Zinc and selenium improve health of cancer patients
Sixty patients (median age 55 years) with cancer of the digestive tract (colon,
stomach, or esophagus) who were undergoing chemotherapy were randomly assigned
to receive supplemental zinc (21 mg/day) and selenium (200 mcg/day) for 50
days or no supplemental zinc and selenium (controls). At baseline and after
60 days, all patients were malnourished, as determined by various anthropometric
and biochemical parameters. However, 70% of patients treated with zinc and
selenium showed no further worsening of nutritional status and experienced
a significant decrease of asthenia and an increase of appetite. In contrast,
only 20% of control patients showed no further worsening of nutritional status.
Comment: These results suggest that supplementation with selenium and zinc
may improve the general condition of patients with cancer of the digestive
tract who are undergoing chemotherapy. Some oncologists have expressed concern
that concomitant use of antioxidants such as zinc and selenium might interfere
with the anticancer effect of chemotherapy. The basis of their concern is that
many chemotherapy drugs promote the formation of oxygen-derived free radicals,
and that these free radicals might be scavenged or quenched by antioxidants.
It is true that many chemotherapeutic agents cause free radicals to form; however,
the anticancer effects of these drugs do not, in general, seem to depend on
the formation of free radicals. Consequently, antioxidants might reduce the
adverse effects of the drugs, without inhibiting their beneficial effects.
While the bulk of the evidence available to date supports that possibility,
more research is needed to determine which antioxidants can be used safely
and effectively with which chemotherapeutic agents.
Federico A, et al. Effects of selenium and zinc supplementation on nutritional
status in patients with cancer of digestive tract. Eur J Clin Nutr 2001;55:293-297.
High-dose vitamin K2 decreases mortality in patients with liver cancer
One hundred twenty-one patients with hepatocellular carcinoma were randomly
assigned to receive conventional therapy, with or without the addition of
oral vitamin K2 (45 mg/day). At 12 months, the incidence of portal vein invasion
was 2% in the vitamin K2 group and 23% in the control group. At 2 years,
these percentages were 23% and 47%, respectively. One-year survival was 76%
in the vitamin K2 group and 66% in controls. Two-year survival was 66% in
the vitamin K2 group and 28% in controls.
Comment: Previous studies have shown that vitamin K2 inhibits the growth of
hepatocellular carcinoma cells in vitro. The results of this new study suggest
that vitamin K2 can slow the progression of hepatocellular carcinoma and increase
survival times. Vitamin K2, which is synthesized by intestinal bacteria, differs
to a small extent from the vitamin K1 (phytonadione), which is present in food.
It is not known whether vitamin K1 would have the same anticancer effect as
vitamin K2. The latter has been used in Japan for the past several years as
a treatment for osteoporosis, and appears to be safe when administered at a
dose of 45 mg/day.
Jancin B. Vitamin K cuts hepatocellular Ca mortality. Fam Pract News 2002(July
Proteolytic enzymes beneficial for multiple myeloma
Two hundred sixty-five patients with multiple myeloma stages I-III were treated
with standard chemotherapy. One hundred sixty-six of these patients also
received oral enzymes for more than six months, while 99 patients either
did not receive enzymes or received them for less than six months (control
group). Treatment allocation was not randomized, but was assigned on the
basis of the availability of the enzymes on the first day of chemotherapy.
The enteric-coated enzyme preparation (Wobe-Mugos) contained 100 mg of papain,
40 mg of trypsin, and 40 mg of chymotrypsin per tablet. The dose was 2 tablets
3 times per day for 1 year, starting on the first day of chemotherapy; in
most cases the dose was reduced to 1 tablet 3 times per day after the first
year, and was continued indefinitely. The proportion of patients achieving
complete remission, partial remission, or stable disease was significantly
higher in the enzyme group than in the control group (97.6% vs. 69.7%; p
= 0.001). In stage III patients, the proportion of nonresponders was 3.7%
in the enzyme group and 38.9% in the control group (p < 0.001). The median
survival time in stage III patients was 47 months in the control group and
83 months in the enzyme group (77% increase; p < 0.002), corresponding
to a 3-year increase in survival time. The observation period was not long
enough to estimate the survival times for patients in stages I and II.
Comment: Proteolytic enzymes have been used for many years in the treatment
of various types of cancer, but there is only a small amount of published research
supporting its use. The present study has a potential flaw, in that patients
who discontinued enzyme treatment (perhaps because they were too sick to continue)
were counted as not having received the treatment. In addition, the non-random
selection of patients may have biased the results. Nevertheless, the outcome
was markedly better in the enzyme group than in the control group, suggesting
that enzyme treatment increases the response rate and prolongs survival in
patients with multiple myeloma. Although the mechanism of action is not known,
it has been suggested that proteolytic enzymes help break through a protective
coating produced by cancer cells, thereby giving the immune system a better
chance to attack the tumor cells.
