The truth about carbs: part two

2 mins to read

Carbs. Are they in or out? Dr Joanna McMillan Price and Judy Davie set the record straight in this second instalment on the pros of carbohydrates.

Everyday health

Why do we need carbs?

There are many good reasons to include carbohydrates in your healthy eating menu, including:

For optimal cognitive performance
To perform at our best during exercise
To maintain a healthy bowel
Carbs are relatively cheap, readily available and easy to store

For optimal cognitive performance

Our brain (and certain other cells in the body including red blood cells) runs almost exclusively on glucose – the carbohydrate that circulates in our blood. While we can make glucose from protein, there is a limit to the rate and capacity to do so.

For our bodies to function, blood glucose must not fall below a certain level. If it were to drop dangerously low, we would fall into a coma, and, without intervention, could die.

That is why our bodies can make glucose from protein; it is a fallback system to ensure there is a constant glucose supply for the brain. In times of famine, the brain adapts and can run on ketone bodies made from fat, but this is not normal metabolism and certainly not the preferred fuel.

Since carbohydrate is clearly an essential fuel in our bodies, it makes sense to bring in fuel in the form it is needed. Research clearly shows that brain function – including memory and concentration – is much improved after eating carbohydrate-containing foods, particularly first thing in the morning.

You may have experienced this yourself if you have tried following a low-carbohydrate diet – common complaints are of headaches, lack of concentration and poor memory.

To perform at our best during exercise

When we exercise, glucose and fat are used as fuel, but glucose becomes increasingly important as the intensity of exercise increases.

Think of fat as the tortoise – the slow steady burner that can run for a long time but cannot go very fast. Glucose, on the other hand, is the hare – it can produce a lot of energy fast but without refuelling will run out pretty quickly.

As we cannot turn protein into glucose quickly enough during exercise, it means we need to have a good store of glucose ready before we start and to adequately fill these stores we need to eat carbohydrate-containing food.

Making exercise a regular part of your life is not an optional extra – it is essential if you want to look, feel and perform at your best. This means you will need to eat sufficient carbs to support your exercise program.

Of course, this also means the more you exercise the more carbs you need and vice versa; but remember, not exercising and not eating carbs means you miss out on the irreplaceable benefits of both.

To maintain a healthy bowel

It's interesting that constipation is almost unheard of in native cultures yet is one of the most common complaints in the Western world. Chronic constipation can lead to all sorts of problems including bloating, indigestion, abdominal pain, flatulence, haemorrhoids, diverticulitis and bowel cancer.

Our sedentary lifestyle plays a huge part in this. An inactive body leads to an inactive gut. A key dietary difference is the amount of fibre we consume.

Fibre is in fact just carbohydrate, but of a type that we cannot break down and absorb in the small intestine. It comes as no surprise therefore to discover the best sources of fibre as also carb-rich foods.

If you choose to follow a low-carb diet you inevitably end up with a low-fibre diet and your bowel will suffer as a result.

Carbs are relatively cheap, readily available and easy to store

From a purely practical point of view, cutting out carbs makes life very difficult, no to mention unsociable. Carbs on the other hand are relatively cheap, you can store them in the pantry making it easier to put together a healthy home-cooked meal without shopping every day, and they are widely available… even your local corner shop will stock bread at the very least.

This is an edited extract from Star Foods: selecting a winning team of foods for good health by Dr Joanna McMillan Price and Judy Davie. Published by ABC Books. RRP $35.