A naturally occurring lipid in the body, cholesterol plays a vital role in providing structural support in cell membranes and making vitamin D. Cholesterol can also be obtained from certain foods. However, people are often warned to stay away from high-cholesterol foods such as bacon, fries, and eggs because too much cholesterol can have adverse effects on your body.
Past studies have identified that patients suffering from Generalized Anxiety Disorder (GAD), Obsessive-compulsive Disorder (OCD), and Post-traumatic Stress Disorder (PTSD) show elevated levels of cholesterol. Whether cholesterol is being overproduced in the liver, or if these individuals are consuming too many fatty foods, has yet to be studied until now. As seen in the September 2014 edition of Behavioral and Brain Functions, Xu Hu from the Institute of Psychology and the Chinese Academy of Sciences in Beijing investigated the effects of a high-cholesterol diet in mice. Hu found that while high-cholesterol diets affected behavior across the board, it also showed vastly different effects in young versus old mice.
Eating Fatty Foods for Eight Weeks
Hu examined 40 rats: 20 aged three weeks and 20 aged 20 weeks. Once the rats were collected, Hu allowed the rats to adapt to the lab and their new environment for one week. During this adaptive period, the rats ate a normal diet of 32 percent protein, 5 percent fat, 2 percent fiber, 1.2 percent phosphorus, and no nitrogen. For the next eight weeks, half of the subjects ate a high-cholesterol diet composed of 2 percent cholesterol, 10 percent lard, 0.3 percent sodium cholate, and 87 percent normal diet. The participant pool was broken up into four smaller comparison groups based on age and diet:
- 10 young rats fed a normal diet
- 10 young rats fed a high-cholesterol diet
- 10 old rats fed a normal diet
- 10 old rats fed a high-cholesterol diet
After each feeding period, anxiety-like behaviors were tested in an elevated plus maze, a common anxiety test for rodents. The apparatus looks like a three-dimensional plus sign with two closed arms and two open arms. The open arms do not have safety walls and put the rodent at risk of falling off of the maze. Each mouse was placed in the center of the maze, facing an open arm. The mice had five minutes to explore the maze. Time spent in the open and closed portions of the maze were recorded.
Older Mice Get Anxious When Eating High-Cholesterol Foods
Hu found that high-cholesterol diets had different effects based on the age of the rat. In comparison to the young control group, the young rats on the high-cholesterol diet spent more time in the open arms. Contrary to the young rats, the old rats on the high-cholesterol diet spent more time in the closed arms than the old control group. “These results suggested that the high-cholesterol diet group displayed anxiolytic-like behavior in young rats and displayed anxiety-like behavior in adult rats comparing to their respective control group that fed the regular diet," deduced Hu. Future studies will need to use human models to determine if high-cholesterol diets can reduce anxiety in the youth and induce anxiety in adults.
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Xu Hu, Tao Wang, Jia Luo, Shan Liang, Wei Li, Xiaoli Wu, Feng Jin, Li Wang. Age-dependent effect of high cholesterol diets on anxiety-like behavior in elevated plus maze test in rats. Behavioral and Brain Functions, 1 September 2014; DOI: 10.1186/1744-9081-10-30
Date of original publication: October 01, 2014
Updated: October 23, 2015