Here’s another reason to get your daily recommended allowances of vitamins and minerals: to lower the odds of vision loss in midlife.
Researchers from several universities in the Netherlands, including Erasmus Medical Center in Rotterdam, found that people who got the highest amounts of several nutrients, including zinc and omega-3 fatty acids, in their diet had a lower risk of developing a condition known as macular degeneration.
The common condition erodes the retina and causes vision loss in more than 6% of Americans age 40 and older. It is treatable with drugs or surgery, but the treatments do not reverse the condition. Age-related macular degeneration accounts for half of all cases of blindness in developed countries.
People with a genetic variation called CFH are 11 times more likely to develop macular degeneration than the general population, and those with another variation called LOC387715S have a 15-times higher risk.
For the new study, the authors studied 2,167 people over age 55 who had one of the two genes known to contribute to macular degeneration. The researchers surveyed the participant’s eating habits and followed-up for 10 years to track vision loss; participants received eye exams every three years.
The researchers found that among those with the CFH gene variation, people who got the most zinc, beta carotene, omega-3 fatty acids or lutein/zeaxanthin in their diets were less likely to develop macular degeneration than those who got the lowest amounts. For example, the rate of vision loss in those getting the lowest amount of omega-3s (about 22 mg per day) was 39 cases out of every 100 people; in people who consumed the most omega-3s (268 mg per day), the rate was 28 cases out of every 100.
Among people with the LOC387715S variation, only two nutrients, zinc and omega-3, were associated with a lower risk of vision loss. But in all cases, the authors found that it wasn’t necessary to eat excessive amounts of the nutrients to see a benefit — getting the government-recommended daily allowances of healthy foods was sufficient.
For women, that means getting 1.1 g of omega-3s and 8 mg of zinc per day. Men should get 1.6 g of omega-3s and 11 mg of zinc daily.
Foods that are rich in zinc include oysters, red meat, nuts and beans. Omega-3 fatty acids are abundant in oily fish like salmon, mackerel, sardines, herring and anchovies. Beta carotene is found in a variety of fruits and veggies, including carrots, sweet potatoes, squash, spinach, apricots and green peppers. Foods rich in lutein and zeaxanthin include eggs and leafy greens.
The authors did not investigate how the nutrients in these foods may contribute to the prevention of macular degeneration, but considering that they’re all highly nutritious foods that the typical American doesn’t get enough of, it probably wouldn’t hurt to up your intake of them.
The study was published in the Archives of Ophthalmology.