Zinc is what is known as an essential mineral. Zinc is naturally occurring in certain foods, added to others and is available as a supplement. Zinc is pivotal for proper immune function and cell division. Zinc is located primarily in the red and white blood cells as well as the liver, bones, pancreas, kidneys, skin and the retina of the eye.
A zinc deficiency can lead to various health defects and can even result in premature labor in pregnant women. A few signs and symptoms of a zinc deficiency include but are not limited to:
- White spots appearing on your fingernails
- A drop in blood pressure
- Retarded growth
- Mood swings and feelings of depression
- Feeling constantly tired and fatigued
- Hair beginning to fall out
- Loss of or poor memory
- A drop in sex drive/low libido
- Wounds taking a long time to heal
- Dulling of the senses of taste and smell
- Trouble with falling and staying asleep
A zinc deficiency is often difficult for doctors to diagnose (due to serum or plasma zinc levels not giving an accurate measurement of zinc in the body) so noting the symptoms is important.
People over the age of 60 and those who eat a vegetarian diet are more likely to become zinc deficient.
1. Zinc Can Improve Your Sense Of Taste And Smell
Hyposmia is a condition in which you begin to lose your sense of smell. Without the healthy amount of zinc in our bodies our sense of smell will begin to fade (1).
Smell and taste are very closely linked and are both needed to taste food properly, in fact it is often the case that you are experience a dulled sense of taste due to a lacking sense of smell.
A healthy amount of zinc can be used to hypogeusia (the loss of the sense of taste) (2).
2. Zinc Stimulates The Activity Of white Blood Cells
White blood cells are also known as leukocytes are imperative to the healthy functioning of our immune systems. Your white blood cell count is important as white blood cells help the body fight off illness and infections due to its ability to attack germs, bacteria and viruses that have entered the body. Having your white blood cell count tested can also indicate whether or not you are suffering from any undiagnosed medical conditions or undetected infections.
Causes of a low white blood cell count include suffering from an overactive spleen, exposure to radiation, a severe vitamin deficiency and rheumatoid arthritis. Symptoms can include fatigue and feeling weak and short of breath.
Zinc is vital to ensuring the health of white blood cells. Zinc is the key to stimulating for aggressive fighting action from white blood cells. Zinc also raises the number of killer white blood cells in the body. These killer cells stimulate extra antibody production from the body’s white blood cells. Zinc supplements have even been shown to slow the growth rate of cancerous cells (3).
3. Zinc Is Useful For Fertility And Pregnancy
Zinc is a powerful weapon in helping couples conceive (4). Zinc has advantages for the health of both women and men when it comes to fertility.
A zinc deficiency in men has been linked directly to impaired sperm production. A zinc deficiency could also result in negative chromosomal changes to the sperm that could result in a miscarriage. Without zinc the tail and the outer membrane of the sperm cannot develop properly. When these parts of the sperm do not develop, the sperm does not have the ability it needs to journey from the man’s epididymis all the way through the woman’s cervix and to the uterus for fertilization to be completed (5).
In women, zinc is needed for hormones like estrogen, testosterone and progesterone to remain balanced which is key for fertilization. Zinc is also needed for eggs to mature healthily and for maintaining proper levels of follicular fluid without which the ripe egg cannot make the journey out of the fallopian tubes into the uterus where it will wait for implantation (6).
Zinc plays an important part during pregnancy as it needed for the baby’s DNA production and function as well as cell growth (7). Zinc during pregnancy is needed for healthy brain function in babies and ensure future brain development and learning (8). A growing fetus uses zinc to change protein to tissue which is needed for the building of muscle (9).
4. Zinc Can Treat Prostate Disorders
Statistically 1 in 7 men will unfortunately suffer from prostate cancer. It is one of the leading causes of fatality in men the world over.
Research shows that zinc, which is a trace mineral, plays a role in overall prostate health (10). Prostate cells actually hold a higher level (10 or 15 times higher) of zinc than any other cells within the human body.
The reason that zinc helps against prostate cancer is because it enables prostate cells to resist transforming in malignant cells because it creates an environment that is toxic to cancerous cells. Zinc is a tremendous tumor suppressor. Zinc activates the process of apoptosis which is a cell death mechanism that is a self-protection mechanism the body uses to eliminate potentially damaging cells.
Cancerous prostate cells have very low levels of zinc compared to healthy prostate cells. This is due to prostate cancer cells not being able to accumulate any zinc.
