Why fried oil might raise blood pressure
The role of repeatedly heated soybean oil in the development of hypertension in rats: association with vascular inflammation
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Fresh soybean oil had no effect on blood pressure — but reheating it just 5 times was enough to start causing harm.
Many assume only burnt or charred oil is dangerous — but this shows even moderate reuse (like a restaurant frying potatoes 5 times) triggers measurable vascular damage.
Practical Takeaways
Never reuse frying oil more than 3 times at home — and never use oil that looks dark, smells rancid, or smokes at low heat.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Fresh soybean oil had no effect on blood pressure — but reheating it just 5 times was enough to start causing harm.
Many assume only burnt or charred oil is dangerous — but this shows even moderate reuse (like a restaurant frying potatoes 5 times) triggers measurable vascular damage.
Practical Takeaways
Never reuse frying oil more than 3 times at home — and never use oil that looks dark, smells rancid, or smokes at low heat.
Publication
Journal
International Journal of Experimental Pathology
Year
2012
Authors
Chun-Yi Ng, Y. Kamisah, O. Faizah, K. Jaarin
Related Content
Claims (6)
If you keep heating soybean oil over and over and feed it to male rats for a long time, their blood pressure goes up by a third — but if you feed them fresh oil, their blood pressure stays normal. This suggests that overheated cooking oil might be bad for blood pressure in animals.
If you heat soybean oil over and over and feed it to male rats, their blood vessels may tighten up more than they should, which could raise their blood pressure.
If you feed male rats the same cooking oil over and over again after heating it multiple times, their main artery walls get thicker and stiffer, which might lead to high blood pressure.
Heating soybean oil over and over again might cause blood vessel damage in rats, making their blood vessels more inflamed and possibly leading to high blood pressure.
If you keep heating soybean oil over and over and feed it to male rats for a long time, their blood vessels start making more of a protein called LOX-1, which is linked to inflammation and artery problems — this might lead to high blood pressure.