Body Systems to Support

General health

Good health should be considered as an absence of disease, a profound sense of well-being, and consistent high energy levels, achieved naturally without the help of stimulants.

Making simple diet and lifestyle changes can help you achieve this. Nutritional therapy looks at how all of your body systems work in unison and how to best maintain and support their function, as well as helping to prevent disease. This is an holistic approach, looking at the body as a whole and as no one part or function in isolation. We look to increase the factors that are positive, whilst reducing those that might harm us. This simply be a question of swapping some choices for more healthy ones, but there are also many factors in today’s world that make this harder such as pollution, toxins and anti-nutrients such as sugar, alcohol and caffeine, in addition to and possibly the most profound of all – stress.


The digestive system extends the whole way from the mouth to the anus and is responsible fordigestion of foods, absorption and assimilation of nutrients and elimination of waste products and toxins. It is also the site for a large part of the immune system and production of some neurotransmitters (brain chemicals).

Digestion, the breakdown of food, involves mechanical action such as chewing and muscular actions in the stomach and intestines and chemical breakdown by digestive enzymes (released into the mouth, stomach and small intestine) and other digestive juices. Any inadequacy in mechanical or chemical digestion may result in indigestion, bloating, flatulence, constipation, diarrhoea and other digestive problems as food is not fully broken down, but can sit around and putrefy, ferment or lead to gas production in the colon.

Once digestion of food has occurred, it needs to be absorbed for us to access its nutritional constituents. Elimination is another vital role of this system.  Faeces contain waste products such as fibres, old blood cells, old hormones and substances that are toxic to the body.  These toxins are usually processed in the liver and released into the gut in bile.  A healthy digestion supports liver health by removing toxins, old hormones, cholesterol and other waste products from the body.


Any substance that is potentially harmful rather than beneficial to the body could be called a toxin. We produce toxic elements from every cell naturally as part of the body’s metabolic processes. We also ingest them in food, breathe them in air, absorb them through the skin, in fact we are exposed to many different toxic substances, every minute of every day and our bodies work hard to remove these in many ways, in processes called ‘detoxification’. It is the role of the liver to render these potentially harmful products into less harmful compounds and pass them to the bowel and kidneys for removal. Each of our cells needs to constantly detoxify and toxic build-up also prevents the uptake of nutrients into food, which can decrease functionality.

How we deal with these substances via detoxification is very important; it can depend on sex, age, health, toxic status, genetics, nutritional and lifestyle factors.  Detoxification is not just about a period of ‘detox’ which we might choose to do as a cleansing routine, but a constant process that needs continual support.


The immune system is a multi-layered, complex, defence system. It protects the body from invasion by external micro organisms such as bacteria, viruses, parasites and any other nasties that would like to make us their home. It also protects us from ourselves, allowing us to distinguish ‘self’ from ‘non-self’ and therefore react only to foreign substances rather than our own body tissues. In cancer or autoimmune diseases, our cells turn on each other, the sign of a mis-signalling or ‘confused’ immune system.

The lymphatic system is an important part of the immune process, transporting fluid from our tissues to our bloodstream. Millions of free ranging immune cells called antibodies (orimmunoglobulins) circulate the body looking for invaders to destroy before they cause damage or spread. Antibodies are pumped out by the blood stream, and brought back via the lymphatic system. Any nasty found on the way is taken to the lymph glands to be dealt with. This is why swollen lymph glands are a sign of infection.

Inflammation is part of the immune system’s armoury of weapons. It is the body’s initial response to injury, irritation or infection. The primary signs of acute inflammation are pain, swelling, redness and heat. This is in fact the first sign of healing and involves the release of the chemicalhistamine. However if for some reason healing fails to occur, chronic inflammation can follow, a sign that the immune system has become over stimulated.

Pre-menopause female sexual and reproductive

A female baby is born with a full quota of egg follicles in her ovaries (around one million), but these will only mature into eggs when she reaches sexual maturity at puberty.  This is the point at which her periods (menstruation) begin, the monthly bleed that occurs at the end of her cycle of between 21 and 32 days, but typically 28 days in length.

