It’s no secret that a diet high in fat can cause trouble to the body, but new research has discovered that the brain can also get caught up in the mess.
One of the ways the brain keeps prime performance is through the work of the immune cells. They bustle around the brain like scavengers, getting rid of damaged cells or infectious agents in the brain.
These immune cells are important for healthy brain function, but when a diet is so high in fat as to cause obesity, they stop bustling and start eating the connections between neurons.
Too much fat in the body seems to cause chronic inflammation, which triggers these immune cells to have an autoimmune response. They stop mopping up toxins and instead turn on their own healthy brain cells. The fallout from this includes a reduced capacity to learn as efficiently.
According to researcher and neuroscientist Dr Alexis M. Stranahan, immune cells ‘eating synapses is contributing to synapse loss and cognitive impairment in obesity.’
It’s a scary prospect, but the damage is completely reversible. Changing to a low-fat diet for two months can reverse the damage completely and restore healthy cognitive function.
The research was conducted using two groups of male mice. (Mice are commonly used in research for their biological and genetic similarity to humans.) One group ate a diet that was 10% fat, the other group ate a diet that was 60% fat. The human version of these diets would be along the lines of a healthy diet versus a fast-food diet.
After eight weeks, the mice on the high-fat diet were fatter – no surprises there – but they were similar to the mice in the low-fat group in terms of brain changes and other physiological measures.
At 12 weeks, the differences between the groups started to show themselves. The high fat mice were obese and there was evidence of reduced brain function.
At this point, half the mice in the high fat group were then placed on the low-fat diet. After about two months, their weight returned to normal, but they had a larger fat pad than their peers, making them a little more vulnerable to weight gain in the future.
The mice that remained on the high fat diet continued to get fatter, and the scavenger cells and neurons in their brain continued to wither.
As explained by Stranahan, ‘Instead of doing garbage disposal, they are taking your mailbox, your front door, your kitchen sink and all the stuff that you need, and not doing their job of getting rid of trash.’
This research is compelling and is further evidence of the way the body and mind are deeply connected. The health of the body will ultimately affect the health of the mind. Obesity is stealing people from the lives they deserve to be living and from the people who love them. What we now know is that it is also stealing the capacity for people to learn and grow and reach their fullest potential. That affects all of us.
Food is meant to be fun, and it’s important to remember that the effect of fat on the brain uncovered by this research didn’t start to emerge until the point of obesity. In the same way that any unhealthy relationship – with people, work, exercise , anything – will cause problems, an unhealthy relationship will food will also bring us undone. The good news it that this is completely reversible. It’s not often we have the problem and the easy solution in one easy package. Thanks science.
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Love this site! The articles are articulate and explained very clearly. Very relevant to the reality of parenthood, especially when we all have our own baggage from our own upbringing.
These articles serves as a kind reminder to be mindful. Thank you.
And I love that you love it. Thank you!
This goes against everything that I am reading that fat is actually incredibly beneficial for the brain. Of course not all fats are created equal and there are definitely good fats like fish oil, and pasture butter, and coconut oil and bad fats such as the unstable fats industrialized seed oils and hydrogenated oils (that we were told were healthy). See Dr. David Perlmutter ‘s book Brain Maker.
Some fats are really healthy and essential for brain health, in particular the fats found in oily fish like salmon, walnuts and the other foods you refer to. You’ll see from the article that the study is referring to fat of the type and quantity that leads to obesity.
Could you put a copy or link to the Research article for further reading. I would like a clearer understanding of the diet that was used.
Sure. The words ‘The research’ in blue are hyperlinked to the original article. It’s at the beginning of the 7th paragraph.
I have spoken about this to all my “college” students. I found out that for them, the taste is ” stronger” than “quality and nutrition” in food. So they go for the “taste.”
Disappointing, especially when people are intelligent but still make decisions based on their “emotions” rather than wisdom.
Yes, absolutely. The problem is that the things that are being added to our food for taste are all sorts of unhealthy, and we probably don’t know the extent of what they can do. If this is what excessive fat does to the brain, we can only wonder what other things are doing. I expect we’ll see some interesting research on this.
How does high sugar affect the brain?
Although many foods are “low fat”, they are LOADED with either high fructose sugar or artificial sweeteners.
Sugar causes weight gain too, but is it a different type of fat from that of “high” fat foods? Is the affect on the brain the same using sweeteners the same?
You’re absolutely right. Our food is loaded with so many things other than fat that cause weight gain. This research specifically looked at the effect of high fat on the brain, so the results are specific to that. It’s early days and there will no doubt be more research to come. I expect that future lines of research will explore the effects of other things, such as sugar, on the brain. It will be really interesting to see what we learn from this.
Even though I don’t have a comment I would like to see what others say.