The 3 Necessary Nutrients For Your Healthy Bodily And Organs Function

The following is a brief introduction into the many organs and parts of the body, and 3 necessary nutrients for healthy function. In general, a balanced diet combined with plentiful exercise is a good first step for maintaining a healthy body and healthy mind.

In this article we cover all these body organs and parts of the body:

Skin • Hair • Nails • Brain • Eyes • Vaculature • Muscles • Heart • Bones • Joints • Lungs • Stomach • Liver • Intestines • Pancreas • Spleen • Kidney

Skin

The skin is the largest organ in the body, having a total area of roughly 2m². Its function is to regulate body temperature, protect us from microbes and external substances, and to help us navigate our external environment through our sense of touch.

It is composed of 3 layers:

Epidermis - the outermost layer which creates our skin tone, colour, and complexion.
Dermis - located beneath the epidermis and contains sweat glands, hair follicles, and connective tissue (which is often composed of collagen).
Hypodermis (also known as deeper subcutaneous tissue) - deepest layer and it is mainly used for fat storage.

Necessary nutrients:

Vitamin C - a well known antioxidant found in many fruits and vegetables. As an antioxidant, it helps reduce oxidative stress and is also involved in the production of collagen which ensures the skin is kept soft and smooth. An observational study found that it may also prevent skin wrinkling¹.
Vitamin A - another well known vitamin and it is used as an effective severe acne treatment. It promotes epidermal cell differentiation and controls dermal growth factors - meaning it prevents formation of clogged hair follicles which is a major cause of acne². Vitamin A can be found in cod liver oil supplements.
Zinc - is an essential mineral necessary for many physiological processes in the body. It is important for healthy wound healing, plays a role in the immune system, and is also necessary for proper formation of the proteins and membranes found in the skin. Furthermore it is required for the transport of Vitamin A in the bloodstream, and studies have shown that Zinc supplementation has led to a significant increase in Vitamin A levels which can therefore promote healthy skin³.

Hair

Hair is a ubiquitous feature of mammals - the phylogenetic class of organisms that humans, apes, and many others belong to. Its function includes protection, thermal insulation, and also as sense organs so we can perceive the world around us.

Hair is an elongated protein filament called keratin which is covered by an oily sheath known as sebum. Sebum is needed for lubrication and protection of the keratin underneath. Both are produced from hair follicles and sebaceous glands which are found in the dermis of the skin.

Essential nutrients:

Biotin - also known as Vitamin B7 is a water soluble vitamin that is required by all organisms. It is necessary for synthesis of keratin growth factor - the hormone that promotes synthesis of keratin4. Care must be taken as excessive biotin ingestion can also induce excessive sebum production in the skin, causing acne.
Protein - composed of lots of amino acids. The amino acid Lysine is commonly found in keratin, and recent studies have found that Lysine-based treatments for male pattern hair loss have increased hair count⁵.
Omega 3 - sebum that is produced from the sebaceous glands is composed of a variety of fatty acids including omega-3s. This gives hair a shiny coat that makes it smooth, waterproof, and strong4.

Nails

Analogous to hair, nails are also derivatives of the skin. They lie on the distal phalanges (fingers and toes) and function for protection, scratching, and aid in picking objects up. Nails are composed of a tough protein called keratin which is also found in horses' hooves and animal horns.

Along with the nutrients that are beneficial for the skin and hair, Vitamin B12 is a key regulator of nail health. Insufficient Vitamin B12 can lead to darkened and rounded nails which are weaker than usual6. Due to the high number of important vitamins and minerals necessary for a healthy body, multivitamins may aid in increasing intake without spending hours taking different supplements.

Brain

The brain is the primary organ of the central nervous system controlling the majority of the bodies conscious and unconscious actions. It is surrounded by the skull and also suspended in cerebrospinal fluid for further protection. In a human adult, it weighs around 1.2 - 1.4kg (around 2% of the average body mass) and consumes the most energy out of any organ in the body (20% of the bodies total energy expenditure).

