Fruit is Bad for You (at Least it is for me)

Those of you who know me are aware of my love for data, and the fact that I collect all kinds of health indicators in a search for patterns.  Over the last year, I was shocked by the rise in my A1C levels, which is an indicator of pre-diabetes.  I was also aware of an occasional blood glucose level above 100 mg/dL, which is also associated with the onset of diabetes.  But, my blood glucose levels were not high enough to warrant A1C levels of about 5.7.  So I did what anyone of you would do, and that is to measure my daily blood glucose levels, giving better statistics than a weekly reading.

Indeed, I saw multiple weekly readings above 100 mg/dL with a high of 110 mg/dL.  Then I noticed in a particular week that not one reading was over 100 mg/dL.  The advantage of my highly structured diet is that it was simple to identify the change, and that was that my wife could not find fresh blueberries that week.  We kept a fresh bowel on the kitchen counter, and I would grab a fistful after a meal or as I was lured to them as I passed buy.  Being my favorite fruit, this my sole source of fructose, aside from a special low-sucrose and high-fat/protein chocolate that I make.  (Not to mention the occasional chocolate chip cookie that I have with my grandson when we visit Starbucks and the exquisite pretzels my sister-in-law ships in creative gift boxes every Christmas.)  Blueberries were the only source of regular fructose that I had been eating for the last couple years.

So, I remained off of blueberries for two months to get a decent amount of statistics, and was blown away by the results, shown in the plot.  First, this plot shows the importance of averaging.  There are large fluctuations in the test and in blood glucose levels that depend on all sorts of factors.  The blue open circles show the results while I was eating blueberries and the red solid circles during the time I stopped eating them.  The lines show a least squares fit to the data in the two regions.  The conclusion is that my blood glucose is a full 10 mg/dL lower when I'm not eating blueberries.  The beauty of averaging lots of data points is that the uncertainty can be determined from the scatter, and corresponds to about 1 mg/dL.  So one can argue whether the difference with and without blueberries is 10 mg/dL or 9 mg/dL, but the difference is both large and statistically significant.

I plan on continuing the zero fructose diet for another month or so, followed by another A1C test, which provides a blood glucose value averaged over three months.  This will allow the averages of both tests to be compared.

I will write more on this topic later when I have more time, but the conclusions are:

1. There is no such thing as a universally healthy diet.

2. There is no such thing as a healthy diet that is customized for a particular person.

Rather, our health is a struggle against internal and external forces, which adapts to evolutionary forces imperfectly.  The best we can do is chose a balance that makes each of us relatively healthy, and then we must accept the negative consequences.  In my case, a super-low-carb diet keeps me fit and trim, provides lots of energy and stamina, and has eliminated pesky annoyances such as heartburn and regular migraine headaches.  On the downside, my diet makes me prone to kidney stones.  These can be mitigated with simple meds, which are benign compared to treatments for diabetes and migraine headaches.  And physical stamina is more important to me than pleasing my sugar-craving reward center.

May your New Year be a happy one, optimized for adequate health and pleasures within reasonable constraints.