The menstrual cycle is a finely tuned series of events, under the fine control of a number of female sex hormones, including oestrogen and progesterone, both produced by the ovaries. The whole purpose of the cycle is to prepare the body for pregnancy, including the release of a mature egg (ovulation), the thickening of the uterine wall and its breakdown and loss at menstruation, if pregnancy does not occur.

The menstrual cycle continues throughout the reproductive life of a woman, until she reaches themenopause, at which point ovulation ceases and she is no longer fertile and able to reproduce.

Female sexual and reproductive system during breastfeeding

Breastfeeding provides a baby with complete nourishment from birth until it is weaned onto solid foods, normally between 6 months to a year of age.  The American Academy of Pediatrics (1997) has officially advocated breast milk as ‘the ideal, exclusive food for babies in the first six months of life’, also advising that ‘breast-feeding continue for at least 12 months or longer if mutually desired’.

Human breast milk has a unique composition that is different to that of other mammals.  It is thought to be the best form of nutrition for a baby, providing all of the required nutrients plus other bioactive substances such as hormones and growth factors, as well as immune-protective and anti-infective agents, including antibodies (primarily immunoglobulin A, or IgA), lactoferrin,Bifidobacterium bifidum and white blood cells.

The composition of human milk changes over time to meet the different needs of the growing baby. The initial ‘milk’ produced by the mother is in fact not milk but a substance calledcolostrum, which is very rich in antibodies, proteins and minerals.  Antibodies in colostrum provide the baby’s immature immune system with some initial protection until it has developed sufficiently. Within 7 to 10 days after birth colostrum begins to give way to milk, which is richer in fat and lower in immune cells.  This milk will provide the baby with all of its fluid and nutrient requirements until it is ready to be weaned.

Female sexual and reproductive system during pregnancy

A woman’s reproductive system consists of the vagina, uterus (the entrance to which is called the cervix), fallopian tubes and ovaries.  The monthly menstrual cycle is around 28 days in length, during which time an egg is released from the ovaries (ovulation) at around day 14 of the cycle.  As well as being the storehouse for eggs, the ovaries produce the female hormones oestrogen and progesterone.  In broad terms oestrogen levels are linked to ovulation and maturation of the uterine lining and progesterone maintains the function of the placenta during pregnancy.

At the time of ovulation, the uterus lining is thick and engorged with blood and provides an ideal environment for a fertilised egg to implant and begin to develop.  The uterus serves a protective environment during the course of the pregnancy and expands to accommodate the growing baby.

Menopausal and post-menopausal female

Menopause is defined as the time when the monthly periods stop for more than 12 consecutive months.  Ovulation no longer occurs and so a woman is no longer able to conceive.  The ovaries no longer produce progesterone and levels of oestrogen dramatically decrease.  After a few years, oestrogen release from the ovaries stops altogether.

As well as its role in the menstrual cycle, oestrogen plays other roles in the body. It is important for the formation of new bone, which is why post-menopausal women are more prone to osteoporosis, with an increased risk of bone fractures.  It also contributes to lowered LDL (‘bad’) cholesterol, arterial and heart health.  After the menopause women are as at much risk of heart disease as men.  Oestrogen also helps to keep skin supple and hair thick.

Male sexual and reproductive

The male reproductive system includes the penis, urethra, prostate gland and testes.  The testes consist of many tubules within which sperm cells develop, a process that takes around three months.  Sperm cells contain the genetic material within 23 chromosomes, which upon fertilisation of an egg provide half of the genetic material for a foetus.

Sperm cells are mixed with fluids secreted from vesicles in the testes and from the prostate gland to form semen.  The prostate is the gland that is wrapped around the urethra (urination tube) at the base of a man’s bladder. Its function is to produce and store about 10-30% of the total seminal fluid that makes up sperm. It also contains some muscles that help the ejaculation process and can be prone to inflammation, enlargement and cancer, so needs much health consideration. Semen provides a nutritive, protective medium for sperm during their journey through the female reproductive tract after ejaculation.

Hormonal (endocrine except for reproductive)

The endocrine system consists of a number of different glands which all secrete hormones – these ‘chemical messengers’ are carried in the blood to act on different organ cells throughout the body, which then carry out functions according to the message sent. Tissue function, mood, growth, sexual function, development and metabolism (how fast body reactions occur) are all affected by the endocrine system.