A study has shown that men who were given over 15 milligrams of zinc had a reduction in the risk of advanced prostate cancer development by up to 66 percent (11).
5. Zinc Can Regulate Diabetes
Diabetes (also known as diabetes mellitus) is a disease that you develop when blood sugar levels within the body are too high. The diabetes disease prevents the body from producing or using insulin which is key in the body’s process of changing glucose into usable energy. Thousands of people are currently living with undiagnosed diabetes.
Zinc is a good regulator of diabetes as it has been shown to mimic insulin when introduced into insulin-sensitive tissues. Zinc also stimulates the action of insulin (12). Zinc binds itself to the body’s insulin receptors and participates in the activation of insulin signalling pathways. Zinc is ultimately responsible for the body’s cells taking in insulin and keeping excess insulin out of our blood. Diabetic patients very often exhibit signs of insulin deficiencies.
A study carried out in Finland followed over a thousand adults living with type 2 diabetes over a duration of seven years. During the seven year study 254 participants suffered from either non fatal or fatal heart attacks whilst 156 of the participants passed away due to heart disease. The zinc levels in all of the participants who suffered from or died from heart disease or attacks were noticeably low compared to the participants who did not have any heart complications (13).
Systolic blood pressure can also be reduced with zinc supplements. Zinc supplements also ensure optimal lipid parameters (14).
Zinc is prescribed to patients who are unable to control their diabetes (15).
Zinc is a natural anti inflammatory and because of this it helps to clear out any substances that cause cell inflammation. This action by zinc helps to preserves the health and insulin sensitivity of the cells (16). One Spanish study found a direct link between low levels of zinc and higher glucose intolerances and lowered insulin resistance.
6. Zinc Improves Your Metabolism
Our metabolisms work because our body contains cells which are full of enzymes that break down the food we eat. After enzymes break the food down it is changed into energy that is in turn used to keep our hearts beating and to keep our limbs moving among so many other uses.
One way in which zinc boosts our metabolisms is because it raises levels of leptin within our bodies. Leptin is a hormones that tells the brain that we are full. Higher levels of leptin keep our appetites in check and prevent us from overeating (17).
Studies show that people suffering from obesity have incredibly poor levels of zinc in their systems. The same obese patients that were administered zinc supplements over time exhibited a healthy decline in their body mass indexes (18).
7. Zinc Can Prevent Alopecia
Alopecia is a disease in which the loss of hair is the main symptom. There are three kinds of alopecia. Alopecia totalis is characterised by loss of the entirety of the hair on the head, alopecia areata is characterised by loss of hair occurring in patches and lastly alopecia universalis which is characterised by a loss of hair over the entire body.
Alopecia (an autoimmune disease) occurs when our immune systems turn on and start attacking healthy hair follicles. Around 5 percent of the world’s population will suffer from one form of alopecia and whilst some hair does sometimes grow back, some people may never regain hair growth. Alopecia is mostly caused by someone’s genetic makeup. Symptoms of alopecia include;
- Bald patches beginning to appear, usually brought to attention by clumps of hair falling out of the head
- Pitting of the fingernails, meaning that small dents begin to appear on the fingernails
- Thin fingernails, white spots appearing on fingernails and rough and or splitting fingernails (fingernails may loosen and fall off in extreme cases)
- Hair loss mainly at the back end of the scalp
Zinc being on of the most important trace minerals found in the body plays a big role in the cycle of hair growth. Without zinc, hair follicles would not be able to produce fresh hair shafts during this growth cycle. Sometimes the zinc levels drop so low in the body that a condition called telogen effluvium is triggered (19).
Telogen effluvium is when hair roots are prematurely pushed into a state of rest usually due to stress. When telogen effluvium occurs we begin to shed hair at a rapid rate. This condition can last for up to a year and cen even become chronic.
Zinc is usually prescribed in conjunction with biotin to treat alopecia. Zinc as an antioxidant protects the hair follicles from damage inflicted by free radicals which is important for anyone suffering from alopecia as their immune system is compromised (20).
A zinc deficiency can our hair follicle’s protein structure which weakens the hair follicles (21). When the structure of hair follicles is weakened hair will fall out more easily. Studies carried out on rats have also shown that zinc plays an important role in the regrowth of hair. Zinc plays a role in RNA and DNA production which also lends itself to strengthening hair and people who take zinc supplements have also noticed a change back from grey hair to their natural color.
