Association Of Elevated Blood Pressure And Impaired Vasorelaxation In Experimental Sprague Dawley Rats Fed With Heated Vegetable Oil

Researchers wanted to understand how cooking with reused vegetable oil might affect blood pressure and heart health. They studied 42 male rats over six months, feeding different groups either fresh soybean oil or oil that had been heated multiple times (1, 2, 5, or 10 times). They measured blood pressure monthly and tested how well the rats' blood vessels functioned.

The results showed that rats eating repeatedly heated oil developed significantly higher blood pressure compared to those eating fresh oil or regular food. The more times the oil was heated, the worse the effects became. The researchers also found that heated oil consumption changed important chemicals in the blood that control blood pressure - it increased levels of a hormone that raises blood pressure while decreasing nitric oxide, a substance that helps blood vessels relax and stay healthy.

When they examined the rats' blood vessels directly, those fed heated oil showed impaired ability to relax and contract properly. This suggests that repeatedly heated cooking oils may damage the delicate lining of blood vessels, making them less flexible and contributing to higher blood pressure.

For people interested in metabolic health and longevity, this study highlights the importance of cooking oil quality. While this research was done in rats, it suggests that repeatedly using the same oil for frying or high-heat cooking might contribute to cardiovascular problems over time. In clinical practice, this supports recommendations to use fresh oils for cooking and avoid reusing cooking oil multiple times, especially for patients managing blood pressure or cardiovascular risk factors.