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Health Related Aspects of Milk and Milk Products: An Introduction
SYMPOSIUM: H EAL T H R E LA TE D ASPECTS OF M I L K A N D MILK PRODUCTS Health Related Aspects of Milk and Milk Products: An Introduction P. C. V A S A V A O A and D. E. S M I T H Department of Animal and Food Science University of Wisconsin-River Falls River Falls 54022 and Department of Food Science and Nutrition University of Minnesota St. Paul 55108 DISCUSSION
Currently the dairy industry produces more milk than is consumed. To remedy this situation an extensive advertising program has been undertaken with money contributed by dairy famers. The thrust of this advertising effort has been to portray milk and milk products as upbeat and fun products that everyone from young to old will enjoy. Implied within the advertisements is the idea that milk is a wholesome food. The idea the health benefits can arise from consuming milk and milk products has been widely held for a long time. Recently, research has indicated benefits in addition to the traditional benefits of providing protein to the b o d y and calcium for the production of strong bones. These newly recognized benefits stem from research involving 1) the relationship of calcium to lowered hypertension and 2) the use of milk as a vehicle to provide fluoride to children and thus reduce tooth decay. Research, also indicates that the consumption of fermented dairy foods will allow those who are lactose intolerant to gain health benefits that milk can contribute. In addition to a focus on health rewards of consuming milk and milk products, a second focus of this symposium will address some of the problems that may arise if milk is not handled properly and microbial growth occurs. In the early days of the United States dairy industry the quality of market milk was poor. Often milk was produced and handled in an unsanitary manner and contained pathogenic organisms that caused diseases in persons consuming milk. Widespread outbreaks of
Received August 30, 1985. Accepted November 4, 1985. 1987 J Dairy Sci 70:381-382
disease caused by contaminated milk led to two popular movements: pasteurization and certification of milk. Although certification of milk emphasizes stringent cleaning and sanitation in milk production, it does not afford protection against pathogenic organisms. Pasteurization is the main safeguard against pathogenic organisms in milk. The dairy industry's efforts to provide safe, wholesome, and quality dairy products are evidenced by compliance with the Pasteurized Milk Ordinance and Code and b y stringent quality assurance programs that are adhered to at all levels of production and processing. The combination of pasteurization, care in production and processing, and improved storage has resulted in a relatively safe milk supply. Milk-borne diseases like tuberculosis, diptheria, and scarlet fever have been practically eradicated. Also, the shelf-life of milk has been increased from a few days to a few weeks. Although quality and safety of milk and dairy products have improved over the years, accidental contamination or improper processing of milk can lead to outbreaks of milkborne diseases. In recent years outbreaks of campylobacteriosis, yersiniosis, salmonellosis, listeriosis, etc. have been traced to contaminated milk or products made from this milk. Although raw milk or unpasteurized milk (including certified raw milk) was the cause in many of the reported outbreaks, improper or faulty pasteurization was to blame in a few cases.
Two of the important milk-borne organisms, Yersina enterocolitica and Listeria rnonocytogenes, and their effects are described by D.
A. Schiemann and E. H. Marth. It has been recognized for a long time that a large number of people, especially those not of 381
382
V A S A V A D A AND SMITH
northern European origin, have problems digesting milk. The most common of these problems is inability of a person to digest the lactose in milk. There are various ways to treat milk and milk products to make it consumable for these lactose intolerant people, e.g., hydrolyze lactose by adding lactase to milk or remove lactose and replace it with another sugar. Also, lactose intolerance often can be overcome by consuming various fermented dairy products. The problem is alleviated because of the ability of the microorganisms to degrade lactose in the milk. The topic of milk intolerance, particularly lactose intolerance with regard to yogurt, is reviewed in a paper by D. A. Savaiano and M. D. Levitt. A wide range of foods cause the formation of acid that leads to the development of dental caries. Recent research has revealed that several cheeses-including Cheddar, Blue, Brie, Gouda, Monterey, Mozzarella, and Swiss-caused very little or no decrease in pH and thus are nonacidiogenic. Cheddar cheese also had unique anticariogenic properties. This research has potential for developing anticariogenic or noncariogenic snack foods. Another area of research related to dental health is fluoridation of milk. Although fluoridation of drinking water is recognized as an important means of preventing dental caries, the approach has met some resistance in certain communities. Also, the effectiveness of fluoridation of drinking water in preventing dental caries has been questioned and still remains somewhat controversial. The idea of adding fluoride to milk may provide an effective alternative to the generalized fluori-
Journal of Dairy Science Vol. 70, No. 2, 1987
dation of drinking water. The role of milk and milk products in dental heahh is reviewed by C. H. White. Among the beneficial aspects of milk and dairy products is their contribution to the dietary, particularly calcium. A quart of milk can provide over 100% of the daily requirement for calcium. Calcium in milk is in a bioavailable form and is readily absorbed. The absorption of calcium is enhanced by the vitamin A and lactose of milk. Adequate intake of calcium is necessary not only during growth, but also in adulthood for prevention of diseases like osteoporosis. Another role of calcium in the diet is in controlling hypertension. Recent reseach has indicated an inverse relationship between dietary calcium intake and blood pressure. The beneficial products are discussed in a paper, " C a l c i u m - O s t e o p o r o s i s and Blood Pressure", by L. L. Rusoff. Our main objective in presenting this symposium is to highlight the healthful aspects of milk and dairy products. In addition, the quality and safety of milk must be considered in order to assure the delivery of safe and wholesome products to the consumer. No amount of publicity regarding the nutritional benefits of milk can compensate for the loss of consumer confidence in milk resulting from an occasional yet important disease outbreak. ACKNOWLEDGMENT
We would like to thank Dairy Research Inc. Rosemount, IL, and the American Dairy Science Association for supporting this symposium.
