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could improve CD4 cell counts and reduce
the incidence of secondary infections.
Many patients with HIV infection who have
super-normal energy intakes fail to gain weight, and in particular
to increase their lean tissue mass. Protein supplementation
promotes increases in body cell mass (BCM). Given intravenously
to stable patients without secondary infections, it increased
protein synthetic rates without increasing breakdown rate.37
Protein intake was also significantly positively correlated with
BCM.38 Thus, there is a need to find a way for these patients
to increase dietary protein.
Muscle building
Most people without HIV infection eat protein
in excess of needs. The Reference Daily Intake (RDI) for protein
is only 50g per day. This is what most Americans without a chronic
condition require and what is used as the reference value on
food labels. In contrast, patients with HIV infection fail to
get adequate protein due to their increased requirements, malabsorption,
and anorexia.
Patients who have catabolic conditions
like sepsis or who have had surgery, or those with chronic conditions
like HIV infection and cancer, have increased protein needs -
about twice the RDI (100 g) - and similar or slightly lower energy
needs - 25 to 35 kcal/kg compared with 40 kcal/kg for normal
subjects.31,33,39
Extra protein is required during HIV infection
because the body is undergoing increased protein turnover (i.e.,
increased synthesis and breakdown). The presence of an infection
also causes cytokines to be released from the monocytes/macrophages,
which precipitates muscle protein wasting.34,40 Muscle is a
key part of the turnover of protein. During an infection like
HIV and acute insults like major surgery or trauma, urea production
is increased. Both cyst(e)ine and glutamine are released more
rapidly from the muscle for the increased urea synthesis. Eventually,
the plasma levels of cyst(e)ine and glutamine become depleted,
reflecting the inability of the muscle to keep up with increased
demand for urea production.41
The body also requires more protein to
make muscle tissue and blood cells at a faster rate than if HIV
infection were not present. In HIV infection, a high-protein
diet has been shown to increase protein synthesis without causing
a concomitant increase in breakdown.37 A poor protein intake
causes the stores of GSH to become depleted, impairing oxidative
status. Dietary protein intake needs to be sufficient to replenish
the loss of muscle and support protein turnover. Proteins also
rich in cysteine and glutamate (i.e., whey) replenish GSH.
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Several studies have been conducted in
which whey protein supplemented the diet of patients with HIV
infection (42,43, Brosgart C. (1996) and Lucas D. (1997) Personal
Communications, on file, Optim Nutrition). Since both whey protein
products (Immunocal™, Immunotech Research Corporation, Ltd.,
Montreal and Promune) contain undenatured proteins and active
immunoglobulins, the results of the following studies using one
diet should be applicable to the other.
Canadian investigators reported on the
use of a whey protein powder (Immunocal) in three male patients
with HIV infection.42 The whey protein was administered in water
or juice beginning with 8.4 g and progressively increasing to
39.2 g per day. (This product was 75% protein.) Patients were
instructed to reduce their protein intake from other sources
to compensate for the increased intake. The diet was well tolerated
at all doses. Although the patients were weight-stable before
the study began, during the 3-month study they gained between
2 kg and 7 kg. Blood mononuclear GSH concentration was abnormally
low in all patients at the beginning of the study; at the end,
it had increased in all. However, only one patient ended with
GSH levels in the normal range. CD4 levels did not change during
the study.
During a 6-month study using the same diet
(Immunocal), 11 children with HIV infection initially received
20% of their dietary protein from whey protein and increased
their intake until 35% was from whey.43 The children ranged
in age from 8 months to 15 years. All patients gained weight;
the average was 8.4% + 5.7%. Although CD4 counts did not change,
6 of the 11 had increases, normalizations, or both of their GSH
levels (p < 0.005). The diet was well tolerated at these
intakes, and there was no evidence of diarrhea or vomiting related
to the whey protein. This whey formula induces weight gain and
increases GSH concentrations.
A 6-week pilot study using two doses (20
g and 60 g) of a different whey protein (Promune) was conducted
in California (Brosgart C., Personal Communication, on file,
Optim Nutrition, 1996). Fifty-four percent (19/35) of the patients
had AIDS according to the Centers for Disease Control criteria.
All had documented weight loss (> 10% of ideal body weight,
or a body mass index [BMI] less than 20 kg/m2). Average weight
gain was 1.54 + 4.84 pounds; there was no difference between
the two dietary regimens in weight gain (p = 0.915). However,
25 of 29 subjects who completed the study maintained or increased
body weight or BCM or both. Body cell mass was assessed by bioelectrical
impedance. The CD4 cell counts and Karnofsky Performance Scores
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