Sakalova A, et al. Retrolective cohort study of an additive therapy with an
oral enzyme preparation in patients with multiple myeloma. Cancer Chemother
Soy milk for essential hypertension
Forty men and women (mean age, 48 years) with mild-to-moderate hypertension
were randomly assigned to receive, in double-blind fashion, 500 ml twice
daily of soy milk or cow's milk for three months. After three months, compared
with baseline, the mean systolic blood pressure decreased by 18.4 mm Hg in
the soy group and by 1.4 mm Hg in the cow's milk group (p < 0.0001 for
group difference), while mean diastolic blood pressure decreased by 15.9
vs. 3.7 mm Hg (p < 0.0001). Urinary genistein was significantly (p = 0.002)
correlated with the decrease in blood pressure, particularly diastolic pressure.
Comment: These results indicate that consumption of 1 liter per day of soy
milk for three months can produce a clinically important reduction in blood
pressure in people with essential hypertension. Although the mechanism of action
of soy is not clear, the effect is probably not due to isoflavones, as supplementation
with soy isoflavones alone did not reduce blood pressure in a previous study.
Soy protein has also been shown to reduce serum cholesterol, another major
risk factor for cardiovascular disease. The present study adds to a growing
body of evidence that the inclusion of soy products as part of a balanced,
whole-foods diet, may help prevent heart disease.
Rivas M, et al. Soy milk lowers blood pressure in men and women with mild to
moderate essential hypertension. J Nutr 2002;132:1900-1902.
Natural alternative to Viagra
Forty-five men (mean age, 56.7 years) with erectile dysfunction (ED) were randomly
assigned to receive, in a 3-way double-blind crossover trial, 1) 3.25 of
L-arginine (provided by 6 g of L-arginine glutamate) plus 6 mg of yohimbine
hydrochloride (AY), 2) 6 mg of yohimbine hydrochloride alone (Y), or 3) placebo.
During each of the 2-week crossover periods, the treatment was taken orally,
on an empty stomach, 1-2 hours before intended sexual intercourse. The primary
endpoint was the change in the Erectile Function Domain score of the International
Index of Erectile Function. Higher scores indicate better erectile function;
the maximum score is 30. At the end of the treatment periods, the mean Erectile
Function Domain scores for AY, Y and placebo were 17.2, 15.4 and 14.1, respectively.
The difference between AY and placebo was significant (p = 0.006), but the
difference between Y and placebo was not. The treatment was considered successful
by 40% of patients receiving AY, 28.9% of those receiving Y, and 17.8% of
those receiving placebo (p = 0.02 for difference between AY and placebo).
Patients with initially mild-to-moderate ED had a better response to treatment
than did patients with more severe ED. No serious side effects were reported.
Comment: L-Arginine (a conditionally essential amino acid) and yohimbine
(a compound present in the herb yohimbe) have each been shown to be effective
in the treatment of ED. However, neither of these compounds has been found
to be effective for on-demand use (i.e., immediately prior to intended sexual
activity); rather, consistent use is necessary to achieve an effect. The present
study demonstrates that on-demand administration of these substances is effective,
if they are taken in combination. Both of these compounds are considered relatively
safe, although yohimbine can cause hypertension, irritability, or other side
effects in some cases. Single-dose treatment with yohimbine plus L-arginine
is probably safer than sildenafil (Viagra®) and is also much less expensive.
Lebret T, et al. Efficacy and safety of a novel combination of L-arginine glutamate
and yohimbine hydrochloride: a new oral therapy for erectile dysfunction. Eur
Low-dose vitamin A does not cause osteoporosis
Eighty healthy men (aged 18-58 years) were randomly assigned to receive, in
single-blind fashion, 25,000 IU/day of vitamin A (retinol palmitate) or placebo
for 6 weeks. Compared with the placebo group, there was no significant change
in the vitamin A group in various markers of bone formation and resorption;
e.g., bone specific alkaline phosphatase, N-telopeptide of type 1 collagen
(NTx), and osteocalcin.
Comment: This short-term study suggests that a moderate dose of vitamin A does
not promote the development of osteoporosis. This finding is in contrast to
several epidemiological studies, in which consumption of as little as 3,300
IU/day of vitamin A from food was associated with an increased risk of hip
fracture. High-dose vitamin A intake in animals is also known to cause bone
disease. However, animal studies have used an enormous dose, the human equivalent
of 7 million IU per day, to induce bone disease, whereas amounts on the order
of 100,000 IU per day (human equivalent) do not seem to affect animals' bones.
