Food Safety Assessment - ACS Publications - American Chemical

Chapter 26

Diet—Health Relationship

Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 28, 2018 | https://pubs.acs.org Publication Date: February 14, 1992 | doi: 10.1021/bk-1992-0484.ch026

Paul A. Lachance Graduate Program in Food Science, Rutgers, The State University, New Brunswick, N J 08903-0231

Diet Diet can be defined as either "Food and drink regularly consumed in the habitual course of living" or " A prescribed allowance or regimen of food and drink with reference to a particular state of health". Given the diverse functions of food, the challenge is to reconcile the pleasure of food and drink with the promotion of optimal health. When food and drink are reduced to chemical terms, the pleasure is essentially absent. Since the number of chemicals which constitute food and drink is substantial and a minority fraction is essential for physiological health, the equivocal chemicals which impart sensory appeal must be distinguished from the chemicals that should be avoided. In all instances, (essential, equivocal, to be avoided) there is a determination of relative risk which must be made. Health Health is defined as "a continued state of soundness and vigor of body and mind". We have no direct measures of health and so we redefine health "as the absence of disease" but the disease state must be pathological to be recognized and indexed. Indicator conditions such as hypertension; or risk factors such as obesity; or risky practices such as smoking; "at-risk" environments such as considerable exposure to elevated ozone and other pollutant levels are invariably "silent" and idiopathic. Practices (dietary, exercise, ecological) which promote health are not a major domain of medicine, not only because the financial rewards to medicine are considerably inferior but because the connection to specialized diagnosis related (DRG's) disease categories are not specific and thus there are few legitimate categories for third party reimbursement. Diet-Health Association The association of diet with health (or disease) has been "in the news" since the 1969 White House Conference on Food, Nutrition and Health. A s a result of the conference, 0097-6156/92/0484-0278$06.00/0 © 1992 American Chemical Society Finley et al.; Food Safety Assessment ACS Symposium Series; American Chemical Society: Washington, DC, 1992.


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nutrition labeling was instituted and is now in the final process of a major revision (7). Labeling now will be mandated for most foods rather than triggered only by advertising claims and otherwise being voluntary. The "Dietary Goals" which emanated in the dying gasps of the Senate Select Committee on Nutrition and Human Needs (2) eventually led to the current joint USDA/DHHS Dietary Guidelines. The documentation for the health benefits of such guidelines are to be found in the over 5,000 scientific references cited in the 1989 Diet and Health report (3) of the National Academy of Sciences. These diet-health association pronouncements are also in part attributable to the yeoman lobbying and news media activity of the Center for Science and the Public Interest and related "Nader type" activists, as well as the peripatetic activities of the civil servants of the government agencies prodding and being prodded by zealous congressional legislative staffers. Both the major professional nutrition societies and the food industry provided debate, reaction and stabilizing inertia. The consumer "at best" has accomodated. Consumer Beliefs and Practices A Gallup survey of consumers conducted in December 1989 (commissioned by the International Food Information Council and the Am. Dietetic Association) revealed (with ±4% accuracy) that 95% of Americans "believe balance, variety and moderation are the keys to healthy eating" and further 83% recognized that what they eat may affect their future health"; but 67% mistakenly choose food based on "good food"/ "bad food" perceptions. In other words, Americans are more apt to opt for quick fixes and the latest health fads. For example, 52% of these (over 18) adult respondents reported increasing their consumption of oat bran but only 8% reported eating more vegetables and only 6% reported eating more fruit or fruit juices. Again "tunnel vision" nutrition is strong and well. Consumers believe one food or ingredient will prevent or maybe cure a disease! It rather fits the fact that Americans are the highest per capita users of over-the-counter and prescription drugs. We prefer and expect "quick fixes". Moreover, the diet-health connection translated into good food/bad food perception leads Americans to state they don't find eating apleasure because 56% worry about fat and cholesterol and 35% are unsure of the difference between food cholesterol and blood cholesterol! Fifty percent say they gain weight if they eat what they like and 35% believe high fat foods cannot be part of a healthy diet even if balanced with low fat foods. In a nation that has serious levels of functional illiteracy, maybe we cannot expect better performance when prerequisites to performance (e.g. poverty, literacy) are limiting. But Americans are healthier today than ever before in our history. We live longer. Since a peak in the '50'S, we now have a lower rate of coronary heart disease deaths and strokes. We have fewer dental cavities and other positive indicators of a lower morbidity yet we have only recently recognized the need to avoid sexual practices that promote AIDS; the need to avoid smoking that promotes both lung cancer and

Finley et al.; Food Safety Assessment ACS Symposium Series; American Chemical Society: Washington, DC, 1992.