The endocrine system consists of the hypothalamus, pituitary and pineal glands situated in the brain, the thyroid and parathyroid glands in the neck, the adrenal glands that sit on top of the kidneys, part of the pancreas and the ovaries or testes (not discussed here). Glands can over act (hyper- conditions) or under act (hypo- conditions), which can have a knock-on effect throughout the whole system, which works interdependently.

In total the endocrine system puts together our body rhythms, helping us to get up in the morning, have energy during the day, stay at a stable weight and go to sleep at night to recover. The endocrine system receives its messages via the brain and the nervous system, so signals from outside the body via our senses and the substances we ingest can end up affecting the hormones running round our bodies and ultimately how they respond.


The urinary system is closely related anatomically to the genitals and it is due to this relationship that the system is collectively known as the genito-urinary system.

The urinary system is responsible for producing urine and excreting it efficiently. It is an intricate system that helps regulate the body by collecting substances such as metabolic wastes, toxins, electrolytes and water, breaking them to safer substances that can be excreted as ‘urine’. In doing this it maintains water balance in the body as too much or too little can affect the way cells are able to function, communicate, take up nutrients and eliminate toxins.

It also maintains the balance of electrolytes (sodium, potassium, magnesium and calcium) because for cells to function normally, these minerals have to remain in balance. They are responsible for electrical signalling in the body, so are needed for both communication between cells and muscle contraction. This includes the way the muscles in the bladder are controlled and frequency of urination.

Brain and nervous system

The nervous system could be considered to be the most important system in our body.

The nervous system is our internal communication network, connecting us from head to toe and coordinating all movement and initiating action and monitoring organ function.  Stimuli are received from many sources, both from inside and outside the body and the nervous system is capable of stopping us receiving too many by halting input via the sensory organs – particularly sight and sound – or we can become overwhelmed.  Once input is analysed, the appropriate response or action is produced. All movement, be it skeletal, glandular or hormonal, as well as all thoughts and actions are completely dependent on the nervous system. The brain is the control centre for the nervous system, consisting of a massive network of nerve cells, sending and receiving signals throughout the body. However it would take too long for all decisions to be made via the brain and reflex actions originate from the spine to quickly divert us from harm.

Heart and circulation

Each day, an adult’s heart pumps about 7500 litres of blood around the human body.  This process known as the circulation, relies on the heart and a vast system of blood vessels.  The heart is basically a muscular pump, which is continually contracting and relaxing to force blood around the body and it is this pumping action that is felt as the pulse.

Every cell in the body depends on a constant supply of blood to receive vital substances, such as oxygen, nutrients and hormones.  Cells also release waste products into the blood to be carried away, for example carbon dioxide and chemical metabolites or break-down products.  It is easy to see why a healthy heart and circulation are so important – if any cell is deprived of a blood supply and therefore oxygen and fuel, it will soon die.  The heart and circulation, together known as the cardiovascular system (CV system), are therefore one of the most crucial and hard working systems in the body.  The heart beats an average of 100,000times a day and an astounding 2.5 billion times in an average lifetime.

Skin, hair and nails

The skin is the largest organ in the body, weighing on average 5kg. It is classified as an organ because it is made of layers of different tissue, which have different roles. Skin not only acts as container for the insides of the body, it acts as a barrier to infection and other substances.  It also allows us to touch, plays an important role in temperature control, is a site of elimination and also produces vitamin D.

There are two main layers to skin: the inner dermis and the outer epidermis.  The top layer of the epidermis is covered in mostly dead, flattened cells that consist largely of the protein keratin. Nails can be seen as an extension of this outer later of skin, and are composed of dense layers of keratin.  They provide protection for the nerve-rich ends of fingers and toes.  Body hair is also composed of keratin, but originates from hair follicles in the dermis layer of skin.  Hair protects the skin from sunlight, helps to control heat loss and improves sensitivity to touch.


The eyes are the organs of sight, our primary sense and human beings – we rely on clear and accurate vision to navigate us through, and make sense of the world around us. They work as a pair, although it is possible to see well with one eye. However abilities such as three dimensional work and judgement of distance are only possible when both eyes work together. Eyes basically work by detecting light and as predatory mammals our eyes face forward and have overlapping fields of vision to allow depth perception. We do not have any natural predators, so are designed to look behind without moving the whole of our head and neck.

