Omega 3 from Fish, Nuts, Olive Oil Associated With
Reduced Risk of Age-Related Blindness
Age-related macular degeneration (AMD), is the
leading cause of severe vision loss among those older than 65 in the
developed world.
Center vision
lost to AMD
May 11, 2009 Those fish oils called omega 3 fatty
acids already associated with a number of health benefits for senior
citizens - have now been found to play a role in lowering the risk of
the number one cause of blindness in senior citizens age-related
macular degeneration. In this study, most of the omega 3 came from fish,
nuts and olive oil. And, it also helps to avoid trans fats.
The supporting evidence comes from two reports in
the May issue of Archives of Ophthalmology, one of the JAMA/Archives
journals.
By 2020, as many as 3 million Americans are
expected to have late-stage age-related macular degeneration (AMD),
according to background information in one of the articles. AMD is the
leading cause of severe vision loss among individuals older than 65 in
the developed world. Established risk factors include age, genetic
markers and smoking (the only consistently reported modifiable risk
factor).
In one report, Jennifer S.L. Tan, M.B.B.S., B.E.,
of Westmead Hospital, University of Sydney, Australia, and colleagues
studied 2,454 participants in the Blue Mountains Eye Study, which began
in 1992 to 1994. At that time, participants completed a food frequency
questionnaire that was analyzed to determine their intake of various
fatty acids. Digital photographs of the retina were used to assess the
development of AMD five and 10 years later.
● After adjusting for age, sex and smoking,
eating one serving of fish per week was associated with a 31 percent
lower risk of developing early AMD.
● The association was stronger among individuals
with a lower intake of linoleic acid, an unsaturated omega-6 fatty acid
found primarily in vegetable oils.
● Eating one to two servings of nuts per week was
associated with a 35 percent lower risk of early AMD.
"In conclusion, our findings support the hypothesis
that increased intake of omega-three polyunsaturated fatty acids and
regular consumption of fish and/or nuts in the diet may protect against
the development of early AMD," the authors write.
These fatty acids may protect the eyes by
preventing the buildup of plaque in the arteries or reducing
inflammation, blood vessel formation and oxygen-related cell damage in
the retina.
Joint effects of protection against AMD were
suggested between the consumption of these foods and other factors, such
as smoking, intake of unsaturated omega-6 fatty acids or beta carotene
and the ratio of total blood cholesterol to HDL or "good" cholesterol.
"These findings also suggest that an appropriate
balance among various nutrients is essential for maximizing nutritional
benefit," they continue.
Further studies are needed to determine whether
changing an individual's diet or recommending supplementation could
prevent or delay the development of AMD.
Exam for AMD
Second report says trans-unsaturated fats
associated AMD
In the other report, Elaine W.-T. Chong, M.D.,
Ph.D., M.Epi., of the Centre for Eye Research Australia, and colleagues
analyzed data from 6,734 individuals age 58 to 69.
Between 1990 and 1994, participants' nutrient
intakes were assessed from a food frequency questionnaire, and they were
tracked for the development of AMD between 2003 and 2006. During the
follow-up period, 2,872 cases of early AMD and 88 cases of late AMD
developed.
Individuals who consumed higher levels of
trans-unsaturated fatsfound in baked goods and processed foodswere
more likely to have late AMD, whereas those who consumed the most
omega-three fatty acids were less likely to have early AMD. "Olive oil
intake (100 milliliters or more per week vs. less than 1 milliliter per
week) was associated with decreased prevalence of late AMD," the authors
write. "No significant associations with AMD were observed for intakes
of fish, total fat, butter or margarine."
Trans-unsaturated fatty acids have been shown to
increase the risk of coronary heart disease through their effects on
cholesterol levels and possibly through inflammation. In contrast,
omega-three fatty acids are believed to protect against damage to the
retina, thereby reducing risk for AMD.
Although the primary fats found in olive oil (oleic
acid and monounsaturated fatty acids) were not associated with AMD risk,
olive oil contains other components that may have a protective effect,
such as the antioxidants and anti-inflammatory compounds.
"Our findings suggest that people who follow a diet
low in processed foods high in trans-unsaturated fatty acids and rich in
omega-three fatty acids and olive oil might enjoy some protection from
developing AMD," the authors conclude.
Keep up with the latest news for senior citizens, baby
boomers
