DEAR DR. BLONZ: I have been researching the subject of glaucoma and hoping to find nutritional approaches to preventing it. I have not been able to locate much in the way of reliable scientific information. A colleague suggested that you might be able to help. -- G.B., Sacramento, California
DEAR G.B.: Glaucoma results when there is damage to the optic nerve, which carries visual information from the eye. This disease can develop without warning and can lead to progressive and permanent damage, including loss of some aspects of vision. Glaucoma is one of the leading causes of blindness, with an estimated 3 million Americans being affected.
As intimidating as this sounds, however, glaucoma can be diagnosed in a routine eye examination and, if caught early, treatment can help slow or prevent vision loss. Routine, professional eye exams should be considered an essential part of health care.
Regarding nutritional approaches to prevention, I am unaware of any "take this and you won't get glaucoma" studies. However, research does suggest that healthful eating, with a complement of antioxidant nutrients, may be of help. The oft-recommended plant-based, whole foods diet fits, as it provides the benefits of naturally occurring phytochemicals, nutrients and antioxidants.
It would also be prudent to have your recommended intake of the mineral magnesium. The logic here is that inadequate dietary magnesium is associated with vasospasm: a spasm of the muscular coat that surrounds blood vessels. Increased vasospasm is involved in several health conditions, including glaucoma; this effect is likely due to vasospasm being associated with impaired autoregulation of blood flow to the optic nerve.
In addition to increased intraocular pressure, which is often measured during an eye exam, risk factors associated with glaucoma include high blood pressure, diabetes, cardiovascular disease and sickle cell anemia. For more information, including areas of research and progress, check with the Glaucoma Foundation (glaucomafoundation.org) or the Glaucoma Research Foundation (glaucoma.org).
DEAR DR. BLONZ: I enjoy reading your articles each week. They are informative and helpful. At the end of a previous article entitled "Coffee and Your Bone Health," you said, "It's also important to avoid any habitual excess of dietary protein." What is considered "excess" when it comes to dietary protein? -- L.V., Walnut Creek, California
DEAR L.V.: Thanks for those kind words; my regrets for having neglected that bit of information.
For most people, the requirement is about 0.8 grams of protein per kilogram of body weight. (One kilogram is roughly 2.2 pounds.) That equates to about 20 grams of protein for every 55 pounds of body weight. Athletes might need more -- perhaps 1.2 to 2 grams per kilogram, spaced throughout the day, depending on their activity level and type of training.
Most research indicates that eating more than 2 grams of protein per kilogram of body weight daily, for a long time, can cause health problems.
Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to email@example.com. Due to the volume of mail, personal replies cannot be provided.