According to research, consuming a Vitamin D rich diet, along with the nutrients methionine and betaine, could help lower age-related macular degeneration risk. An analysis of identical twins also found that the more a person smoked, the higher their risk of developing age-related macular degeneration. The study is the first to look at identical twin pairs in which one twin had early age-related macular degeneration, and the other had late stage age-related macular degeneration.
Age-related macular degeneration is highly hereditary, with genetic factors defining up to 71 % of the severity of the disease as established by a previous study by this same research team. Through studying identical twins having the same genes but whose disease was at different stages, researchers could identify environmental and behavioral factors that may contribute to severity of the disease. The researchers wanted to know why, if they have the same genes, do they have different stages of the disease.
“Eating a healthy diet with plenty of fruits and vegetables will make a difference, even though you have a genetic likelihood of macular degeneration,” said study author Johanna M. Seddon, a specialist in macular degeneration.
Macular degeneration is among the main reasons for vision loss in the elderly. It takes place when cells inside the area of the eye responsible for clear vision, called the macula, slowly die. Macular degeneration may progress so gradually it could take years for serious vision loss to take place but it could also develop quickly, causing vision loss severe enough that that can make it difficult to drive, read or conduct daily tasks.
Each twin completed a questionnaire about nutritional and health behaviors. The research discovered that twins who had early stage macular degeneration tended to eat more vitamin D coming from dietary sources like milk or fish than their siblings. Vitamin D could possibly lessen the risk of macular degeneration as it has anti-inflammatory properties. It could also prevent the growth of new blood vessels which can grow underneath the macula, leaking blood and resulting in vision loss in the more serious phases of the disease. Similarly, the research team also found that higher intakes of betaine and methionine were linked to a slower progression of the disease. These nutrients have also been linked to epigenetic mechanisms, which is a change in DNA, not due to a change in the actual DNA sequence. Methionine is found in fish, poultry and dairy foods, while betaine is found in grains, fish and spinach.
The research also revealed that amongst the sets of twins, the sibling who had been the heavier smoker had a tendency to have the more serious case of macular degeneration. The outcomes show that genetic susceptibility as well as environmental factors are important, and that epigenetic factors could be involved as well, and further emphasizes the importance of modifiable behaviors, particularly no smoking and consuming a healthy diet, to delay the progression as well as help with the prevention of macular degeneration and vision loss.