Towards a standard for disease prevention

A standard does exist

The dietary guidelines for the prevention of Alzheimer's disease confirm once again that the rules for healthy eating are consistently the same, whether for metabolic, degenerative, cardiovascular, neurological or other diseases.

One need only compare the recommendations of the various scientific societies to see that the answer is always similar if not identical: a reduction in the consumption of foods of animal origin, with a consequent lowering of saturated fats, a drastic reduction in trans fats, increased consumption of plant foods (the scientific press is paying growing attention, for example, to legumes), a steady intake of vitamins E and B12 and folic acid, combined with moderate but regular physical activity.

Why this confirmation matters

This consistency of messages is absolutely essential for effective public health interventions, especially at a time when there is an uncontrolled excess of nutrition-related news that can give rise to dangerous misunderstandings.

For those directly involved in nutrition, however, it is equally necessary to evaluate these recommendations with extreme care, trying to identify any critical issues.

Never generalize: each food should be considered individually

When speaking of animal foods (meat and dairy products in particular), it cannot be overlooked that, for the sake of simplification, no distinction is made between one product and another. In this way everything gets “lumped together”, without taking into account the enormous changes that have taken place in animal husbandry.

One example is the recent study on the bromatological composition of cured meats, which showed that the amount of unsaturated fats has increased greatly at the expense of saturated ones.
The same goes for cheeses. Not all milk is equivalent; here too it depends on the type of fatty acids present (think of conjugated linoleic acid (CLA), whose positive effect on health now seems established) — and these are just two examples of a very complex reality.

There is much to discover, and important factors must not be underestimated

The truth is that little is known about the real composition of foods, and there is therefore a risk of reasoning on the basis of theoretical data that are at times approximate and thus misleading.

Nor should we forget the differences in the eating habits of different populations, not only culturally but also genetically. In this regard, the wide-ranging debate sparked by the substantial and highly successful study by Prof. Campbell (China Study) is symptomatic of how research often underestimates the influence of genetic factors in the statistical-comparative assessment of the onset of diseases linked to eating habits.

Another observation concerns the recommendation on vitamin B12: it is advised to increase its intake also through the “fortification” of foods. Nothing wrong with that, but there may be another route, through an “in the field” analysis of individual foods, so as to identify important nutritional sources of B12 in foods that might mistakenly be considered ones to ban.

The major epidemiological studies, albeit with some differences, have unequivocally pointed out a path to follow; it is, however, up to those who deal with the issue scientifically and professionally to find solutions suited to different population types, and with the knowledge available to us today this is possible only through in-depth study of each food, of the interactions between known foods and of their impact on human health.