IFIC Review: Nutrition and Oral Health: Making the Connection
(This publication is available
How does the mouth relate to good health? The mouth is the
entry point for food and the beginning of the gastrointestinal tract. The
ability to chew and swallow is a critical function required to obtain essential
nutrients for the body-the building blocks of good health. The links between
oral health and nutrition are many. Thus, oral health plays an integral role in
assuring adequate nutritional status. (1)
Interestingly, oral health and nutrition share an
interdependent and sometimes antagonistic relationship. By promoting healthy
development and maintenance of the mouth's tissues and natural protective
mechanisms, good nutrition promotes good oral health. In contrast, certain foods
can cause plaque development increasing the risk for oral disease. How the foods
are eaten can stimulate saliva flow, reducing the risk. The interactions are
complex, with food and nutrition having the potential for both positive and
negative effects on oral health.
In addition, the mouth serves as a window for the skilled
dental practitioner to view overall health status. The regular dental
examination makes it possible for your dentist to check for gum disease as well
as precancerous or cancerous lesions. More sophisticated screening mechanisms
can produce early warnings of stroke by displaying calcifications in the corotid
artery, or chemotherapy-induced weakening of the jaw.(2)
Taking care the mouth is an important step on the road to good
health. Good eating habits, regular brushing, flossing and fluoride are all part
of maintaining good health.
Oral Health - What Causes Dental Caries?
Caries (often referred to as tooth decay or cavities) is a
bacterial disease that is caused or hindered by many interacting factors -
bacteria, saliva flow, minerals, fluoride in water supply or dentiffices, the
properties of the food eaten, frequency of eating, dental care and dental
For many years, the primary focus of oral health care has been
the prevention of cavities in children with an emphasis on dietary influences on
caries formation. With evolving science, specific foods no longer are being
singled out as major risk factors for caries. In today's world, however,
prevention focuses on fluoride, use of sealants, frequency of eating, and good
All these factors interact by encouraging or discouraging the
cariogenic bacteria that cause progressive destruction of tooth enamel, known as
demineralization. Plaque is an almost invisible deposit of bacteria and their
byproducts that constantly forms on everyone's teeth. The bacteria in plaque use
carbohydrates to produce acids that can attack tooth enamel. The decaying action
of the plaque bacteria depends on its ability to adhere to tooth surfaces and to
hold acids on the teeth. After many such attacks, the tooth enamel may break
down, forming a cavity.(3)
The Role of Saliva
Saliva has a powerful, protective role in the oral cavity where
it preserves the integrity Of the soft tissues and increases the caries
resistance of the dental tissues. Minerals in saliva, such as phosphorus and
calcium, also play a role in helping to reform the tooth enamel, a process known
as remineralization. The mechanisms of repair are not well understood and are
being actively studied. Fluoride in the mouth enhances saliva's role in the
remineralization process. Additionally, saliva contains other substances that
serve as buffers to neutralize the acid created by bacteria. Saliva also works
to help remove food particles from the mouth.
In effect, saliva is to tooth enamel what blood is to the cells
of the body. just as body cells depend on the blood stream to supply nutrients,
remove waste and protect the cells, enamel depends on saliva to perform similar
Sugars (fruit sugar, milk sugar and table sugar) and
cooked starches (cookies and bread, etc.), known as fermentable carbohydrates,
are the only foods that can impact caries. Because carbohydrates can be used by
caries -promoting bacteria to produce acid and ultimately tooth decay, eating
habits rather than the foods themselves are a key factor in causing or
preventing tooth decay.
Frequency of eating is important because the acids are released
to work on the teeth for about twenty to forty minutes following each eating
occasion. The greater the frequency of eating, the more opportunity for the acid
to work. Decay occurs when periods of acid attack or challenge to the tooth
(demineralization) occur more frequently than periods of recovery
Similarly, those foods that tend to adhere to the teeth pose
greater risks of decay than those that clear the mouth quickly. Consumer
perceptions of foods that stick or adhere to the teeth usually are different
from reality, as the following chart demonstrates. Surprisingly, chips and
crackers adhere longer than jelly beans and caramels.(5) This may be because
caramels and jelly beans contain soluble sugars that are washed away more
quickly by saliva than foods such as bread or crackers, that are not dispersed
rapidly by saliva, and thus linger longer on the teeth.The first column on the
chart shows the consumer rating of the "stickiness" of the food, while the
second and third columns show the weight of the food particles remaining on the
teeth, or "sticking" to the teeth, one minute and five minutes after swallowing.
