414 Chapter 16
Conjugated linoleic acid (CLA), a natural
component of milk fat, has been reported to
improve the human body ’ s poor regulation of
insulin when administered for eight weeks or
longer. It improves utilization of glucose,
lowering its level in the blood of type - 2 dia-
betic patients.Bone Health and Prevention
of Osteoporosis
Osteoporosis is related to progressive loss of
bone tissue, which results in skeletal weak-
ness and consequently leads to bone fractures
after age 50. Optimum bone growth needs
adequate amounts of dietary protein; vita-
mins A, C, D, and K; and calcium; phospho-
rus; magnesium; copper; manganese; zinc;
and fl uoride. These nutrients should be sup-
plied by a variety of food sources. Dairy
products are signifi cant sources of calcium,
phosphorus, and magnesium in the American
diet.
Optimum bone development requires ade-
quate dietary calcium to achieve peak bone
mass. Bone is comprised of 50% protein and
approximately 50% calcium phosphate crys-
tals. The bone tissue process is in a dynamic
state throughout life. The older bone breaks
down and newer bone tissue constantly
replaces it. During childhood and the teen
years, provided that adequate nutrients are
available, bone formation by far exceeds the
breakdown (resorption) phase. Approximately
85% to 90% of peak bone mass is achieved
by age 18 in girls and age 20 in boys. Bone
mass in the early stages of life is a good
determinant of bone strength later in life.
In adults, the rate of bone resorption is in
equilibrium with that of bone formation. If
bone resorption exceeds bone formation, a
net loss of bone mass occurs, leading to bone
porosity, fragility, and fractures. Certain
types of bone cells involved in bone remodel-
ing cease to function, resulting in progressive
loss of bone mass. Patients with osteoporosis
receive medications to activate remodelingsubjects have indicated that during caloric
reduction, there is a greater loss of body
weight and body fat in diets containing ade-
quate calcium from calcium supplements.
Interestingly, this loss is relatively greater
when the identical level of calcium is con-
tributed by dairy sources. It appears that
weight and fat loss by a calorie - controlled
diet is caused by changes in metabolic parti-
tioning of dietary energy, which is maxi-
mized by calcium intake (1,200 to 1,300 mg/
day) from dairy products.
Another mode of calcium action in weight
loss in a low - calorie diet may be interaction
of calcium with dietary fat to form a soap -
like material in the gut, which is not absorbed
and is subsequently excreted. The distribu-
tion of body fat loss is also different in that
a reduced - calorie diet alone resulted in a 19%
loss of body fat around the trunk area;
however, the loss around the trunk area was
50% in a diet containing calcium from sup-
plemental sources and 66% in a diet contain-
ing dairy products (Zemel et al., 2005 ). It is
important to note that the fat loss with added
dairy products is conditional upon the restric-
tion of total caloric intake. When the diet is
high in calories, adding dairy products does
not help in weight and fat loss. Accordingly,
weight and fat loss should occur when three
to four servings of dairy products are part of
a low - calorie diet.
Type 2 Diabetes
Management of type - 2 diabetes is critical for
controlling the resulting complications,
namely cardiovascular disease, renal failure,
blindness, and amputations. Dietary inter-
vention for controlling this disorder is the
subject of research, and several studies have
shown that lifestyle modifi cations, including
diet, are important factors in preventing type -
2 diabetes. Epidemiological studies have
indicated that consuming high levels of dairy
foods signifi cantly reduces the risk of devel-
oping type - 2 diabetes in men and women.