Cooking garlic and onions at high heat can form trans fats, study finds

Medical Xpress / Meijo University / Food Research International ^ | Dec. 27, 2024 | Junji Obi et al

[ConservativeMind]

Trans-fatty acids (TFA) are a major cause of cardiovascular diseases. These harmful fats can accumulate along artery walls, restricting blood flow and increasing the risk of heart attacks.

Studies indicate that unsaturated fatty acids (UFAs) can undergo trans-isomerization, a molecular reconfiguration that transforms them into TFAs when heated at 150°C or higher.

This raises the question of whether these sulfur compounds also promote the trans-isomerization of UFAs in everyday cooking. Understanding the impact of natural sulfur compounds on the cooking process can help regulate TFA intake, particularly for those who avoid processed foods.

The researchers first evaluated the effects of sulfur compounds on triacylglycerols (TAGs) in a model system using reagents. Then, tests were conducted using ingredients (garlic, onion, leek, cabbage, horseradish, and broccoli sprouts) and vegetable oils (soybean and olive oils) to simulate actual cooking processes.

The study revealed that sulfur compounds significantly promote heat-induced trans-isomerization of UFAs in vegetable oils, especially when cooking temperatures are above 140°C.

The addition of antioxidants significantly reduced the promotion of UFA's isomerization by isothiocyanates, whereas they did little to inhibit the promotion of isomerization by polysulfides.

This explains that cooking polysulfide-rich vegetables such as garlic and onions in vegetable oil at high temperatures can generate TFAs. In fact, this study demonstrates that garlic and onions significantly promote the trans-isomerization of UFAs.

Under normal cooking conditions, the corresponding increase in the trans isomer ratio is expected to be minimal, at most, a few percent.

"Release of TFAs under normal cooking conditions is expected to be minimal. Therefore, excessive caution is unnecessary," concludes Dr. Honda, the corresponding author of this paper. "However, it is important to understand that cooking with ingredients rich in natural sulfur compounds may increase the risk of TFA intake."

[Adder]

I don’t think its the onions and garlic, per se. Its the high temperature cooking of them.

No need for that anyway...I always use evoo and never hit its smoke point. Dishes turn out fine.

[Erik Latranyi]

The point is that we have had these “scientific” studies tell us that eggs, red meat and butter are bad for you only to discover that that was wrong.

I don’t trust them any longer and use my own judgement and utilize raw ingredients while avoiding anything processed.

[Vermont Lt]

My Italian Mother is Law was all about teaching our kids how to cook garlic and onions (and shallots too!)

Her handwritten recipe for her sauce indicates “Don’t burn the garlic” a couple times. LOL

[If You Want It Fixed - Fix It]

Legal killing of your infant and legal marijuana still OK.

Wshew. Priorities intact.

[Bloody Sam Roberts]

Unless I’m deep frying (which is never) it’s EVOO all the way.

[Sirius Lee]

Cooking garlic and onions at high heat can form trans fats, study finds

Don't care.

Without sautéed garlic and onions you might as well already be dead. It's a flavor to savor. You'd be surprised at how many dishes I add crumbled bacon to as well.

[PUGACHEV]

Forty years ago, who could cook the best meals I’ve ever had. On one occasion, she used the simplest of ingredients, red pepper, garlic, olive oil, and fettuccini. The result was amazing! I would watch her closely but could never come close to duplicating what she did, even though I was cooking on the same stove and using the same things from my shelf that she did. After many years, and many failed attempts, I have come to the understanding that it was all about time and temperature: she had a sharp intuition in that area. Just a few degrees too hot or cold, a few seconds too long or too less in the pan makes the difference between an epicure’s delight and junk.

[PUGACHEV]

S/B Forty years ago I had an Italina girlfriend ...

[telescope115]

Once a year, fight before Christmas, my wife and I make Sicilian sausage bread.
It requires cooked onions and Italian sausage as the filling. As much as we make it , I’m not gonna worry about it.🙂👨‍🍳

[Nifster]

Precisely

[Sacajaweau]

I found peeled Garlic in a jar...from Turkey...I have been freezing peeled garlic in a bag in the vegie section. I think these little 7 oz jars will work better. Roland in brine.