The Genetics Of Zinc Metabolism

Why Is Zinc Important For Us?

Zinc is an essential trace mineral that plays a crucial role in numerous aspects of cellular metabolism.

It’s involved in the function of approximately 300 enzymes and is necessary for immune function, wound healing, DNA synthesis, cell division, and normal growth and development.

Zinc also supports the human body’s sense of taste and smell.

What Are The Different Forms Of Zinc?

Zinc comes in various forms, each with different absorption rates and amounts of elemental zinc.

Elemental zinc refers to the amount of zinc in each form that is available for the body to use.

Here are some of the most common forms of zinc found in dietary supplements:

Zinc Gluconate

This form of zinc is one of the most common types found in over-the-counter zinc supplements.

It’s a good source of elemental zinc and is often used in lozenges designed to support immune function and soothe a sore throat.

Zinc Citrate

Zinc citrate is another commonly used form of zinc in supplements.

It contains approximately 31% elemental zinc, meaning that it provides a substantial amount of usable zinc for the body.

It is known for its relatively mild, less metallic taste compared to other forms.

Zinc Sulfate

Zinc sulfate is an inorganic form of zinc and is often used in supplements and to fortify foods.

However, it tends to have a more unpleasant, bitter taste compared to other forms of zinc, which is something to consider when choosing a supplement.

Zinc Acetate

This type of zinc has been used in various studies and has been shown to support immune function, especially in the formulation of lozenges for the common cold.

Zinc acetate is a chelated form of zinc that allows for a higher absorption rate.

Zinc Picolinate

Zinc picolinate is a chelated form of zinc, meaning the zinc is bound to the organic compound picolinic acid to aid in absorption.

Some research suggests that this form of zinc may be better absorbed than other types, though more research is needed to confirm this.

Zinc Oxide

This form of zinc is not as easily absorbed as other forms, but it’s often used in topical ointments for skin conditions and in sunscreens.

It’s also used as a pigment in paints and in the manufacture of rubber.

Zinc Orotate

Zinc orotate is a chelated form of zinc where the mineral is bound to orotic acid.

This form is believed to be more easily absorbed by the body, although more research is needed in this area.

Zinc Methionine

This form is a chelated zinc supplement that is often used in animal nutrition.

Zinc methionine is highly absorbable and resistant to antagonists, making it beneficial for livestock supplementation.

When choosing a zinc supplement, it’s important to note that while some forms may be absorbed better than others, the differences are not typically enough to significantly impact overall health in people with balanced diets.

The choice between forms should be based on personal preference, tolerance, and any specific recommendations from a healthcare provider.

Zinc: Historical Significance and RDA

Zinc is one of the essential trace minerals vital for many biological functions in the body.

It plays a significant role in gene expression, enzymatic reactions, immune responses, protein synthesis, DNA synthesis, and cell division.

Because the human body doesn’t have a specialized storage system for zinc, it’s necessary to get adequate amounts regularly through the diet.

A Quick Timeline

The realization of zinc’s importance started in the early 20th century, but it wasn’t until the mid-1960s that zinc was officially recognized as essential to human health.

Early studies of zinc deficiency in humans in the Middle East showed that low zinc levels led to growth retardation, delayed sexual maturation, skin changes, and compromised immune function.

In the 1970s, the National Academy of Sciences (NAS) and the World Health Organization (WHO) started recommending daily dietary allowances of zinc.

Today, these recommendations are made by the Food and Nutrition Board at the Institute of Medicine of the National Academies (formerly NAS), taking into account the latest scientific research.

RDA

The Recommended Dietary Allowance (RDA) for zinc is based on age, sex, and life stage.

For example, adult men and pregnant women need more zinc than adult women and children due to their higher metabolic requirements.

However, meeting the RDA for zinc can be challenging for certain populations.

For instance, vegetarians might require as much as 50% more of the RDA for zinc than non-vegetarians.

This is because zinc is more bioavailable from animal foods, and plant foods contain phytates, which inhibit zinc absorption.

Over the years, researchers have also discovered that zinc requirements can be influenced by several other factors, including physiological conditions, genetic factors, and the presence of disease.

Understanding these factors is crucial for tailoring individual dietary recommendations and preventing zinc deficiency.

Overall, the story behind zinc requirements is one of ongoing discovery, as researchers continue to uncover the complex roles of zinc in human health and the many factors that can influence individual zinc needs.

Genetics Of Zinc Requirements

Zinc requirements can be influenced by several factors, including genetics.

