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Feb 18

Another very simple brain hack for better memory and cognitive function is do what you can to keep low, safe blood sugar levels. Sure someday we might develop drugs to improve your cognitive ability, but you can do something right now to increase your brain ability and that is not to let your blood sugar levels get too high.

Previous research has indicated that diabetics are 1.5 more likely to experience a cognitive decline and dementia (Cukierman et. al., 2005). I don’t think any of you would want to develop dementia. Beyond the increase in dementia in people with diabetes there is also an increase in incidence of Alzheimer’s disease. So what should you do - exercise and eat well so you don’t develop type II diabetes. Lower your intake of carbohydrates, of the carbs you eat try to insure they are low glycemic. And yes volume counts. Instead of just thinking of glycemic index you should think of glycemic load, which is simply glycemic index x the number of grams of carbs for a particular food.

A new study examining 2,997 diabetics and looked at the relationship between blood glucose levels (A1C levels) and the performance of 4 cognitive tasks (Cukierman-Yaffe et. al., 2009).

A simple 1% increase in blood sugar levels was linked with lower scores in memory, multiple task management, global cognitive function, and psychomotor speed. Hence, you can see that there was a global decrease in mental ability in those with higher blood sugar levels. The researchers will subsequently examine if lowering blood sugar levels can improve the cognitive ability.

Take home message:

What else can I say to convince you that you must strive to keep your blood sugar levels in the healthy range. Some would even argue if you want to decrease you mental aging you should try for the low end of normal.


Do you even know your blood sugar levels? Or maybe you know one reading - but like blood pressure measurements there can be large difference depending on what you are doing, time of day, and for blood sugar levels obviously when and what you last ate.

One simple and fairly cheap solution to this is that you can buy a blood glucose meter from any drug store and they are realitively cheap (they make money selling the test strips). Go out and buy one and periodically test your blood sugar levels. The simplest measurement you should obtain is your overnight fasting level. This is the one you can best compare to the published and ‘normal range’ levels.

Background info - normal blood sugar values:

Despite widely variable intervals between meals or the occasional consumption of meals with a substantial carbohydrate load, human blood glucose levels normally remain within a remarkably narrow range. In most humans this varies from about 80 mg/dl to perhaps 110 mg/dl (3.9 to 6.0 mmol/litre) except shortly after eating when the blood glucose level rises temporarily (up to maybe 140 mg/dl or a bit more in non-diabetics).

There are many other times that you might find it useful to see what your blood sugar levels are - e.g. after various meals. You can develop your own individual glucose response to foods. Are you getting large spikes after eating X, etc? I will discuss more about this in another piece.

And you might want to consider lowering your carb intake, and of the carbs you eat pick low glycemic ones. You could try a Mediterranean based diet (which is already linked with improved cognitive ability), or any other diet that keep your blood glucose levels at a nice low healthy level.

Very simple daily healthy choices in food selection could go along way in keeping your blood sugar levels low and hence maintain your current cognitive ability - what could be more important than keeping your brain functioning normally.

2 Responses

  1. brad Says:

    Naaa, sugar tastes so good Ward…

    I’ll get a meter and do a full week or more of sugar levels, because I need more brain power so I can learn two new programming languages this week!

  2. Ward Says:


    yes it will be interesting to find out your blood sugar levels. I am not advocating starving yourself to get super low blood sugar levels - just eat health whole food with low glycemic index so your blood sugar levels don’t get too high. The high levels won’t warm your cognitive function that day (unless you suffer a sugar crash) but the long term consequences are not good. Usually the easy ‘now’ reward you end up paying a very high long term cost.

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