Agriculture Reference
In-Depth Information
and supplements appearing in commerce that contain enhanced levels of N-3 fatty
acids. Antioxidants have become an extremely broad and potentially very impor-
tant segment of the functional food market. The natural antioxidants are primarily
polyphenolic compounds, which include a very broad class of plant-based materials.
These compounds have many in vivo functions, ranging from oxygen and free-rad-
ical scavenging to regulating the expression of various genes. The changing of gene
expression or nutrigenomics is a critical function. One of the primary pathways that
is impacted in nutrigenomics is the chronic inflammatory pathway. Chronic inflam-
mation leads to many conditions, including coronary heart disease, Alzheimer's
disease, and some cancers. Understanding how polyphenolics regulate the genes in
the inflammatory pathways may eventually lead to improved screening for risk and
personalized nutritional recommendations.
defInItIon
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u n C t i of n a L
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Essentially all foods and ingredients in foods have functions. Food ingredients can
provide texture and flavor, and others provide biological functions, which generally
are related to health benefits. Foods function to provide us with necessary nutri-
ents, health benefits, and the pleasure of eating. The Institute of Medicine's Food
and Nutrition Board (IOM/NAS, 1994) defined
functional foods
as “any food or
food ingredient that may provide a health benefit beyond the traditional nutrients
it contains.” In recent years, the term
functional food
has been used as a descriptor
for foods that provide a biological or health-related benefit. This chapter focuses
on the biological or health benefits of foods and ingredients. The term has evolved
to mean a “food that provides value beyond basic nutrition.”
Basic nutrition
is the
delivery of carbohydrates, protein, fat, vitamins, and minerals that are essential for
growth and maintenance of the body. Functional foods provide extra value, such as
antioxidants that help protect the body from chronic diseases or components that
help improve plasma cholesterol levels by increasing high-density lipoprotein (HDL)
while decreasing low-density lipoprotein (LDL) cholesterol. Some functional foods
act by providing bioactive ingredients that are absorbed and elicit specific reactions
such as antioxidant activity, or they can induce specific gene expression. There are
also functional foods that deliver fiber to the diet that is not absorbed. The fiber sup-
plies substrate for production of short-chain fatty acids used for energy and as gut-
lining growth factors and nutrient source.
Demonstration of bioactivity of foods or supplements is difficult since many of
the activities delivered by bioactive ingredients have endpoint markers that may not
appear until later. For example, antioxidants that prevent lipid oxidation in the short
term can reduce lifetime risk of cardiovascular disease and some types of cancer.
To demonstrate these benefits would require feeding the bioactive material to large
numbers of subjects for many years, making any clinical trial prohibitively expen-
sive. Model systems have therefore been developed to assess the benefits of a wide
variety of bioactive ingredients.