January 2011

National Institutes of Health • Department of Health and Human Services • newsinhealth.nih.gov

Inside News: 3 Protein Shapes... 4 Dialysis and Kidney Patients... College Drinking... Dietary Supplements

Your Aging Eyes “You might find you’re holding your book farther away to read it. You How You See as Time Goes By might even start thinking your arms You may barely notice the changes just aren’t long enough,” says Dr. at first. Maybe you’ve found Emily Chew, a clinical researcher at yourself reaching more NIH’s . “A good often for your glasses to and simple treatment for presbyopia see up close. You might is reading glasses.” have trouble adjusting to Cloudy areas in the lens, called glaring lights or reading , are another common eye when the light is dim. You problem that comes with age. may even have put on blue More than 22 million Ameri- socks thinking they were cans have cataracts. By age black. These are some of 80, more than half of us the normal changes to will have had them. Some your eyes and vision as cataracts stay small and have you age. little effect on eyesight, but As more Americans others become large and head toward retirement interfere with vision. Symp- and beyond, scientists toms include blurriness, expect the number of people with of disability in older adults,” says Dr. difficulty seeing well at night, lights age-related eye problems to rise Cynthia Owsley, an eye researcher at that seem too bright and faded color dramatically. You can’t prevent all the University of Alabama at Birming- vision. There are no specific steps to age-related changes to your eyes. ham. Vision changes can make it dif- prevent cataracts, but tobacco use But you can take steps to protect ficult to perform everyday activities, and exposure to sunlight raise your your vision and reduce your risk for such as reading the mail, shopping, risk of developing them. sur- serious in the future. Ef- cooking, walking safely and driving. gery is a safe and common treatment fective treatments are now available “Losing your vision may not be life- that can restore good vision. for many disorders that may lead to threatening, but it certainly affects The passage of time can also blindness or . You your quality of life,” Owsley says. weaken the tiny muscles that con- can also learn how to make the most The clear, curved lens at the front trol your eye’s pupil size. The pupil of the vision you have. of your eye may be one of the first becomes smaller and less responsive “Vision impairment and blind- parts of your body to show signs of to changes in light. That’s why people ness are among the top 5 causes age. The lens bends to focus light in their 60s need 3 times more light and form images on the retina at for comfortable reading than those in the back of your eye. This flexibility their 20s. Smaller pupils make it more Definitions lets you see at different distances— difficult to see at night. up close or far away. But the lens Trouble seeing at night, coupled Retina hardens with age. The change may with a normal loss of peripheral Light-sensitive tissue at the back of begin as early as your 20s, but it continued on page 2 your eye that converts light into elec- can come so gradually it may take trical signals that travel to your brain. decades to notice. Eventually, age-related stiffening Pupil and clouding of the lens affects just @ The round, black-looking opening about everyone. You’ll have trouble Subscribe that lets light into your eye. It gets focusing on up-close objects, a con- smaller in bright light and larger in dition called presbyopia. Anyone over newsinhealth.nih.gov dim light. age 35 is at risk for presbyopia. 2 January 2011 http://newsinhealth.nih.gov/issue/Jan2011 continued from page 1 your visual processing speed—how vision as you age, can affect many quickly you can process visual infor- Web Links daily activities, including your ability mation and make decisions behind the wheel.” to drive safely. Loss of peripheral For more about eyes and aging, To find better ways to assess driver vision increases your risk for auto- see our links online: mobile accidents, so you need to be safety, Owsley and her colleagues more cautious when driving. are giving 2,000 older drivers differ- http://newsinhealth.nih.gov/issue/Jan2011/Feature1 “Keeping older adults active and ent types of vision screening tests, on the road as drivers, as long as including tests of visual processing in the center of your eyesight. “AMD they’re safely able to do so, is consid- speed. By tracking their driving re- is the leading cause of blindness in ered important to their health and cords for several years, the scientists Americans over age 65,” says Chew. psychological well-being,” says can figure out which tests were best A large NIH-supported clinical Owsley. But she notes that tests for at predicting safe or dangerous driv- study by Chew and others found that motor vehicle licenses tend to focus ing, including car crashes. These find- a specific combination of vitamins on visual acuity—how well you can ings might eventually lead to more and minerals can prevent AMD from read the letters on an eye chart. accurate screening tests to identify progressing to a more severe form. “Visual acuity tests may not be the potentially unsafe drivers. Scientists also found that people who best way to identify drivers at risk for If you’re not convinced you should eat diets rich in green, leafy vegeta- crashes,” she says. “Other issues are have regular eye exams, consider that bles—such as and spinach—or also important, like contrast sen- some of the more serious age-related fish are less likely to have advanced sitivity, your peripheral vision and eye diseases—like glaucoma, age- AMD. A larger study of 4,000 AMD related (AMD) patients is now testing to see if fish and diabetic eye disease—may have oil or a vitamin/mineral combination Wise Choices no warning signs or symptoms in might slow progress of the disease. Protect Your Vision their early stages. Diabetic eye disease, another lead- Glaucoma comes from increased ing cause of blindness, can damage n Have a comprehensive eye exam fluid pressure inside the eye that the tiny blood vessels inside the each year after age 50. damages the optic nerve. “Glaucoma retina. Keeping your blood sugar n Stop smoking. can slowly steal your peripheral vi- under control can help prevent or n Eat a diet rich in green, leafy sion. You