The brain is composed of 3 main parts - brainstem, cerebellum, and cerebrum. Each part is responsible for different processes, however every single part of the brain has to be healthy for normal functioning. Due to the complexity of the human brain there is much research investigating the effects of diet on brain function⁷.

It has been found that omega-3 fatty acids can aid cognitive processes (such as thinking) and has also been found to reduce incidence of severe depression⁸.
As the brain uses so much energy it is highly susceptible to oxidative damage from metabolism therefore antioxidants have much publicised positive effects on the brain such as increased cognition, age span, and memory. These antioxidants include:
- Alpha lipoic acid which is found in spinach, broccoli, liver, kidneys.
- Vitamin E found in vegetable oils, nuts, and green vegetables.
- The spice curcumin is main compound found in turmeric.
On the other hand, the modern Western diet high in saturated fats has been found to increase neurological dysfunction in both animals and humans⁷. Therefore it is a good idea to moderate intake of saturated fats!

Eyes

The eye is the optical apparatus responsible for sight. It has many components that are crucial to focus an image onto the retina, which is then transported by the optic nerve to the brain for processing. Some key components of the eyes include:

Cornea - clear front part of the eye that protects and helps focus light.
Iris - coloured part of the eye that regulates amount of light entering by controlling the size of the pupil.
Lens - transparent structure that that focuses light onto the retina. Oxidative damage in the lens is the primary cause of cataracts, which causes cloudiness that inhibits vision.
Retina - a layer of nerves that detect light and converts this to electrical impulses which then transmit the information to the brain.

Essential nutrients:

Vitamin C - the powerful antioxidant that is ubiquitous for growth, development, and functioning of many parts of the body. Has been found associated with slowing the progression of age related macular degeneration and formation of cataracts⁹.
Lutein & Zeaxanthin - nutrients found in leafy green vegetables and eggs. They are both antioxidants that filter damaging high-energy blue wavelength light in order to protect the cells in the retina. These antioxidants neutralise the free radicals that cause oxidative damage, thus reducing the risk of cataract formation⁹.
Zinc - trace mineral that is essential in transporting Vitamin A3. Vitamin A is necessary to produce melanin which is a protective pigment in the eye. Zinc is highly concentrated in the retina and the tissue underlying it.

Vasculature

The word vasculature comes from the latin word vascularis and refers to the arrangement of blood vessels in the body. The blood plays a fundamental role to the body by supplying oxygen and nutrients to the cells around the body, removing waste such as carbon dioxide, and regulating temperature. Therefore movement of the blood is imperative for these to function normally. There are three main types of vessels:

Arteries transport blood away from the heart.
Veins transport blood to the heart.
Capillaries are the smallest type of vessel and this is where oxygen and other nutrients diffuse across into the tissue layers⁴.

Every artery is comprised of three layers of tissue:

Tunica intima is the innermost layer that is closest to the blood. There is a thin layer composed of specialised cells called the endothelium which are important as a barrier and detecting blood pressure, temperature, and pH. The endothelium is the most important part that represents the healthiness of the arteries as damage and disrepair leads to many diseases.
Tunica media is a thick middle layer containing muscle and fibres to withstand the high blood pressure in the arteries.
The outermost layer Tunica adventitia is composed of connective tissue and small blood vessels that feed blood to the walls of the thick arteries.

How to keep it healthy?

It is already understood that mild to moderate exercise protects against the development of atherosclerosis - a build up of fatty deposits (plaque) on the insides of arteries. Atherosclerosis can inhibit blood flow which is the predominant cause of strokes and heart attacks¹⁰.
Going hand-in-hand with exercise is a healthy diet. Eating less saturated fats results in less plaque formation.
Consumption of foods that increase nitric oxide. Nitric oxide relaxes the blood vessel walls allowing for easier flow, lower blood pressure, and thus prevention of blood clots. Nutrients such as nitrates and amino acids (arginine and citrulline) are all necessary for formation of nitric oxide. These come from sources including beetroot, green vegetables, watermelon, fish and lean meats.
Antioxidants once again prevents oxidative damage allowing for healthier vessels and unimpeded blood flow. Major sources come from flavonoids and Vitamin E.