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coronary heart disease etc. There are certain types of information the average consumer fears because they do not understand and certain mismanaged public incidents have served to rationalize an attitude that is unscientific. A two day symposium at these ACS meetings is focusing on the realities of chemophobia (4). Abelson (5) states that "for most of the public, the word "chernicar elicits antipathy and fear". No doubt lack of and/or the poor quality of science education at all levels of our education system, even at the University level, can be implicated; however, there is no generic American consumer. If there were, the number of items in the supermarket would not have risen from 12,000 to 25,000 in the last 10 years in order to meet the demands of an increasingly segmented consumer market place. The need for market segmentation began when "Rosie" became the riveter during World War II and the double income family life style was born. It really did not flourish until more recently when marriage at a later age and planning on fewer children became the norm. By the year 2,000, more people in the U S A will be over 50 than under age 18. One reason is a significant increase in life span. In theory, the "balance" of the diet was better in 1900 but life span was 50 years or so. The discovery of vitamins, minerals and antibiotics and other rniracle drugs has shifted the causes of infirmities and death from infections and deficiency diseases to chronic diseases and decreased resistance to acute diseases. The decreased resistance is associated with the decreased integrity of aging organ systems. The household is smaller. Both the delay in marriage, and the increase in older Americans has produced more one and two person households (6). An unknown countervening force could be the yet to be fully established reality that the fastest growing segment of our population is Asian Americans followed by the already larger Hispanic-American population. A major variable contrasting these population segments is the initial educational level and goals of these two emerging population segments, both of which also have quite different food heritages and preferences. The realities of the foregoing facts are simply not challenging the scientific and medical communities. Disease-Health Practices Associations The report of the Surgeon General (7) and the Diet & Health report of the National Academy of Sciences (3) has gelled recognition by both the public health community and the scientific community of the medical establishment that many of today's major causes of mortality and morbidity are associated with clinical indicators (e.g.. obesity, blood pressure and blood lipid profiles) that are amenable to routine public health screening; and that certain modifiable practices of individuals (smoking, dietary choices) have significant effects in or on the pathogenesis of the diseases associated with the leading causes of mortality and morbidity. A listing of the chapter headings of the Diet and Health report (see Box) efficiently serves to identify the associations now recognized.


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Diet and Health: Implications for Reducing Chronic Disease Risk


Part III: Impact of Dietary Patterns on Chronic Diseases Chapter 19. Chapter 20. Chapter 21. Chapter 22. Chapter 23. Chapter 24. Chapter 25. Chapter 26.

Atherosclerotic Cardiovascular Diseases Hypertension Obesity and Eating Disorders Cancer Osteoporosis Diabetes Mellitus Hepatobiliary Disease Dental Caries

While few scientists now disagree with the associations that have emerged, considerable debate ensues relevant to the practical aspects of the recommendations made in the Diet and Health report. The Surgeon General's report is less controversial because it makes less judgemental conclusions. There is considerable agreement in both reports on the importance of the role of obesity, hypertension and smoking as clinical indicators but less agreement (and more complex scientific interactions and unknowns) on the role of type and quantities of dietary polyunsaturated fatty acids;the type and quantity of micronutrient intakes above levels needed to thwart deficiency diseases;the predictive value of total or H D L or lipoprotein (a) levels in clinical screenings etc. The Surgeon General's report (7) mentions the issues of microbiological food safety. Neither report considers the issues of chemical food safety. The fact is that the lack of an extensive body of human pathology attributable to naturally occurring food chemicals or food additives does not signal a lack of concern or knowledge or both. The beneficial and deleterious linkage between the chemistry of food and the pathogenesis of diseases are only now being explored. A considered approach until controversial recommendations can be clarified with more quantitative scientific insights is to apply the concept of "limiting" and accordingly to determine the most valuable strategy to pursue. I am of the opinion that the control of obesity should have the greatest priority relative to its strong association with atherosclerosis and thus coronary heart disease and stroke, and that the limiting and most valuable strategy would be to control saturated fat intake and increase exercise. Relevant to the second greatest cause of mortality, namely cancer, the limiting and most valuable strategy is to curtail smoking and sources of carcinogens (including food). The most valuable strategy available is to enhance the intake of dark green and yellow vegetables for factors such as beta carotene, ascorbic acid and other antioxidant food sources which are highly associated with lower risks of several major types of cancer. The necessary dietary strategy for both a decrease in saturated fat (animal fats)and an increase in plant foods has existed as a dietary guideline for more than two generations and can be readily communicated to and practiced by the consumer (Figure 1). It should supercede the current nebulous dietary guideline of "eat a variety of foods". The benefits of this simple "peace symbol" food array guideline is the concomitant assurance of low fat, low saturated fat, high fiber, high


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carotenoid and a high nutrient density dietary without the need to account for individual nutrient or chemical components.