When consumed with beverages, these rankings may be modified.
||Dry weight (mg) of|
retained food particles
|Chocolate-caramel peanut bars
|Hot fudge sundaes
|Milk chocolate bars
|Source: Kashket, S., Van Houte, J., Lopez, L.R. and
Stocks, S. Lack of correlation between food retention on the human dentition and
consumer perceptions of food stickiness. Journal of Dental Research, 1991. Vol.
70. No. 10. Pp 1314-1319
|Figure 1: Consumer perception of
food stickiness compared with actual
High carbohydrate containing foods produce less acid when eaten
with a meal than when eaten alone because saliva production is increased during
a meal to help neutralize acid production and clear food from the mouth. A small
piece of cheese at the end of the meal can help combat the acids produced from
carbohydrate foods during the meal.
Lack of Access to Dental Care
Few data exist on access to dental care, but a 1987 report by
the National Center for Health Statistics showed that only 5 percent of children
in the United States under age 2 had ever seen a dentist. There has been a
profound decrease in caries over the past two decades - a drop from a mean of 18
to 8 decayed, missing or filled surfaces among 17-year-olds -and half of 5 to 17
year old children in the country were free of dental decay. However, data
suggest that socioeconomic status plays a role in caries development. "Closer
examination .... disclosed there was a marked polarization in the distribution
of caries among children - 20 percent have 60 percent of the decay .... it is
the have-nots that have most of the dental disease. "(6)
Population-wide use of dental sealants remains low. However,
between the 1986-87 and 1988-94 National Health and Nutrition Examination
Surveys (NHANES 11 and NHANES 111), use of dental sealants more than doubled.
Sealants are plastic films painted onto the chewing surfaces of teeth to protect
them from decay. The NHANES III survey found sealants on the primary teeth of
less than 2 percent of children, and the permanent teeth of 19 percent of
children and adolescents. Use of sealants on permanent teeth was three times as
common in white children (22 percent had "Sealants) as in African American
children (8 percent) or Mexican American youngsters (7 percent).(7)
Baby Bottle Tooth Decay
Baby bottle tooth decay, sometimes known as nursing caries, is
a dental condition in which theteeth of an infant or young child are severely
damaged. It is caused by frequent prolonged exposure of a child's teeth to
liquids containing sugars. Even lactose (the milk sugar found in cow's milk,
formula milk and breast milk) can cause decay when in prolonged contact with the
teeth. Bottles containing juices or other liquids containing sugars are the most
Normal feeding is not a problem because the liquids clear from
the mouth quickly. But offering a child a bottle containing sweet liquid many
times a day as a pacifier, or allowing a child to fall asleep with a bottle of
formula or juice during naps or bedtime can lead to serious dental problems.
Simple steps taken by parents and caretakers can prevent or
alleviate the problem, according to Dr. Steven Moss, a pediatric dentist at New
York University. The steps, according to Moss, are:
- After each feeding, wipe the child's teeth and gums with a damp washcloth or
gauze pad to remove plaque.
- Begin brushing your. child's teeth with a soft toothbrush and a pea-shaped
amount of fluoride toothpaste as soon as the first tooth erupts.
- If your child needs a comforting bottle at nap time or during the night,
fill a nursing bottle with water rather than formula, Juice, milk or sweetened
liquids. You could also give the child a clean pacifier recommended by your
dentist or pediatrician.
- Start visits to a dentist or pediatric dentist when the child is between six
and twelve months of age. Such visits help assure the child's teeth are
developing normally and that sealants, if indicated, are applied as the child
grows. Make appointments regularly.'
Dental Caries - A Disease in Decline
The Fluoride Factor
Far and away the most important factor in reducing caries
during the last two decades has been the widespread introduction of fluoride
into water supplies as well as fluoridation of toothpaste. Precisely how
fluoride works to treat and, in effect, prevent formation of dental cavities is
still being studied, but the. evidence of effectiveness is overwhelming?
