Canola oil compared with olive oil for heart and cancer risk
What it found
Short-term studies in people found canola oil improved some blood fat markers, but there is no long-term evidence it matches extra-virgin olive oil for heart or cancer protection.
Canola oil also breaks down more easily than olive oil when heated for frying.
What they found
Studies in people
Heart risk markers
In short-term feeding trials in people, canola oil lowered total cholesterol and LDL cholesterol about as well as olive oil. One trial of eighteen people over three weeks found lower LDL cholesterol after eating canola oil. There are no long-term studies in people showing canola oil prevents heart attacks or strokes like olive oil does.
Cancer links
Studies tracking people over time gave mixed results for alpha-linolenic acid, the main fat in canola oil linked to benefits. One study in older men found higher intake raised the risk of advanced prostate cancer. In China, breathing fumes from unrefined rapeseed oil used for cooking was linked to cancer in people.
Brain health
People in long-term studies who ate more olive oil showed less memory decline. The authors found no studies testing whether canola oil affects memory or brain ageing in people.
Animal and lab studies
Frying and toxic fumes
Canola oil contains a fat called alpha-linolenic acid that breaks down quickly when heated. In lab tests at 180 degrees, canola oil produced about five times more acrolein fumes than olive oil. Acrolein irritates the eyes, skin and airways, though the authors say normal home frying with fresh canola oil has not been shown to pose a breathing risk.
Other findings
How the oils are made
Extra-virgin olive oil is pressed at low temperatures without chemicals, keeping many natural plant compounds. Standard canola oil needs solvents, bleaching and deodorising to extract it from rapeseeds. This heavy processing removes most of the natural antioxidants originally in the seeds.
What the authors conclude
- They conclude that current evidence does not support using canola oil as an equal swap for extra-virgin olive oil in a Mediterranean-style diet.
- They note that standard canola oil loses many natural plant compounds during production and breaks down more easily when heated.
- They suggest that new methods to improve canola oil, such as adding olive plant extracts, might create a better product in the future.
How it was done
Olive trees only grow in Mediterranean climates, so countries without them looked for a cheaper local cooking oil. The authors wanted to see if canola oil could replace olive oil in a Mediterranean-style diet.
The authors gathered and compared published lab, animal and human studies on rapeseed oil (called canola oil in some countries) and olive oil. They looked at how each oil is made, what happens during cooking, and links to heart disease, cancer and brain health up to April 2014.
What it can’t tell you
- This work gathers past studies rather than running a new trial, so it cannot prove that one oil causes better health than the other.
- Most canola oil research measured short-term changes in blood markers instead of tracking actual heart attacks or cancers over many years.
- Lab tests heating oils in controlled settings may not match exactly what happens in a home kitchen.
Who paid
- Authors work at
- University of Hertfordshire, UK; Cancer Institute, France
The paper
- Title
- Can rapeseed oil replace olive oil as part of a Mediterranean-style diet?
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Hoffman R, Gerber M (2014). Can rapeseed oil replace olive oil as part of a Mediterranean-style diet?. The British journal of nutrition. doi:10.1017/S0007114514002888Free full textPubMed 25322908DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error