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The Impact of Nutrition and Diet on Oral Health


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cannot be synthesised in the body and, therefore, must be obtained through the diet. The most prevalent form of dietary fat are the triglycerides, which are composed of 3 fatty acids and a glycerol molecule.

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      From the endogenous fat, liver produces very-low-density lipoproteins (VLDL) which are the main carriers of triglycerides, supplying fatty acids to adipose and muscle tissues. The end-products of VLDL metabolism are low-density lipoproteins, which carry approximately 60–80% of cholesterol in plasma. High-density lipoproteins remove fat molecules (phospholipids, cholesterol, triglycerides, etc.) from the cells and tissues and transport them back to the liver [16].

      Micronutrients

      Vitamins and minerals are nutrients that are found in small amounts in most foods and are essential, in minute amounts, for normal metabolic function.

      Vitamins are a group of organic compounds that cannot be synthesised by humans and should be provided by the diet; otherwise their deficiency could cause adverse health conditions. While vitamins have few chemical similarities, their metabolic functions have been defined in 1 of 4 general groups: (i) membrane stabilisers, (ii) hydrogen and electron donors and acceptors, (iii) hormones, and (iv) coenzymes [8]. They also have important roles in gene expression in humans. Vitamins are classified into 2 groups based on their solubility: fat-soluble and water-soluble. The main functions and dietary sources of vitamins are presented in Table 2; with more details provided in Chapter 6. The fat-soluble vitamins are absorbed passively by intestinal mucosae in the presence of fat. This group of vitamins is mainly found in the lipid portions of the cells such as membranes and lipid droplets. Fat-soluble vitamins are excreted with faeces via the enterohepatic circulation [8]. The water-soluble vitamins are also mainly absorbed by passive diffusion, except for vitamin B1 (thiamine) which is absorbed by a sodium-dependent transport mechanism and vitamin C which is absorbed by both passive diffusion and sodium-dependent active transport. Vitamin B12, a collective term for a group of cobalt-containing compounds known as corrinoids, is absorbed by active transport in the terminal ileum after binding to salivary haptocorrin and “intrinsic factor” (a protein cofactor secreted by the parietal cells of the stomach). The water-soluble vitamins are not stored in significant amounts in the body and are excreted in the urine [8].

      In nutrition, minerals are a group of inorganic elements that cannot be made by the body and are necessary for a variety of functions, including: the formation of bones and teeth, as essential constituents of body fluids and tissues, as components of enzyme systems and for normal nerve function. Based on the quantity needed by the body, minerals have been categorised into 2 major groups: macrominerals with a requirement of =100 mg/day and microminerals (trace elements) with a requirement of <15 mg/day, which include ultra-trace elements that are necessary at a level of µg/day, although specific requirements have not been established for some of them (Table 3) [8]. Minerals take up 4–5% of the body weight of an average adult. Although macrominerals occur mainly in the ionic state in the food and the body, some minerals also exist as components of organic compounds such as phospholipids and haemoglobin. They are usually absorbed in the ionic state, with heme iron being exceptional, by an active transport mechanism. The unabsorbed minerals are excreted in the faeces [8]. For more detail, the reader is referred to Chapters 3, 4 and 5.

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      Diet, Nutrition and Oral Health

      There is a synergistic multidirectional relationship between oral health and nutrition and diet.

      Oral infectious diseases, as well as acute, chronic, and terminal systemic diseases with oral manifestations, influence the ability to eat and consequently to achieve an adequate diet and attain nutrient balance. Equally, nutrition and diet can impact the development and status of the oral cavity and the progression of oral diseases.