Protein

Proteins are macromolecules (Big molecules), made from repetitions of amino acids. Just like carbohydrates they are polymers. But, not all proteins are the same. They also differ in size and constituents. Protein type depends on what amino acids they are made from and as far as scientist have found 64 types of amino acids. Each protein may have several types of combinations in different proportions. A typical protein contains 200-300 amino acids but some are much smaller, and some are larger (the largest to date is titin, a protein which is found in skeletal and cardiac muscle).

So far there are eight amino acids that the body cannot make itself, and it has to be acquired through diet. These are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Infants additionally need food sources of histidine and possibly taurine. Collectively, these are called essential amino acids.

Amino acids which can be synthesised by the body is called Non-Essential Amino acids.

Some of the protein you eat contains all the amino acids needed to build new proteins. This kind of protein is called complete protein. Animal sources of protein tend to be complete. Other protein sources lack one or more amino acids that the body can't make from scratch or create by modifying another amino acid. Called incomplete proteins, these usually come from fruits, vegetables, grains, and nuts.

Vegetarians need to be aware of this. To get all the amino acids needed to make new protein - and thus to keep the body's systems in good shape - people who don't eat meat, fish, poultry, eggs, or dairy products should eat a variety of protein-containing foods each day. Which means Vegetarians and Vegans need to diversify their food sources in order to get complete protein. Some dietary choices tend to have a lack in protein this include fruitarian or raw food diet.


Functions of Protein:

1. Organisms and cells depends on protein for movement as protein is the main constituents in contractile protein (Muscle are mainly proteins).
2. Making enzymes for chemical reactions in the body.
3. Components of transport materials in body fluids.
4. Components of hormones and signalling molecules in the body. (E.g. Progesteron and testosterone is protein).
5. For maintaining tissues and sustaining growth.

How much protein do we need?

Type of person Amounts Required (g/day)

Infants/Children

0-12 months -12.5-14.9

1-3 yrs - 14.50

4-10 yrs -  19.7-28.3

Boys

11-14 yrs - 42.1

15-18 yrs - 55.2

Girls

11-14 yrs  - 41.2

15-18yrs  - 45

Men

19-50 yrs - 55.5

50+ yrs  - 53.3

Women

19-50 yrs - 45

50 + yrs -  46.5

During pregnancy extra 6g/day

Breast feeding 0-6mths extra 11g/day

Breast feeding 6+ mths extra 8g/day


The RNI is a daily amount that is enough or more than enough for 97% of people. The RNI is similar to the Recommended Daily Amount used previously in the UK.


The US Recommended Dietary Allowances introduced in 1989 are similar to the UK values.

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Source of Protein:

For Vegetarian:
The foods which commonly supply the most protein in a vegan diet are pulses (peas, beans, lentils, soya products), grains (wheat, oats, rice, barley, buckwheat, millet, pasta, bread), nuts (brazils, hazels, almonds, cashews) and seeds (sunflower, pumpkin, sesame).

For Non-Vegetarian:

Proteins are mainly acquired from Meat, Fish Cheese, Milks and all the food derived from them. Animal proteins are complete for human body but they have several drawbacks.

A Ray of light on SOY and Nuts...

Recently soybeans are noted for the potein because researches have noted that regularly eating soy-based foods decrease cholesterol level, alleviate hot flashes and may prevent breast and rostate cancer, they may also aids weight loss and may decrease the risk of osteoporosis.

Nuts are also excellent source of proteins. They also may give benefits for human such as decreasing risk of heart attack, lowers risk of myocardial infarction and cardiovascular disease.

Nuts contain unsaturated fats that help lower LDL (Low density lipoprotein LDL is not good for our body) cholesterol and raise up HDL cholesterol ..(High density lipoprotein - HDL is a good one) cholesterol.

In walnuts, a group of unsaturated fat (omega-3 fatty acids which is also found in fishes (salmon and bluefish)) are found to prevent erratic (unstable) heart rhythms, as well as prevent blood clots. Nuts also contains arginine which is the constituents if Nitric oxide, well nitric oxide is a molecule that relaxes constricted blood vessels and facilitate blood flow.

Nuts also contains Vitamin E, Folic Acid, Pottasium and Fibres among others.

FOR MORE INFORMATION ABOUT THIS PLEASE VISIT HERE

Too Much Of Protein?

Excessive protein consumption may be associated with health risks. Kidney function can be compromised by too much protein in older people and in patients with kidney disease; also, a high protein intake may adversely affect calcium balance and contribute to mineral loss from bone. Diets rich in meat protein lead to more uric acid in the urine, and a general increase in urine acidity. because of the acidity, the uric acid does not easily dissolve and can form into kidney stones. Reference HERE

Some suspect excessive protein intake is linked to several problems:

Overreaction within the immune system
Liver dysfunction due to increased toxic residues

NOT Enough Protein?

Not enough protein intake in human, particularly in children may cause you to get kwashiorkor, a condition where the body's shape is abnormal with the stomach generally larger and protruding. This is common in Third World Countries (War, Famine and Drought).

On the other hand developed country may also face this problem but in a different spectrum. Mainly because of not eating the right type of protein or deficient in a type of protein. Cases usually due to poverty or dieting.

Overall lack of protein may lead to weakened immune system and retarded growth in children, both physically and mentally.

TIPS about Protein

DO eat protein in moderation and in different sources, this may give you chance to get all the required type of protein.

BALANCE between protein and carbohydrates intake.

WATCH out for other nutrients when buying protein products. Some may have too much fats or sugar and give you other aspect of consideration. Choose low fat and low sugar product.