Widespread use of fluoride is credited with a dramatic decline
in dental caries during the last 20 years in the United States, according to a
survey by the National Institute of Dental Research (NIDR). The number of
cavity-free children has increased from 28 percent in the early 1970s to 55
percent in the permanent teeth of 5 to 17 year olds in the 1988-94 National
Health and Nutrition Examination Survey (NHANES III).(10) An increase in the
number of people who regularly visit their dentist and an overall improved diet
are also cited as factors in the decline of dental caries, says the NIDR.(11)
Despite the overwhelming scientific evidence of the benefits of
fluoride, it has had its share of critics. Dental fluorosis - small, chalky,
opaque areas on the surface of the teeth - is a concern of critics. This
condition has been observed in communities when systemic fluorides are available
in greater than optimal amounts for lengthy periods. A 1991 Public Health
Service Review of the benefits and risks of fluoride concluded that the risks
were minimal compared with the benefits, especially when water supplies were
fluoridated according to government recommendations.
Other Oral Health Problems
Three forms of tooth wear may affect the teeth. When teeth wear
through tooth to tooth contact this is termed attrition. Abrasion results
from the application of external mechanical factors such as incorrect
toothbrushing. Dental erosion is defined as the loss of hard tooth tissue
caused by acids other than those produced by bacteria involved in dental caries.
Tooth wear is similar to caries only in that a large number of factors combine
to determine if an individual is at risk.
Some factors in dental erosion are internal and are seen in
persons suffering gastric reflux or eating disorders - when acid enters the
mouth from the stomach though regurgitation or vomiting. Other determinants are
external with acids entering the mouth through the consumption of acidic foods,
drinks or medicines. Both external and internal factors may be involved and the
picture is often complicated by the contribution of the other forms of tooth
wear, namely attrition and abrasion, especially in adults. Severe tooth wear is
Acidic foods and drinks include fruits (especially citrus fruits) and their
Juices, vinegary foods such as pickles, and fruit based or carbonated soft
drinks. Unusual eating or drinking habits such as sucking on segments of citrus
fruits (as athletes may do) and swishing or holding drinks in the mouth may be a
greater factor in tooth erosion than the amount consumed.
Saliva is the key protective factor in the mouth to protect the teeth against
erosion as well as against caries. Saliva flow is stimulated when acids enter
the mouth as saliva neutralizes and dilutes the acid and clears it from the
mouth. Therefore, the teeth are more at risk when saliva flow is low - as in
some elderly people, in athletes who are mouth breathing or as a result of
medications such as antihistamines. (12)
Periodontal disease is a widespread infectious disorder that destroys the
supporting tissues of the teeth. Seen primarily in adults, it is initiated by
plaque. Nutrient deficiencies may play a role in bringing about the condition,
but good oral hygiene and regular visits to the dentist are the primary
New Directions in Oral Health Research
Over the last forty years, dental health researchers have
shifted their focus from specific foods, such as candy, to the role of
carbohydrates in general (starches and sugars), as well as to examining
how eating habits influence plaque build-up. With fluoride now recognized as a
dental caries combatant, future research and preventive measures are expected to
- Ways in which dentists can utilize the routine dental visit as a screening
mechanism to provide early warnings of eating disorders, of cancer, or of soft
tissue problems pointing to osteoporosis. Some contemporary dentists now use the
routine teeth cleaning as a time to administer a special x-ray of the carotid
artery that can detect future risk of stroke or of chemotherapy-induced
weakening of the jaw structure.
- The role of nutrients (such as vitamin A and protein) on salivary gland
structure and function, and the implications of deficiencies.
- The role of antioxidants (such as vitamin E and carotene) on protective
mechanisms against periodontal damage.(13)
- The diet and lifestyle risk factor of tobacco and alcohol in the etiology of
oral cancer. Additional research is needed on such protective factors as
- Formation of new partnerships among dentists, pediatric dentists, dental
hygienists and dietitians in oral health screening, nutrition screening and
- Influence of aging, malnutrition and skeletal diseases such as osteoporosis
on oral soft tissues in the elderly.