8. Zinc Strongly Impacts Your Mental Functions
Zinc is a known regulator of communications between the hippocampus and neurons in the brain, an action which improves our learning capabilities and memory. Including healthy amounts of zinc in our diets can stave off the cognitive decline that comes with old age (22). Zinc has also been found to play an integral role in cognitive stability and the formation of memories.
A study on mice at Duke university removed all zinc from the brains of the mice and noted a significant decline in the communication between neurons in the brain. An absence of zinc in the brain of the test animals stopped advanced communication and upon reintroduction of the mineral, enhance communication, memory and improved learning were restored to the hippocampal region.
A study proved that people who were losing zinc were often disoriented and struggled with memory loss, much like someone suffering from age related senility. When zinc was reintroduced into the patient’s systems their normal mental and ability and function quickly returned (23).
Tests also confirm that people living in developing countries suffer from mental loss at a much higher rate than people living in developed countries, this is due to zinc not being as readily available in the diets of people living in poorer countries.
9. Zinc Can increase The Healing Rate Of Wounds
Zinc is a powerful healer as it plays a role in cell division, the inhibition of bacterial growth, protein synthesis, DNA synthesis, immune response and the maturation of T-lymphocytes (white blood cells) (24).
Zinc speeds up the rate at which the skins heals whilst protecting the wound from any bacteria buildup and infection. Zinc is required for cellular metabolism (the chemical reactions that are continuously occurring in order to keep us alive). Zinc works to maintain the structure of mucosal membranes and dermal tissue (25).
10. Zinc Can Alleviate Chronic Fatigue
The disorder chronic fatigue syndrome is when you feel constantly tired no matter how much rest you get. The causes of this debilitating disorder are not clear and can range from psychological stress to viral infections. This disorder is not well understood so can be difficult to treat. A few symptoms of chronic fatigue syndrome include;
- Having trouble with recalling information
- Struggling to concentrate
- Pain in the joints
- Frequently suffering from a sore throat
- Swelling and tenderness in the lymph nodes
- Muscle pains
- Frequent headaches
- Feeling unrested after a full night’s sleep
Zinc has a profound effect on our immune systems and is present in some quantity in every single cell of the body. Zinc works well for fatigue as our body would not be able to utilize the vitamins we receive in our diets to the fullest without it (26). When your body does not fully absorb vitamins and nutrients, you are left with a weakened capacity for the production of energy resulting in being constantly fatigued.
11. Zinc Is Useful For The Prevention Of Acne
Acne occurs when the sebaceous gland found in the skin become infected or inflamed resulting in pimples or in extreme cases welts mainly on the face. Acne can be painful, embarrassing and expensive to treat.
A study carried out in Turkey found that participants suffering from acne had much lower levels of zinc than those who did not have acne. A dozen studies have all shown that zinc supplements have a positive effect on eliminating acne (27).
Zinc attacks and kills the bacteria that is responsible for acne and reduces keratinocyte activation. Keratinocyte cells are responsible for the production of keratin (the protein our hairs and nails are made of which also binds or skin cells). When we have too much keratin, it stops skin cells separating and results in blocked pores which causes acne.
12. Zinc Supports The Health Of Your Liver
Our liver is the largest gland in our bodies and supports to some extent in the work of every other organ.
Zinc deficiencies have been directly linked to cirrhosis of the liver (when healthy liver tissue is replaced with scar tissue) and various studies have shown that a healthy amount of zinc in the body can protect us from developing chronic and acute liver diseases (28). Zinc is a natural antioxidant and in animals trials has shown the ability to protect the liver from oxidative damage.
13. Zinc Can Prevent Diarrhea
Diarrhea is an increased and uncontrollable discharge of fecal matter in liquid form from the body. Diarrhea is the number one cause of mortality in children under the age of five.
We need zinc for cellular differentiation, metabolism and growth all which increase our body’s strength against possible infection which can reduce the severity and duration of diarrhea (29).
Zinc supplements can also reduce the likelihood of infections that may be introduced into the body during the period of diarrhea (30).
14. Zinc Can Be Used To Fight Eczema
Eczema is a chronic skin condition in which the skin becomes inflamed, flaky and itchy (usually a rash covering the skin on the hands, face, feet or back of your knees). Eczema (also known as atopic dermatitis) affects mostly children and those suffering from eczema often develop further allergic condition like hay fever and asthma.
