Flaxseed
Flaxseed provides fiber, lignans, and ALA. Whole/ground seed effects can differ from oil alone.
Overview
What is flaxseed?
Flaxseeds are the seeds of the Linum usitatissimum plant. Flaxseeds are a good source of omega-3 fatty acids, fiber, vitamins and protein.
Dosage
A typical dose of whole or ground flaxseed is 10 to 60 grams per day.
Effect graph
Effect heatmap
SupplementDEX Database
29 conditions for , and rated at least stars. All purchase bands. No minimum star filter.
Database Snapshot
Most flaxseed research is concentrated in a handful of conditions.
- High cholesterol accounts for 20 of 91 studies (22%).
- Breast cancer accounts for 9 of 91 studies (10%).
- Diabetes accounts for 8 of 91 studies (9%).
- Sparse coverage remains for Cardiovascular disease, Prediabetes, Prostate cancer.
Safety
Dose windows
Long-term
Ground flaxseed is likely safe when used at typical doses (30-60 grams per day) in the short and long term.
Frequently Asked Questions
References
Sources78 references
SupplementDEX uses only high-quality sources to determine supplement effectiveness.
SupplementDEX Database · Constipation
4 references1.SupplementDEX Database: Constipation — Effects of flaxseed supplementation on functional constipation and quality of life in a Chinese population: A randomized trial2020
In a 4-week RCT of 90 Chinese adults with functional constipation, 50 g/day flaxseed flour and lactulose both significantly improved Wexner constipation scores and bowel habits.
2.SupplementDEX Database: Constipation — Effect of flaxseed or psyllium vs. placebo on management of constipation, weight, glycemia, and lipids: A randomized trial in constipated patients with type 2 diabetes2019
In a 12-week single-blind RCT of 77 constipated type 2 diabetes patients, cookies containing 20 g/day flaxseed or psyllium improved constipation symptoms versus placebo.
3.SupplementDEX Database: Constipation — The effects of flaxseed dietary supplement on lipid profile, bone mineral density, and symptoms in menopausal women: a randomized, double-blind, wheat germ placebo-controlled clinical trial2004
In a 12-month RCT of 199 menopausal women, 40 g/day flaxseed reduced total and HDL cholesterol versus wheat germ placebo but did not significantly change bone mineral density or menopausal symptoms.
4.SupplementDEX Database: Constipation — Nutritional attributes of traditional flaxseed in healthy young adults1995
In a 4-week crossover RCT in healthy young adults, 50 g/day flaxseed increased adipose alpha-linolenic acid, urinary lignan excretion, and bowel movements by 30%, and reduced LDL cholesterol up to 8%.
SupplementDEX Database · Diabetes
7 references5.SupplementDEX Database: Diabetes — Effects of flaxseed supplementation on weight loss, lipid profiles, glucose, and high-sensitivity C-reactive protein in patients with coronary artery disease: A systematic review and meta-analysis of randomized controlled trials2024
A meta-analysis of 6 RCTs in coronary artery disease patients found flaxseed supplementation did not significantly change weight, lipids, hs-CRP, or glucose.
6.SupplementDEX Database: Diabetes — Flaxseed supplementation significantly reduces hemoglobin A1c in patients with type 2 diabetes mellitus: A systematic review and meta-analysis2023
A meta-analysis of 13 T2DM trials found flaxseed supplementation significantly lowered HbA1c versus control, without consistent effects on weight, blood pressure, fasting glucose, or lipids overall.
7.SupplementDEX Database: Diabetes — Effect of flaxseed (Linum usitatissimum) supplementation on glycemic control and insulin resistance in prediabetes and type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials2022
A meta-analysis of RCTs found flaxseed supplementation modestly reduced fasting glucose, HbA1c, and HOMA-IR in people with prediabetes or type 2 diabetes.
8.SupplementDEX Database: Diabetes — Flaxseed supplementation on glucose control and insulin sensitivity: a systematic review and meta-analysis of 25 randomized, placebo-controlled trials2018
A meta-analysis of 25 flaxseed RCTs found supplementation significantly reduced fasting glucose (−2.94 mg/dL), insulin, and HOMA-IR and increased insulin sensitivity, without significant HbA1c change.
9.SupplementDEX Database: Diabetes — Daily flaxseed consumption improves glycemic control in obese men and women with pre-diabetes: a randomized study2013
In a crossover RCT of 25 overweight adults with prediabetes, 13 g/day ground flaxseed for 12 weeks reduced fasting glucose and insulin versus 0 g, while 26 g/day did not differ from placebo.
