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!
Improving memory with magnets
28.03.2017 | McGill University
Graphene-based neural probes probe brain activity in high resolution
28.03.2017 | Graphene Flagship
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy