Dr. Grossman’s Blog

Evidence continues to show that oxidative stress contributes to age-related maculopathy (ARM) and that consuming appropriate antioxidants such as zeaxanthin may protect against this condition. 

The term maculopathy is associated with diseases of the macula, an area at the center of the retina that is associated with highly sensitive, accurate vision.  Age-related macular degeneration (AMD) is an example of maculopathy.

A study published in the American Journal of Clinical Nutrition investigated the link between lower intakes of antioxidants and ARM.   828 healthy Irish participants between the ages of 20 and 60 years were analyzed for risk factors for ARM and dietary intake of relevant nutrients.

Researchers showed that several variables related to risk for ARM are associated with a relative lack of key nutrients in the diet.  They determined that the most important and universal risk factor for ARM is a lack of dietary zeaxanthin.

Zeaxanthin is one of the two carotenoids contained within the retina of the eye.  Ultraviolet radiation is absorbed by the lens, but visible or “blue” light penetrates to the retina, enabling us to see.  Along with lutein, zeaxanthin absorbs the potentially harmful effects of blue light.

How can you ensure you are consuming zeaxanthin?  Good dietary sources include green vegetables such as spinach, kale, turnip greens, collard greens, romaine lettuce, broccoli, zucchini, corn, garden peas and Brussels sprouts.

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

Learn about natural zeaxanthin products

SOURCE:  O’Connell, et al, Diet and risk factors for age-related maculopathy, American Journal of Clinical Nutrition, Vol. 87, No. 3, 712-722, March 2008.

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.

Research shows bilberry extract helps fight against macular degeneration and cataracts in lab rats

Cataracts and macular degeneration are the major cause of vision deterioration in the elderly. A study by Russian scientists shows that taking bilberry supplements may help ward off these diseases.

Researchers used a particular strain of lab rats (OXYS rats) capable of reproducing many of the key features of human age-related cataracts and macular degeneration. From 1.5 to 3 months, these rats were given either a control diet or a diet supplemented with bilberry extract.

At 3 months, more then 70% of the rats in the control group had cataract and macular degeneration. Rats in the group given bilberry extract had no impairments in the lenses and retina.

Bilberry is also known as European blueberry, and is closely related to North American wild and cultivated blueberries and huckleberries. Bilberry is known to be a potent antioxidant and has been shown to help other vision problems such as glaucoma. (Read more about bilberry and glaucoma).

Results suggest that long-term supplementation with bilberry extract is effective in prevention of macular degeneration and cataract.

Read more research on cataracts and macular degeneration

Learn about natural bilberry supplements

Source: “Dietary supplementation with bilberry extract prevents macular degeneration and cataracts in senesce-accelerated OXYS rats”, Fursova et al, Adv Gerontol, 2005; 16: 76-9.