may not notice it until it’s slow the problem. vegetables and fish. advanced,” says Chew. It can be treat- The only way to detect these seri- ed with prescription eye drops, lasers ous eye diseases before they cause n Exercise. or surgery. If not treated, however, it vision loss or blindness is through n Maintain normal blood pressure. can lead to vision loss and blindness. a comprehensive dilated eye exam. n Control if you have it. AMD causes gradual loss of vision Your eye care professional will put drops in your eyes to enlarge, or n Wear sunglasses and a brimmed dilate, the pupils and then look for hat any time you’re outside in Definitions signs of disease. “Having regular bright sunshine. comprehensive eye care gives your n Wear protective eyewear when Optic Nerve doctor a chance to identify a problem playing sports or doing work The largest sensory nerve of the eye. very early on and then treat it,” says around the house that may It carries signals for sight from the Owsley. Annual eye exams are espe- cause eye injury. retina to the brain. cially important if you have diabetes. “Many of the healthy behaviors that help reduce your risk for long- NIH News in Health (ISSN 1556-3898) term diseases, like heart disease National Institutes of Health Editor Harrison Wein, Ph.D. and cancer, can also help to protect Office of Communications Assistant Editor Vicki Contie your eyesight,” says Owsley. These & Public Liaison Contributors Emily Carlson, Vicki Contie, Alan Building 31, Room 5B64 include not smoking, eating a healthy Defibaugh (illustrations), Bryan Ewsichek (design) diet and controlling conditions like Bethesda, MD 20892-2094 and Harrison Wein [email protected] diabetes and high blood pressure. Tel: 301-435-7489 Fax: 301-496-0019 newsinhealth.nih.gov “It’s nice to know that healthy living not only adds years to your life, Attention Editors Reprint our articles and illustrations in your own publication. Our material For more health information from NIH, visit but also protects your vision as is not copyrighted. Please acknowledge NIH News you get older,” Owsley says. n in Health as the source and send us a copy. http://health.nih.gov http://newsinhealth.nih.gov/issue/Jan2011 January 2011 3 Biological Blueprints Protein Shapes Help Treat Disease How many proteins do you think you disease-causing viruses or bacteria. have in your body? The answer is in One structure-based success came in the billions. Proteins deliver oxy- 1989, when NIH-funded scientists dis- gen to your tissues, defend against covered the shape of HIV protease, a infection, digest food and even make protein that helps the AIDS virus get new proteins. These molecules are into our cells. The researchers showed uniquely designed to carry out their that the protein, like a butterfly, was tasks. If we can understand how pro- made up of two equal halves, and the tein shapes affect what they do, we site at the protein’s center was essen- might be able to understand what tial for infecting new cells. goes wrong in some diseases and Eventually, other researchers used develop better treatments. this knowledge to come up with a Proteins are made of long strings new class of drugs, called protease of amino acids. These basic build- inhibitors, that are now widely used ing blocks are chained together in a to block the action of HIV protease specific sequence dictated by that and stop the virus from infecting protein’s gene. In less than a sec- more cells. Protease inhibitors helped ond, the chain twists and buckles to revolutionize the treatment of HIV/ into a 3-dimensional structure. Each AIDS, transforming HIV infection from protein’s shape is unique. The shape a death sentence into a treatable lets the protein interact with other condition that people can live with molecules to trigger all the reactions for decades. that run our bodies. Unfortunately, HIV is a moving than 90% of known global HIV strains Shape is so important that just target. When it reproduces inside the from infecting human cells. This one amino acid change can alter a body, it can churn out slightly al- advance will hopefully let researchers protein’s entire structure—and its tered viruses with different protease design more effective HIV vaccines. performance. These switches can shapes. The inhibitor drugs might not Many other scientific problems will lead to life-threatening disorders work on these altered proteins. Some benefit from a better understand- like sickle cell disease, cystic fibrosis researchers are now developing new ing of protein shapes. NIH research- and Alzheimer’s disease. Knowing a generations of HIV protease inhibi- ers recently used discoveries about protein’s shape can help scientists tors that will combat these drug- the influenza (flu) virus structure design drugs that fix the flawed pro- resistant viral strains. to generate antibodies that attack tein or even block its activity. Scientists have also been using a wide array of influenza viruses in Protein structures can also help their structural knowledge of HIV mice, ferrets and monkeys. This ac- pinpoint the Achilles’ heels of to develop other approaches for complishment may point the way combating the virus. They recently to a universal flu vaccine. Trials are identified an unchanging region on already under way in humans to test Wise Choices the HIV surface and isolated human the approach. Help Fight AIDS antibodies that react with it. The In the future, research on protein antibodies were able to stop more structures could lead to new treat- Did you know you can help NIH ments for a variety of diseases and scientists fight AIDS by donating conditions that are more potent, unused time on your home Definitions more convenient to take and have computer? FightAIDS@Home fewer side effects. n provides free software that you Gene download and install. The software A stretch of DNA, a substance you uses your computer’s idle cycles inherit from your parents, that Web Links to help researchers discover new dictates the order in which amino drugs and build on our growing acids link together to form a protein. For more about research on protein knowledge of the structural biology of AIDS. To learn more, go Antibodies structure, see our links online: to http://fightaidsathome.scripps.edu. Germ-fighting molecules made by http://newsinhealth.nih.gov/issue/Jan2011/Feature2 the body. 4 January 2011 http://newsinhealth.nih.gov/issue/Jan2011

