Understanding the Significance of Protein-Free Foods: A Comprehensive Guide to Therapeutic Nutrition

• To be used under medical supervision;
• Intended for the complete or partial nutrition of patients with a limited or disturbed capacity for intake, digestion, absorption, metabolization or excretion of commonly used foods or of some nutrients or metabolites contained therein;
• Intended for the complete or partial nutrition of patients whose dietetic treatment cannot be achieved by modifying the normal diet or by using other dietetic products which are not foods for special medical purposes.

More precisely, quoting the Ministerial Circular of 5 November 2009, aproteic/low-proteic products are defined as substitutes, with a protein residue not exceeding 1%, of foods of current use with a significant protein content, of vegetable origin such as bread, pasta, biscuits, baked goods and the like.

This category also includes foods with a protein residue between 1 and 2%, and substitutes for protein-rich drinks, including those of animal origin, with a protein residue not exceeding 0.5%.

Labeling

Given the importance of these foods in the therapeutic management of patients suffering from chronic and congenital pathologies, it is essential that all products meet specific composition and labeling requirements that allow the user to evaluate the ingredients present and the relative concentrations.

More precisely, the concentrations of “nutrients” must be defined on the label, indicating if necessary that of specific amino acids, sugars, fatty acids or other substances useful for safeguarding the patient’s health as well as:

• Indications for use both dietary and clinical;
• Warnings relating to the use of the product under medical supervision;
• Warnings relating to avoiding the use of the food in question as the only food source, given the dietary and nutritional incompleteness;
• Warnings relating to the risk of using the product in patients not affected by the disorders and pathologies for which its use is indicated.

Indications for use – Protein-Free Food

Why are apoprotein foods used?

The use of protein-free dietetic foods is indicated in particular pathological congenital conditions characterized by impaired absorption, digestion, metabolism or excretion of specific amino acids, as well as in the case of chronic conditions such as chronic renal insufficiency. The latter represents the main indication for the use of low-protein foods, contextualised in a more general low-protein diet, which limits the daily protein intake to 0.6 – 0.8 g/kg.

Despite the reduced protein intake, dictated by obvious physio-pathological conditions, the nutritionist should in any case be able to meet the patient’s amino acid needs, thus using proteins with a high biological value such as those derived from foods of animal origin. It is precisely for this reason that it is essential to resort to the use of protein-free foods, in such a way as to reduce as much as possible the consumption of proteins with low biological value, such as those present in flour, cereals and derivative products; in this way it will be possible to easily compensate for the plastic and structural needs of the organism by resorting to the specific integration of essential amino acids.

Despite the important protein dietary restrictions, in order for the patient suffering from chronic renal insufficiency to preserve his state of health, slowing down the progressive deterioration of the renal function, it is advisable that he also pay the utmost attention to the consumption of foods rich in potassium, given the reduced excretion capacity and the consequent risk of hyperkalemia, of phosphorus, known therefore the altered homeostasis, and of calcium, whose concentrations tend to decrease significantly given the reduced renal activity in the hydroxylation of vitamin D.

Different studies have shown that compliance with these dietary rules can significantly improve the quality of life of patients with chronic renal insufficiency, delaying the deterioration of renal function and significantly reducing the incidence of clinically relevant pathologies such as osteoporosis, acidosis systemic and above all cardiovascular pathologies.

Refund ability

Given the importance of protein-free dietary foods in the management of renal disease, the national health system has established a reimbursement system, commensurate with the financial capacity of the patient and his family, for the expenses incurred for the purchase of these products currently included in Band C, therefore until recently entirely paid by the citizen.

This mechanism has triggered an important virtuous system, as demonstrated by the various studies, capable of increasing the patient’s therapeutic compliance, therefore improving their quality of life while lengthening its duration at the same time.

News from the scientific world

Very interesting are the results published in the literature concerning the use of protein-free dietary foods, in the context of hypo- or protein-free diets, outside the normal clinical prescriptions.

In particular, the study of hormonal responses has demonstrated how low-protein diets can induce:

• Hypoinsulinemia, with consequent alteration of glucose homeostasis and increase in noradrenergic tone;
• Significant reduction of blood concentrations of testosterone, luteinizing hormone and follicle stimulating hormone, thus compromising reproductive capacity, fortunately in a reversible and transient manner;
• Significant reduction of lean mass, and in particular of skeletal muscle mass;
• Altered adrenergic/noradrenergic control with significant vascular and cardiac disorders.

From this evidence, the importance of a correct protein intake in safeguarding the functional and structural integrity of entire tissues, organs, apparatuses and systems can easily be seen, thus rejecting dietary trends, without scientific support, which significantly limit, in the absence of pathological conditions that require it, the consumption of protein.