7.1 Developments in nutrition science

The health benefits of seafood consumption can be viewed against the

background of developments in nutrition science, as described by Schaafsma

and Kok (2005) and summarized here briefly.

Since the beginning of the 20th century nutrition science developed rapidly

and in the first period of this science (until about 1970), all indispensable

nutrients, that we know now, were discovered and their biochemical role in the

body was elucidated. Deficiencies of one or more of these nutrients are known to

cause the classical deficiency diseases, like beri beri (vitamin B1), rickets

(vitamin D), scurvy (vitamin C) and anaemia (iron). Research in that period

resulted in setting up so-called Recommended Daily Intakes (RDIs) of most

nutrients for various groups of the population. These RDIs are very helpful for

nutrition education, for the planning of diets, for the evaluation of the adequacy

of food intake and for the assessment of the nutritional value of single foods.

Although new research may lead to further refinement and substantiation of the

RDIs, it is not expected that new indispensable nutrients will be discovered.

Whereas in Western societies classical nutrient deficiencies have become scarce,

they unfortunately still occur on a large scale in food-deprived Third World

countries.

After this so-called period of classical nutrition, scientists and health care

authorities became aware that, particularly in affluent Western societies, ade-

quate nutrition is more than just the prevention of classical nutrient deficiencies.

Unbalanced diets appeared to be involved in the occurrence of chronic diseases,

such as cardiovascular disease, diabetes type II, osteoporosis and cancer. Since

then, nutrition science became involved in finding the optimal (balanced) diet.

7

Introduction to Part II:health benefits of seafoodG. Schaafsma, HAN University, The Netherlands

Dietary guidelines, aiming to reduce the risk of chronic diseases, were

disseminated. This is a continuing process and it is expected that future research,

including that of SEAFOODplus, will generate new knowledge in this field.

Until about 1990, the main focus of nutrition science in Western countries

was on the adequacy of total diets, rather than on health aspects of individual

foods. Whereas nutrition scientists continue their efforts to improve and

substantiate further the dietary guidelines, since about 1990, under the influence

of Asian countries (e.g. Japan), the concept of functional foods came up in

Europe. These foods can be considered as foods, which are designed especially

to exert a health benefit. They are marketed with nutrition claims and health

claims.

7.2 Nutritional role of seafood

For many population groups, seafood is a nutritionally significant part of the

diet, but between groups and between individuals within groups, seafood

consumption may show a wide variation. From a nutritional point of view and in

conformity to the text above, seafood can be considered in three ways: (1)

source of indispensable nutrients, (2) food that lowers the risk of chronic

diseases, and (3) food that serves as a basis for the design of functional foods.

7.2.1 Seafood, an excellent source of indispensable nutrients

It is well known that seafood (lean and fatty fish, shell fish) is an excellent

source of a large variety of nutrients. These include high-quality protein,

vitamins (especially vitamins A and D in fatty fish, and B vitamins), minerals

and trace elements (especially iodine and selenium) and long chain poly-

unsaturated omega-3 fatty acids. Because of its high nutrient content, seafood

consumption can make a significant contribution to cover the needs of indis-

pensable nutrients. Its high content of a large variety of nutrients compared to its

energetic value, means that seafood perfectly fits into low-energy diets, designed

for weight management. Challenging new information is reported in Chapter 9

in this book where new aspects of diets for weight management have been found

when including fish or fish oils in the diets.

7.2.2 Seafood as a food that lowers the risk of chronic diseases

Research in various population groups on the relationship between food con-

sumption and the occurrence of chronic diseases (so-called epidemiological

nutrition research) has demonstrated protective effects of fish consumption

against cardiovascular disease, colon cancer and the metabolic syndrome. The

metabolic syndrome is a condition which includes elevated blood pressure,

elevated blood lipids (especially triglycerides), and raised blood glucose levels

and body fat content. The metabolic syndrome is associated with a strongly

114 Improving seafood products for the consumer

increased risk of cardiovascular disease and diabetes type II. A disadvantage of

epidemiological research is that this type of research cannot assess whether these

beneficial relationships are causal. Theoretically, they could be spurious,

because of confounding factors related to life style and not directly to fish

consumption. Therefore it remains necessary to perform controlled intervention

trials in humans in which the effects of fish consumption on the risk of the

chronic diseases mentioned above are directly investigated. And this is exactly

the aim of the nutrition research within SEAFOODplus. In the following

chapters, written by Dr Liz Lund, Prof. Inga Thorsdottir and Dr Ingeborg

Brouwer, studies are described in three areas. A specific focus in these respec-

tive chapters is on the beneficial effects of fatty acids from fish as well as on fish

protein.

7.2.3 Seafood as a basis for the design of functional foods

It is beyond the scope of this introduction to address in detail this particular

issue. For a description of the concept of functional foods, the reader is referred

to an overview written by Schaafsma and Kok (2005) and in Part IV of this book

examples are given of how functional foods and/or functional food ingredients,

with seafood as a basis, can be made by novel food processing and aquaculture

techniques, which is also covered in Part V of this book.

7.3 References

SCHAAFSMA G and KOK FJ (2005), Nutritional aspects of food innovations: a focus on

functional foods. In: Jongen WMF and Meulenberg MTG (ed), Innovation in Agri-

food Systems. Wageningen Academic Publishers, pp 207±220.

Introduction to Part II: health benefits of seafood 115