For links to more information, see these stories online: Health Capsules http://newsinhealth.nih.gov/issue/Jan2011/Capsule1 More Frequent Dialysis Helps Kidney Patients Kidney patients fare better on an The researchers randomly Featured Web Site almost-daily hemodialysis regimen assigned nearly 250 dialysis patients NIH Office of Dietary than on the standard 3-times-a-week to 2 groups. One group received Supplements plan, scientists report. Although more 6 treatments a week. The other research is needed, the finding could received 3 treatments each week. http://ods.od.nih.gov lead to changes in the standard of The scientists found that patients care for patients who need dialysis. receiving more frequent dialysis had Most adults in the U.S. take one or Nearly 400,000 Americans improvements in heart health and more dietary supplements. Learn how depend on dialysis to survive. These blood pressure, as well as in overall to choose and use these products treatments are needed when kidneys health. More frequent treatments wisely, and get reliable answers to fail and can no longer remove also helped avoid high blood levels common questions at this newly waste products from the body. In of phosphate, which are often a updated site. Download a free mobile the most common kind of dialysis, problem for patients on dialysis. A app for the iPhone or iPad to track the hemodialysis, your blood flows downside is that access to blood supplements you take. through a special filter that removes vessels needed to be modified wastes and extra fluids. The clean about twice as often in patients who blood is then returned to your body. received more treatments. Despite recent advances in The scientists couldn’t address technology and medication, up to whether more frequent treatments 1 in 5 patients on dialysis die each affected death rates. Still, this study year. NIH-funded scientists set out offers hope that simple changes to to test whether adding more dialysis current dialysis treatments could sessions could improve patients’ greatly improve the health of the survival and well-being. patients who need them. n

that students at the intervention Reducing College Drinking schools were much less likely to drink College students are less likely to get To test a community-based pro- to intoxication at off-campus parties, drunk when universities and sur- gram, NIH-funded scientists worked bars and restaurants. rounding communities work together with 14 public universities. Half the “Nearly as significant was that we to reduce drinking, a new study finds. schools used community-based alco- saw no concurrent increase in drink- Similar strategies may help reduce hol interventions for at least 2 years. ing at non-targeted settings such as drinking on campuses nationwide. The program included drunk-driving parks, beaches or residence halls,” Each year among U.S. college stu- checkpoints, better prevention of says lead researcher Dr. Robert Saltz dents, alcohol contributes to about alcohol sales to minors and stiffer of the Prevention Research Center in 1,800 deaths, 600,000 unintentional penalties to prevent parties that dis- Berkeley, California. “Some fear that injuries and 700,000 assaults. Many turb the peace. The other 7 schools more rigorous alcohol control mea- college efforts have tried to reduce were monitored for comparison. sures will merely drive college stu- drinking by targeting students on The researchers analyzed about dent drinking to other, presumably campus. But fewer studies have 20,000 online student surveys col- more dangerous, settings. But this looked at a broader approach. lected over 4 years. Results showed was not the case here.” n How to get NIH News in Health Read it online. Get it by email. Get it in print. Visit newsinhealth.nih.gov Click the “Subscribe” button on Contact us (see page 2) to get print our home page to sign up for copies free of charge by mail for display email updates when new issues in offices, libraries or clinics within the are posted online. U.S. You can also download PDF versions Subscribe suitable for printing at our web site.