Protein is one of the most amazing molecules in your body and is a major component of each and every cell. An average lean adult is made up of approximately 12-18% protein. Its importance for the growth and development of your entire body cannot be understated.
Protein makes up your muscles, skin, glands and organs as well as being essential for the synthesis of neurotransmitters and the creation of DNA and RNA. There are hundreds of thousands of proteins that are responsible for your own unique characteristics.
The building blocks of protein are nitrogen containing molecules called amino acids. Although there are hundreds of amino acids, protein is typically constructed from only 20 of these, which are termed ‘essential’ because we can only get them from our diet.
Amino acids connect together in a multitude of different sequences which create the variations in proteins we need to form the cells and organs that allow the body to function.
Why is protein so important?
Because protein has so many diverse functions in the body we simply can’t do without it! It’s hardly surprising that any deficiencies in protein or specific amino acids can have detrimental effects on tissue and organ function and consequently your general health and well-being.
These are just a few of the ways protein is used in the body:
- Hormones – Many of these are made up of proteins, insulin and progesterone are examples of these. Insulin is essential for blood sugar balance. Progesterone plays a key role in the reproductive system and the stress cycle.
- Oxygen transport – a blood protein called haemoglobin transports oxygen to the cells
- Movement – without the proteins in muscle tissue you wouldn’t be able to move.
- Enzymes – All enzymes are made up of protein. Enzymes are crucial for all chemical reaction in the body. Without enzymes your liver would not be able to carry out its detoxification functions.
- Brain health – proteins are essential for the synthesis of mood enhancing neurotransmitters in the brain such as tryptophan and serotonin.
- Transportation – Protein helps transport nutrients around the body, delivering and releasing them where they are needed.
- Fuel conversion – Proteins can be converted to sugar or fat to be used as fuel. When fed adequately your body only uses 10-15% of its dietary intake of protein on energy production. However, if there is insufficient carbohydrate and fat available, your body can mobilise amino acids to provide energy.
- Immune Function – The immune system is complex and comprises of numerous pathogen fighting compounds. Many of these such as cytokines and anti-bodies are protein based.
- The keeper of genetic information – Your genetic code consists of proteins such as RNA and DNA.
- Structural proteins – are required to support connective tissues like tendons, ligaments and bone. Your bones for instance consist of a protein matrix that is filled with calcium and other minerals. Other structural proteins include keratin, collagen and cartilage all necessary for skin, hair, nails and joint health.
How much do you need?
There are many factors that affect each individual’s protein requirements and this will change throughout your life. Your weight, age, activity levels, state of health and habits such as alcohol consumption and smoking may dictate how much you need on a daily basis.
It is safe to say that on average, the protein requirements that are needed to maintain an average healthy adult are approximately 45g for women and 55g for men. Most people easily exceed this amount. As an example a 3oz serving of chicken provides 28g protein, a 3oz serving of salmon 22g, a large egg 6g and half a cup of pinto beans provides 11g.
What happens if you don’t get enough?
If you don’t manage to get enough protein in your diet, or you have gastrointestinal problems that affect the digestion and absorption of proteins your body may start to show some signs and symptoms. These might include:
- Dry itchy skin and flaking nails
- Hair loss or thinning of hair
- Loss of apetite
- Muscle wasting
- Frequent infections due to poor immunity
Consequences of too much protein
Eating too much protein can lead to weight gain. In addition to this overconsumption can put unnecessary stress on your kidneys which have to work harder to remove more nitrogen waste products from your blood.
What are the highest quality sources of protein?
Meat, poultry, eggs, fish and milk are considered ‘complete’ proteins because they contain the correct proportions of essential amino acids to meet your body’s requirements. If you are a vegan or vegetarian you will need to combine a range of plant protein sources to ensure you get all of the necessary amino acids in the right proportions.
Most plant sources of protein such as beans, nuts and seeds are not considered ‘complete’ proteins. However, there are some exceptions, so it is worth including hemp seeds, soy beans, quinoa, chia seeds, spirulina and amaranth in your diet to be sure that you don’t miss out on valuable amino acids.
Protein is found in practically everything we eat so the likelihood of becoming deficient is pretty low, provided a normal healthy balanced diet is observed. Cutting down on your protein consumption is fine if you think you may be eating too much. Just don’t give it up completely!
Other diet related reads:
- Plant vs animal protein: New study shows what to eat for longevity
- New study shows that dietary fats are key to healthier, longer life
- Can a Gluten-Free Diet Influence Gut Health?
- Top Tips for Squeezing Extra Fruit and Veggies into Your Diet
- Barth CA & Metges CC. Metabolic Consequences of a High Dietary-Protein Intake in Adulthood: Assessment of the Available Evidence. American Society for Nutritional Sciences. J. Nutr. 2000; 130: 886–889.
- Gibney et al (2002). Introduction to Human Nutrition. Blackwell Science Ltd: Oxford.
- Mann & Truswell (2002). Essentials of Human Nutrition. Oxford University Press: Oxford.
- Murray & Pizzorno (2005). The Encyclopaedia of Healing Foods. Atria Books: USA.