Glucose mon amour: in defence of carbs

In last decades carbs have gained a bad reputation: it seems they are the only responsible for the epidemic spread (in affluent countries) of overweight and obesity. Many types of diet recommend a very low intake of carbs, especially sucrose and those carbs derived from cereals, in order to prevent or reduce any accumulation of fat storage and diet-related diseases (diabetes, cardiovascular diseases, etc.). This is partially true, since any excess of dietary energy (in form of carbs, proteins or lipids) is stored as fat in the adipose tissue ⁽¹⁾. 

In nutrition it is defined as essential any necessary dietary compound which cannot be synthetized by our body; these compounds to fulfil our physiological requirements must be obtained from food. Glucose cannot be termed as essential since our body can produce this molecule from non-carbohydrate substrates: the process is called as gluconeogenesis and occurs in the liver, where amino acids, lactate and triacylglycerol can be converted into glucose. Gluconeogenesis is a crucial process since it allows the survival of those tissues which energetically depend only on glucose (e.g. red blood cells, brain), when glucose availability is too law. Unfortunately the rate of glucose production by gluconeogenesis is lower than the rate of glucose oxidation by tissues, therefore it is necessary to use exogenous glucose deriving from the diet in order to avoid detrimental consequences for our body. This requires that at least 20 -30% of our energy intake must come in form of carbs (mainly glucose and its polymers, such as dextrin, starch).

There are two rules to keep in mind:

1^st – no energy no life;

2^nd – no natural dietary compound can be considered as noxious for our body; its toxicity depends on the amount consumed. So don’t avoid glucose, sucrose or starch, just learn the right level you need to eat.

Ciao and take care.

 

⁽¹⁾ I’d like to highlight that the immediate decrease of weight produced by low carb diets doesn’t correspond to a real adipose tissue reduction: the loss of weight is due to a reduction of the water associated to glycogen (that is the form in which carbs are stored in our body).