Weight Management to Fight Macular Degeneration
A study published in the Archives of Ophthalmology shows that people with a body mass index of less than 25 are less likely than their peers to develop macular degeneration. Daily exercise also helped keep the eye disease in check. Over the course of the four year study patients who participated in vigorous exercise at least three times per week reduced the chance that the disease would worsen by 25%.
Another study substantiates this information, finding that AMD is associated with higher body mass index, waist circumference, and waist-hip ratio.
Researchers interested in identifying preventative measures to help this group lessen their risk of advanced AMD conducted a survey of 261 participants from a hospital-based retinal practice. Participants were aged 60 years or older, with some sign of non-advanced AMD and visual acuity of 20/200 or better in at least 1 eye.
The results of the study showed that obesity (measured in body mass index) greatly increases the risk for progression to the advanced forms of AMD.
- Larger circumference of the waist resulted in 2 times the risk for advanced late-stage macular degeneration. The larger the waist, the greater the risk.
- A larger waist-hip ratio also increased the risk for development of early stage macular degeneration to the advanced condition (choroidal neovascularization)
- People who had more physical activity in their daily life, at least 3 times a week, developed the late stage 25% more slowly.
- Update: in separate research, scientists have concluded that being physically fit is actually more important than not being over-weight in terms of overall health and well-being. These researchers came to the similar conclusion, that while obesity increases the risk of late-stage macular degeneration, increasing activity reduces that risk.
Published: Progression of Age-Related Macular Degeneration, Seddon, et al, Arch Ophthalmol. 2003;121:785-792
More evidence: Abdominal Fat & AMD
Accumulated weight around the waist (abdominal fat) may be linked to an increased risk of age-related macular degeneration (AMD). AMD is the most common cause of loss of vision and blindness in adults.
A recent study published in the Archives of Ophthalmology examined the association between changes in the waist-to-hip ratio (a measure of abdominal obesity) and risk of AMD. A total of 12,515 people aged 45 to 64 were followed over six years.
Researchers found that a higher waist-to-hip ratio (WHR) was associated with elevated risk of AMD.
The good news is that study participants who reduced their WHR generally saw a reduction in risk of AMD. Overall, a 3 per cent or more decrease in WHR was associated with a 29 per cent reduced risk of AMD. The effect was greatest among those participants classified as obese: a decrease in WHR was associated with 59% lower odds of AMD.
Researchers concluded that middle-aged people who had a 3% or greater reduction in WHR over time were less likely to have AMD, particularly among those who were initially obese.
SOURCE: Peeters, et al. Changes in Abdominal Obesity and Age-Related Macular Degeneration: The Atherosclerosis Risk in Communities Study, Arch Ophthalmol. 2008;126(11):1554-1560
Cut Fat Intake & Stop Smoking
Age is a major factor in the development of as macular degeneration, but the two major contributors to the development of macular degeneration are ones that you can avoid: smoking and fat intake.
The good news related to smoking and the development of macular degeneration is that you can cut your risk significantly if you quit (unlike some diseases where a past history of smoking is as bad a being a current smoker). It’s another good incentive to kick the habit.
Regular intake of both animal and vegetable fats (including trans fats and hydrogenated fats) can make one twice as susceptible to macular degeneration. It is important to focus on the good fats like those found in essential fatty acids.
A recent study shows that higher doses of vigorous exercise are associated with lower risk of age-related macular degeneration (AMD). AMD is one of the leading causes of blindness in the United States.
Paul Williams, an epidemiologist in Berkeley Lab’s Life Sciences Division studied 41,708 runners (29,532 men and 12,176 women) more than seven and a half years. He tracked their average daily running distance (kilometers per day), their cardiorespiratory fitness, their body mass index (BMI), cigarette use, and diet. This data was collected in the National Runners’ Health Study.
- Men who reported having AMD were significantly more likely to have once smoked cigarettes
- AMD risk was greater in the men and women who consumed more meat and less fruit
- Men and women who reported having AMD ran for exercise significantly less than those who remained unaffected
- The relative risk for AMD decreased 10% per km/d increment in running distance. Compared with the men and women who averaged less than 2 kilometers/day: those averaging 2 to 4 kilometers/day had 19% lower adjusted risk of AMD; those averaging 4 kilometers/day had 42% to 54% lower adjusted risk of AMD
Williams concluded that higher doses of vigorous exercise such as running are associated with lower risk AMD risk irrespective of weight, cardiorespiratory fitness, and cigarette use.
Source: Prospective Study of Incident Age-Related Macular Degeneration in Relation to Vigorous Physical Activity during a 7-Year Follow-up, Williams, Paul, Investigative Ophthalmology and Visual Science. 2009;50:101-106.
Stop Smoking to Fight Macular Degeneration
Long-term heavy smokers have a 2.5 to 3.5 times greater risk of losing vision from age-related macular degeneration, according to medical geneticist John R.W. Yates, Ph.D., of the University of Cambridge.
A study in the British Journal of Ophthalmology shows a strong link between smoking and age-related macular degeneration. The study also shows the risks associated with exposure to second-hand smoke.
In a controlled study in the UK, researchers looked at the relationship between smoking and the two forms of later-stage age-related macular degeneration: — geographic atrophy and choroidal neovascularization.
Between 2001 and 2003, more than 400 patients with ARMD were compared to nearly 300 controls. 261 patients were diagnosed with choroidal neovascularization, 106 patients were diagnosed with geographical atrophy, and 68 had a mixed condition. The patients competed questionnaires to determine how much and for how long they smoked. The patients who were identified as smokers were those who smoked at least one cigarette daily for at least a year.
The scientists then quantified the smoking habit by pack-years, number of packs a day times the number of years smoked. Not surprisingly, there was a strong connection between ARMD and pack-years.
For 40 pack-years, compared to non-smokers:
- Geographic atrophy: The risk was more than triple.
- Macular degeneration: The risk was almost triple
- Choroidal neovascularization: The risk was more than double
And even for second-hand smoke, non-smokers with exposure for second-hand smoke were two times as likely to develop macular degeneration.
Published: “Smoking and age related macular degeneration: the number of pack years of cigarette smoking is a major determinant of risk for both geographic atrophy and choroidal neovascularization,” Khan, et al, Br J Ophthalmol 2006;90:75-80.
In a study of the impact of mothers’ smoking on their children while in utero, researchers found that maternal smoking increases the chances of the development severe retinopathy of prematurity (ROP) in children. A low birth weight, a long duration of artificial ventilation and oxygen supplementation, and the presence of chronic lung disease also contribute to ROP in infants.
Omega-3 Helps Smokers
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 researchers found that people who are smoking now are 1.9 times more likely to develop macular degeneration, and former smokers are 1.7 times as likely to develop AMD.
They also found that consuming omega-3 fatty acids from fish reduces the risk of macular degeneration, particularly if two or more servings of fish were eaten each week.
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.
Published: 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.