Genetic variations can affect the efficiency of zinc absorption and utilization in the body, potentially altering individual zinc requirements.

The primary molecules involved in zinc transport in the body are zinc transporters and metallothioneins.

Variations in the genes that code for these proteins can affect an individual’s zinc status.

Zinc Transporters

Zinc transporters are proteins that control the movement of zinc into and out of cells.

Two major families of zinc transporters have been identified: ZIP (Zrt-Irt-like proteins) and ZnT (zinc transporter).

Zinc proteins that aid in zinc transport

ZIP proteins increase cellular zinc levels by moving zinc into cells or from intracellular compartments to the cytosol, while ZnT proteins decrease cellular zinc levels by moving zinc out of cells or into intracellular compartments.

Variations in the genes that code for these transporters can affect their function, potentially influencing the amount of zinc that is absorbed from the diet and utilized in the body.

For example, a variation in the SLC39A4 gene, which codes for the ZIP4 transporter, has been associated with acrodermatitis enteropathica, a rare genetic disorder characterized by severe zinc deficiency.

Check your AncestryDNA, 23andMe raw data for the SLC39A4 gene variants

Metallothioneins

Metallothioneins are proteins that bind to various metals, including zinc.

They play a key role in the regulation of intracellular zinc levels.

Variations in the genes that code for metallothioneins can affect their ability to bind to zinc, potentially influencing an individual’s zinc status.

Single Nucleotide Polymorphisms (SNPs)

Specific single nucleotide polymorphisms (SNPs) can also impact zinc metabolism.

For example, the SNP rs2272662 in the gene SLC30A3 (which encodes a zinc transporter) has been associated with alterations in cellular zinc transport, and individuals with this SNP may have different zinc requirements than those without it.

Check your AncestryDNA, 23andMe raw data for the SLC30A3 gene variants

SNP ID	Gene Name	Impact
rs2272662	SLC30A3	Variations can alter the function of the zinc transporter, possibly influencing zinc requirements.
rs78449040	SLC39A4	Variations are associated with acrodermatitis enteropathica, a rare disorder characterized by severe zinc deficiency.

Please note, the relationships between these SNPs, the associated genes, and zinc metabolism are complex and still being researched.

The presence of these SNPs does not definitively determine an individual’s zinc status or requirements, but they may contribute to individual variations in zinc metabolism.

Always consult with a healthcare provider or a genetic counselor for personalized advice.

Section Summary

While the study of genetics and zinc requirements is a relatively new field, it is clear that genetic factors can significantly influence an individual’s zinc status.

However, more research is needed to fully understand these genetic influences and to develop personalized dietary recommendations based on an individual’s genetic makeup.

Symptoms Of Zinc Deficiency

Zinc deficiency can lead to a variety of symptoms, including impaired immune function, delayed wound healing, loss of appetite, taste abnormalities, mental lethargy, and delayed sexual maturation in adolescents.

Symptoms Of Excess Zinc

Excessive zinc intake can lead to zinc toxicity, which can present as nausea, vomiting, loss of appetite, stomach cramps, diarrhea, and headaches. Long-term high zinc intake can lead to copper deficiency.

How You Can Test Your Zinc Levels

Zinc levels in the body can be evaluated using a plasma or serum zinc test. However, because zinc is distributed in tissues, these tests may not accurately reflect whole-body zinc status. An alternative approach is the zinc taste test, though it is less precise.

What Are The Health Benefits Of Zinc?

Zinc is a crucial trace mineral with several health benefits owing to its role in numerous biological processes. Here are some of the key health benefits associated with zinc:

1. Immune System Support

Zinc plays a crucial role in the immune system.

It is necessary for the function of immune cells like T-lymphocytes and natural killer cells, which are important for the immune response.

Zinc deficiency can lead to a weakened immune system, making you more susceptible to infections and diseases.

2. Wound Healing

Zinc is commonly used in hospitals as a treatment for burns, certain ulcers, and other skin injuries.

It plays a vital role in collagen synthesis, immune function, and inflammatory response, all of which are essential for proper wound healing.

3. DNA Synthesis and Cell Division

Zinc plays a fundamental role in cell division and the synthesis of DNA and proteins, which are vital processes for the growth and repair of tissues.

4. Proper Sense of Taste and Smell

Zinc is necessary for the proper function of a group of enzymes called gustin, which are involved in taste perception. Zinc deficiency can lead to a decrease in the sense of taste and smell.

