Safflower seed extract and heart risk markers in twenty men
What it found
Four weeks of safflower seed extract lowered several blood and urine markers linked to oxidation and inflammation in healthy men.
Arterial stiffness dropped in about half the group.
What they found
Studies in people
Oxidation markers fell
After four weeks, levels of oxidized LDL in the blood and a marker called 8-isoprostane in urine were lower than at the start. These drops were seen in most of the twenty men.
Inflammation markers dropped
A blood protein called sVCAM-1, which is linked to inflammation, fell after four weeks and returned to its starting level once the men stopped taking the extract.
Artery stiffness in some
Overall, there was no clear change in artery stiffness or blood pressure across the whole group. However, eleven of the twenty men did show lower artery stiffness, along with lower blood pressure.
Serotonin levels rose
Whole-blood serotonin went up during the four weeks of supplementation and stayed slightly above the starting level even after the break. No other similar brain chemicals changed.
Blood fats unchanged
Total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and blood sugar stayed about the same throughout the trial.
Who benefited most
Men who started with higher levels of oxidation markers, inflammation markers, or stiffer arteries tended to see bigger improvements after taking the extract.
What the authors conclude
- They suggest that safflower seed extract has the potential to protect people from oxidative damage and inflammatory reactions.
- They note that older men, or those with higher blood pressure or stiffer arteries, may gain more from taking it.
- They call for longer, placebo-controlled trials with more participants to confirm whether the extract truly lowers cardiovascular risk.
How it was done
Earlier work by these authors showed that safflower seed extract protected mouse arteries and slowed damage in lab tests. They wanted to see if the same extract could lower signs of oxidative stress and artery stiffness in people.
Twenty healthy Japanese men, average age 37, took 2.1 g of safflower seed extract in capsules every day for four weeks. Researchers measured their blood pressure, artery stiffness, and various blood and urine markers before, during, and after a four-week break from the supplement.
What it can’t tell you
- This trial had no placebo group, so some changes might reflect normal variation over time rather than the extract itself.
- Only twenty men took part, all employees of the company that funded the work, so the results may not apply to women or the wider public.
- The study lasted just four weeks, so it cannot show what happens with long-term use.
Who paid
- Authors work at
- Research Institute for Health Fundamentals, Japan
The paper
- Title
- Effects of safflower seed extract supplementation on oxidation and cardiovascular risk markers in healthy human volunteers
- Type
- Clinical trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Koyama N, Suzuki K, Furukawa Y, et al (2009). Effects of safflower seed extract supplementation on oxidation and cardiovascular risk markers in healthy human volunteers. The British journal of nutrition. doi:10.1017/S0007114508025786Free full textPubMed 18590590DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error