In March 2019, researchers in China published a study in The Journal of Prevention of Alzheimer’s Disease, showing a connection between diet and cognitive function.
What were they looking for?
The researchers searched through 4 journal databases, looking for any studies that had investigated connections between cognition and dietary fat intake. For cognition, they specifically focused on 4 conditions:
- Mild cognitive impairment
- Alzheimer’s disease
- Cognitive impairment
Regarding dietary fat intake, they targeted studies that measured fat consumption or the percentage of energy from fat consumption.
As a result, they found 9 studies, with a combined participant total of over 23,000.
What did they find?
What the researchers discovered was that participants who consumed the most saturated fat also had an increased risk of cognitive impairment and Alzheimer’s. Unsaturated fat intake, on the other hand, didn’t seem at all connected to cognition, no matter the level.
So, what is saturated fat?
Well, to get a bit technical for just a moment, fats are made of long chains of carbon atoms, all linked together. Some carbon atoms are linked by just one bond, and others are linked by two. Double bonds can react with hydrogen to form single bonds; when they do, one of their bonds splits and each half connects to (or saturates with) the hydrogen atom.
Saturated fat occurs naturally in all kinds of foods, both animal-based and plant-based. Take olive oil, for example, generally regarded as a healthy oil:
In the above chart, we see that about 14% of the fat content of olive oil is saturated fat. Its unsaturated fat content is, of course, is much larger, at just under 86%.
Now, let’s compare it to butter:
Where we saw that saturated fat made up a small percentage of the fat content of olive oil, here we see that it makes up a large proportion of butter fat, roughly 2/3, in fact.
Generally speaking, most animal-based fats contain large proportions of saturated fat. Unsaturated fats are, for the most part, associated with plant-based foods. As we mentioned, however, most foods contain a combination of saturated and unsaturated fats. Even so, some vegetable oils—such as coconut oil and palm kernel oil—are primarily saturated.
One characteristic of saturated fat that separates it from unsaturated fat is that it has a higher melting point, which is why foods such as butter and coconut oil keep their solid-like state, even when left out at room temperature.
This is one more study in a growing body of research showing a connection between what we eat and our mental health. Here at Truehope, we’ve been promoting nutrition as mental health treatment for over 20 years.