Muscles

Muscles are responsible for many things including movement and posture. The human body has around 650 muscles from the prominent gluteus maximus (bottom) to the much smaller masseter which helps close the jaw. On the face alone there are 43 muscles which are necessary for eating, controlling senses, and making facial expressions⁴.

There are three groups of muscles:

Skeletal muscles move the external parts of the body. These are usually the prominent muscles that people such as body builders aim to improve. These include the deltoids (shoulder), biceps brachii, triceps brachii, etc.
Smooth muscles are responsible for movement in the organs and arteries. When food is digested, the organs have to move in a manner that pushes the food along the gastrointestinal tract (for digestion). Therefore these muscles are imperative for healthy functioning of the human body.
Last but definitely not least are cardiac muscles. These only exist in the heart and are necessary to pump blood with extremely high force so it can circulate around the body. Therefore healthy functioning of muscles is extremely important!

What you can do to improve muscular health:

Exercise - there are numerous guides, videos, and gyms readily available for anyone to learn. Even without a readily available gym, running and bodyweight fitness are options that anyone can perform. One important thing to note is to ensure there is a balance in training the muscle groups - so rather than doing bicep curls all day, it is important to balance this out with tricep and core exercises!
Stretching - a very underrated part of modern life. As people have "9 to 5" desk jobs, sometimes muscles which are not used very much grow tight such as the hamstrings. Furthermore after exercise muscles can tighten up, therefore stretching is an extremely beneficial complement to exercise so a wide range of motion is maintained.
Diet - a healthy and low fat diet filled with plentiful proteins, carbohydrates, vitamins and minerals. Hydration is often neglected, but muscles are around 70% water so this is indispensable in maintaining muscular health.

Heart

The heart is the most important muscle in the human body. It is responsible for pumping blood (which contains nutrients and expels wastes) around the body. There are two main circuits: the systemic circuit that pumps oxygenated blood around the body so each cell has the sufficient nutrients, and the pulmonary circuit which pumps deoxygenated blood to the lungs where toxic carbon dioxide can be expelled whilst oxygen can diffuse back into the blood. Just like all muscles it contracts, and this contraction forces blood away from the heart at high pressure, whereas relaxation allows the heart to fill with blood. It houses four chambers: the right atrium, right ventricle, left atrium, left ventricle. Blood is pumped out through the ventricles and allowed in at the atria. In an average lifespan the heart will pump over 3 billion times⁴!

As the heart is a muscle it requires blood supply so the muscle fibres have the nutrients enabling them to contract at a high force. This blood supply does not directly come from the blood in the atria and ventricles because this blood is pumped at such a high pressure that the cells would not be able to absorb any oxygen. Instead the heart receives blood through the coronary arteries which become implicated in diseases such as the common and aptly named coronary heart disease (see vasculature).

How to ensure your heart is healthy:

Do not smoke - smoking is associated with many complications. Studies have found that all levels of smokers have an increased risk for coronary heart disease. Furthermore, many studies have found that the risk of heart attacks and coronary heart disease are lower among former smokers than continuing smokers - the risk for both halving after quitting smoking for just one year¹¹.
Maintain a healthy weight - obesity promotes a cascade of secondary pathologies including diabetes, inflammation, high blood pressure, and high cholesterol. These collectively heighten the risk for diseases related to the heart¹². As this is one of the most readily changeable risk factors, a healthy weight is essential for a healthy body.
Avoid high cholesterol - cholesterol is a fat-like substance and over time, it builds up on the walls of arteries. This buildup leads to a "hardening of the arteries" which can block or slow blood flow. If this occurs in the coronary arteries which supply the heart then the heart does not get enough oxygen, leading to a heart attack¹³.

Bones

Bones are living growing tissues that are constantly breaking down and remodelling. Collagen is a protein that forms a soft framework and calcium phosphate is a mineral that adds strength and rigidity to this framework. The combination of hard and soft makes bones strong and flexible enough to withstand the many stresses of daily life⁴. Bones also contain connective tissues, nerves, blood vessels, marrow, and are the location for blood cell formation.

