Article in Diabetes Forecast about Hypoglycemia and how it affects the brain


Going low the complications of hypoglycemia. How the brain responds to low blood glucose


Could you summarize what it says and give us a link? I think many would be interested.


Sorry Brian, I thought I had attached the link.

Summary -

5 Facts to Know About Going Low
1.Blood glucose is considered low when it’s at 70 mg/dl or below.
2.Alcohol can cause hypoglycemia soon after drinking and for up to 24 hours after that. If you’re drinking alcohol, it’s important to do frequent blood glucose checks.
3.Exercise can cause blood glucose to drop immediately—and for up to 24 hours post-workout.
4.If your medications put you at risk for hypoglycemia, test before driving. If you’re running low, be sure to treat before getting behind the wheel.
5.Skipping or delaying meals can be a trigger for lows. Carry fast-acting sources of glucose just in case.

The article also has some interesting first hand accounts of people describing their hypos.


I think I know most of how it affects MY brain! I’ve been low so many thouands of time that it is literally impossible for me to quantify it accurate. I’ve been below 50 at least 7,000 times. It used to freak me out, but not anymore. I know I can deal with it on my own–no need to call out for help from family or coworkers, etc. when I have too many lows in a short span I THINK that it contributes to some short term memory loss that doesn’t clear up for months, but I can’t prove that is the cause. Now that I’ve been on Lyrica for about 2 years, STML is more pronounced and consistent. I’m no doc so I don’t know LITERALLY what it does to the brain–I’m just giving my account of the only result that I seem to receive from too many lows. It may well be doing other things, but I can’t worry about stuff I don’t have complete control over.


that isn’t a list of how it effects the brain. that’s a list of tips and don’ts.


Curious, has anyone lost their “mind’s eye”? Mine is only there as a flash…I can’t hold onto an image in my mind. And I’m still working on visualizing driving routes prior to getting in the car.


Do you mean while low, or since you have had lows since becoming diabetic?


I thought it was an excellent article, much more serious than most of Diabetes Forecast’s articles. It does go into some details about why the brain is affected by low BG.

The latest edition also had an interesting article on current research on encapsulating beta cells for transplantation.


Thanks for the link. It’s informative to read about others’ experience with hypos. I’ve found that my low threshold is 65 mg/dl. That’s when my body start to produce symptoms and counter-regulatory events start.

While most of the body can use a range of fuels to generate energy, breaking down fat or muscle when the food supply is low, our gray matter is picky. “The brain is fundamentally dependent on a continuous supply of glucose,” says McNay. “The brain is unique in that respect—other tissues can use alternative fuel, like fatty acids. The brain can’t do that. It needs that specific sugar.”

It’s my understanding that the brain can also run quite nicely on ketones in the absence of glucose. I only mention this because there is a myth in the diabetes professional ranks that says a person needs a minimum of 130 grams of carbohydrates per day to meet the needs of the brain. This is not true. Many people can maintain extended fasts without suffering brain-shut down. I like to fast for 24 hours once per week and if my basal rates are calibrated well, I don’t go low. In fact, it’s often reported by people when fasting that they feel an elevated sense of brain clarity. The body can also produce some glucose from protein, when needed.

This is an important topic. I appreciate the link.


When I have less than 50g carbs for more than 2 or 3 days in a row - AND when I’m fasting even for one day - I feel a sense of lethargy and listlessness. I start to make a lot of judgement errors and errors in my work, etc. So, I think it’s another one of those YDMV topics.


But doesn’t the brain require time to “convert” to running on ketones? And while converting, doesn’t the brain require some level of glucose to carry on?


@Thas and @YogaO - I believe that there’s an adjustment period when starting to eat a reduced carb diet. I remember that the Adkins’ followers referred to this period as the “Adkins flu.” I think this adjustment period only lasted a week or two. I remember being surprised that this adjustment period substantially reduced the allure of carbs while feeling satisfied and full for many hours between meals.


It makes sense that the brain needs glucose to bridge to the time when it can use ketones. I think that in the absence of sufficient carbohydrates the body can easily convert proteins via gluconeogenesis.


My understanding is that brain can run on ketones fine. The real problem is what is called Neuroglycopenia. If you have a bad hypo because of excess insulin that will suppress the generation of alternate fuels that can be used in place of circulating glucose. The liver which does both ketogenesis (generation of ketones) and gluconeogenesis (generation of glucose) essentially slows/stops those processes when it sees insulin.


back in 2010, I tried a week where I didn’t eat > 50G of carbs and ran > 30 miles (in the week, LOL…) for the first time ever and was fine so I agree that you don’t “need” that many carbs and I also find it easier to keep my BG flat when I do that. I think the hazard of cutting out carbs is getting enough calories as it can be quite challenging to make up 1800 or 2000 calories/ day with a low carb diet. When I did T25, I tried aiming for 50/30/20, or at least 40/40/20 (protein/carb/fat…) and was able to do it but really, the days when I’d hit 50, I was having a couple of protein shakes, multiple hunks of chicken and maybe tossing in a can of tuna to boot. It seems like many folks pursuing low carb simply cut out the carb without upping the other elements to cover the calories we may need to fuel activities.