Zinc is used to treat eczema as it soothes skin that has become inflamed (31). Eczema is some cases caused by leaky gut syndrome which is a condition which results in large amounts of zinc being excreted from the body (32).
15. Zinc Can Prevent Night Blindness
Night blindness is the loss of the ability to see accurately in the dark or reduced light and is usually a symptom of a problem in the retina of the eyes.
Vitamin A is largely responsible for the health of the eyes but without healthy zinc levels in our systems our body is unable to use vitamin A correctly. Zinc paired with vitamin A has much better effects on night blindness than vitamin A alone (33).
15 Best Zinc Foods
Garlic being used for health benefits stretches 3000 years back to, it was also used in World War I to treat wounds as it works as an antiseptic. Garlic is a good source of sulphur, iodine, chlorine, calcium, iron and phosphorous.
Garlic can treat eye infections and ear aches. Both raw and cooked garlic have antifungal, antibiotic and antiviral properties. The quercetin, vitamin C and selenium found in garlic help to reduce swelling brought on by eye infections.
Colitis, dysentery and diarrhea are all intestinal problems that can be cured with garlic. Garlic destroys all the potentially harmful bacteria that builds up in the gut whilst leaving the helpful gut bacteria untouched. Garlic is also a useful tool for expelling intestinal worms. Garlic aids the natural work of our intestines which results in smooth bowel movements.
Consuming garlic reduces platelet aggregation (platelets are blood cells and platelet aggregation is when these blood cells begin to cling to each other) which reduces the risk of thrombosis (when a blood clot begins to form within a blood vessel and causes and obstruction of blood flow).
Watermelon seeds are a great source of protein. Just one cup of seeds can provide you with over 60 percent of the recommended daily intake of protein. The protein found in watermelon seeds are made up of varying amino acids, one of these being arginine. Arginine has a multitude of benefits including working to treat coronary heart disease and regulating blood pressure within the body.
Watermelon seeds are incredible rich in magnesium. Magnesium has a calming effect on people suffering from anxiety or nerves. Magnesium boosts the production of an acid called gamma-aminobutyric. When this acid is in low quantities in the brain feelings of unease and worry become heightened. Magnesium also clears the brain of metal build up which can also result in anxiety.
Magnesium can be used as a sleep aid as it promotes healthy sleep cycles. It also works to prevent migraines, keep a healthy pregnancy, ease muscle aches and spasms and regulates calcium within the body (makes sure that calcium is sent to the bones to build new stronger bone instead of collecting in the arteries and blood vessels where it could create blood clots).
Watermelon seeds contain lycopene, an antioxidant that works to protect our bodies from multiple disease caused damages. Lycopene is also good for improving fertility in men.
Chickpeas provide twofold heart health benefits. Chickpeas contain omega-3 fatty acids, a healthy polyunsaturated fat that is vital to overall health, which reduces inflammation and promotes heart health. Chickpeas are also high in soluble fibre which strips cholesterol from the heart, arteries and blood vessels minimising the risk of clot formation.
Chickpeas contain folate. Folate is known for protecting against birth defects and is an important supplement during pregnancy. When folate levels dip during pregnancy there is a high risk of neural tube defects.
Chickpeas are a legume and also a complex carbohydrate. Complex carbohydrates are digested very slowly by the body and keep blood levels in a healthy range unlike simple carbohydrates that result in a sudden spike in blood sugar followed by a large drop. Being a complex carbohydrate makes chickpeas a good food choice for those suffering from diabetes.
The fibre content in chickpeas are good for our digestive systems. Fibre pulls out water from within our bodies and adding them to the stool being formed adding bulk and resulting in smoother bowel movements. This can lower instances of constipation and irritable bowel syndrome. Fibre also balances bacteria and pH levels in our guts.
Oysters are considered an aphrodisiac (a food which boosts sexual desire and performance) and this is due to the incredibly high levels of zinc found in oysters. Low levels of zinc are thought to be responsible for erectile dysfunction and impotency in men.
