# Comparisons of the Effects of Low‐ or High‐Fat Diets Rich in Soybean Oil, Lard, and Tea Seed Oil on Markers of Blood–Brain Barrier and Neuroinflammation in Ovariectomized Mice

## TL;DR

This study compares how different high-fat diets affect the blood-brain barrier and brain inflammation in mice that have had their ovaries removed.

## Contribution

The study reveals that tea seed oil may have better effects on brain health markers compared to soybean oil and lard in high-fat diets.

## Key findings

- Tea seed oil reduced markers of brain inflammation and improved blood-brain barrier function in mice.
- High-fat diets with tea seed oil increased brain-derived neurotrophic factor levels compared to other oils.
- Dietary fat type significantly influenced brain health markers under high-fat conditions but not in normal diets.

## Abstract

High‐fat diets (HFDs) may affect the blood–brain barrier (BBB) function and cause neuroinflammation. Different dietary oils may influence BBB and neuroinflammatory responses due to their unique fatty acid compositions. To elucidate the potential effects of different dietary oils, this study compared the effects of tea seed oil with those of soybean oil and lard on markers of BBB and neuroinflammation. Six‐week‐old ovariectomized mice were fed a normal or HFD for 12 weeks. The mice′s brain lipid profiles, brain‐derived neurotrophic factor (BDNF), BBB function–related markers (i.e., S100 calcium‐binding protein β [S100β], matrix metalloproteinase‐9 [MMP‐9], zonula occludens‐1, and glial fibrillary acidic protein [GFAP]), and inflammation marker levels were evaluated. When mice were fed diets containing large amounts of fat (i.e., HFDs), different types of fat seemed to elicit different effects on these measures. However, different dietary fats had no different effects on the measurements during normal diet intervention. The mice fed the tea seed oil–based HFD exhibited upregulated levels of BDNF and downregulated levels of GFAP, S100β, MMP‐9, and proinflammatory cytokines compared to those fed the soybean oil– and lard‐based HFDs. While HFDs might impact BBB function and neuroinflammation, the type of dietary fat consumed might play a significant role, suggesting that tea seed oil might have beneficial effects on BBB markers and neuroinflammation compared to soybean oil and lard in ovariectomized mice under HFD conditions. However, further studies are warranted to determine the effects of these HFDs on cellular composition within the brains of these ovariectomized mice.