Obesity The most prevalent indicator of chronic diseases today is obesity and the incidence increases (Figure 2). It is associated with diabetes, especially type II (adult onset), hypertension and heart disease. Obesity complicates physiological conditions such as pregnancy and increases the risk of several other common medical conditions such as cholecystitis and appendicitis, etc. The daily per capita grams of saturated fat in the food supply has not dramatically changed since about 1920 but the daily per capita grams of both monounsaturated and polyunsaturated fat has increased with PUFA essentially doubling since 1935 (Figure 3). In the relatively same time period, per capita energy intake has dropped and the percent calories from fat has also dropped from 42% to 37% of calories. The food categories from which dietary energy has been derived has shifted substantially. Cereal grain products were a much more important contributor to the diet prior to WWII. With affluence came an increased consumption of higher quality (and more expensive) sources of protein. Balance in food group proportions began as a dietary goal circa post WWII, and these guideline proportions (the basic four) have remained the practical definition of balance, yet national surveys have repeatedly and consistently demonstrated that Americans fail to meet these proportions (Figure 4). A l though we "eat a variety of foods", we consume an expensive profile with emphasis on high quality protein entrees and inadequate quantities of cereal grain products and fruits and vegetables. The increase in the quality of foods per se coupled with the discovery, manufacture and utilization of micronutrient fortificants has permitted the lowering of energy intakes coupled to a less energy demanding environment, and the incidents of frank nutrient deficiency diseases so evident in the first half of the century are exceedingly rare. We now have an increasingly sedentary society that has shifted its caloric intake downward but not sufficiently to thwart obesity and other diet associated risk factors in the chronic disease causes of morbidity and mortality. Smoking Thirty percent of persons (in 1985) aged 18 and older were smokers, and the prevelance was equal for men and women under 30 years of age. Smoking is a risk factor for cancer and cardiovascular disease. An important but not frequently reported fact is that the food consumption patterns and dietary intakes of smokers and nonsmokers differ. Smoking is a marker for a poor diet. Whereas, a similar percentage (38%) of smokers and nonsmokers report eating snacks on a daily basis, 38% of smokers habitually skip breakfast in contrast to 18% of nonsmokers. In a study of career age women in 1985-86 women smokers consumed less fruits and vegetables and more coffee and alcoholic beverages than nonsmokers (5). N H A N E S I I results showed that median vitamin C intakes were lower in current


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plant Food; /

Fruits and Vegetables

V \

Milk Products


/

Cereal Grain Products

\ \

Protein - Rich , Foods / Meat / Legumes >S

Serving Quantity No Emphasis

Serving Quantity Emphasized

Figure 1. The basic four food groups required, remembering number of servings recommended per group, namely 4:4:2:2. A graphic representation immediately illustrates the proportions of the plate or day that should be allocated to each food group to promote balance. (Reproduced with permission from ref. 23. Copyright 1981 Food Technology.) OVERWEIGHT (1976-80 HANES II)

MALE WHITE F i g u r e 2. The male and >27.3 survey exceeds and approaches

FEMALE BLACK

p r e v a l e n c e o f o b e s i t y d e f i n e d as a BMI > 27.8 i n i n female p a r t i c i p a n t s i n the 1976-80 HANES I I 25 p e r c e n t i n w h i t e s , 30 p e r c e n t i n b l a c k males 50 p e r c e n t i n b l a c k f e m a l e s . Adapted from r e f . # 8.



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-L 1915

1905

±

JL

1925

1935

1945

1955

1965

1975

1985

Year F i g u r e 3. Per c a p i t a amounts o f s a t u r a t e d , monounsaturated, and p o l y u n s a t u r a t e d f a t s i n the U.S. food s u p p l y : U.S. Food Supply S e r i e s , 1909-85.

Basic Four Goal Fruits & — Vegetables (28.0%) Y

Milk Products (19.0%)

C

e

r e a l & ^ • ' ^ G r a i n Products \ (32.0%)

Animal & Legume Foods (21.0%)

NFCS (USDA), 1977-1978

Hanes (DHEW), 1971-1974 Fruits & — ^ - - - - - - ^ v ^ ~ Cereal & Vegetables^

Food Safety Assessment - ACS Publications - American Chemical

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