Over the past year, I’ve offered myself up as guinea pig to a variety of clinical tests. I have a keen interest in neuroscience in general and Alzheimer’s disease in particular, so most of my inquiries have been brain-related. I have taken the online tests at mindcrowd.org, joined the Brain Health Registry, and evaluated my authentic happiness.   I spent two mornings at the Brandeis Memory and Cognition and Research Lab punching keys to record my facility at replicating lists of words and numbers with speed or accuracy – sometimes both. I scored as a satisfactory human being, except when it came to pattern manipulation. Then my spatial skills rocked me off the chart; a guy who’s been an architect for over thirty years is graphically dexterous. Each of these endeavors were considered baseline activities, helping research groups develop databases of normal functioning from which they can investigate the cool stuff: abnormalities.

My primary source for finding clinical trials is Alzheimer’s Association Trialmatch. I get a list of potential trials every few months and am on a first name basis with Katie, who follows my process of query and rejection as study after study determines me an unfit candidate.

My first rejection was a VA study of physical fitness and cognitive brain function. Who better, I wondered, than an exercise maniac whose brain runs on overdrive? However, I was disqualified in the phone interview round for being color-blind. People say there are actual numbers in those damnable computer circles with red and green dots. I swear they are all the same color.

Then I was rejected from Prospective Evaluation of the Sensitivity and Specificity of Cognitive Tasks for Diagnosis of the Cerebellar Cognitive and Affective Disorder at MGH for being left-handed. That felt like medieval prejudice.

Last month I got excited about Neuroimaging Study of Exercise and Memory Function because it included a regular exercise regimen. But they wanted couch potatoes, so my daily routine tossed me out of contention.

I chose not to pursue a study that required taking injections of an experimental drug. It seemed unwise for a person predisposed to avoiding drugs to start ingesting a substance burdened by a list of potential side effects that spilled onto a second page.

But then I found the egg study: The Effect of Daily Consumption of Eggs on Cognitive Function in the Elderly. I could eat two eggs a day (or four ounces of egg substitute if I wound up in the control group) for six months in the name of science. I filled out the application, passed my phone interview, and headed off to the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University for my intake interview.

I didn’t understand any of the science in the abstract, but the study logistics were plausible. There was an initial on-site interview and test, then a follow-up clinical exam to verify suitability. During the study I would visit the center every month to get eggs, and have a series of tests performed when the study commenced, and again after three and six months.

The Tufts Nutrition Center is in a tower designed by my former firm, SBRA, during that period when we really didn’t like cities. The 1970’s concrete behemoth has an insignificant entrance and casts deep shadows over Washington and Stuart Streets near Chinatown. I remembered models and plans from the office, so anticipated the bright, airy three-story atrium that defines the upper floors. But anyone else would be confounded by the difference between the mean-spirited lobby and the sunny clinical areas.

I filled out paperwork, got shuttled from nurse to nurse, and eventually met Elizabeth Johnson, who took me into a small room off the atrium and administered a macular pigment density study. Turns out Elizabeth is the principal investigator, and took time to explain the study’s objectives to me.

Carotenoids are plant pigment found in yellow/orange fruits and vegetables. The more carotenoids we consume, the more we have in our bodies. But these plant pigments also contribute to other aspects of our health, and may contribute to increased cognition. Lutein, a carotenoid common to green leafy vegetables as well as egg yolk, is of particular interest. According to Dr. Johnson, it’s difficult to design a study that can directly measure neural lutein levels and the relationship with cognition.

Fortunately, brain lutein levels are positively correlated to lutein levels in our retina, and we can do simple, quick, non-invasive tests to determine our lutein levels in the retina.

In broad terms, the study plans to measure baseline lutein status and cognition for two subject groups. One group will eat more eggs, whose yolks are high in lutein, while the control group will eat similar amounts of egg whites only. After six months, if the hypothesis proves true, cognition will improve among egg eaters relative to egg white eaters. Improved cognition implies decreased propensity for Alzheimer’s. The scientific path is not always a straight line between two points. In this case measuring lutein levels is a round about way of exploring whether there is a neurological benefit of eating eggs. Never mind that cholesterol business.

Dr. Johnson adjusts instrument controls while I stare through a lens in a small box at a fuzzy, blue dot that comes into ever-sharper focus. It’s much like any ophthalmologist’s exam. She tells me the good news – my macular pigment (lutein in the macular area of the retina) is 0.7 on a scale from 0 to 1.0, very high for a person my age. (I have reached that stage in life where every commentary on my physical being is qualified by an age reference.) Unfortunately, Dr. Johnson explains, the bad news is that my eyes are too good to be part of the study. They are looking for people over age 50 in the 0.3 range. “We simply can’t expect to find any measureable change in your lutein levels when starting from such a high baseline.”

My guinea pig cravings have been thwarted once again; first, too much exercise, then color-blindness, left-handedness, and now high lutein levels. I’ll keep looking for a study that wants me. After all, I’m only getting older and eventually my body will deteriorate to a level suitable for research.

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Special thanks to Dr. Elizabeth Johnson, who reviewed and edited my science or this article.