The Impact of Nutrition and Diet on Oral Health

F.V. Zohoori, R.M. Duckworth, F. Vida Zohoori, Ralph M. Duckworth, F. Vida, Zohoori, Ralph M., Duckworth, Adrian Lussi, Marilia A. R. Buzalaf, Adrian, Lussi, Marilia A.R., Buzalaf, Vida, Zohoori, Ralph, Duckworth

• Publisher: S. Karger
• Year: 2019
• Print ISBN: 9783318065169
• eBook ISBN: 9783318065176
• Topic: Medicine
• Subtopic: Nutrition, Dietics & Bariatrics

Most oral diseases are preventable, yet they remain the most globally common noncommunicable disorders, affecting people throughout their lifetime. Lifestyle, including diet and food choice, is central to the occurrence of oral disease. Nutrition and diet can impact the development and status of the oral cavity as well as the progression of illness. Also, poor oral health can influence the ability to eat and, consequently, to maintain an adequate diet and nutrient balance. This book, consisting of 14 chapters, provides current information on the impact of nutrients (macro- and micro-elements and vitamins) and diet on oral health and vice versa (i.e., the impact of oral health on diet/nutrition). It also reviews possible oral health effects of probiotics as well as relationships between genotype and diet, which are important for determining oral disease risk. This book is a helpful resource for under- and postgraduate students. It will also be useful to dentists and nutritionists/dietitians as they integrate nutrition education into medical practice.

Impact of Diet and Nutrition on Oral Health

Zohoori FV, Duckworth RM (eds): The Impact of Nutrition and Diet on Oral Health. Monogr Oral Sci. Basel, Karger, 2020, vol 28, pp 68–76 (DOI: 10.1159/000455373)

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Chapter 7: Sugar and Dental Caries

Maxim Lagerweij · Cor van Loveren

Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands

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Abstract

Sugar is added to food for a multitude of functions: fermentation, preservation, physical and chemical, and also to satisfy the consumer’s preference for sweetness. Unfortunately, sugar consumption is also a main aetiological factor for dental caries. The relationship between sugar and caries was established in the latter half of the 19th century. Many factors influence this relationship: the availability of sugar for bacterial digestion, the presence of acidogenic bacteria in the plaque on teeth, and the ability of fluoride and saliva to counteract bacteria and acids. The importance of the frequency of administering sugars over the amount has been demonstrated in various studies in humans. Through guidelines, world and national health organizations advocate the reduction of sugar consumption to below 10E% (daily dietary energy percentage consumption per capita), but voluntary implementation on an individual basis is difficult for many, and maybe more compulsory strategies that aim to reduce both the amount and frequency of sugar intake are needed.

© 2020 S. Karger AG, Basel

Introduction

Throughout the world sugar is added to food by manufacturers and consumers for a variety of purposes: biological (fermentation), antimicrobial preservation, physical (viscosity, crumble as crystals, dryness), and chemical (caramelization, antioxidation), but mostly for its sweetness [1]. In this chapter, we will use the following definitions of total, added, and free sugars. Total sugars are all mono- and disaccharides, either intrinsic or extrinsic. Intrinsic sugars include naturally occurring sugars made by plants during photosynthesis for energy storage and are found in unprocessed products (fruit, vegetables, legumes, potatoes, rice, fish, meat, poultry, and eggs), juices, fruit concentrates, bread, and lactose in dairy. Added sugars are all sugars that are added during food manufacturing and preparation including raw, white, and brown sugar, honey, and syrups. Free sugars include added sugars plus sugars that are naturally present in honey, syrup, fruit juices, and fruit concentrates. Sucrose is composed of glucose and fructose molecules. It is found in many plants but is most concentrated in sugar beets and sugar cane. The health implications of high intake of sugars is the subject of scientific debate. Overconsumption may result in too high energy intake which can result in a higher risk for obesity, cardiovascular disease, and diabetes mellitus. But also in a higher risk for caries, because as we eat and drink sugar, the bacteria in our dental plaque are also fed. The bacteria in plaque metabolize the fermentable sugars into organic acids which can dissolve tooth minerals and eventually create cavities.

History of Sugar Consumption

Until 1500 AD, industrialization of the production of sugar was limited and only the wealthy could afford to consume enough sugar to develop dental caries. For instance, Queen Elizabeth I of England (1533–1603) was well known for her blackened teeth which was attributed to her fondness and consumption of sweets. Around 1800 AD, production and consumption of sugar was cheap and large enough to cause caries in > 50% of the British population [2]. Since then the consumption of added sugar gradually reached a plateau of 25E% (energy percentage of total energy consumed) or 186 g per person per day in the US in 1995 [3]. Nowadays, the total amount of added sugar consumed in the United States, for example, has been slowly reduced to 14E% per person [4]. Comparable percentages are also found in other Western countries, for instance in the Netherlands added sugar consumption was 12E%, free sugar was 14E%, and total sugar was 22E% [5].

