Preferably not Necessarily; Whole Grains Recommendation in the Mediterranean Diet

Grain-based foods are the primary suppliers of carbohydrates and proteins also the dominant low-fat staple foods in the Mediterranean diet. The importance of their intake becomes more profound in the time of a worldwide crisis such as the coronavirus disease outbreak. They are essential regarding global food security due to providing around two-third of the total energy intake in the form of affordable, portable, versatile, and shelf-stable products. Moreover, they are rich sources of a wide range of bioactive compounds such as dietary fibers and phytochemicals. Above all, total grains consumption boosts the immune system through having antioxidant, anti-inflammatory, and immunomodulatory activities. Since most of these beneficial impacts are associated with the consumption of the whole portion of the grain-based products, the majority of dietary guidelines suggest the exclusive intake of whole-grain products and not their refined-grain counterparts. However, the Mediterranean diet stands out by recommending preferably and not necessarily consumption of whole-grain products. This review provides more insight into this recommendation by enlightening several issues and deliberations, including the lack of a universal standard definition of whole grains and a meaningful quantity of them that should be presented in a food product to be considered significantly health-promoting. These issues, later on, lead to a non-uniformity in the methodical calculation among studies that examined whole- and refined-grain intakes and their health outcomes and consequently make them incomparable and inconsistent. Other discrepancies exist, such as differences in the diet backgrounds of the population under examination and covariations between dietary variables themselves. All these confounding factors trigger a greater caution for interpretation of any research in the literature. Finally, some drawbacks of whole-grain products are explained that hinder the incorporation of such products by the overall population in their diets, for instance, not being widely available for all the types of products, having higher economics, and lesser palatability compared to other food choices. In conclusion, a more achievable goal is increasing the whole-grain intake by replacing some portions of refined grains rather than prohibiting all refined grains without considering nutritional and culinary impacts on the overall diet.