Why you should prioritise protein...

No matter what diet or nutrition plan you follow, I think we can all agree that protein is vital for good health.  Proteins, or their component parts amino acids, are found in the structure of pretty much every cell in our bodies.  I think that that in itself is an excellent reason to make sure we include only high-quality protein sources in our diets.  So, sit back and let me tell you a bit more about protein – cast your mind back to biology at school…

The science bit…

As I mentioned above, proteins are made up of amino acids.  There are 20 of them altogether, and they combine in various ways depending on their function.  Some of these amino acids are needed throughout our lives and some are conditionally essential amino acids.  This just means that we only need them at certain times – I’ve marked these with a *.

There are 9 essential amino acids – these are the ones that our bodies can’t make, so we have to supply them in our diet (hence it's essential that we get them from our food).  I find their names very pleasing for some reason:

• Histidine

• Isoleucine

• Leucine

• Lysine

• Methionine

• Phenylalanine

• Threonine

• Tryptophan

• Valine

And then there are the 11 non-essential amino acids – these are the ones that our bodies can create naturally:

• Alanine

• Arganine*

• Asparagine

• Aspartic Acid

• Cysteine*

• Glutamic Acid

• Glutamine*

• Glycine*

• Proline*

• Serine

• Tyrosine*

It’s okay, you don’t have to memorise them – I won’t be giving a pop quiz later!

If protein is so great, what does it actually do for us?

Honestly?  Without protein, we would just be a soupy mess!  Proteins are the building blocks of body tissue so they have the following functions, among others:

• Repairs and builds muscle

• Production of antibodies

• Making hormones and enzymes

• Aids the digestion and absorption of food

• Helps transport oxygen to tissues

• Makes up the structure of muscles, tendons, organs, bones, hair and skin

See what I mean?  It’s pretty important!

Okay, so how does our body digest and use protein?

Fun fact – 90% of the protein we eat is broken down into amino acids.  These amino acids form a standby team which is used to build and repair tissue, produce antibodies, and so on.  However, they have no direct form of storage in the body so we need to ensure we eat protein-based foods regularly – preferably the high-quality type!

When protein-based food reaches our stomach, the enzyme pepsin starts the process of digesting it.  The first stage is to break the protein down into large polypeptides, after which the partially digested food moves on into the small intestine.

Here, enzymes from the pancreas (trypsin and chymotrypsin among others) break these polypeptides down into smaller chains.  The main reason for this is that proteins are quite large structures and need to be broken down in order for the body to absorb and use them.  The body is amazing really, that it has solved these problems over millennia of evolution – but that’s a topic for a whole other article, so don’t get me started on that here!!

Anyway, once the polypeptides have been broken down into smaller chains, the enzyme aminopeptidase works to break them up into the amino acids that we have come to know and love.  These amino acids are then absorbed through the walls of the villi in the small intestine, enter the bloodstream, and are transported to the liver.

Proteins – what are the options?

There are so many choices when it comes to picking a protein source.  What you go for will be based on personal preference, religious and ethical beliefs, dietary requirements, allergies, intolerances, availability…  Realistically, there is no right or wrong answer when it comes down to it.  Some might consider consuming animal-based products morally wrong, and that’s absolutely fine – I’m not going to get into the discussion around that here, but I do appreciate that this is very important to some people.

Keep a look out for the next article where I'll be looking at some animal- and plant-based protein options that you can easily include in your weekly food rotations!