Eye health indicates body health

Harvard: Deteriorating eyesight in older people is accelerated by a poor diet, smoking and being overweight, say doctors at the Harvard Medical School and Harvard School of Public Health.

Age-related macular degeneration (AMD) is the main cause of vision loss in developed countries. In the US some 13 million people in show some signs of AMD, which is uncommon in people younger than 55. The health of eyes are also an indicator of the body’s general health.

This new study shows that diet, smoking, and BMI (body mass index) may affect the chances of getting AMD.

Johanna Seddon, MD, one of the researchers and his colleagues studies 934 people who were on average 67 to 71 years old. Half of the participants were screened at a Boston eye and ear clinic. The others were screened at an eye clinic in Portland, Ore.

A total of 184 participants didn’t have AMD. The rest had mild AMD (201 patients), moderate AMD (326 patients), or advanced AMD (223 patients).

Participants completed surveys about their diet and lifestyle. They also gave blood samples, which Seddon’s team checked for levels of C-reactive protein (CRP) and homocysteine, which have been linked to increased risk of heart disease.

The researchers had previously reported that CRP and homocysteine are associated with age-related macular degeneration. This time, they checked how diet and lifestyle affected levels of CRP and homocysteine, as well as AMD risk.

None of the participants were asked to change their diets or lifestyles. The researchers just looked for patterns among the participants’ habits, blood chemicals, and AMD diagnosis.

Eye-Opening Data

The researchers found that people who smoked, were overweight, and consumed fewer antioxidants (natural chemicals found in many fruits and vegetables) tended to have higher levels of CRP and homocysteine.

For instance, people who reported eating fish more than twice per week had lower CRP levels. This was also true for people who consumed higher levels of vitamin C, beta-carotene, and the antioxidants lutein and zeaxanthin.

CRP levels were higher for people who smoked or had higher BMI, the study also shows.

Lower homocysteine levels were seen in people with more vitamin E in their blood and those who consumed more antioxidants and vitamin B-6. But higher blood levels of vitamin E were also tied to higher CRP levels. That contradiction should be studied further, note Seddon and colleagues.

Seddon commented: “Overall, these findings suggest that sick eyes may occur in sick bodies related to smoking, being overweight, and other unhealthy behaviors,” they write.

“AMD is associated with immune, inflammatory, and other cardiovascular mechanisms, and these results emphasize the need to adhere to healthy lifestyles for your eyes and your body overall.”