Long-term daily multivitamin supplement use may lower cataract risk in men, according to a study of nearly 15,000 male physicians published this month in Ophthalmology, the journal of the American Academy of Ophthalmology.
Past observational studies have indicated a relationship between nutritional supplement use and eye health. However, randomized trial data on the effects of long-term multivitamin supplement use and risk of eye diseases are limited and, in some cases, non-existent. To address this, researchers based at Brigham and Women's Hospital and Harvard Medical School – as part of the Physicians' Health Study II (PHS II) – conducted a randomized, double-blind study from 1997 to 2011 of 14,641 U.S. male doctors age 50 and older. Half took a common daily multivitamin, as well as vitamin C, vitamin E and beta carotene supplements. The other half took a placebo.
The researchers followed the participants to identify how many participants in each group developed new cases of two common eye diseases: cataract, which is a clouding of the eye's lens, and age-related macular degeneration (AMD), the deterioration of the eye's macula that is responsible for the ability to see fine details clearly.
The researchers found that in the placebo group 945 cases of cataract developed, which were self-reported and confirmed by medical records, while only 872 cases of cataract developed in the multivitamin group, representing a 9 percent decrease in risk. This risk was even lower, at 13 percent, for nuclear cataract, which occurs at the center of the lens and is the most common variety of cataract associated with the aging process. Given that an estimated 10 million adults in the United States have impaired vision due to cataract, even a modest reduction in risk of cataract has potential to improve public health outcomes.
"If multivitamins really do reduce the risk of cataract, even by a modest 10 percent, this rather small reduction would nonetheless have a large public health impact," said William Christen, ScD, the study's lead author and researcher from Harvard Medical School.
In terms of AMD risk, the researchers found there were 152 new cases of visually significant (best corrected visual acuity of 20/30 or worse) AMD in the multivitamin group compared to 129 in the placebo group, but the difference was not statistically significant. While this finding may seem to contradict results of other studies, such as Age-Related Eye Disease Study (AREDS), the researchers note that the studies had different nutrient supplements, dosing and objectives. AREDS included daily zinc and a high-dose antioxidant combination of vitamin E, vitamin C and beta carotene, whereas the multivitamin in PHS II included these nutrients and many others. All the nutrients were provided to the PHSII participants at the U.S. Recommended Dietary Allowance dose levels, which are much lower than the AREDS supplements. Furthermore, the objective in AREDS was to prevent AMD progression among persons who already had the disease, whereas the objective of PHS II was to prevent new cases of AMD, and thus persons with a diagnosis of AMD at baseline were not included.
"This finding of more cases of AMD in the multivitamin group than in the placebo group, although not statistically significant, does raise some concerns," added Dr. Christen. "Clearly, this finding needs to be examined further in other trials of multivitamin supplements in both men and women."
The American Academy of Ophthalmology recommends the use of antioxidant vitamin and mineral supplements as recommended in the AREDS reports, including high daily doses of vitamin C, vitamin E, beta-carotene, zinc and copper only for patients who have intermediate or advanced AMD. Patients are advised to contact their ophthalmologist to learn if these supplements are appropriate for them. Some people should not take large doses of antioxidants or zinc for medical reasons. Current smokers and patients with a smoking history should be advised to avoid taking beta-carotene because of the increased risk of lung cancer and consider taking the other components of the AREDS formulation. The recent AREDS2 results would suggest other nutrients such as lutein and zeaxanthin may be an appropriate substitution for beta-carotene in the formulation.
The Academy does not at this time have a recommendation for the use of nutritional supplements to prevent cataracts or delay their progression.About the American Academy of Ophthalmology
Media Relations | EurekAlert!
Custom-tailored strategy against glioblastomas
26.09.2016 | Rheinische Friedrich-Wilhelms-Universität Bonn
New leukemia treatment offers hope
23.09.2016 | King Abdullah University of Science and Technology
Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.
Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
30.09.2016 | Event News
29.09.2016 | Event News
28.09.2016 | Event News
30.09.2016 | Materials Sciences
30.09.2016 | Earth Sciences
30.09.2016 | Life Sciences