One use of hydrogenated oil is to preserve the shelf life of food. Products that contain hydrogenated oils are often highly processed with added sugar and salt.

Hydrogenated oil comes in two forms: partially or fully hydrogenated.

In 2015, the Food and Drug Administration (FDA) said that partially hydrogenated oil is not safe, and removing it from food could prevent thousands of heart attacks each year.

The following article discusses what hydrogenated oil is, the types, why artificial trans fat is bad, and why food manufacturers use hydrogenated oil in foods.

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Hydrogenated oil is a type of fat that food manufacturers use to keep foods fresher for longer.

Hydrogenation is a process in which manufacturers add hydrogen to a liquid fat, such as vegetable oil, to turn it into a solid fat at room temperature.

There are two types of hydrogenated oil: partially hydrogenated and fully hydrogenated.

Partially hydrogenated oil (trans fat)

In the past, manufacturers added partially hydrogenated oils to processed foods.

According to the World Health Organization (WHO), foods that may contain large amounts of artificial trans fat include:

  • most baked goods, including crackers, pies, and biscuits
  • margarine
  • vegetable shortening
  • fried foods
  • baked or fried restaurant foods

In 2015, the FDA declared that trans fat is not “generally recognized as safe” and manufacturers had to phase it out as an additive by 2020.

However, trans fat may still be present in some foods. According to the American Heart Association (AHA), trans fat occurs naturally in certain animals, such as cows.

Fully hydrogenated oil

Fully hydrogenated oil also uses a process to take a liquid oil and transform it into a solid at room temperature. As the name suggests, the oil is fully or nearly completely hydrogenated, which reduces the amount of trans fat in the final product.

Unlike partially hydrogenated oil, the FDA still allows products to use fully hydrogenated oil.

For example, the Code of Federal Regulations accepts using the minimum amount of fully hydrogenated rapeseed oil to meet the intended purpose, such as a stabilizer or thickener.

Though hydrogenated oils may be safe, they are not necessarily good for consumption. Products containing them are often highly processed with added sugar and salt.

People may benefit from avoiding foods with hydrogenated oils and opting for fresh fruits, vegetables, whole grains, and lean proteins instead.

Food manufacturers use hydrogenated oil as a preservative. They also use it to enhance flavor and texture.

According to the AHA, food manufacturers add hydrogenated oils to foods for several reasons, including:

  • cutting costs
  • preserving foods
  • enhancing texture
  • enhancing taste

Instead of using trans fat or partially hydrogenated oils, manufacturers may combine different oils to enhance taste and texture.

Hydrogenated oil, particularly partially hydrogenated oil, has several potential side effects that can negatively affect a person’s health.

According to the FDA, trans fat can raise a person’s low-density lipoprotein (LDL) cholesterol, also known as “bad cholesterol.”

Higher LDL cholesterol levels increase the risk of heart disease, which is a leading cause of death in the United States.

The AHA adds that trans fat can also reduce levels of high-density lipoprotein (HDL) cholesterol, known as “good cholesterol.”

The increase in LDL cholesterol and decrease in HDL cholesterol can raise the risk of a person developing stroke and type 2 diabetes.

Other health issues that trans fats may contribute to include:

As manufacturers no longer use partially hydrogenated oil and trans fat in their processes, they have switched to using a combination of oils, including fully hydrogenated oil.

Foods that may contain higher levels of hydrogenated oils include:

  • canned frostings
  • baked goods
  • margarine sticks
  • coffee creamers
  • snack foods

Some of these foods may still contain a small amount of trans fat as a result of the manufacturing process.

The WHO recommends that adults limit trans fat consumption to less than 1% of their total calorie intake. For a 2,000-calorie diet, this would mean a limit of 2.2 grams daily.

To achieve this, people may need to limit or replace foods containing hydrogenated oils.

People can try to include the following foods:

  • whole grains
  • non-tropical vegetable oils
  • unsweetened dairy
  • variety of fruits and vegetables
  • skinless poultry
  • fish
  • legumes

People may benefit from avoiding the following:

  • sugar-sweetened beverages
  • foods with added sodium
  • foods high in saturated fat
  • foods containing some trans fat

In other words, a person may benefit from avoiding or limiting highly processed food, such as fast food, baked goods, and other foods high in saturated fat, hydrogenated oils, salt, and sugar.

Many processed foods contain hydrogenated oil to increase shelf life and enhance flavor.

There are two types of hydrogenated oil: partially and fully hydrogenated. Partially hydrogenated oil contains trans fat, and manufacturers can no longer add it to foods in the United States.

Manufacturers can still use fully hydrogenated oils in their manufacturing processes. However, foods containing these oils are still not a healthy option, so people may benefit from avoiding or limiting them.

The easiest way to cut out hydrogenated oil is to avoid processed foods. Instead, people can make whole foods, including vegetables, fruits, nuts, lean protein, and unsweetened dairy, part of their regular diet.