Essential nutrients:

Calcium - the bones contain 99% of the bodies total calcium in order to ensure bone strength. Low calcium can result in reduced bone strength, however high calcium intake needs to be combined with hormonal signals to ensure that the calcium goes straight to the bones. It has been estimated that 90% of women may not be getting enough calcium¹⁴.
Vitamin D - is necessary to synthesise the hormonal signals so that calcium can get absorbed by the body15. Therefore even if someone has the requisite intake of calcium, without vitamin D the body will not absorb it. In addition it has been estimated that over 50% of women treated for bone loss do not have the necessary levels of Vitamin D14.
Proteins make up 20-30% of the bones mass. Whilst protein has been debated as being both detrimental and beneficial to bone health, higher protein diets are actually associated with greater bone mass and fewer fractures when calcium intake is adequate¹⁶.

Joints

Joints (also known as articulations) allow for the strong and rigid skeletal system to move. They are strong connections joining bones, teeth, and cartilage together. They can be categorised either by function or structure - below are the categories based on function:

Joint that permits no movement at all are known as synarthrosis. E.g. the joints connecting teeth to the skull.
Joints permitting slight movement are ampiarthrosis. E.g. the joints between the invertebral disks in the back that form the spine.
Diarthrosis are freely moveable joints. This includes the knee, elbow, shoulder, wrist, etc.

Arthritis is a general term for conditions affecting the joints and surrounding tissue. This often involves inflammation and becomes more prevalent as people age. A couple of strategies to maximise joint health:

Maintaining a healthy weight. This reduces load on the joints which also lessens wear and tear.
Studies have found that treatment with omega-3 fatty acids have been associated with improvement in some symptoms of rheumatoid arthritis. Furthermore these decrease the long-term need for some nonsteroidal anti-inflammatory drugs^17,18.
Sulforaphane is an antioxidant that has been found to protect cartilage from degradation¹⁹. This can be consumed naturally from the commonly available vegetables kale and broccoli.

Lungs

The lungs are intricately linked with the vasculature (blood vessels) and the heart. The heart is responsible for pumping blood around the body whilst the lungs serve to oxygenate this blood and remove the toxic carbon dioxide. Humans have two lungs (right and left) that are both surrounded by ribs for protection.

Air enters the body through the nose or mouth and then travels down the trachea (also known as windpipe). The trachea then splits into two bronchi, each going to a separate lung. The bronchi then branch off many times and get smaller and smaller, eventually reaching the site of gas exchange that is known as alveoli. It is here that oxygen can diffuse into the capillaries and carbon dioxide can diffuse out. It is estimated that if the lungs were spread out completely, its surface area would cover roughly one side of a tennis court!

How can we improve our lung health?

Minimise breathing in air pollutants - it is well characterised and understood that smoking, second hand smoke, and radon are carcinogens that greatly increase the risk of lung cancer20. From the US Surgeon General's Report 1990:
- 1 to 9 months after quitting coughing and shortness of breath decrease; lung function improves and risk of infection decreases.
- 10 years after quitting the death rate from lung cancer halves.
Fresh fruit and vegetables contain many of the necessary vitamins and minerals. It is recommended that these are consumed daily, offsetting the need for many different types of supplements21.
Numerous studies suggest that antioxidants, particularly vitamin C, and to a lesser extent others, have a protective effect against lung diseases and may protect against poor breathing in young adults^21,22.

Stomach

After food is swallowed, it travels via the oesophagus down towards the stomach. The stomach is a bean shaped organ that is stretchy and can hold up to 2-3L of food. It acts as a food blender, primarily chemically digesting the food before it can continue along into the small intestines. A mixture of acid and digestive enzymes (Gastric juices) are secreted into the stomach, converting eaten food into a semiliquid mixture known as chyme. This chyme can be seen (and smelled!) when someone vomits^4,23,24.

Liver

The liver is the largest gland in the human body and the largest organ after the skin. It weighs approximately 1.5 kg and is located on the right side of the body protected by the bottom of the rib cage. Its function is to filter the blood coming from the digestive tract before it continues around the rest of the body. This means that it has to filter out potential toxic substances such as alcohol, medicine, and other foreign matter.