The iron present in oysters has great health benefits for your energy levels. Iron is absolutely crucial to the body’s red blood cell formation. Red blood cells are the cells that carry oxygen throughout the body to our organs. More fresh red blood cells result in organs receiving higher volumes of oxygenated blood which increases their activity. Iron is also the body’s number one defense against a anemia. Anemia occurs when the body becomes crucially low on iron and the symptoms can include;
- Feeling very weak or fatigued
- Cognitive malfunctions
- Feeling dizzy
- Shortness of breath or trouble breathing
- A tingling sensation in the legs
- Craving strange things like clay or soil
- Losing colour in the skin
- A swollen or sore tongue
Just one serving of oysters can give you up to 90 percent of your daily iron recommendation.
Cashews contain oleic acid, an acid that has shown benefits for those suffering from diabetes or prediabetes as it improves blood circulation, insulin sensitivity and fasting plasma glucose (blood sugar).
Many people avoid eating too many nuts because of the fats they contain but these fats are very heart healthy! Cashews contain polyunsaturated fats and monounsaturated fats without which our bodies would not be able to efficiently absorb fat soluble vitamins such as vitamins D, A, E and K.
Cashews are high in minerals, particularly copper, and can ensure that the healthy balance of minerals in your body stays stable. Just one serving of cashews provides you with over 30 percent of your daily recommended intake of copper. When you are copper deficient you may experience the following symptoms;
- Osteoporosis (brittle and weak bones)
- Pale skin
- Poor circulation of blood
- Sudden and unexplained weight loss
- Stunted growth
- Feeling tired and weak
- Pain in the joints and or muscles
- Dilated veins
- Thyroid disorders
- A drop in your count of white blood cells
Copper works hand in hand with melanin to provide coloration to our skin, eyes and hair. Incorporating copper into your diet can help stave off grey hairs. Copper is vital for the synthesis of myelin (a white, fatty substance the covers the nerves), collagen and hemoglobin (protein present within red blood cells responsible for carrying oxygen). Copper also helps the body produce elastin which works with connective tissues to keep your skin flexible.
Copper has brain health benefits and when ingested in the correct amounts can result in more effective thought processes.
Beef is an important source of protein. Every organ in your body needs protein to function as it should. Red meat is also rich in iron, zinc, vitamins B12, B6 and vitamin D.
Mushrooms contain an antioxidant called ergothioneine. Ergothioneine works to protect our immune systems from damage caused by free radicals (a molecule with unpaired electrons which damages cells) and to boost the overall health and stability of it. Mushrooms are also full of natural antibiotics which work similarly to penicillin which work to inhibit fungal infections and microbial growth. These natural antibiotics also speed up the healing of ulcerous wounds and protect these wounds from the development of infections.
Mushrooms are a good source of the trace mineral selenium. When our bodies are selenium deficient we are at danger of developing Keshan disease. Keshan disease regularly leads to myocardial necrosis which weakens the heart. A selenium deficiency can also cause Kashin-Beck disease which leads to necrosis (cell damage) of cartilage tissue within our joints.
Selenium increases blood flow within the body, works to combat coronary heart disease, fights inflammation and reduces oxidative stress caused by free radicals. Selenium is mostly found in animal proteins so mushrooms are a great food based source of the mineral for vegans and vegetarians.
Mushrooms have a high protein content, are low in carbohydrates, contain fibre, water, various minerals and vitamins and are completely devoid of cholesterol and fats. All this together makes mushrooms a perfect food for diabetics.
Shrimp are chock full of minerals and vitamins. Shrimp contain calcium, sodium, magnesium, zinc, phosphorous, potassium, iodine, thiamine, niacin, riboflavin and vitamins E, A, B12 and B6.
The vitamin A present in shrimp controls the development of red blood cells. The vitamin A works to stimulate genes that developing cells need to transform from being stem cells to being mature and functioning red blood cells. Vitamin A also allows red blood cells to gain access to iron needed for oxygen transportation.
Shrimp are rich in astaxanthin, a carotenoid which acts as a potent antioxidant, reducing skin damage (aging) caused by prolonged direct exposure to UV rays.
Shrimp can be used to fight age related macular degeneration. Age related macular degeneration is when an area of your retina known as the macula becomes damaged and is the leading cause of eye damage and blindness worldwide. Astaxanthin and the heparin-like compound present in shrimp help to protect against age related macular degeneration and can relieve eye fatigue that some people suffer from due to work involving looking at computer or TV screens for extended periods of time.
The magnesium, phosphorous, calcium and protein found in shrimp all contribute to maintaining bone health.
