PROSTATE
SAW PALMETTO SHRINKS PROSTATE TISSUES
A randomised, double-blind, placebo-controlled clinical
trial involved 44 men with symptomatic prostate enlargement.
The subjects took 320mg of saw palmetto (Serenoa serrulata)
extract with nettle root (Urtica dioica) extract, or placebo,
for 6 months. The study included an ultrasound-guided prostate
biopsy to assess the changes in the participants’
prostate tissue. Biopsies were taken at baseline and after
6 months of treatment.
The saw palmetto suppressed swelling of the prostate epithelium,
causing a contraction in the tissues in the epithelium of
the prostate and the transitional zone, without affecting
the levels of testosterone or dihydrotestosterone. This
shows that the herb works by an unidentified by non-hormonal
mechanism, and this is the first evidence that it actually
shrinks enlarged prostate tissues.
Overmeyer, M.
UROLOGY TIMES 1999, 27 (6) 1,42
Courtesy HERBALGRAM
PHYSICAL ACTIVITY AND BENIGN PROSTATIC HYPERPLASIA
Benign prostatic hyperplasia (BHP), a condition characterised
by hyperplastic nodules in the periurethral region and transition
zone of the prostate, overall prostatic enlargement, and
lower urinary tract symptoms, is highly prevalent among
middle-aged and elderly men. Sympathetic nervous system
activity, which is decreased by physical activity, is associated
with increased prostatic symptoms. Therefore a study was
carried out to determine whether physical activity leads
to fewer lower urinary tract symptoms. Men who were aged
40-75 years at baseline in 1986 were observed for subsequent
incidence of surgery for BHP.
After controlling for age, race or ethnicity, alcohol consumption,
and smoking, physical activity was inversely related with
total BHP (Odds ratio, OR, 0.75), surgery for BHP (OR, 0.76),
and symptomatic BHP (OR, 0.75). Walking, the most prevalent
activity, was inversely related to BHP risk; men who walked
2-3 h/wk had a 25% lower risk of total BHP. Therefore, the
results indicate that more physically active men have a
lower frequency of urinary tract symptoms.
Platz, E.A. et al
ARCH. INT. MED. 1998, 158 (21) 2349-56
SAW PALMETTO EXTRACTS FOR TREATMENT OF BENIGN PROSTATIC
HYPERPLASIA
Symptomatic benign prostatic hyperplasia (BHP) is one of
the most common medical conditions in older men. As many
as 40% of men aged 70 years or older have lower urinary
tract symptoms consistent with BHP. Therefore, a review
was carried out of the existing evidence regarding the therapeutic
efficacy and safety of the saw palmetto plant extract, Sereoa
repens, in men with BHP. A total of 18 randomised controlled
trials involving 2939 men were analysed. The mean study
duration was 9 weeks.
Compared to men receiving placebo, men treated with S.
repens had decreased urinary tract symptom scores, nocturia,
and improvement in self-rating of urinary tract symptoms.
Similar results were found when comparing S. repens use
with finasteride. Adverse effects due to S. repens were
mild and infrequent. Thus, the evidence suggests that Serenoa
repens improves urologic symptoms and flow measures and
is associated with fewer adverse treatment effects compared
with finasteride.
Wilt, T.J. et al
J.A.M.A. 1998, 280 (18) 1604-9
VITAMIN E MAY REDUCE PROSTATE CANCER INCIDENCE
The results of a large primary-prevention trial in Finnish
men have shown that vitamin E supplements could reduce prostate-cancer
incidence and mortality by one-third in men who smoke. More
than 29,000 male smokers aged 50-69 years were randomly
assigned to receive 50 mg ?-tocopherol, 20 mg ?-carotene,
both, or placebo daily for up to 8 years. At the end of
the study, 246 new cases of prostate cancer and 62 deaths
from the disease had occurred. However, the incidence was
32% lower, and mortality 41% lower in men taking a-tocopherol,
with or without ?-carotene, than in those not taking the
vitamin. ?-carotene non-significantly reduced the risk of
prostate cancer in non-drinkers, but increased the risk
in drinkers, the risk rising with increased alcohol consumption.
