Speaking of Supplements... interest studies on zinc

[Guest guest]

It does NOT say how much they took!

1)

The link:

http://www.medscape.com/viewarticle/475438

The article:

Zinc Supplements Associated With Improved Survival

Laurie Barclay, MD

May 10, 2004 — Zinc supplements are associated with improved

survival in patients with ocular disorders, according to the results

of a randomized trial published in the May issue of the Archives of

Ophthalmology.

" Various ocular disorders (eg, visual impairment and cataract and

those in persons with diabetes mellitus, severe retinopathy, or

visual impairment) have been reported to be significant predictors

of a decreased life span, often even after extensive adjustment for

potential confounders, " write Traci E. Clemons, PhD, from EMMES

Corp. in Rockville, land, and colleagues from the Age-Related

Eye Disease Study (AREDS) Research Group. " Ocular disorders, in

particular cataract, may be markers of systemic processes that are

associated with accelerated physiologic aging and earlier death. For

example, generalized oxidative damage might play a role in the

development of cataract and the aging process. "

Using baseline fundus and lens photographs, the investigators graded

the macular and lens status of AREDS subjects, who were then

randomized to receive oral supplements of high-dose antioxidants,

zinc, antioxidants plus zinc, or placebo. Median follow-up was 6.5

years.

Of 4,753 AREDS participants, 534 (11%) died during follow-up.

Compared with subjects with few or no drusen, those with advanced

age-related macular degeneration (AMD) had a 41% increase in

mortality (relative risk [RR], 1.41; 95% confidence interval [CI],

1.08 - 1.86). Advanced AMD was also associated with cardiovascular

deaths.

Compared with subjects with good bilateral visual acuity, those with

visual acuity worse than 20/40 in one eye had increased mortality

(RR, 1.36; 95% CI, 1.12 - 1.65). All-cause mortality was increased

in subjects with nuclear opacity (RR, 1.40; 95% CI, 1.12 - 1.75) or

cataract surgery (RR, 1.55; 95% CI, 1.18 - 2.05), and cancer deaths

were also more frequent in these groups.

Compared with subjects not taking zinc, those randomized to receive

any zinc (zinc alone or with antioxidants) had 27% lower mortality

(RR, 0.73; 95% CI, 0.61 - 0.89).

The major study limitation was the potential for bias, especially

selection bias, inherent in all clinic-based studies.

" The decreased survival of AREDS participants with AMD and cataract

suggest that these conditions may reflect systemic rather than only

local processes, " the authors write. " This is the first large

randomized trial to report a potential benefit of the use of high

doses of zinc on survival. Other randomized studies of zinc

supplementation and mortality are needed to confirm these findings. "

The National Eye Institute, the National Institutes of Health, the

Department of Health and Human Services, and Bausch & Lomb Inc.,

supported this study. The authors report no relevant financial

interest in this article.

Arch Ophthalmol. 2004;122:716-726

Reviewed by D. Vogin, MD

2)

The second link: Excessive Zinc Supplementation May Increase

Prostate Cancer Risk

Excessive Zinc Supplementation May Increase Prostate Cancer Risk

Laurie Barclay, MD

July 1, 2003 — Zinc supplementation may increase prostate cancer

risk, according to the results of a study published in the July 2

issue of the Journal of the National Cancer Institute. Reviewing

data from the Health Professionals Follow-up Study, the

investigators suggest that zinc supplementation of 100 mg/day or

more or use of supplements for more than 10 years can more than

double the risk of prostate cancer.

" The high concentration of zinc in the prostate suggests that zinc

may play a role in prostate health, " write F. Leitzmann, MD,

from the National Institutes of Health in Bethesda, land, and

colleagues. " Whether dietary zinc intake affects intraprostatic zinc

levels is unknown. However, ingestion of 150 mg/day or more of zinc

has undesirable metabolic effects, such as immune dysfunction and

impaired antioxidant defense that are potentially related to

prostate cancer. "

During follow-up from 1986 through 2000 of 46,074 U.S. men enrolled

in the Health Professionals Follow-up Study, 2,901 developed

prostate cancer, including 434 cases of advanced cancer.

Although supplemental zinc up to 100 mg/day was not associated with

prostate cancer risk, men who consumed more than 100 mg/day of

supplemental zinc had more than double the risk of advanced prostate

cancer compared with nonusers (relative risk, 2.29; 95% confidence

interval [CI], 1.06 - 4.95; P = .003 for trend). In men who used

zinc supplements for at least 10 years, relative risk was 2.37 (95%

CI, 1.42 - 3.95; P <.001 for trend).