Brown rice is rich in powerful antioxidants. The antioxidant enzyme in brown rice known as superoxide dismutase keeps cells protected against oxidation damage which typically occurs during the production of energy. Brown rice has been shown to be superior to white rice in preventing oxidation-mediated diseases (heart disease).
The high fibre and antioxidant content of brown rice also makes it a potent anti cancer food. Brown rice has been shown to be able to help prevent leukemia, breast cancer and colon cancer. Fibre binds itself to toxins that cause cancer which renders these toxins unable to attach themselves to your colon wall.
The manganese and vitamin B found in brown rice can keep the brain’s cognitive function running smoothly. Brown rice also contains magnesium which acts as a calcium regulator, keeping calcium in the bones and out of nerve cells. The gamma-aminobutyric acid in brown rice combats the onset of neurodegenerative diseases including Alzheimer’s disease.
Egg yolks are often omitted and only egg whites used in an effort to lose weight, but the vast majority of vitamins that eggs have to offer are found exclusively in the egg yolks. Vitamins A, D, E, K, B6, B12 and folate are all found in egg yolks. Minerals found in eggs include magnesium, selenium, iron, potassium, calcium and sodium.
Egg yolks contain the macronutrient choline. Choline supports brain development, nerve function, movement of muscles, liver function, energy levels and keeps a healthy metabolism. Choline is especially important for pregnant and breastfeeding women. A choline deficiency could result in the following symptoms;
- Feeling fatigued
- Loss of memory
- Decline in cognitive function
- Damage to nerves
- Mood disorders or sudden mood changes
One large egg can supply you with nearly 150 milligrams of choline.
It is true that egg yolks are high in cholesterol but they also raise the level of HDL (high density lipoprotein) cholesterol which is known as the good cholesterol.
Egg yolks also contain zeaxanthin and lutein, both of which help to protect the eyes against the onset of cataracts (when the lens of the eye becomes clouded and vision becomes blurred).
Turkey is a great source of protein and contains a very small amount of fat.
Turkey contains niacin or vitamin B3. Niacin plays a role in normalising our digestive systems. Niacin is a useful tool in combating erectile dysfunction and a low libido. Niacin reduces levels of LDL cholesterol (the bad cholesterol) and raises levels of HDL cholesterol (the good cholesterol), this aids in protecting the body from diseases like atherosclerosis (a disease where LDL cholesterol build up results in the narrowing and hardening of the arteries).
Turkey is a good source of the essential amino acid tryptophan. Tryptophan boosts serotonin production and is used to treat anxiety, depression, sleep apnea, insomnia and premenstrual dysphoric disorder, among other disorders.
A single cup of peas contains up to 10 milligrams of coumestrol. Coumestrol is a polyphenol that has been shown to be able to protect against stomach cancer.
Peas are a rich source of anti inflammatory phytonutrients, those along with the vitamins, omega-3 fatty acids and minerals present in peas help peas to prevent candida (fungal infection), bronchitis, wrinkles, alzheimer’s and osteoporosis.
Dark chocolate is full of copper and magnesium which regulates heart rhythm and blood pressure. Dark chocolate also enables blood vessels to be more flexible and maximises endothelial cell (cells making up the lining of blood vessels) which allows for better blood circulation. Polyphenols in dark chocolate also contribute to keeping your vascular health.
Consuming a healthy amount of dark chocolate can lower cholesterol levels in the body anywhere from 10 to 12 percent.
Those suffering from anemia can find relief by consuming dark chocolate due to the flavonoid compounds it holds. Dark chocolate also contains serotonin and antioxidants.
Pumpkin seeds are an excellent source of omega-3 fatty acids that are plant based, which is a good way for vegetarians and vegans to get this important oil into their diets. Omega-3 fatty acids can sooth symptoms of anxiety, ADHD, arthritis, cardiovascular disease and improve hair and skin quality, fertility, diabetes and aid in weight loss.
Pumpkin seeds contain phytoestrogens which can decrease the joint pains, hot flashes and changes in blood pressure some women experience due to being premenopausal.
Pumpkin seeds contain the amino acid (amino acids are protein building blocks) tryptophan which is converted to serotonin upon entering the body. This serotonin is then changed to melatonin which is a hormone that ensure restful sleep and regular sleep cycles.
Beef liver is high in vitamin A. When your body is vitamin A deficient you may experience a drop in the strength of your immune system as it is vital for white blood cells to grow normally. Beef liver is also incredibly rich in iron and vitamin B12.