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STUDIES OF WHEY PROTEIN IN NORMAL VOLUNTEERS
Since the whey protein concentrate Promune
was originally intended as a drug, two extensive safety and toxicity
tests were conducted in 1994 (unpublished data, Optim Nutrition,
on file, 1994). The first was an open-label study conducted
to assess the dose response to whey protein in 21 subjects.
The subjects consumed the whey protein in addition to their normal
food intake; however, no records were available showing the
energy and protein contribution of these foods. Participants
received 0.84 g/kg/day of whey protein (0.65 g protein/kg/day)
as the low dose; 4.2 g/kg/day (3.3 g protein/kg/day) as the middle
dose; and 8.4 g/kg/day (6.5 g protein/kg/day) as the high dose.
All of the subjects (n = 6) in the high group dropped out before
the study ended, as did 2 of the 7 in the middle group. Subjects
consumed the diets for 3 days and were followed for 4 days afterwards.
The chief complaints of the participants were related to the
gastrointestinal tract. They included increased stool frequency
(57%), nausea (52%), bloating (39%), reduced appetite (42%),
fatigue (24%), and headache (27%). The BUN concentration rose
twofold. Both gastrointestinal complaints and BUN concentrations
were dose-dependent.
These are extremely high intakes of protein
from whey for healthy volunteers to consume, particularly as
they were also eating their regular diet. Therefore, the abnormal
symptoms and blood tests were not surprising; they resolved upon
discontinuation of the whey protein. The next study was conducted
with a dose of whey protein that was expected to be better tolerated,
and that could be consumed by patients in need of a high-protein
diet, e.g., those with AIDS, cancer, and burns and trauma, and
major surgical patients. Subjects again ate their regular meals;
again, no record of their intakes was available.
In the second study, 20 healthy volunteers
received the whey protein for 10 days, followed by a 10-day period
with no treatment to observe symptoms. Each subject received
3 g/kg/day of the whey powder (2.3 g protein/kg/day), which would
be 210 g of whey powder or 161 g of protein for a 70-kg man.
The RDA for protein is 63 g for men, and most patients require
twice that.31 There were 8 females and 12 males in the study;
the men averaged 25 years of age and the women 29 years.
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There were no significant differences in
any of the measurements between the sexes. Three subjects did
not complete the study. Their baseline data did not differ from
the mean data at the beginning of the study. Adverse events included
fatigue (60%), nausea (50%), diminished appetite (5%), headache
(45%), bloating (35%), thirst (35%), and cramps (25%). Symptoms
subsided within several days of stopping the whey protein.
The BUN again increased twofold as in the
previous study. Other markers of renal insufficiency (e.g.,
creatinine, osmolality, and the like) remained normal, indicating
that the problem was related to protein loading rather than renal
function. Three subjects had mild elevations in liver function
tests, but these subsided during the study.
Immunologically, there was a mild rise
in serum IgG (1,124 to 1,177 mg/dL) and IgA (211 to 222 mg/dL).
The CD4/CD8 (2.1 to 2.6) rose during treatment, and remained
high at the conclusion of the study. Thus, the whey protein
appeared to be well tolerated at this dose and showed mild improvements
in immune function in normal volunteers.
STUDIES OF WHEY PROTEIN IN PATIENTS
WITH AIDS
Most patients with HIV infection become
malnourished during the course of illness. Before the era of
"highly active antiretroviral therapy" (HAART), this
malnutrition was often characterized as extreme cachexia. Patients
were presented with extreme muscle wasting and loss of fat stores.32-34
Today, patients still develop protein calorie malnutrition,
but present with increased deposition of fat and sometimes a
modest weight gain.35 This lipodystrophy is characterized by
fat deposition on the back of the neck and on the abdomen; and
in women, breast enlargement occurs. Often surreptitious is
the extreme muscle wasting that occurs simultaneously. However,
patients with lipodystrophy may have a false sense of security,
thinking that they are not malnourished because they have extra
fat.
Use of supplemental whey protein may benefit
patients with HIV infection who are already malnourished or are
at risk of becoming so. There is evidence that intravenously
administered immunoglobulins slow the decline of CD4 cell counts
in children.36 In addition, there is a reduction in serious
bacterial and viral infections. This would suggest that other
means of providing immunoglobulins (e.g., undenatured whey protein)
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