Omega-3
vetzuur voor gezonde ogen*
Bij het ouder worden wordt het gezichtsvermogen minder en volgens een studie, weliswaar met muizen blijkt deze vermindering te voorkomen door voeding rijk aan het omega-3 vetzuur
DHA. Bij het ouder worden hopen zich afvalstoffen als N-retinylidene-N-retinyl-ethanolamine (A2E) op in de retina, waardoor het gezichtsvermogen minder wordt. Normaal tijdens het leven verdubbelt deze hoeveelheid afvalstoffen. In de studie kregen de muizen of een normale voeding of een voeding waarvan 1% van hun vetinname bestond uit DHA. In deze laatste groep muizen met de DHA bleek bij het ouder worden geen toename van de afvalstoffen A2E plaats te vinden.
Age-Related Vision Loss Prevented By Fish Oil
An omega-3 fatty acid found in fish, known as DHA, prevented age-related vision loss in lab tests, demonstrates recently published medical research from the University of Alberta.
Faculty of Medicine & Dentistry researcher Yves Sauve and his team discovered lab models fed DHA did not accumulate a toxic molecule at the back of the eyes. The toxin normally builds up in the retina with age and causes vision loss.
"This discovery could result in a very broad therapeutic use," says Sauve, whose work was recently published in the peer-reviewed journal Investigative Ophthalmology & Visual
Science.
"In normal aging, this toxin increases two-fold as we age. But in lab tests, there was no increase in this toxin whatsoever. This has never been demonstrated before - that supplementing the diet with DHA could make this kind of
difference."
The team recently started another study, looking at people who have age-related macular degeneration (AMD), a condition that results in the loss of central vision and is the main cause of blindness in those over the age of 50. The researchers will look for DNA markers in the blood of study participants. The team wants to determine if participants with certain genetic markers will respond better to increasing amounts of DHA in their diet and if so, why.
Dietary Docosahexaenoic Acid Supplementation Prevents Age-Related Functional Losses and A2E Accumulation in the Retina
1. Blake Dornstauder1, 2. Miyoung Suh2, 3. Sharee Kuny1, 4. Frédéric Gaillard1,
5. Ian M. MacDonald1, 6. Michael T. Clandinin3 and 7. Yves Sauvé1
+ Author Affiliations
1. From the 1Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada; the
2. 2Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; and the
3. 3Alberta Institute for Human Nutrition, University of Alberta, Edmonton, Alberta, Canada.
1. Corresponding author: Yves Sauvé, Department of Ophthalmology, 7-55 Medical Sciences Bldg, University of Alberta, Edmonton AB, Canada, T6G 2H7; ysauve@ualberta.ca.
Abstract
Purpose With age, retina function progressively declines and A2E, a constituent of the toxin lipofuscin, accumulates in retinal pigment epithelial (RPE) cells. Both events are typically exacerbated in age-related retina diseases. We studied the effect of dietary docosahexaenoic acid (DHA, C22:6n-3) supplementation on these events, using a transgenic mouse model (mutant human ELOVL4; E4) displaying extensive age-related retina dysfunction and massive A2E accumulation.
Methods Retina function was assessed with the electroretinogram (ERG) and A2E levels were measured in E4 and wildtype (WT) mice. Dietary DHA was manipulated from 1 to 3, 1 to 6, 6 to 12, and 12 to 18 months: 1% DHA over total fatty acids (E4+, WT+) or similar diet without DHA (E4−, WT−).
Results Increased omega-3/6 ratios (DHA/arachidonic acid) in E4+ and WT+ retinas were confirmed for the 1- to 3-month and 1- to 6-month trials. Although 1- to 3-month intervention had no effects, when prolonged to 1 to 6 months, RPE function (ERG c-wave) was preserved in E4+ and WT+. Intervention from 6 to 12 months led to maintained outer and inner retina function (ERG a- and b-wave, respectively) in E4+. At 12 to 18 months, a similar beneficial effect on retina function occurred in WT+; A2E levels were reduced in E4+ and WT+.
Conclusions DHA supplementation was associated with: preserved retina function at mid-degenerative stages in E4 mice; prevention of age-related functional losses in WT mice; and reduced A2E levels in E4 and WT mice at the oldest age examined. These findings imply that dietary DHA could have broad preventative therapeutic applications (acting on pathologic and normal age-related ocular processes).
References:
Sauve is a researcher in both the Department of Ophthalmology and the Department of Physiology in the Faculty of Medicine & Dentistry at the U of A.
Various organizations funded the research, but the primary funder was the Canadian Institutes of Health Research (CIHR).
University of Alberta Faculty of Medicine & Dentistry (September 2012)
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