The Spanish Arteriosclerosis Society (SEA for its initials in Spanish) has always had a firm commitment to the study and dissemination of the importance of diet in cardiovascular prevention. On this basis, the document published in 20181 has been updated, due to the many advances introduced since that time making this a necessity.2 This undoubtedly meritorious update has involved great efforts and has been achieved thanks to the commitment of the authors, and in particular its two coordinators Emili Ros and Vicente Pascual. In representation of the editorial group, they deserve our recognition for the excellent quality of their work.The magnificent and enjoyable introduction offers us a general overview of the recently evolved themes and the future prospects of nutritional sciences. It is also positive that care has been exercised to structure the text by foods and not by nutrients, maintaining the commitment to recommend each food, specifically, according to its level of evidence. This is not an easy task because existing knowledge gaps force us to make recommendations that are sometimes negotiated and debatable, such as the comparison between salt consumption and the consumption of processed meats. In the case of the former, it is concluded that salt “strongly” increases cardiovascular risk, whilst the consumption of processed meat (sausages, cold cuts, salami, etc.) is linked to cardiovascular risk with only moderate evidence. However, given the fact that processed foods usually contain a lot of salt, sugar, trans fats or nitrates, a stricter recommendation would be expected, with clearer advice against them to help avoid their consumption in our diet. We would agree that details of this type do not detract from the value of the document, but rather reflect how difficult it is to make certain recommendations, largely because much evidence is usually based on observational studies and we will probably never have enough available clinical trials to be more forceful. A document on nutrition cannot therefore be compared with another on pharmacological prevention, since the latter can generally be based on evidence supported by industry funding. As relevant exceptions to these limited nutrition studies we can find the PREDIMED and CORDIOPREV clinical trials, both on the cardiovascular benefits of the Mediterranean diet and which have offered strong support in this document for making higher quality recommendations.
The authors deserve recognition for their extensive efforts to update, which is reflected, among other things, in the 301 references included. This bibliographic support has enabled them to probe into topics about which there are doubts, because they have less scientific support. An example of this is that of natural juices without sugar. According to the section on consumption frequency, five daily portions of a combination of fruits and vegetables are recommended, including natural juices (without sugar). By including these natural juices in the diet, the intention is that the recommendation of 5 daily portions which is normally so difficult to achieve on a regular basis would be met. These juices may probably be healthier for the prevention of cardiovascular risk than traditional juices, with sweeteners or added sugar, but they will never be comparable to whole fruit because, as they do not contain fibre, their “natural” sugar is more bio-available and the satiating effect of fibre is also lost. Most certainly the authors do not intend to replace fruit with juices, but the way in which the recommendation is made could appear to suggest this. It is worth mentioning that the bibliographic support for this recommendation is based on a narrative review, with low evidence value and where the first author is related to the Advisory Board of the European Fruit Juice Association.3
The document contains recommendations that contrast with popular sentiment, such as the consumption of eggs or dairy products. Both are a major source of vitamins and important nutrients and the document advocates their consumption without reservation. It is true that due to their nutritional value, their low cost and their traditional consumption, these foods deserve to be included among those recommended. Although they do not reduce cardiovascular risk, their recommendation is positive due to the other health benefits they provide. In line with this opinion, we would like to point out the frequently reductionist concept of the majority of documents from scientific societies, which approach their recommendations in a way that is biased towards the interests of the drafting group, be it diabetes, hypertension, dyslipidaemias, obesity, etc. This document partially breaking away from this dynamic, with cardiovascular prevention being raised from a global perspective and not from that of a risk factor, ignoring the poorer vision that underlies other documents that are too singularly focused. This generic approach is important because we may recommend a food that may be beneficial for a specific process but damaging to another aspect of health, as may be the case with alcohol. On this subject, the document indicates that there is medium-level evidence that moderate alcohol consumption reduces cardiovascular risk and that the best way to consume it is as wine, with meals. However, the presence of alcoholic beverages in the diet is one of the most controversial issues in existence, especially if health is observed from a global perspective and not limited to an isolated system. Regardless of whether it reduces cardiovascular risk, alcohol is considered a toxic with carcinogenic, hepatotoxic, neurotoxic and social poisoning action, even in low doses, so the utmost caution should be taken in its recommendation.4 In a cohort of 550 men and women, followed by both imaging and functional studies of the nervous system, it was shown that even a moderate amount is associated with cognitive deterioration and brain lesions, with a dose effect, especially with atrophy of the hippocampus.5 This study involved a 30-year follow-up, sealing its broad authority whilst questioning other studies that analyse effects on a single organic system for short periods of time. Projects such as the one recently started by the University of Navarra will not be able to provide reliable information due to its short duration of 4 years6 and will not be able to prove the hypothesis it proposes. In line with these facts, the World Health Organisation launched its Global Action Plan on Alcohol 2022–2030,7 based on the fact that, at a population level, any level of alcohol consumption is associated with multiple health problems. Therefore, the question is, can we recommend a product that is toxic to multiple organic systems because of its debated beneficial effect on the cardiovascular system?
A particularly interesting section in the document is that of other dietary models, all of which share fresh foods, especially fruits and vegetables, legumes, whole grains and fish. Special mention should be made of the Planetary Diet, proposed in a publication led by Walter Willett and which proposes a dietary model capable of preserving the planetary ecosystem and reducing non-communicable diseases, including cardiovascular disease.8 This model, considered a flexible-vegetarian diet, is very similar to the traditional Mediterranean diet, in which animal protein sources are scarce. Despite the reflection made in the document, that the application of this diet to each population is complex, it is regrettable that the authors did not at least consider starting the transition towards it by above all reducing the recommendation of meat consumption and promoting the intake of vegetable protein sources instead. In short, we have here an excellent document, which provides bibliographic support to the many open debates on the benefits of the different nutrients on cardiovascular health. Both the SEA and the authors of the document deserve to be congratulated for this initiative.