Concerning the epidemiological studies, the major contributors to vitamin A
intake in the American diet (aside from liver) are fortified milk* (1,500 mcg/L),
fortified sugary breakfast cereals (up to 375 mcg per serving), fortified margarine
(approximately 150 mcg per tablespoon), and eggs (95 mcg per egg). A high-vitamin
A diet would therefore presumably contain relatively large amounts of one or
more of the following: animal protein and phosphorus (from eggs, milk, and
liver), trans-fatty acids (from margarine), refined sugar (from breakfast cereals),
and xenobiotic chemicals (from liver). One or more of these components of the
diet, rather than the vitamin A, may account for the increased risk of osteoporosis
associated with higher vitamin A intake.
*While many assume that drinking milk helps prevent bone loss, a number of
studies indicate that milk is not protective, and may even increase the risk
of osteoporotic fractures.
Kawahara TN, et al. Short-term vitamin A supplementation does not affect bone
turnover in men. J Nutr 2002;132:1169-1172.
Osteoporosis therapy: don't forget the phosphorus
The effect of calcium intake on the absorption of phosphorus was assessed in
543 studies of healthy women aged 35-65 years and in 93 men and women aged
19-78 years. Mean net absorption of phosphorus was 60.3% for the first group
and 53% for the second group. For each 500-mg increase in calcium intake,
phosphorus absorption decreased by 166 mg.
Comment: This study indicates that increasing dietary intake of calcium decreases
the absorption of phosphorus. A deficiency of phosphorus can lead to impaired
bone mineralization, which might account for the equivocal results seen in
some calcium supplementation trials. The authors of the present study point
out that one of the most effective trials in elderly patients used tricalcium
phosphate as the calcium source (N Engl J Med 1992;327:1637-42). The interaction
between calcium and phosphorus should not be of concern for many individuals,
since most Western diets contain ample or excessive amounts of phosphorus.
However, individuals with marginal nutritional status (such as the elderly)
who supplement with large amounts of calcium may be at risk of developing phosphorus
deficiency. The presence of a low serum or urinary phosphorus level may indicate
low or suboptimal phosphorus status. When the potential for calcium-induced
phosphorus deficiency is a concern, it may be advisable to administer a proportion
of the supplemental calcium in the form of a calcium phosphate preparation
Heaney RP, Nordin BEC. Calcium effects on phosphorus
absorption: implications for the prevention and co-therapy of osteoporosis.
J Am Coll Nutr 2002;21:239-244.
Nutritional supplement improves antisocial behavior among criminals
Two-hundred-thirty-one young-adult prisoners (aged 18 years or older) were
randomly assigned to receive, in double-blind fashion, a multivitamin/mineral
formula plus essential fatty acids (Efamol Marine) or a placebo for an average
of 20 weeks. The nutritional supplement contained the following: beta-carotene
(4.5 mg), vitamin D (400 IU), thiamine (1.2 mg), riboflavin (1.6 mg), niacinamide
(18 mg), pantothenic acid (4 mg), folic acid (400 mcg), vitamin B6 (2 mg),
vitamin B12 (3 mcg), vitamin C (60 mg), vitamin E (10 IU), biotin (100 mcg),
calcium (100 mg), magnesium (30 mg), iron (12 mg), zinc (15 mg), copper (2
mg), chromium (200 mcg), selenium (50 mcg), manganese (3 mg), iodine (140
mcg), molybdenum (250 mcg), phosphorus (77 mg), linoleic acid (1,260 mg),
gamma-linolenic acid (160 mg), eicosapentaenoic acid (80 mg), and docosahexaenoic
acid (44 mg). Compared with the placebo group, the supplemented group committed
an average of 26.3% fewer offenses that required disciplinary action (p < 0.03).
Comment: There is evidence that individuals
who engage in antisocial behavior consume diets lacking in essential nutrients
and that this could adversely
affect their behavior. The results of the present study suggest that antisocial
behavior, including violence, among prisoners can be reduced by supplementation
with vitamins, minerals and essential fatty acids. These findings may also
have implications for those eating poor diets in the community. It is likely
that more than one component of the supplement regimen was responsible for
the observed improvement, and that different participants responded to different
nutrients. Biochemical testing and individualized supplement regimens would
likely improve the outcome in some cases, although a "shotgun approach," as
used in the present study, appears to be a cost-effective method of helping
a large number of people.
Gesch CB, et al. Influence of supplementary vitamins, minerals and essential
fatty acids on the antisocial behaviour of young adult prisoners. Randomised,
placebo-controlled trial. Br J Psychiatry 2002;181:22-28.