Vitamine A tegen rimpels.*
Dagelijks een simpele lotion of crème met vitamine A doet rimpels als gevolg van het ouder worden duidelijk verminderen, blijkt uit een Amerikaanse clinical trial. Rimpels en bruine vlekken als gevolg van het ouder worden ontstaan het eerst op die gedeelte van de huid die vaak blootgesteld worden aan de zon. Bij het ouder worden wordt door verminderde productie van collageen de huid dunner, slapper en verschijnen rimpels.
Uit deze studie blijkt dat het 3x per week aanbrengen van een lotion of crème met vitamine A na 24 weken de rimpels met bijna 20% doet verminderen en ervoor zorgt dat stoffen gevormd worden die de productie van collageen doen verhogen.
Vitamin
A Cream Helps Reduce Wrinkles Associated With Natural Skin Aging
Applying
vitamin A to the skin appears to improve the wrinkles associated with natural
aging and may help to promote the production of skin-building compounds,
according to a report in the May issue of Archives of Dermatology, one of
the JAMA/Archives journals.
The wrinkles and brown spots associated with aging appear first and most
prominently on skin exposed to the sun, according to background information in
the article. "Human skin not exposed to the sun also ages but less
dramatically," the authors write. "In intrinsic, natural or
chronological aging, skin loses its youthful appearance by becoming thinner,
laxer and more finely wrinkled. These changes are readily appreciated by
inspecting the upper inner arm." Thinner skin results from a reduced
production of the protein collagen and may slow wound healing, presenting a
public health issue. "Safe and effective therapies to reverse the atrophy
of natural skin aging do not exist currently," the authors note.
Reza Kafi, M.D., then of the University of Michigan Medical School, Ann Arbor,
and now of Stanford Medical School, Palo Alto, Calif., and colleagues assessed
the effectiveness of vitamin A (retinol) lotion in 36 elderly individuals
(average age 87 years). Researchers applied a lotion containing 0.4 percent
retinol to participants' right or left upper inner arms, and lotion with no
retinol to the other arm, up to three times a week for 24 weeks. Wrinkles,
roughness and overall severity of aging were each graded on a scale from zero
(none) to nine (severe) before treatment and two, four, eight, 16 and 24 weeks
after beginning treatment. In addition, 4-millimeter biopsy specimens of skin
were taken from both arms at the beginning and end of the 24-week treatment
period.
A total of 23 individuals completed the full study and 13 withdrew from the
study prior to completion. When the researchers included the individuals who had
dropped out of the study by assuming their skin did not change after their last
measurement, wrinkles, roughness and overall aging severity were all
significantly reduced in the retinol-treated arm compared with the control arm.
The skin biopsies revealed that the retinol increased the production of
glycosaminoglycan and procollagen, structural components of the skin.
"Topical retinol improves fine wrinkles associated with natural aging,"
the authors conclude. "Significant induction of glycosaminoglycan, which is
known to retain substantial water, and increased collagen production are most
likely responsible for wrinkle effacement [reduction]. With greater skin matrix
synthesis [production of compounds that form new skin], retinol-treated aged
skin is more likely to withstand skin injury and ulcer formation along with
improved appearance."
###
(Arch Dermatol. 2007;143:606-612)
Improvement of Naturally Aged Skin With Vitamin A (Retinol)
Objective To
evaluate the effectiveness of topical retinol (vitamin A) in
improving the clinical signs of naturally aged skin.
Design Randomized,
double-blind, vehicle-controlled, left and right arm comparison study.
Setting Academic
referral center.
Patients The study
population comprised 36 elderly subjects (mean age, 87 years),
residing in 2 senior citizen facilities.
Intervention
Topical 0.4% retinol lotion or its vehicle was applied at each visit
by study personnel to either the right or the left arm, up to 3 times
a week for 24 weeks.
Main Outcome Measures
Clinical assessment using a semiquantitative scale (0, none; 9, most
severe) and biochemical measurements from skin biopsy specimens
obtained from treated areas.
Results After 24
weeks, an intent-to-treat analysis using the
last-observation-carried-forward method revealed that there were
significant differences between retinol-treated and vehicle-treated skin
for changes in fine wrinkling scores (–1.64 [95% CI, –2.06 to
–1.22] vs –0.08 [95% CI, –0.17 to 0.01]; P<.001). As
measured in a subgroup, retinol treatment significantly increased
glycosaminoglycan expression (P = .02 [n = 6])
and procollagen I immunostaining (P = .049 [n = 4])
compared with vehicle.
Conclusions Topical
retinol improves fine wrinkles associated with natural aging.
Significant induction of glycosaminoglycan, which is known to retain
substantial water, and increased collagen production are most likely
responsible for wrinkle effacement. With greater skin matrix
synthesis, retinol-treated aged skin is more likely to withstand skin
injury and ulcer formation along with improved appearance.
Trial Registration
clinicaltrials.gov Identifier: NCT00272610
Author Affiliations: Department of Dermatology, University of Michigan Medical School, Ann Arbor. Drs Kafi and Kwak are now with the Department of Dermatology, Stanford Medical School, Palo Alto, Calif, and Dr Cho is now with the Department of Dermatology, Seoul National University, Seoul, South Korea. (Juni 2007)