Nutrition scientists take a look at cataract prevention

August 09, 2005

Age-related cataract, the world's leading cause of blindness, affects more than 20 million Americans over the age of 40 years. Surgical correction is currently the only known option for intervention, but researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University recently sought, in three different studies, to determine if prevention is possible. Their findings suggest that vitamins and polyunsaturated fatty acids--two categories of nutrients believed to have health benefits--may both affect cataract development, although not necessarily in beneficial ways.

In one study, lead scientist Paul Jacques, DSc, director of the Nutritional Epidemiology Program at the Center, and his colleagues analyzed the diets and examined the eyes of a group of Boston-area women over the course of five years. Among the study participants, who were all members of the larger Nurses' Health Study, women who reported supplementing their diets with vitamin E (a powerful antioxidant) for 10 years or more had significantly less progression of cataract development at the five-year follow-up exam. A similar relative decrease in cataract progression was seen in women who reported higher intakes of two of the B vitamins, riboflavin and thiamin, when compared to women with lower intakes.

"Our results," says Jacques, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts, "suggest that vitamin supplementation, particularly long-term use of vitamin E, may slow down cataract development." These results build upon some of Jacques' earlier work. In 2001, while examining the same group of Nurses' Health Study members, Jacques and his colleagues found support for a similar role for vitamin C in the prevention of cataracts.

"On the other hand," says Jacques, "the results were not so clear when we looked at dietary fat." In the same population of women, Jacques and his colleagues found that high dietary intake of either or both an omega-6 polyunsaturated fatty acid (PUFA) found in sunflower, safflower, corn, and soybean oils, and an omega-3 PUFA found in canola, flaxseed, and soybean oils, may increase the risk of developing cataracts in one of the three lens locations examined. The results of this study, which were published in the American Journal of Clinical Nutrition, are not consistent, however, with findings of other studies on the relationship between PUFAs and cataracts. In a study that was recently published in the American Journal of Epidemiology, Jacques and colleagues observed that higher overall fat intake increased the risk of cataract development or progression, while omega-3 fatty acids, in particular the types found in dark-fleshed fish, appeared to contribute to the prevention of cataract formation.

"The results of these studies provide added support for a relationship between nutrient intake and cataracts," says Jacques. However, since there is inconsistency among studies of fat intake and cataracts, he cautions that more research is needed. Jacques adds, "finding ways to delay age-related cataract formation through diet, or even through supplementation, would enhance the quality of life for many older people, but many questions regarding the role of diet in cataract prevention remain unanswered."
-end-
Jacques PF, Taylor A, Moeller S, Hankinson SE, Rogers G, Tung W, Ludovico J, Willett WC, Chylack LT. Archives of Ophthalmology. April 2005; 123:517-526. "Long-term Nutrient Intake and 5-Year Change in Nuclear Lens Opacities."

Lu M, Taylor A, Chylack LT, Rogers G, Hankinson SE, Willett WC, Jacques PF. American Journal of Clinical Nutrition. April 2005; 81:773-779. "Dietary Fat Intake and Early Age-related Lens Opacities."

Lu M, Cho E, Taylor A, Hankinson SE, Willett WC, Jacques PF. American Journal of Epidemiology. May 15, 2005; 161(10):948-59. "Prospective study of dietary fat and risk of cataract extraction among US women."

Tufts University

Related Vitamin Articles from Brightsurf:

Vitamin C's effectiveness against COVID may hinge on vitamin's natural transporter levels
High doses of vitamin C under study for treating COVID-19 may benefit some populations, but investigators exploring its potential in aging say key factors in effectiveness include levels of the natural transporter needed to get the vitamin inside cells.

Vitamin B6, leukemia's deadly addiction
Researchers from CSHL and Memorial Sloan Kettering Cancer Center have discovered how Acute Myeloid Leukemia is addicted to vitamin B6.

Fatty foods necessary for vitamin E absorption, but not right away
A fresh look at how to best determine dietary guidelines for vitamin E has produced a surprising new finding: Though the vitamin is fat soluble, you don't have to consume fat along with it for the body to absorb it.

Vitamin D: How much is too much of a good thing?
A three-year study by researchers at the Cumming School of Medicine's McCaig Institute for Bone and Joint Health published in the Journal of the American Medical Association (JAMA), showed there is no benefit in taking high doses of vitamin D.

10 million new cases of vitamin D deficiency will be prevented by adding vitamin D to wheat flour
Adding vitamin D to wheat flour would prevent 10 million new cases of vitamin D deficiency in England and Wales over the next 90 years, say researchers at the University of Birmingham.

Muscling in on the role of vitamin D
A recent study conducted at the Westmead Institute for Medical Research has shed light on the role of vitamin D in muscle cells.

Vitamin D may not help your heart
While previous research has suggested a link between low levels of vitamin D in the blood and an increased risk of cardiovascular disease, a new Michigan State University study has found that taking vitamin D supplements did not reduce that risk.

Does sunscreen compromise vitamin D levels?
Sunscreen can reduce the sun's adverse effects, but there are concerns that it might inhibit the body's production of vitamin D.

How obesity affects vitamin D metabolism
A new Journal of Bone and Mineral Research study confirms that vitamin D supplementation is less effective in the presence of obesity, and it uncovers a biological mechanism to explain this observation.

Why vitamin E effect is often a matter of luck until now
Vitamin E's positive effects often fail to manifest themselves as strongly as expected, but sometimes administering vitamin E actually has detrimental effects.

Read More: Vitamin News and Vitamin Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.