Lately, I have been seeing a lot of theorizing about the role that saturated fats might be able to play in your brain health. There are two versions of this overall theory: one being that you are more mentally sharp in the moments that you’re ingesting saturated fats - which is hard to prove and easy to speculate - and the long term effects of saturated fats on brain health. The latter is more of what I want to focus on for our discussion today.
The Types of Evidence
I really want to root this whole conversation we are having today in the role of evidence. Evidence plays a huge role in the decisions we make, especially when it comes to our health. It convinces us to do one thing over another, it convinces us to stop doing something and it can convince us to start doing something new altogether.
Let me put it this way. If you were trying to travel to visit a couple friends in another state, let’s say you ask each of them what is the best way to get there. One friend might look at a map on their phone and tell you the route that is fastest based on the map, and your other friend might tell you that they drive that route every day and it takes twice as long to get to the destination.
Who do you listen to? Do you listen to the person who has an idea of what might work, or do you listen to the person who has actually experienced it? I think you would go with the latter, because that experience is real, lived evidence of what you should be doing.
Bottom Line: All evidence is not created equal. When we think about the choices we want to make for our body, we need to go with results that are tested and proven, time and time again.
Short Term Versus Long Term
This is one of those critical things that sometimes people have a hard time grasping. Sometimes, we get caught up in this idea that if something makes us feel better in the moment, that it must make us feel better in the long term. This is dangerous thinking, because sometimes those actions can have definite health consequences.
Bottom Line: Intuitions and judgments in the moment are not something that we should be relying on when it comes to our health. We need good, evidence-based data that can tell us what we should be doing. We only get one shot to grow old the right way, and we need to know that the choices we make are good for us now and in the long run.
Saturated Fats & Your Brain
This whole idea of saturated fats being good for brain health is based on a pretty simple idea. People have noticed that your saturated fats help your brain, so they make the direct connection that more must be good for you. It sounds simple enough, and it sounds like it would work, but does it?
I want to go through what I have seen people talking about when they talk about saturated fats, and the evidence that they have been using - and whether or not it is right or wrong. I want to dive into the science, so that you can get a better idea of the role saturated fats can play in your body’s overall health.
Brain Aging and Saturated Fats
One of the many things I have noticed about the discussions surrounding saturated fats is the role it can play in offsetting brain aging (and its adverse effects). Today, I want to peel back the layers on some of the literature I have seen. I want to show you what people are saying, talk to you about whether or not it is true, so that you can make the best choices for your body.
Sound good? Well, let’s get started!
In an article called “How Eating Fat Can Make You Smarter,” I read that “saturated fat is actually one of the main components of brain cells, and is therefore necessary for healthy brain function. In one study, it was found that people who ate more saturated fat reduced their risk for developing dementia by 36 percent” (1). In order to make their claim, the author cited the study associated with the “36 percent” claim about reduced risk for developing dementia. I actually read this report. Oddly enough, they never used the number “36” anywhere in the study. In fact, the only time the word “saturated” was used was right here:
“The . . . NIH . . . recently commissioned an independent . . . report that included a comprehensive systematic review of the evidence related to risk factors for AD and cognitive decline. . . . The factors with the most consistent evidence included diabetes mellitus, current smoking, depression, cognitive inactivity, physical inactivity, and poor diet (high saturated fat/low vegetable intake)” (2).
So, not only did the report cited not say that saturated fat could cut your risk for developing dementia by 36%, but they actually said that saturated fat intake was one of the documented risk factors for causing dementia.
Saturated Fats In Your Diet
Another paper that I recently read argued that your brain needs saturated fat to function, period. It argued that you need it to keep your brain cells insulated. This article also referred to an actual study. Here’s what this paper had to say: “Brain cholesterol is synthesized in situ by astrocytes and oligodendrocytes and is almost completely isolated from other pools of cholesterol in the body . . . The major apolipoprotein constituent of HDL in the CNS is apolipoprotein E, which is produced by astrocytes and microglia. Apolipoprotein A-I, the major protein component of plasma HDL, is not synthesized in the CNS” (4).
That sounds like a lot of sciency language, so what does it mean? It means that your brain does need cholesterol and saturated fat, but it actually makes it when it needs it. Roughly 7% of your circulating cholesterol actually comes from your diet.
Key Insight: Your brain is not dependent on your diet for cholesterol. Your brain makes its own cholesterol, as needed, and that cholesterol is made from different constituents than the cholesterol in your bloodstream.
The fact of the matter is that your brain does not run out of cholesterol or saturated fat the minute you stop eating it. It makes it when it needs it, and it does not need to get it from your diet.
Saturated Fats and Risk Reduction
Yet another author cited another study and suggested that it prove saturated fat helped the brain. They said that “individuals eating more of the ‘dreaded’ fat actually have a substantial risk reduction” (5). So, what did the researchers themselves say? They did not say that saturated fat caused a reduction of risk. In fact, they said there was no trend suggesting that saturated fat reduced risk (6).
Last, but not least, I have even read endorsements that say “over half of your diet should be made up of saturated fat” (7).
The Science Behind Saturated Fat
The most comprehensive clinical review to date, which specifically looked at types of dietary fat and the rates of dementia found that “several lines of evidence support for the hypothesis that high saturated or trans fatty acids increase the risk of dementia. Of all the different types of fatty acids, the findings are most consistent for an increased risk of cognitive decline with a higher intake of saturated fatty acids” (8).
Key Insight: Doesn’t this sound different than everything I mentioned before? All of those articles, without evidence, were suggesting that saturated fat intake is beneficial - and maybe even necessary - for brain health. Yet, here we are, and the largest clinical review suggests the exact opposite.
There were also four large studies that looked at the relationship between saturated fat and Alzheimer’s disease. Another four looked at how it might affect mild cognitive impairment (MCI) and four looked at its effects on cognitive decline (9).
Bottom Line: None of these credible and proven studies suggest any protective role for saturated fats and brain function. In fact, the vast majority of these studies showed that saturated fats worsen Alzheimer’s disease, MCI and cognitive decline.
Another one of the largest studies done on saturated fats showed that “when compared with carbohydrates, every 5% increase of total calories from saturated fat was associated with an 8% higher risk of overall mortality from causes like Alzheimer’s disease, cardiovascular disease and cancer” (10).
Your Body and Saturated Fats
It’s true that many parts of your body do use saturated fat and cholesterol. However, these are not essential fats. In the body’s natural state, it can make as much of these fats as it needs - whenever it needs them!
This does not mean that they are harmless, though. A common thread among all societies found to have higher rates of longevity and lower rates of chronic disease is that they have diets low in total fat and low in saturated fat.
Bottom Line: Saturated fats are not a health food, and there is no credible evidence suggesting that they will protect your brain from aging or will it help it work better.
Protect Your Body, Love Your Body
I felt very much compelled to directly counter these points, because the vast majority of available evidence says the exact opposite. I do not believe in miscommunicating, and in misinterpreting evidence. It gives people the wrong idea, and it takes your health out of your hands. The fact of the matter is that the more saturated fats you consume, the greater your risk is for early death and brain impairment.
Please, do what is right for your health and always look into the science or your dietary choices. I always advocate for learning more about your body, which is why I stress the importance of taking the thyroid quiz today (11). Learn more about your body, and start feeling your best today.
Dr. Alan Glen Christianson (Dr. C) is a Naturopathic Endocrinologist and the author of The NY Times bestselling Adrenal Reset Diet.
Dr. C’s gift for figuring out what really works has helped hundreds of thousands of people reverse thyroid disease, lose weight, cure diabetes, and regain energy. Learn more about the surprising story that started his quest.