In ancient civilisations eyes were considered the gateway to the soul and even today bright, clear eyes are a sign of health and beauty.

Breathing and respiratory

Put most simply, breathing brings oxygen into the body and transports carbon dioxide out, which happens on a large scale through the lungs, but also for each and every one of the cells throughout your entire body. Oxygen is vital to life, without it we will die in a few short minutes. It is the respiratory system that provides the means for oxygen to enter bodies via our lungs, into the blood stream and ultimately through the whole body. All cells need a constant supply of oxygen to function, if oxygen is denied the death of the cell will follow. Breathing also provides the means for carbon dioxide to be excreted, which is the by-product of each cell’s breathing or ‘respiring’ – much like the body’s ‘exhaust fumes’.

The respiratory system also filters out, dust, bacteria and other microbes that might have a negative effect on our health. It has a protective mucous lining and if sensing pollution our nervous systems are signalled to produce more shallow breaths for protection.

Bones and joints

There are approximately 206 bones in the human body.  They provide the structural support for the skeleton, which moves, supports and protects us, preserving body shape and encasing internal organs, with the skull and ribs. However, bone is also a living tissue that produces blood cells and plays an important role in the balance (homeostasis) of the mineral calcium in the blood stream, as well as storing other minerals that may be needed for body functions.  Bone is constantly being formed and broken down to meet the needs of growth, repair and changes in calcium status.

Joints occur where two bones meet and allow the skeleton to move. There are many kinds of joints but most have a layer of cartilage in them to prevent bones from rubbing together and causing damage. This is encased by a fibrous joint capsule and filled with synovial fluid for shock absorbing, protection and flexibility. In the condition osteoarthritis, this cartilage layer has been worn away causing damage to joints, pain and inflammation.  Rheumatoid arthritis is an autoimmune disease where the immune system attacks its own tissues and characterised by chronic inflammation of joints.


Muscle tissue makes up a large part of the human body, specifically around 43% in a man and 34% in a woman. Altogether the body contains about 650 muscles, the vast majority of which hold our bones in place and are called skeletal muscles.

The remaining 30 muscles, called the cardiac and smooth muscles, perform such vital functions as pumping blood through the body, and helping internal organs such as the gut and lymphatic system to operate efficiently.  In terms of day-to-day functioning muscles are important for us to react, breath, move, express ourselves and as protective reflex actions – right from the large heart muscle, to the tiny contractions in a skin shudders.

It must be emphasised how very important strong muscle tone is, not just to keep you toned and standing erect, but to ensure the efficient running of the heart, digestive system and lymph flow. Muscles hold in our intestines and colon and poor posture can result in loss of digestive function. If the tone of the muscles in the gut is weakened through weight gain, low exercise or bacterial overgrowth, the wave-like muscular action that moves food along all the way from the throat to the anus can become compromised and so can digestion, possibly ending in constipation and other conditions. Calf muscles play an important part in pumping blood back from the legs to the heart.

Exercise and nutrition

First and foremost, nutrition is important to meet the basic needs of an athlete. Due to physical stresses and strains, as well as increased energy demands, athletes can require as much as ten times of a given nutrient than the average person. This can be because during exhausting physical exercise some vitamins are used up extremely quickly in order to create energy, while minerals may be lost through increased sweating, meaning that often, higher nutrient intakes are required simply to avoid a performance-sapping deficiency. Additionally, some athletes may require extra support tailored to their particular sport. For example a long-distance runner may require additional nutritional joint support in order to avoid injury and long-term damage that would inhibit their performance at a basic level.

Once these essential nutritional demands are met, individualised dietary macronutrient (meaning carbohydrates, fats and proteins) balance can be tailored for particular sports in order to maximise performance. For example, the macronutrient needs of a gymnast will be very different from those of a bodybuilder, whose needs, in turn, will differ greatly from those of a marathon runner.

During exercise the body, as part its normal metabolic processes, produces substances called free radicals. Free radicals inflict a type of chemical injury on the body called oxidative damage, which is believed by many researchers to be the reason that professional athletes rarely remain competitive in any sport past the age of 30. Of course, this means that with the correct protection, through the use of antioxidant nutrients, it may be possible to not only enhance training performance, but also to continue as a sports professional for much longer.