To maintain a healthy liver it is mostly about avoiding detrimental actions rather than trying to consume things to improve its health. The most effective action is to cut consumption of alcohol as alcohol is the most frequent cause of liver disease in western countries. It has been reported that heavy alcoholics who consume at least 80 g of alcohol (around 6 standard drinks) per day for more than 10 years will develop liver disease at a rate of nearly 100%²⁵.

Intestines

The intestines are a long and winding tube that connects the stomach to the anus. It is the main site for absorption of nutrients from our food.

The small intestine is connected to the stomach and is in the more central area compared to the large intestine. It is extremely tortuous (winding) and when an adult humans is stretched completely, it is around 7 m long! The chyme from the stomach passes through here and most of the nutrients from this mixture are absorbed. It is divided into three parts: duodenum, ileum, jejunum.

The large intestine is where food travels after passing through the small intestine. Contrary to the name, it is actually shorter than the small intestine, only having a length of around 1.5m. It surrounds the small intestine and absorbs water from the chyme. Once the water has been absorbed, the remaining chyme hardens forming a semi-solid stool commonly known as faeces⁴. The large intestine is divided into five main parts: cecum and appendix, the transverse colon, descending colon, sigmoid colon, and the rectum.

So what can we do to maintain the health of our intestines?

A diet high in dietary fibre. Dietary fibre is a term to describe both insoluble and soluble fibres. Insoluble fibre does not dissolve in water, and comes from plants like wheat, seeds, and vegetables. Soluble fibre dissolves in water and is found in legumes, oats, fruits, and barley. Fibre plays a large role in intestinal/digestive health. Fibre is the fuel that large intestinal cells use to keep themselves healthy. Fibre also helps to keep the digestive tract flowing, by keeping bowel movements soft and regular²⁶.
Exercise - nothing moves by itself in this universe, therefore the chyme in the intestines is reliant on muscles to help it move. A 2014 study found that exercise increased intestinal motility, meaning that exercise can help the movement of chyme through the intestines which can prevent constipation²⁷.
Probiotics - the digestive tract relies on "good bacteria" (gut flora/microbiota) to perform many functions. They inhibit pathogens to prevent unwanted bacteria from colonising the intestines, they help develop the immune system, and they even help break down certain carbohydrates! Therefore probiotics and fermented foods (kimchi, sauerkraut, etc.) should be consumed to bolster the gut flora²⁶.

Pancreas

The pancreas is an oddly shaped accessory gland located behind the stomach nestled near the liver and spleen. The function of the pancreas is not as well known as the stomach for example, but it has extremely important functions. It secretes pancreatic juices into the small intestine to aid in digestion of some foods, and it also secretes glucagon and insulin into the blood. Insulin and glucagon are hormones that are released in response to changing blood glucose levels. This needs to be maintained at a constant level, as all the cells in the body use glucose as an energy source. If blood glucose levels drop too low then important organs such as the brain cannot get the energy they need which can lead to fainting. This is an issue in diseases such as diabetes⁴.

Spleen

The spleen is a fist shaped organ located near the stomach in the left part of the abdomen. It has a wide range of important functions such as filtering the blood, controlling the amount of red blood cells, and helps fight infection. Consuming plentiful water can improve spleen health as this provides the necessary water that helps flush out toxins from the body.

Kidney

The kidneys remove excess wastes, salts, and water from the blood to form urine. Most humans have two functioning kidneys although it is possible to survive with only one. They lie towards the back of the body, just above the waist and near the spine. All the blood in the human body flows through the kidneys multiple times per day, and the filtration takes place in millions of microscopic units known as nephrons.

How to ensure kidney health:

An adequate amount of water is necessary in ensuring health of the kidneys. Drinking low amounts of water and drinking hard water increases the risk of kidney stones that cause lots of pain28.
Kidneys filter excess salts and proteins from the blood. If there is excessive amounts of either, then the kidneys have to work extra hard to filter the blood. Therefore moderating intake of protein and salts can allow the kidneys to not work as hard, ensuring they can stay healthy for longer. Salt intake is a modifiable risk factor for the progression of kidney disease²⁹.

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