" Excessively high zinc intake was associated with an increased risk

of advanced prostate cancer, " the authors write. " Although we cannot

rule out residual confounding by supplemental calcium intake or some

unmeasured correlate of zinc supplement use, our findings, that

chronic zinc oversupply may play a role in prostate carcinogenesis,

warrant further investigation. "

J Natl Cancer Inst. 2003;95:1004-1007

Reviewed by D. Vogin, MD

3)

The third link:

http://www.medscape.com/viewarticle/411376

The article:

Zinc and Antioxidants May Delay Progression of Age-Related Macular

Degeneration

New York (MedscapeWire) Oct 15 — In people older than 55 years who

have findings on dilated eye exams that indicate intermediate age-

related macular degeneration, a supplement of antioxidants plus zinc

may delay progression of the disease, according to an Archives

Express article in the October issue of the Archives of

Ophthalmology.

Researchers with the Age-Related Eye Disease Study (AREDS, Report

No. 8) studied 3640 individuals aged 55 to 80 years for an average

of 6.3 years who were evaluated for signs of age-related

degeneration of the macula (AMD), the leading cause of visual

impairment and loss in people over age 65.

The researchers evaluated the effect of high-dose vitamins C and E,

beta carotene, and zinc supplements on AMD progression and visual

acuity. The observational and experimental data suggest that

antioxidant and/or zinc supplements may delay progression of AMD and

vision loss. Participants with signs of early AMD who took

antioxidants plus zinc significantly reduced their risk of

developing advanced AMD.

The participants were divided into 4 categories based on preexisting

eye lesions and degeneration present before the study, roughly

corresponding to their risk of AMD progression. They were evaluated

every 6 months for retinal changes indicating AMD progression. The

participants were randomly assigned to receive 1 of 4 daily

supplements:

• antioxidants (vitamin C, 500 mg; vitamin E, 400 IU; and beta

carotene, 15 mg)

• zinc, 80 mg, as zinc oxide; and copper, 2 mg, as cupric

oxide

• antioxidants plus zinc

• placebo

" Comparisons with placebo demonstrated a statistically significant

odds reduction for the development of advanced AMD with antioxidants

plus zinc [28% reduced risk], " the researchers write.

" The [reduced risks] for zinc alone and antioxidants alone are [25%]

and [20%] respectively, " they add. " The only statistically

significant reduction in rates of at least moderate visual acuity

loss occurred in higher-risk persons assigned to receive

antioxidants plus zinc [27% reduced risk]. "

The authors note that the doses of vitamins C and E and the dose of

zinc used in the study are higher than the recommended daily amount

and therefore can only be obtained by taking supplements. They

recommend that, because of adverse effects documented in other

studies, smokers should not take beta carotene.

" Based on data from AREDS, persons older than 55 years should have

dilated eye examinations to determine their risk of developing

advanced AMD, " the authors conclude. " Those with extensive

intermediate size drusen, at least one large druse, or noncentral

[atrophy] in one or both eyes or those with advanced AMD or vision

loss due to AMD in one eye, and without contraindications such as

smoking, should consider taking a supplement of antioxidants plus

zinc such as that used in this study. "

In a related article, with AREDS (Report No. 9) found that a high-

dose formulation of vitamin C, vitamin E and beta carotene had no

apparent effect on reducing the risk of development of age-related

cataract.

In an accompanying editorial, Lee M. Jampol, MD, of the Department

of Ophthalmology at Northwestern University, Chicago, notes that in

the growing trend to prevent or ameliorate medical conditions and

the aging process, many patients " attack " by taking various

supplements. He states that because the cause of AMD is uncertain,

it is difficult to determine what supplements might be helpful.

Dr. Jampol states that, " Surprisingly and fortunately, [the AREDS]

results demonstrate impressive efficacy of the interventions for

intermediate and advanced AMD. This contrasts with the disappointing

results to date of similar supplementation for the prevention of

cancer, stroke and cardiovascular disease. "

Dr. Jampol notes that, " ... the study tells us nothing about the

value of supplementation in [Categories 1 and 2]. Supplementation

was not demonstrated to prevent progression from Categggory 2 to

category 3 or 4.

" Only the combination of zinc and antioxidants statistically reduced

the odds of patients developing advanced AMD, " Dr. Jampol

states. " The only statistically significant reduction of moderate

visual loss occurred in patients assigned to antioxidants plus zinc.

" ... the results do demonstrate a consistent and cohesive picture of

the modest efficacy of the zinc alone, the antioxidants alone, and

more of an effect from the combination of the 2, " Dr. Jampol

observes. " We do not, of course, know whether 1, 2, or all 3 of the

antioxidants are responsible for the beneficial effect.

" I would conclude that those patients of any age who demonstrate

extensive intermediate sized drusen, large drusen, or especially

those who have advanced AMD in one eye, should consider taking a

supplement containing these dosages of anti-oxidants and zinc, Dr.

Jampol summarizes. " It seems desirable that this supplement should

be taken indefinitely, though AREDS cannot determine ideal duration

of treatment. "

According to background information in the article, AMD is the

leading cause of visual impairment and blindness in the United

States and elsewhere among people 65 years and older. There is no

proven treatment to slow or prevent development of advanced AMD.

Arch Ophthalmol. 2001;119:1417-1436, 1439-1452, 1533-1534<