Almonds and markers of oxidative stress in eight trials in adults
What it found
Eating more than 60 grams of almonds a day lowered several markers of cell damage and raised one protective enzyme in adults.
Smaller daily amounts did not show these changes.
What they found
Studies in people
Cell damage marker MDA
Across all doses, almonds made no clear difference to MDA, a marker of fat damage in cells. But when people ate more than 60 grams a day, MDA levels dropped compared to the control group.
DNA damage marker 8-OHdG
People who ate almonds had lower levels of 8-OHdG, a sign of DNA damage from oxidation. This drop was seen across the studies that measured it.
Uric acid levels
Almond eating led to lower uric acid levels in the blood compared to the control groups.
Protective enzyme SOD
Levels of SOD, an enzyme that helps defend cells, rose in people who ate almonds overall. When the authors split the data by dose, neither the smaller nor larger amounts alone showed a clear rise.
Protective enzyme GPx
Almonds did not change levels of GPx, another enzyme that protects cells from damage.
What the authors conclude
- They say eating more than 60 grams of almonds a day lowers markers of cell and DNA damage while raising one protective enzyme in adults.
- They suggest almonds could be used as part of a diet to manage oxidation in the body.
- They call for future trials to use the same almond form, dose, and length so results are easier to compare.
How it was done
An imbalance between damaging oxygen molecules and the body's defenses can harm cells and is linked to long-term illnesses. Almonds contain vitamin E, plant compounds, and healthy fats that might help protect cells, but scientists wanted to see what all the trial data showed together.
The authors gathered eight trials involving 424 adults, including healthy people, smokers, and those with heart or cholesterol conditions. Participants ate between 5 and 168 grams of almonds daily for four to 24 weeks. The researchers combined the results to look at blood markers of cell damage and antioxidant defense.
What it can’t tell you
- These trials lasted up to 24 weeks, so they cannot show what happens over years of eating almonds.
- The studies tested different forms like raw nuts, roasted nuts, powder, and oil, making it hard to know which type works best.
- Because the trials mixed healthy people with those who have long-term illnesses, the results might not apply equally to everyone.
Who paid
- Conflicts
- Declarations. Competing interests: The authors declare no competing interests.
- Authors work at
- Tehran University of Medical Sciences, Iran; Islamic Azad University, Iran; Tabriz University of Medical Sciences, Iran
The paper
- Title
- The impact of almond supplementation on oxidative stress biomarkers: a systematic review and meta-analysis of randomized control trials
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Kolahi A, Movahed S, Tejareh F, Saeedy SAG, Gholizadeh M (2025). The impact of almond supplementation on oxidative stress biomarkers: a systematic review and meta-analysis of randomized control trials. Scientific reports. doi:10.1038/s41598-025-14701-wFree full textPubMed 40804320DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error