Glaucoma is an insidious disease—literally happening before your very eyes undetected, having virtually no symptoms until, in a blink, you’ve got eye surgery on your plate and you may even be going blind. You may think that, nowadays, glaucoma is easily treatable, but one form of glaucoma, pseudoexfoliation glaucoma (called “PEX” or sometimes just exfoliation glaucoma) is much harder to fix than others. Research from Harvard Medical School, though, is showing that the more folate you get each day, the less likely PEX will develop.


PEX is caused by pressurized buildup of debris that clogs the eye’s ability to drain, and it can lead to cataract formation, destruction of the optic nerve and blindness. PEX can happen because it’s in your genes or because your eyes have been exposed to too much of the sun’s ultraviolet (UV) light. People who live in some northern parts of the world, such as Scandinavia (possibly because of genes) and higher altitudes (where the thin air encourages more UV-radiation exposure) are also more at risk for this eye disease. People with PEX also have high levels of an amino acid called homocysteine in their blood, tears and eye fluid. Because B vitamins can help keep homocysteine levels in check, some researchers thought that getting enough B vitamins was the key, but the team from Harvard Medical School discovered that it’s not quite that simple—it appears that you must get a certain B vitamin in a certain specific way.


To get a clearer picture, the Harvard researchers analyzed information from about 120,000 people from two very large, long-term health study databases, the Nurses’ Health Study and the Health Professionals Follow-up Study, with a specific focus on people who were 40 years old or older, were free of glaucoma at the start of the study, had had eye exams within a certain two-year period and had provided information about their dietary habits. They discovered that people who ultimately got PEX were deficient in one particular B vitamin, folate. They also found that, although the amount of folate gotten only from food had little impact on prevention of PEX, getting enough from a supplement made a big difference.


People with the highest intake of folate—at least 335 micrograms (mcg) per day for women and 434 mcg for men—from vitamin supplements had an 83% reduced risk of PEX compared with people who did not take such supplements. The good news is that any high-quality B complex vitamin supplement, which will generally contain 400 mcg of folate, together with a diet rich in green leafy vegetables, fortified whole grains, beans and peas and especially beef liver (if you have a taste for it) will supply you with enough folate to protect you from PEX. You can even find folate supplements that contain 800 mcg or more, but be aware that the daily tolerable upper limit of supplemental folate for adults, according to the Institute of Medicine, is 1,000 mcg. Also, be aware that folate supplements can interfere with the anticancer effectiveness of the drug methotrexate. Speak with your doctor if you take that drug. Folate supplements also aren’t well absorbed in people taking antiepileptic drugs or sulfasalazine (Azulfidine, used to treat ulcerative colitis), so guidance about folate supplement dosage, in these instances, also should be discussed with a doctor.

We’re increasingly being told by medical experts to ditch vitamin supplements and get our nutrients from whole foods. Although I think this is generally sound advice over pill-popping, even if those pills are vitamins, I also think it’s important to pay heed to studies like this one that show that a supplement is exactly what’s needed to stave off a serious condition. And sight-robbing glaucoma is serious enough in anyone’s book!