Oral health is to some degree related to the physical and chemical properties of the ingested foods. The relationship between frequent consumption of carbohydrates subject to fermentation (sucrose and processed starch) and the risk for caries has been well investigated and documented. Also the beneficial effect of polyols (sugar alcohols i.e. sweeteners not fermented by plaque bacteria) on teeth has been documented. Acidic foods, on the other hand, especially those containing citric and phosphoric acids may cause teeth erosion. Such knowledge has led to an increasing interest taken in the effect of food ingredients, both active and passive, on oral health cavity from the point of view of disease prevention (1). The idea of functional food, meaning foods consumed as a part of daily diet, containing factors that promote health and reduce the risk of various diseases was first introduced in Japan in the 1980s. Functional foods may be products based on natural ingredients, or enriched (fortified) with components of documented beneficial, pro-health effect (such as minerals, vitamins, plant extracts). Such foods, officially termed Foods for Specified Health Use (FOSHU) are produced in Japan on an industrial scale, yet have not been defined by legislation in Europe so far (2). Nonetheless, both active and passive effect of some functional food ingredients on health is recognized by the European Safety Authority (EFSA), including the beneficial impact of sugar-free gums on the condition of teeth (3).

The aim of this study is discuss foods whose ingredients may modulate the caries process. In part one the properties of milk and dairy products are presented, whereas part two discusses other ingredients containing polyphenols.

For ages, milk and dairy products have been staples of human diet. In present times, it is mainly cow’s (bovine) milk and its derivatives (dairy products) that are consumed on a large scale. The annual intake of milk is estimated at 40.69 l per person, cheese 11-11.4 kg per person, and yoghurt 6.48 kg per person (4). Full fat (whole) milk is a liquid containing 87.4% water, and in its remaining part comprised in 4.7% by fat, 3.5% by protein (including 2.8% of casein and 0.6% of whey proteins), 4.8% by lactose and 0.6% by minerals. Overall, cow’s milk contains over 100 chemical components, among which proteins, calcium, phosphates, potassium, vitamins D, A, B₁₂ and B₃ are the most important nutrition-wise. The calorie content of milk and dairy products depends on their fat content. Milk is a heterogeneous combination of proteins, with casein playing a dominant role (80%). Using electrophoresis, casein may be separated into four components, namely alpha-, beta-, gamma- and kappa-casein. Casein precipitates only at a pH of 4.6, and this quality is used for cheese making. Whey proteins, that account approximately for 20% of milk content, predominantly contain beta-lactoglobulin and alpha-lactalbumin, while also including albumins, immunoglobulins A, G and M, Proteose-Peptones, lactoferrin and transferrin. Milk has important nutritive value, as it is a source of varying amounts of all the 9 amino acids not synthesized by the human body (5-7).

Various types of milk (non-pasteurized, pasteurized, UHT, micro-filtered, condensed, thickened, lactose-free milk) are commercially available, as well as milk with different amounts of fat, and the so-called flavoured milks (milk with added aromas, dyes, and sugars), dairy products, such as yoghurts (drinking, natural, fruit, cream, breakfast varieties), kefirs (kephir), buttermilk, fermented (cultured) milk, fortified milk (with the addition of calcium, Omega-3 acids, probiotics, prebiotic fiber), milkshake-like drinks (e.g. chocolate or fruit milkshakes), and a plethora of various cheese varieties.

Fermentation of milk results in the production of lactic acid, associated with pH decrease thus inhibiting the growth of multiple pathogens in the oral cavity. Fermented milk products include yoghurt (produced by adding Lactobacillus delbrueckii ssp. Bulgaricus and Streptococcus salivarius ssp. thermophilus bacteria to milk), kefir (based on a unique microorganism culture known as kefir grains), fermented milk (produced as a result of the fermentation of fresh milk bacteria, and also known as fermented or sour milk) and buttermilk (produced by skimming churned cream, and containing lactic acid). Cheeses come in a plethora of varieties, classified according to the method of their production and maturation into the following types: rennet-based (soft, such as brie, gorgonzola, Polish sheep “bryndza” cheese, semihards, e.g. Tilsiter cheese, and hards, e.g. Gouda cheese), high-acid (non-maturing – cottage cheese, and maturing – gomolka), those combining a high-acid and rennet-based formula (white cheese), and whey-based (ricotta) (5).