5. Eye Health

Zinc is present in high concentrations in the eye, particularly in the retina, and plays a crucial role in maintaining vision.

It’s also involved in the metabolism of melanin, a protective pigment in the eyes.

6. Bone Health

Zinc is essential for bone health.

It plays a role in bone development and mineralization and is necessary for the synthesis of the bone matrix.

7. Mental Health

Studies suggest that zinc plays a role in neurotransmission and cognitive function.

Some evidence suggests that zinc deficiency could contribute to mood disorders like depression, and zinc supplementation might have a potential role in the management of these conditions.

8. Antioxidant Properties

Zinc is an essential part of superoxide dismutase, an antioxidant enzyme. It helps fight oxidative stress and reduces the chance of disease development.

Section Summary

Ensuring sufficient zinc intake is a crucial part of maintaining overall health, supporting everything from our sense of taste to our immune response.

While many people can meet their zinc needs through diet alone, certain groups may be at a higher risk for zinc deficiency and may benefit from supplementation.

Non-Genetic Factors Influencing Zinc Levels

Diet

The most significant non-genetic factor influencing zinc levels is diet.

Foods high in zinc include oysters, red meat, poultry, seafood, whole grains, dairy products, and fortified cereals.

However, plant-based foods often contain phytates, compounds that can inhibit zinc absorption.

This is why vegetarians and vegans may have lower zinc levels and require a higher dietary zinc intake.

Age

Zinc requirements can change throughout life.

Infants, children, teenagers, pregnant women, and lactating women often have increased zinc needs due to growth and development.

Digestive Disorders

Conditions such as inflammatory bowel disease (IBD), celiac disease, or other disorders that cause malabsorption can result in decreased zinc absorption, leading to lower zinc levels.

Alcohol Consumption

Alcohol can interfere with the absorption of zinc and other nutrients. Chronic heavy drinking can lead to zinc deficiency.

Chronic Kidney Disease

Patients with chronic kidney disease (CKD) may have impaired zinc homeostasis, which can lead to decreased zinc levels.

Certain Medications

Some medications, including certain diuretics and antibiotics, can interfere with zinc absorption or increase zinc excretion, potentially leading to decreased zinc levels.

Physical Stress

Physical stress, including trauma, burns, or surgery, can increase the body’s demand for zinc, potentially leading to decreased zinc levels.

Pregnancy and Lactation

Zinc needs are increased during pregnancy and lactation due to the high demand for zinc in developing fetuses and infants.

Understanding these non-genetic factors is crucial for managing zinc levels and preventing deficiency.

If you suspect you may have a zinc deficiency, it’s important to consult with a healthcare provider for personalized advice.

Ensuring Adequate Zinc Intake Through Diet

Getting enough zinc through your diet involves mindful meal planning and understanding which foods are rich in zinc. Here are some strategies to help ensure that your diet is rich in zinc:

Include Zinc-Rich Foods in Your Diet:

This is the most direct way to increase your zinc intake. Foods rich in zinc include:

Seafood: Oysters, crab, and lobster are particularly high in zinc.
Meat and Poultry: Beef, pork, lamb, and chicken.
Dairy: Milk, cheese, and yogurt are good sources of zinc.
Legumes: Chickpeas, lentils, and most types of beans.
Nuts and Seeds: Pumpkin seeds, cashews, and almonds.
Whole Grains: Oats, quinoa, brown rice, and whole grain bread.

Pair Zinc with Foods High in Protein

Zinc is best absorbed when consumed with protein-rich foods.

So, pairing zinc-rich foods with a source of protein can help improve zinc absorption.

Increase Intake of Fermented Foods

Fermentation can help reduce the levels of phytic acid, a compound found in plant foods that can inhibit zinc absorption.

Foods like sourdough bread, tempeh, and some types of fermented tofu and soy sauce can be better sources of zinc.

Consider Fortified Foods

Many types of cereals and plant-based milk are fortified with zinc.

These can be a good source of zinc, especially for vegetarians, vegans, and those who have difficulty getting enough zinc through other sources.

Cooking Methods

Some cooking methods, such as soaking and sprouting grains and legumes, can help improve zinc bioavailability by reducing phytic acid levels.

Remember, while it’s essential to get adequate zinc, it’s also possible to get too much, which can cause various health issues.

Balance is key, and if you have any concerns about your zinc intake, it would be best to consult with a healthcare professional or a registered dietitian.