In this solo presentation, Dr. David Perlmutter discusses a 2018 Neurology study of 1,212 non‑diabetic Swedish women followed for 34 years, which found a U‑shaped association between fasting insulin levels measured in 1968 and later dementia risk. Women with the lowest insulin levels had a 2.34‑fold higher risk of dementia, while those with the highest levels had a 28 % increased risk compared with mid‑range insulin values. Dr. Perlmutter uses this finding to illustrate the broader “Goldilocks” or U‑shaped pattern seen with many health variables—alcohol, sleep, blood glucose, exercise, cortisol—emphasizing that both too little and too much can be harmful. He stresses the importance of contextualizing laboratory targets and lifestyle recommendations to the individual’s genetics, sex, and overall health, advocating for personalized medicine over blanket “lower‑is‑better” or “higher‑is‑better” rules.
Chapters
Hello everyone, Dr. David Perlmutter here. You know, there's a tendency, I think, in all of us, certainly speaking for myself, to adopt the notion that if some is good, more is better. And if having a low level of something is good, then even a lower level is better. And the reality is that's not necessarily true. We have Understanding that there's a sweet spot, there's an ideal place where things need to be in terms of being the most helpful recommendations that we can make. And a very interesting article recently appeared that I'd like to take a look at right now. A very interesting report recently appeared entitled Low Fasting Insulin, or low fasting serum insulin measured in the blood. And dementia in non-diabetic women followed for 34 years. And this was published in the journal Neurology in July of 2018. And what this study did was really quite interesting. They checked the fasting insulin and glucose levels from 1,212 non-diabetic, non-demented women living in Sweden between their ages of 38 to 68. years of age, and they— this occurred in 1968, and then in the year 2000, these individuals were reevaluated. Now, the findings of this study were actually quite profound, that the highest risk for dementia actually occurred in those individuals who originally had the lowest level of insulin, and in fact Those with the lowest level of insulin had about a 2.34 times increased risk of developing dementia in comparison to those in the middle values of insulin levels. As expected, those having the higher levels, the highest levels of insulin, had about a 28% increased risk, again, as you might expect. And this defines what we call a U-shaped curve where there's a sweet spot, and that's an unfortunate pun as it relates to sugar and insulin, but nonetheless, where too low of a value is associated with increased risk and a higher value is also associated with increased risk. We call this a classic U-shaped curve, and it relates to dementia risk. You could also call it perhaps the Goldilocks curve where As you'll recall, one bed was too hard, one was too soft, but one was just right. And the porridge as well, one was too hot, one was too cold, but the sweet spot, the best choice was right in the middle. And I would indicate to you that we see this classic U-shaped curve describing risk for dementia associated with quite a few other things like alcohol consumption. Sleep. We've just talked about insulin. Certainly having too low of a blood sugar is associated with risk. The amount of exercise we get as well, and even cortisol. You know, we talk about the stress hormone cortisol as universally being a bad thing for the brain, but in reality, at low levels, cortisol is actually— allows for memories to be consolidated. So we need to have— Not none, not too much, but just that right amount. And I also want to state that we always have to look at these recommendations and ask ourselves, what is their context? In other words, who is the person that we're talking about when we talk about the right values of the various things that we're recommending? So again, the context of the recommendations that are made, I think, are very important. That levels of certain blood parameters, for example, blood sugar, hemoglobin A1c, even fasting insulin, should be looked at in the context of the individual. How much exercise would be appropriate for that person? Do males and females have different requirements in terms of their laboratory values? And taking it to where we are today, that's really what personalized medicine is all about. Rather than making blanket recommendations that are important for everyone and that everyone should follow, getting their laboratories into the so-called normal range, more importantly, I think it's very critical to look at the individual and ask yourself based upon that person's genetics and very subtle changes or alterations or nuances of that person's genes, what are the recommendations that are specific for him or her. So very interesting to really embrace this notion of the U-shaped curve. Thanks for joining me. I'm Dr. David Perlmutter. Bye for now.
