Nutritive and Health Attributes of Dairy Ingredients 415a benefi cial role of including three servings
of dairy foods in diets high in fruits and veg-
etables in preventing hypertension.
As discussed in previous sections, milk
proteins are precursors of bioactive peptides
that are capable of inhibiting the activity of
the angiotensin - I - converting enzyme (ACE).
This enzyme regulates blood pressure, elec-
trolytes, and fl uid balance in the body. ACE
converts inactive angiotensin - I hormone into
angiotensin - II, which constricts vascular
smooth muscle, leading to elevation of blood
pressure. Thus, an inhibitory effect of the
peptide derived from milk protein lowers
blood pressure. In this regard, whey protein
hydrolyzates are particularly cited for their
blood pressure lowering ability (Miller et al,
2007 ).Cancer
The effect of diet on risk of cancer is signifi -
cant: 30% of all cancers are related to diet. It
is known that certain components of foods,
when consumed excessively, may promote
cancer; this includes calories, alcohol, and
fat. On the other hand, some food compo-
nents, including dairy, are preventative.
Calcium and vitamin D are be benefi cial
against colon cancer. Dietary calcium nor-
malizes hyperproliferation of colonic epithe-
lium cells in individuals at risk of colon
cancer. CLA and vacceinic acid found in all
dairy foods confer desirable anti - carcinogenic
and anti - atherogenic effects. CLA is also
benefi cial in glucose and fat metabolism in
type - 2 diabetic subjects. Because the fat
content of popular dairy foods is low, their
CLA content is also low. The isolated CLA
is now being used as a supplement ingredient
in foods.Enhancement of Health Properties
by Culturing of Milk
Fermented milks such as yogurt are enhanced
functional foods because they contain thecells and are encouraged to consume calcium,
vitamin D, and other dietary nutrients. The
2005 Dietary Guidelines recommend three
cups of low - fat or nonfat milk or equivalent
from dairy products for adults to help main-
tain bone health.
Osteoporosis occurs more commonly in
women than men. Key elements in develop-
ing osteoporosis are genetic factors, age,
physical activity, and nutrient intake. In
women, osteoporosis is aggravated by meno-
pause (loss of estrogen). Nevertheless, there
is a consensus that maximizing peak bone
mass by adequate calcium, phosphorus, and
other minerals from dairy and food sources
early in life is necessary for retaining higher
bone mass and reducing the risk of bone frac-
tures later in life.
Hypertension Control
Calcium and potassium are positively associ-
ated with regulation of blood pressure. Milk
and dairy foods are good sources of these
minerals and are now regarded as exerting an
antihypertensive effect. Various population
studies have shown the relationship between
dietary intake of 1,000 mg/day or more and
40% to 50% reduction in the prevalence of
hypertension. Randomized clinical trials
have shown that calcium from food sources
is more effective than calcium from supple-
ments. The blood - pressure - lowering effect of
dairy foods is not related solely to calcium
content, but it is related to other minerals
such as potassium and magnesium, vitamins,
proteins, and essential fatty acids (Huth et al.,
2006 ). In this regard, milk proteins are docu-
mented to be sources of bioactive peptides
generated by proteolytic enzymes involved in
digestive processes or by the action of lactic
cultures used in fermented dairy products.
These peptides lower blood pressure by
ACE - inhibitor activity, as shown in animal
and human trials to reduce blood pressure
from the hypertensive range to normal levels
(Wrick, 2007). The scientifi c evidence shows