflammation and bacterial growth. When zinc is applied on wounds, it not only corrects a local zinc deficit but also acts pharmacologically.”
However, research has not consistently shown that use of zinc sulfate in patients with chronic wounds or ulcers is effective at improving healing rate.
6) Decreased risk of age-related chronic disease
Researchers at Oregon State University have found that improving zinc status through diet and supplementation may reduce the risk of inflammatory diseases. It has been known for decades that zinc has a significant role in immune function. Deficiency has been linked to increased inflammation in chronic disease and triggering new inflammatory processes.
8) Prevention of age-related macular degeneration (AMD)
Zinc prevents cellular damage in the retina, which helps in delaying the progression of AMD and vision loss, according to a study published in the Archives of Ophthalmology.
9) Enhances fertility
Several studies and trials have linked poor zinc status with low sperm quality. For example, one study in the Netherlands found that subjects had a higher sperm count after zinc sulfate and folic acid supplementation. In another study, researchers concluded that poor zinc intake may be a risk factor for low quality of sperm and male infertility.
10) Other possible zinc benefits
Zinc may also be effective for the treatment of:
Acne – one study, published in JAMA, showed promising results of zinc sulfate for the treatment of acne
Attention deficit hyperactivity disorder (ADHD)
Osteoporosis
Prevention and treatment of pneumonia
Recommended intake
Adequate zinc intake is especially important for children because even mild zinc deficiency can impede growth, increase risk of infection, and increase risk of diarrhea and respiratory disease. The recommended intake for children 1-8 years old ranges from 3-5 milligrams, increasing as the child gets older.
Males 9-13 years old require 8 milligrams of zinc per day. After the age of 14, the requirement increases to the 11 milligrams per day that is required for all adult males. For females over the age of 8, the requirement stays stable at 8 milligrams per day, except for ages 14-18, where the recommendation increases to 9 milligrams per day.
Pregnant and lactating women have an increased need for zinc at 11-13 milligrams per day, depending on age.
Sources of zinc
The best sources of zinc are beans, animal meats, nuts, fish and other seafood, whole grain cereals, and dairy products. Zinc is also added to some breakfast cereals and other fortified foods. Vegetarians may require up to 50 percent more than the recommended intake of zinc because of low bioavailability of zinc from plant-based foods.
Foods with the highest reported zinc content are: raw oysters (Pacific), lean chuck roast, braised beef, canned baked beans, cooked crab, lean ground beef, cooked lobster, lean pork loin, cooked wild rice, cooked, cooked green peas, plain yoghurt, pecans and roasted peanuts.
Zinc supplements are also available in the form of capsules and tablets. However, the tolerable upper limit for zinc is 40 milligrams for males and females over 18 years.
It has been proven time and again that isolating certain nutrients in supplement form will not provide the same health benefits as consuming the nutrient from a whole food. First focus on obtaining your daily zinc requirement from foods, then use supplements as a backup if necessary.
Deficiency
Normally, zinc deficiency is due to insufficient dietary intake. However, it may also be due to malabsorption and chronic illnesses such as diabetes, malignancy (cancer), liver disease, and sickle cell disease. Signs of zinc deficiency include: loss of appetite, anaemia, slow wound healing, skin conditions such as acne or eczema, abnormal taste and smell, depressed growth, altered cognition, depression, diarrhea and hair loss. Zinc deficiency during pregnancy may increase the chances of a difficult or prolonged birth.
Precautions
Zinc has many health benefits, but excessive zinc intake can be harmful. Adverse effects of severely high zinc intake may include: nausea, vomiting, loss of appetite, stomach pains, headaches and diarrhea
Excess zinc may suppress copper absorption, according to a study published in Biological Trace Element Research.
There is also some evidence that increased levels of zinc in the body might play a role in the development of kidney stones. Research into this and other health benefits of zinc are happening now, but we have known for decades that zinc is important to good health.
• Adapted from
www.medicalnewstoday