Currently the dairy industry produces more milk than is consumed. To remedy this situation an extensive advertising program has been undertaken with money contributed by dairy famers. The thrust of this advertising effort has been to portray milk and milk products as upbeat and fun products that everyone from young to old will enjoy. Implied within the advertisements is the idea that milk is a wholesome food. The idea the health benefits can arise from consuming milk and milk products has been widely held for a long time. Recently, research has indicated benefits in addition to the traditional benefits of providing protein to the b o d y and calcium for the production of strong bones. These newly recognized benefits stem from research involving 1) the relationship of calcium to lowered hypertension and 2) the use of milk as a vehicle to provide fluoride to children and thus reduce tooth decay. Research, also indicates that the consumption of fermented dairy foods will allow those who are lactose intolerant to gain health benefits that milk can contribute. In addition to a focus on health rewards of consuming milk and milk products, a second focus of this symposium will address some of the problems that may arise if milk is not handled properly and microbial growth occurs. In the early days of the United States dairy industry the quality of market milk was poor. Often milk was produced and handled in an unsanitary manner and contained pathogenic organisms that caused diseases in persons consuming milk. Widespread outbreaks of
Received August 30, 1985. Accepted November 4, 1985. 1987 J Dairy Sci 70:381-382
disease caused by contaminated milk led to two popular movements: pasteurization and certification of milk. Although certification of milk emphasizes stringent cleaning and sanitation in milk production, it does not afford protection against pathogenic organisms. Pasteurization is the main safeguard against pathogenic organisms in milk. The dairy industry's efforts to provide safe, wholesome, and quality dairy products are evidenced by compliance with the Pasteurized Milk Ordinance and Code and b y stringent quality assurance programs that are adhered to at all levels of production and processing. The combination of pasteurization, care in production and processing, and improved storage has resulted in a relatively safe milk supply. Milk-borne diseases like tuberculosis, diptheria, and scarlet fever have been practically eradicated. Also, the shelf-life of milk has been increased from a few days to a few weeks. Although quality and safety of milk and dairy products have improved over the years, accidental contamination or improper processing of milk can lead to outbreaks of milkborne diseases. In recent years outbreaks of campylobacteriosis, yersiniosis, salmonellosis, listeriosis, etc. have been traced to contaminated milk or products made from this milk. Although raw milk or unpasteurized milk (including certified raw milk) was the cause in many of the reported outbreaks, improper or faulty pasteurization was to blame in a few cases.
Two of the important milk-borne organisms, Yersina enterocolitica and Listeria rnonocytogenes, and their effects are described by D.
A. Schiemann and E. H. Marth. It has been recognized for a long time that a large number of people, especially those not of 381
382
V A S A V A D A AND SMITH
northern European origin, have problems digesting milk. The most common of these problems is inability of a person to digest the lactose in milk. There are various ways to treat milk and milk products to make it consumable for these lactose intolerant people, e.g., hydrolyze lactose by adding lactase to milk or remove lactose and replace it with another sugar. Also, lactose intolerance often can be overcome by consuming various fermented dairy products. The problem is alleviated because of the ability of the microorganisms to degrade lactose in the milk. The topic of milk intolerance, particularly lactose intolerance with regard to yogurt, is reviewed in a paper by D. A. Savaiano and M. D. Levitt. A wide range of foods cause the formation of acid that leads to the development of dental caries. Recent research has revealed that several cheeses-including Cheddar, Blue, Brie, Gouda, Monterey, Mozzarella, and Swiss-caused very little or no decrease in pH and thus are nonacidiogenic. Cheddar cheese also had unique anticariogenic properties. This research has potential for developing anticariogenic or noncariogenic snack foods. Another area of research related to dental health is fluoridation of milk. Although fluoridation of drinking water is recognized as an important means of preventing dental caries, the approach has met some resistance in certain communities. Also, the effectiveness of fluoridation of drinking water in preventing dental caries has been questioned and still remains somewhat controversial. The idea of adding fluoride to milk may provide an effective alternative to the generalized fluori-
Journal of Dairy Science Vol. 70, No. 2, 1987
dation of drinking water. The role of milk and milk products in dental heahh is reviewed by C. H. White. Among the beneficial aspects of milk and dairy products is their contribution to the dietary, particularly calcium. A quart of milk can provide over 100% of the daily requirement for calcium. Calcium in milk is in a bioavailable form and is readily absorbed. The absorption of calcium is enhanced by the vitamin A and lactose of milk. Adequate intake of calcium is necessary not only during growth, but also in adulthood for prevention of diseases like osteoporosis. Another role of calcium in the diet is in controlling hypertension. Recent reseach has indicated an inverse relationship between dietary calcium intake and blood pressure. The beneficial products are discussed in a paper, " C a l c i u m - O s t e o p o r o s i s and Blood Pressure", by L. L. Rusoff. Our main objective in presenting this symposium is to highlight the healthful aspects of milk and dairy products. In addition, the quality and safety of milk must be considered in order to assure the delivery of safe and wholesome products to the consumer. No amount of publicity regarding the nutritional benefits of milk can compensate for the loss of consumer confidence in milk resulting from an occasional yet important disease outbreak. ACKNOWLEDGMENT
We would like to thank Dairy Research Inc. Rosemount, IL, and the American Dairy Science Association for supporting this symposium.