Hydrogenated oil

Studies in people

• Concern

  Heart and blood sugar risk³

  In adults, hydrogenated oil and ruminant trans fats can raise heart and blood sugar risk factors, especially cholesterol.

• Concern

  Heart and blood vessel risk⁴

  In people, hydrogenated oil's trans fats raise the bad-to-good cholesterol ratio, a sign of heart risk.

• Concern

  Heart disease risk⁷

  Eating hydrogenated oil raises the bad cholesterol and lowers the good, which is linked to heart disease.

• Open question

  Trans fat intake⁸

  Hydrogenated oil is a source of trans fats, and how much people eat varies by country and diet.

• Concern

  Breast cancer risk⁹

  In women, eating more industrial trans fats was linked to a higher chance of breast cancer.

• Concern

  Heart attack risk¹⁰

  People who ate the most hydrogenated oil fats had more heart attacks than those who ate the least.

• Concern

  Long-term death risk¹¹

  In people, higher levels of elaidic acid from hydrogenated oil were linked to more deaths over time.

• Concern

  Colon cancer risk¹²

  In people, trans fats from partially hydrogenated fats were weakly linked to colon cancer in women, but not in men.

• Concern

  Heart and blood vessels¹³

  In studies, eating trans fatty acids from margarine may raise heart disease risk more than saturated fats.

How it’s made and used

• Dietary fat sources⁵

  In Slovenia, butter and meat were the main sources of trans fats, not hydrogenated oil.

• Trans fat intake in Canada⁶

  Most Canadians already ate less trans fat than the recommended limit, and hydrogenated oil was not the main source for young children.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.