Safflower oil and fish oil effects on blood fats in ten women
What it found
In ten young women, eating safflower oil for five days raised linoleic acid levels in the blood.
Eating fish oil instead raised EPA and DHA levels.
What they found
Studies in people
Linoleic acid rose
Women who ate the safflower oil diet had more linoleic acid in their blood after five days. Women who ate the fish diet had less linoleic acid in their blood.
EPA and DHA rose
Blood levels of two fats called EPA and DHA went up in the group eating the fish diet. These levels did not rise in the group eating safflower oil.
Fat ratios shifted
The ratio of n-6 to n-3 fats was lower in the blood of women eating the fish diet compared to those eating safflower oil. The ratio of EPA to arachidonic acid was higher in the fish diet group.
Other findings
Daily fat amounts
Total daily fat intake was 54.4 g for the fish diet and 56.2 g for the safflower oil diet. Fat coming specifically from fish was 16 g per day, while fat from safflower oil was 23 g per day.
What the authors conclude
- They conclude that the fish diet enriched blood fats in the n-3 family, especially EPA, even over just five days.
- They note this happened despite the small amount of these fats eaten in a typical Japanese diet.
How it was done
Humans cannot make certain fats called polyunsaturated fatty acids and must get them from food. The authors wanted to see how two common fat sources in Japanese meals change the fats found in blood.
Ten female students aged 21 to 22 were split into two groups of five. One group ate meals made with fish oil and the other ate meals made with safflower oil for five days. Blood samples were taken before the diet started, on day three, and on day five.
What it can’t tell you
- Only ten young women took part, so the results may not apply to men, older adults, or children.
- Five days is very short, so it cannot show what happens when people eat these oils for months or years.
Who paid
- Authors work at
- University of Ilorin, Nigeria
The paper
- Title
- Effect of fish oil and safflower oil in common Japanese diet on human plasma fatty acid composition
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Ogunleiye AJ, Muraoka A, Niizeki S, et al (1990). Effect of fish oil and safflower oil in common Japanese diet on human plasma fatty acid composition. Journal of nutritional science and vitaminology. doi:10.3177/jnsv.36.4-supplementi_423Free full textPubMed 2150530DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error