Development of Hypotheses on the Relationship of Sugar and Caries

Already in the second half of the 19th century, the relationship between sugar and caries was demonstrated in the laboratory of Magitot who immersed teeth in fresh saliva and sucrose. After several months of incubation at room temperature, the teeth showed caries-like pathology [6]. Magitot did not know about the role of bacteria in saliva and thought that solely organic compounds in saliva could cause caries. Miller, familiar with the theories of Pasteur, found in 1857 that sugars could be fermented into acids by salivary microorganisms. Subsequently, Miller postulated the chemo-parasitic caries theory, in which bacteria were identified as producers of acids which could dissolve tooth minerals [7].

Observational Human Studies

Since the introduction of the chemo-parasitic theory, many studies have been conducted to elicit the relationship between fermentable sugar consumption and caries. Human observational and epidemiological research shows that when the caries data from industrialized and non-industrialized countries with different amounts of sugar availability per capita were analyzed, sugar ingestion per person could explain between a fifth and a third of the variation in caries experience in the non-industrialized countries. On the other hand, in industrialized countries where the usage of fluoridated toothpaste was widespread, the relationship was even negative [8, 9]. In a recent systematic review of clinical studies conducted from 1950 till 2011, lower consumption of sugar, to <10E% or <5E%, resulted in significantly lower caries levels [10]. One of those studies was in Finland by Ruottinen et al. [11]. They reported 1.4 teeth being either decayed, missing or filled (DMFT) in 10-year-old children who had a high sugar consumption above 10E% and a DMFT of 0.5 when sucrose intake was approximately 8E%. Another opportunity to study the relationship between sugar intake and caries emerged when temporary changes in availability of sugar occurred. For instance, UN sanctions in Iraq in 1990–1995 restricted the intake of sugar by 75% (from 136 to 33 g per person per day) and caused the number of DMFT to drop from 8.8 by >70% in 11–12 year olds, but even with the low sugar consumption children still had caries: 2.0 DS [12].

Experimental Human Studies

Since it is hard to truly control the diet of individuals and due to ethical considerations, only a limited number of experimental human studies trying to change the cariogenicity of the diet have been carried out. In the latter half of the 1940s, the Vipeholm study was conducted [13]. People in a mental institution were exposed to different diets with extra sugar added to their daily diet to increase the cariogenicity. The control group (n = 48) received extra calories through fat, test groups received extra sugar: a sucrose group consumed an extra 300 g of sucrose in solution during their meal per day, a bread group consumed additionally 345 g of sugar with sugared sticky bread, a chocolate group consumed 110 g of extra sugar. Next to groups that received their extra sugar during their meals there were groups that received the extra sugar between their meals: 4 × 15 g sugar in chocolate, a caramel group consumed caramels 4 times per day (22 caramels per day, i.e., 70 g sugar), an 8 toffee group (40 g of sugar) were handed out the toffees and a 24 toffee group (120 g sugar) had the toffees available ad libitum throughout the day. After 4 years the number of DMFT had increased considerably with the groups ranked from low to high caries levels as follows: control < sucrose < bread < chocolate < caramel <8 toffees <24 toffees. However, when the extra sugar was offered during meals, caries increment was limited (1–2 DMFT increase in 2 years), while the increase in caries experience was considerable when sugar was offered between meals (5 DMFT increase in 2 years). From this study and subsequent animal and laboratory studies it can be concluded that supplying sugar frequently to dental plaque results in more frequent organic acid formation events and more pH-drops dissolving the enamel and limiting the time for remineralization [14].

Since the Vipeholm study with its ethical issue of creating cavities, only experimental human studies that aimed to reduce caries by reducing sugar intake were performed. In Turku, Finland, an experiment was started in which sugar in the diet was substituted with non-fermentable sugar alcohols [15]. The adults were divided into 3 groups, consuming during 25 months a diet with sucrose, fructose or xylitol as the sole sweetener. The allocation of the groups was voluntary and not blinded. To ensure the diet was maintained, a shop was supplied with 100 dietary food products, especially made for this study by 12 manufacturers [15]. At the end of the experiment, the participants in the xylitol group developed very few new caries lesions, while participants in the sucrose group had, on average, 7 new lesions. The participants in the fructose-only group had 4 new lesions on average. The effect of low sugar intake on caries was also observed in people with fructose intolerance. People with this metabolic disease eat approximately 1/20th of the sugar amount (i.e., only 8 g of sugar per day or 1.5E%) compared to people with a normal diet, and consume as a source of carbohydrate mostly starchy foods. They experienced 90% less cavities in comparison with their peers [16].

Influence of Fluoride on the Relationship between Sugar and Caries

During the last decades, caries inc...

Table of contents

• Cover Page
• Front Matter
• Background
• Impact of Nutrients on Oral Health
• Impact of Diet and Nutrition on Oral Health
• The Impact of Nutrition and Diet on Oral Health
• Author Index
• Subject Index
• Back Cover Page