Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

People lacking vital antioxidants and exposed to sunlight more likely to develop eye disease later in life

14.10.2008
People who lack essential antioxidants, and who have high levels of sunlight exposure, have a higher risk of developing advanced macular degeneration (AMD), according to a study published today in the journal Archives of Ophthalmology. AMD is the leading cause of poor vision in the UK.

The EUREYE study, led by Astrid Fletcher, Professor of Epidemiology of Ageing at the London School of Hygiene & Tropical Medicine, is the first to report in human populations an adverse association between sunlight exposure and AMD in people with low levels of antioxidants. It is also unprecedented in the level of detail the researchers used, taking into account not only lifestyle and medical factors but even going so far as to estimate levels of cloud cover in each of the countries from which participants were recruited.

The eye is particularly vulnerable to the damaging effects of sunlight. Ultraviolet radiation is absorbed by the lens, but visible or “blue” light penetrates to the retina so allowing us to see. Protection against the harmful effects of blue light is provided by the antioxidant vitamins C and E, the carotenoids (lutein and zeaxanthin) which filter blue light, and zinc.

Animal and laboratory studies have previously shown that blue light may be a factor in the pathogenesis of AMD, but results have been inconsistent in the few studies that have investigated associations between sunlight exposure and AMD in human populations. Little attention has been paid to the possible interactions between antioxidant levels and light exposure, although it is thought that the adverse effects of sunlight may be mitigated by the protective effects of antioxidants.

4,753 participants aged 65 years were selected randomly in seven centres, Bergen in Norway, Tallinn in Estonia, Belfast in the UK, Paris-Creteil in France, Verona in Italy, Thessaloniki in Greece and Alicante in Spain. The average age of participants was 73.2 and 55% were women. Blue light exposures tended to be higher in participants from centres in southern Europe while participants in an exclusively urban centre (Paris) had the lowest exposures.

Participants underwent fundus photography, and gave a blood sample for antioxidant analysis. They completed a residence and job history in advance, and attended a face-to-face interview. They were asked about their education, smoking and alcohol use, medical history, lifetime residence and level of sunlight exposure, including how much time they had spent outdoors between the hours of 9am and 5pm, and 11am and 3pm each day since they left school and throughout their working life.

Information was collected separately for summer and winter, and for different occupational time periods (including time spent looking after the home) and in retirement up to their current age. For each period, they were asked about their use of eyewear (glasses, contact lenses and sunglasses). The information on sunlight exposure and area of residence was sent to the University of East Anglia and combined with metrological information to estimate lifetime blue light exposure for each participant.

The results indicated that those with the lowest levels of antioxidants were most at risk of AMD due to blue light. In particular, the combination of blue light exposure and low levels of zeaxanthin, alpha tocopherol and Vitamin C was associated with a nearly four-fold likelihood of developing AMD. The researchers found that the associations of blue light in those with low antioxidant status appeared stronger at older ages, reaching a peak at 50-59 years.

The combination of blue light exposure and low concentrations of antioxidants in the blood was also found to be associated with the early stages of AMD, which are common in the population, and that exposures in middle age might be more damaging than at younger ages.

Professor Fletcher comments:
‘In the absence of cost-effective screening methods to identify people in the population with early AMD, we suggest that recommendations on protecting the eyes, ensuring that diets contain the right nutrients and antioxidants, are targeted at the general population, and especially middle-aged people’.

‘We are not telling people to stay out of the sun altogether. The benefits of sunlight are well documented, in particular its role in vitamin D synthesis. But if people want to avoid macular degeneration as they get older, they should avoid exposing their eyes to too much sunlight when they are outside, and take simple precautions, such as wearing a wide-brimmed hat and sunglasses,.

‘Nor are we recommending that people should take vitamin supplements. It is perfectly possible to achieve the recommended dietary reference intakes for these essential antioxidants by following a balanced diet’.

Gemma Howe | alfa
Further information:
http://www.lshtm.ac.uk

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>