Flaxseed vs Chia Seeds
Flaxseed (Linum usitatissimum) and chia (Salvia hispanica) compared: what meta-analyses of trials found for each, why results cannot be lined up, and safety points.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Short answer: flaxseed and chia are both seeds studied in trials, but the meta-analyses looked at different outcomes, and we found no study that compared them head to head. Proper evidence not found for a direct comparison: we searched PubMed for flaxseed and chia together and read the reviews below.
What each one is
Flaxseed is the seed of Linum usitatissimum L. (family Linaceae). Chia is the seed of Salvia hispanica L. (family Lamiaceae); both names were checked against GBIF this session. [1][2] The two are unrelated plants. See Flaxseed and Chia seeds. The meta-analyses call their interventions "supplementation," and the abstracts we read do not always say whether the seed was whole, ground or another form. That matters, because results for one form do not transfer to another.What the research found
| Question | Flaxseed | Chia | Strength of evidence |
|---|---|---|---|
| Blood fats | A meta-analysis of 62 randomized trials (3,772 people) found lower total cholesterol, triglycerides and LDL cholesterol with flaxseed supplementation, and no effect on HDL. [3] | An umbrella review of 8 meta-analyses (about 2,500 people) reported reductions in total cholesterol, LDL and triglycerides, and a small reduction in HDL. [4] | Both promising but limited |
| Apolipoproteins | Flaxseed supplementation reduced apo-B and lipoprotein(a); heterogeneity was high for apo-B (I2 = 83.2%). [5] | Not found in the chia sources we read. | Flaxseed: mixed |
| Inflammation | Not covered in the flaxseed sources we read. | A meta-analysis of 4 trials (210 people) found lower C-reactive protein and no significant effect on IL-6 or TNF-alpha. [6] | Chia: promising but limited (few trials) |
| Overall certainty | The authors call for high-quality, long-term trials. [5] | The umbrella review says certainty ranged from moderate to low for most outcomes and effectiveness remains uncertain. [4] | Both limited |
Because the pooled studies differ in outcome, dose, form and duration, these rows cannot be read as flaxseed beating chia or the reverse. The numbers are results for supplementation in trials; they are not a recommended amount.
No universal winner
Choosing between them depends on allergies, digestion, medicines and taste. A clinician or pharmacist can advise.Frequently asked questions
Is flaxseed or chia better for cholesterol?
Both have meta-analyses reporting lower LDL cholesterol, but they were different analyses and no head-to-head study was found. [3][4]
Does chia reduce inflammation?
A meta-analysis of 4 trials found lower C-reactive protein but no significant change in IL-6 or TNF-alpha. [6] The trial base is small.
Is raw flaxseed safe?
NCCIH advises not to eat raw or unripe flaxseeds. [7]
Can flaxseed affect medicines?
NCCIH describes theoretical reasons it might interact with anticoagulant or antiplatelet drugs. [7] Ask the prescriber or pharmacist.
Are they the same plant?
No. Flaxseed comes from Linum usitatissimum and chia from Salvia hispanica, in different plant families. [1][2]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Limits and uncertainty
- Biomarkers such as cholesterol are not the same as heart attacks or strokes; the sources we read measured markers.
- Traditional use: NCCIH notes flaxseed has a long history of traditional use for health and industrial purposes. [7] Traditional use is not evidence of effect.
Safety and who should ask a clinician
- Raw or unripe flaxseed. NCCIH advises not to eat raw or unripe flaxseeds because they may contain potentially toxic compounds. [7] No preparation methods are given here.
- Medicines. NCCIH says there are theoretical reasons to suspect flaxseed or flaxseed oil might interact with other drugs, such as anticoagulant or antiplatelet drugs, and advises talking with a health care provider before use. [7] See Medication interactions.
- Pregnancy and breastfeeding. NCCIH says some studies of flaxseed in pregnancy suggest it is possibly unsafe, but the evidence is not conclusive, and little is known about breastfeeding. [7] See Pregnancy and breastfeeding.
- Digestive effects. NCCIH says higher doses of flaxseed or flaxseed oil supplements may cause bloating, fullness and diarrhea. [7]
- Allergy. A review found chia is a potential emerging food allergen, with clinical evidence limited to a small number of case reports and one case series. [8] For urgent allergic reactions see Food allergy basics and emergency signs; call 911 for trouble breathing or swelling of the face or throat.
- Choking and swallowing. We searched PubMed for chia choking and esophageal obstruction and found nothing usable, so proper evidence not found. For more on each seed see the Chia seeds page.
References
- GBIF Secretariat. Linum usitatissimum L., species match. Read 2026-10-22.
- GBIF Secretariat. Salvia hispanica L., species match. Read 2026-10-22.
- Effect of flaxseed supplementation on lipid profile: an updated systematic review and dose-response meta-analysis of sixty-two randomized controlled trials. 2020. PubMed 31899314. Read 2026-10-22.
- A critical review of the health benefits associated with chia seeds (Salvia hispanica L.). 2025. PubMed 41076614. Read 2026-10-22.
- Does flaxseed supplementation affect apo-lipoproteins? A GRADE-assessed systematic review and meta-analysis. 2024. PubMed 39002708. Read 2026-10-22.
- Chia seed supplementation and inflammatory biomarkers: a systematic review and meta-analysis. 2024. PubMed 39703891. Read 2026-10-22.
- National Center for Complementary and Integrative Health (NCCIH, US). Flaxseed and Flaxseed Oil. Read 2026-10-22.
- Chia seed allergy: emerging clinical evidence, molecular allergens, and the unresolved question of cross-reactivity. 2026. PubMed 42797010. Read 2026-10-22.