Dr. Grossman’s Blog

Data in US Twin Study also shows consumption of fish rich in omega-3 fatty acids helps fight AMD

In a study of male twins, research shows that those who smoke have an increased risk of developing age-related macular degeneration.  Men who ate more fish rich in omega-3 fatty acids had a lower risk of developing the disease.

Researchers collected data on 681 elderly male twins from the National Academy of Sciences National Research Council World War II Veteran Twin Registry.  The twins were given an eye exam and completed a food frequency and a risk-factor questionnaire.  222 of the twins had intermediate and late-stage age-related macular degeneration, while 459 of the twins had no signs of the disease.

The study showed that current smokers had a 1.9-fold increased risk of developing age-related macular degeneration, while past smokers had about a 1.7-fold increased risk.

Consumption of omega-3 fatty acids from fish reduced the risk of AMD, particularly if two or more servings of fish were consumed each week.

Although researchers noted that genetics are important in determining who will get AMD, lifestyle choices, such as smoking, play a role as well. 

What can you do to reduce your risk of AMD?  Eat a healthy diet, including omega-3 fatty acids from fish such as mackerel, lake trout, sardines, albacore tuna and salmon.  Experts also recommend exercising, refraining from smoking, and maintaining a normal healthy weight.

Learn more about Age-Related Macular Degeneration (AMD)

Read more studies about the benefits of omega-3 fatty acids for healthy vision

SOURCE:  Seddon, et al; Cigarette Smoking, Fish Consumption, Omega-3 Fatty Acid Intake, and Associations With Age-Related Macular Degeneration; Arch Ophthalmol. 2006;124:995-1001.

A new European study suggests that the combination of low levels of antioxidants and blue light exposure from the sun is associated with certain forms of age-related macular degeneration (AMD).

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 an adverse association between sunlight exposure and AMD in people with low levels of antioxidants.

It is known that the eye is vulnerable to the damaging effects of sunlight. Ultraviolet radiation is absorbed by the lens, but visible or “blue” light penetrates to the retina, enabling us to see. Protection against the harmful effects of blue light is provided by antioxidant enzymes—including vitamins C and E, the carotenoids (lutein and zeaxanthin) and zinc.

Researchers measured levels of these nutrients in the blood of 4,753 older adults (average age 73.2) who were part of the European Eye Study. Participants were interviewed about their lifetime sunlight exposure and had photographs taken of their retinas to detect AMD.

Participants with the lowest concentrations of antioxidants in the blood were found to be most at risk of AMD due to blue light exposure. In fact, participants with the combination of blue light exposure and low levels of zeaxanthin, alpha tocopherol and Vitamin C were nearly four times more likely to develop AMD. Researchers also noted that blue light exposure 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’.

Study authors don’t advise people to stay out of the sun altogether — sunlight is important for its role in vitamin D synthesis. However, they do recommend avoiding exposing eyes to too much sunlight by wearing a wide-brimmed hat and sunglasses when outdoors.

In addition, study authors advise consumption of key antioxidants, which can be accomplished by consuming recommended dietary intake levels of vitamin C and zinc and increasing consumption of carotenoid-rich fruits and vegetables.

Learn more about macular degeneration

Read more about antioxidants and nutrient food sources for good eye health

SOURCE: Fletcher AE et al. Sunlight exposure, antioxidants, and age-related macular degeneration. Archives Ophthalmology 2008; 126:1396-1403.

Researchers using data from the Third National Health and Nutrition Examination Survey (1988 through 1994) have found evidence that consuming vitamin D may help ward off age-related macular degeneration (AMD). 

In this study, 7752 individuals (including 11% with AMD) were given retinal photographs, dietary intake questionnaires, and blood tests to calculate blood vitamin D (25-hydroxyvitamin D) levels.  Based on these vitamin D blood levels, participants were divided into 5 groups.   Participants in the group with the highest vitamin D levels showed 40% lower risk of developing early AMD than those in the lowest group. 

Analysis was also conducted to evaluate associations with important food and supplemental sources of vitamin D. 

• People who drank milk daily decreased their risk of developing AMD, as did those who took supplemental vitamin D consistently but didn’t drink milk daily. 
• Fish consumption was also linked with a lower risk of advanced AMD.

What are good sources of vitamin D?  Consider fish — it’s naturally rich in vitamin D.  Milk and breakfast cereals are generally fortified with vitamin D as well. 

Read more about AMD

Learn tips for taking vitamins and maintaining good digestion

SOURCE:  “Association between vitamin D and age-related macular degeneration in the Third National Health and Nutrition Examination Survey”, Parekh N, et al. Arch of Ophthalmol 125:661-69, 2007.