- Decreased saliva flow in the elderly.
Dramatic declines in tooth decay are being seen around the
world as well. The World Health Organization Oral Health Programme has set a
Year 2000 Goal of three or less decayed, missing or filled teeth by age 12. To
date, over 100 countries have achieved that goal. Those countries where fluoride
is widely available show the sharpest declines. (14)
Zoom in on this
|Figure 2: The global decline in caries for a section of
countries over a 20-year period. (15,16)
- Caries - Scientific name for dental cavities. It is both singular and
- Cariogenic - Capable of promoting the development of caries (cavities).
Describes any food containing sugars or cooked starches that can be used to form
acid by bacteria living in plaque on teeth.
- Cavity - The hole occurring in the outer surface of the tooth enamel.
- Cooked starches - Contained in cooked foods such as pasta, rice, bread,
potatoes, chips, crackers and baked goods.
- Demineralization - The process by which minerals are leached out of tooth
enamel. This occurs when the bacteria in plaque produces acids that can attack
- Enzyme - A protein which acts as a catalyst in promoting one or more of the
many chemical reactions in the body. Enzymes in saliva help dissolve cooked
starches into sugars so they become soluble and can clear the mouth or be
fermented by plaque bacteria.
- Fermentable carbohydrates - Any sugar or cooked starch that can be
metabolized by oral bacteria to produce acid.
- Fructose - A simple sugar found in honey and fruits.
- Glucose - A simple sugar, also known as dextrose, found in many foods.
- Plaque - An invisible, sticky film that forms on teeth, giving them a "fuzzy
feel." Plaque contains bacteria which can ferment sugars and cooked starches in
foods to form acid.
- Remineratization - The process by which the minerals from saliva enter the
tooth surface to repair it.
- Starch - A carbohydrate polymer composed of glucose molecules. All starches
are broken down in the body to the simple sugar glucose before they can be used.
- Sucrose - The scientific name for table sugar, a mixture of the two simple
sugars, glucose and fructose.
- The American Dietetic Association. ADA Reports: Position of the American
Dietetic Assocation: Oral Health and Nutrition. 1996 J.Am. Diet. Assoc. 96:
- Carter, L.C., A.D. Holler, et. al. 1997. Use of Panoramic Radiography Among
An Ambulatory Dental Population to Defect Patients at Risk of Stroke. J. Am.
Dent. Assoc. 128: 978-983.
- American Dental Association. 1990. Diet and Dental Health.
- Moss, S. 1997. The Relationship Between Diet, Saliva and Baby Bottle Tooth
Decay. Int. Dent Jnl. 46: 399-402 (Suppl) 8.
- Kashket, S., J. Van Houte, L.R. Lopez and S. Stocks. 1991. Lack of
Correlation Between Food Retention on the Human Dentition and Consumer
Perception of Food Stickiness. J. Dent. Res., 70/10: 1314-1319.
- Mandel, I.D., American Dental Association. Caries Prevention: Current
Strategies, New Directions. J. Am. Dental Assoc. 127:477-488.
- National Institute of Dental Research. 1996. News release, March/96
- American Dental Association. 1989. Baby Bottle Tooth Decay. 166.
- Public Health Service. Review of Fluoride: Benefits and Risks. February
- National Institute of Dental Research. News releases. March 11, 1996 and
June 21, 1988.
- International Food Information Council. 1997. Food Insight, January/February
- Imfeld, T., 1995. Etiology, Mechanisms and Implications of Dental Erosion:
Dental Erosion. Definition, classification and links. September. 151-155.
- Levitch, L.C., et al: 1994. Non-carious Cervical Lesions. Jnl of Dentistry,
- World Health Organization. 1995. The Oral Health Programme: Dental Caries
Levels at 12 Years. May.
- World Health Organization. 1995. Oral Health Global Indicator for 2000
Dental Caries Levels at 12 Years. WHO, Geneva.
- Hescot, P., Roland, E. 1993. Dental Health in France. DMF Scores for 6, 9
and 12 Years Old. French Union for Oral Health (UFSBD).