?-tocopherol is thought to block tumour progression from
subclinical to clinical phase. The researchers warn, however,
that studies with vitamin supplements are not a good basis
for dietary advice. The bioavailability of supplements may
be quite different from that of natural sources. And such
studies cannot replicate potential interactions with other
beneficial compounds in a natural diet, as occurs between
vitamins C and E in fruit and vegetables.
Bonn,D.
LANCET 1998, 351 (9107) 961
CAROTENE SUPPLEMENTATION FOR PATIENTS WITH LOW BASELINE
LEVELS AND DECREASED RISKS OF TOTAL AND PROSTATE CARCINOMA
Observational epidemiologic studies have indicated that
individuals with diets high in fruits and vegetables, particularly
those rich in ?-carotene, are at lower risk for cancer incidence,
suggesting a role for ?-carotene in the primary prevention
of cancer. Therefore, a trial was carried out that included
supplementation with ?-carotene (50 mg every other day)
in the primary prevention of cancer among 22,071 U.S. male
physicians aged 40-84 years. Baseline blood samples were
collected from 14,916 of the participants. 1,439 men were
subsequently diagnosed with cancer over 12 years of follow-up
(631 with prostate carcinoma).
It was found that men in the lowest quartile for plasma
?-carotene at baseline had a marginally significant increased
risk of cancer compared with those in the highest quartile
(relative risk [RR], 1.30). Men in the lowest quartile assigned
at random to ?-carotene supplementation had a possible but
non-significant decrease in overall cancer risk compared
to placebo. This was primarily due to a significant reduction
in the risk of prostate carcinoma (RR, 0.68) in this group.
Thus, this research appears to support the idea that ?-carotene
supplementation may reduce the risk of prostate carcinoma
among those with low baseline levels.
Cook, N.R. et al
CANCER 1999, 86 (8) 1783-92
DAIRY PRODUCTS AND PROSTATE CANCER
Researchers at Harvard University, USA, analysed data from
a population based case-control study in Sweden to try and
find out why dairy products have consistently been associated
with an increased risk of prostate cancer. The found that
calcium intake was an independent predictor of prostate
cancer, while high consumption of dairy products was associated
with a 50% increased risk. The results support the hypothesis
that high calcium intake may increase the risk of prostate
cancer.
Chan, J.M. et al,
CANCER CAUSES CONTROL 1998, 9 (6) 559-66. Courtesy WORLD
CANCER RESEARCH FUND
SELENIUM AND RISK OF PROSTATE CANCER
Selenium, an essential trace nutrient found largely in
grains, fish, and meats, enters the food chain through plants
at geographically variable rates dependent on selenium concentrations
in the soil. For this reason selenium intake varies substantially
across populations. The recommended daily allowance for
selenium in men is 70ug in the USA and 75ug in the UK.
A US study has revealed an inverse association between
advanced prostate cancer and toenail selenium concentrations.
The multivariate-adjusted relative risk comparing the highest
with the lowest quintile of toenail selenium was 0.35. With
daily median selenium intake estimated on the basis of toenail
concentration, intake was 86 ug among men in the lowest
quintile and 159 ug among those in the highest quintile.
The evidence now available indicates that substantial increases
in consumption of selenium by men taking 80-90 ug a day
or more may have a striking impact on prostate cancer rates.
In the UK, selenium intakes have been falling over several
decades largely because of a decrease in imported flour
from North America in favour of selenium-poor flour of European
countries. Recent surveys indicate that the average intake
of selenium may be as low as 30-40ug/day.
Giovannucci, E.
LANCET 1998, 352 (9130) 755-6
VITAMIN E INDUCES APOPTOSIS IN ERYTHROLEUKEMIA, PROSTATE,
AND BREAST CANCER CELLS
Scientists at East Carolina University School of Medicine
have shown the effect of vitamin E on a number of cancer
cell lines, including 2 erythroleukemia, a hormone responsive
breast and prostate cancer cell lines. Results showed a
dose-dependent inhibition of cell growth, and apoptosis,
in all cell lines studied, with breast and prostate cancer
cells significantly more sensitive than erythroleukemia
cells.
Sigounas G. et al,
NUTR. CANCER 1997, 28 (1) 30-5
Courtesy POSITIVE HEALTH, March 1998