10.SupplementDEX Database: Diabetes — Flaxseed supplementation improved insulin resistance in obese glucose intolerant people: a randomized crossover design2011
In a crossover RCT of 9 obese glucose-intolerant adults, 40 g/day flaxseed for 12 weeks reduced lipid peroxidation (TBARS) and HOMA-IR versus wheat bran, without changing inflammatory cytokines.
11.SupplementDEX Database: Diabetes — Effects of a flaxseed-derived lignan supplement in type 2 diabetic patients: a randomized, double-blind, cross-over trial2007
In a 12-week crossover RCT of 68 Chinese type 2 diabetic patients (ages 50–79), 360 mg/day flaxseed lignan produced modest but statistically significant improvements in glycemic control versus placebo.
SupplementDEX Database · High blood pressure
5 references12.SupplementDEX Database: High blood pressure — Flaxseed Lowers Blood Pressure in Hypertensive Subjects: A Meta-Analysis of Randomized Controlled Trials2024
A meta-analysis of 5 RCTs found flaxseed supplementation significantly lowered systolic blood pressure by 8.6 mmHg and diastolic blood pressure by 4.9 mmHg in hypertensive patients.
13.SupplementDEX Database: High blood pressure — Effect of flaxseed supplementation on blood pressure: a systematic review, and dose-response meta-analysis of randomized clinical trials2023
A meta-analysis of 33 trials (2,427 participants) found flaxseed supplementation reduced systolic BP by 3.19 mmHg and diastolic BP by 1.96 mmHg, with larger effects at higher doses and longer duration.
14.SupplementDEX Database: High blood pressure — Effects of flaxseed on blood pressure, body mass index, and total cholesterol in hypertensive patients: A randomized clinical trial2021
In a 12-week triple-blind RCT of 112 hypertensive patients (ages 35–70), 30 g/day flaxseed reduced systolic BP by 13.4 mmHg, diastolic BP by 5.6 mmHg, BMI, and total cholesterol versus placebo.
15.SupplementDEX Database: High blood pressure — Flaxseed consumption may reduce blood pressure: a systematic review and meta-analysis of controlled trials2015
A meta-analysis of 11 studies (14 trials) found flaxseed supplementation modestly reduced systolic BP by 1.8 mmHg and diastolic BP by 1.6 mmHg, with greater diastolic effects from whole flaxseed over ≥12 weeks.
16.SupplementDEX Database: High blood pressure — Effects of flaxseed supplements on blood pressure: A systematic review and meta-analysis of controlled clinical trial2015
A meta-analysis of 15 flaxseed trials (1,302 participants) found supplementation reduced systolic BP 2.85 mmHg and diastolic BP 2.39 mmHg, with greater effects in trials ≥12 weeks.
SupplementDEX Database · High cholesterol
17 references17.SupplementDEX Database: High cholesterol — Effect of Flaxseed (Linum usitatissimum L.) Supplementation on Vascular Endothelial Cell Morphology and Function in Patients with Dyslipidaemia-A Preliminary Observation2022
In a preliminary study of dyslipidemia patients given 28 g/day flaxseed for 10 weeks, flaxseed lowered total and LDL cholesterol but had only slight effects on endothelial cell function in vitro.
18.SupplementDEX Database: High cholesterol — Effects of Flaxseed on Blood Lipids in Healthy and Dyslipidemic Subjects: A Systematic Review and Meta-Analysis of Randomized Controlled Trials2021
A meta-analysis of 14 RCTs (1,107 participants) found flaxseed significantly lowered total cholesterol, LDL, and triglycerides in dyslipidemic patients; healthy subjects showed HDL increases without LDL reduction.
19.SupplementDEX Database: High cholesterol — Comparisons of the effects of different flaxseed products consumption on lipid profiles, inflammatory cytokines and anthropometric indices in patients with dyslipidemia related diseases: systematic review and a dose-response meta-analysis of randomized controlled trials2021
A dose-response meta-analysis of 31 RCTs (1,698 participants) found flaxseed products lowered total cholesterol, LDL, triglycerides, apoB, and IL-6 in dyslipidemia-related disease, with whole flaxseed showing strongest effects.
20.SupplementDEX Database: High cholesterol — Effect of flaxseed supplementation on lipid profile: An updated systematic review and dose-response meta-analysis of sixty-two randomized controlled trials2019
An updated meta-analysis of 62 flaxseed RCTs (3,772 participants) found supplementation significantly reduced total cholesterol (−5.4 mg/dL), triglycerides (−9.4 mg/dL), and LDL (−4.2 mg/dL).
21.SupplementDEX Database: High cholesterol — Effect of Flaxseed Powder on Cardiovascular Risk Factor in Dyslipidemic and Hypertensive Patients2019
In an 8-week double-blind RCT of 80 hyperlipidemic hypertensive patients (ages 20–60), 36 g/day flaxseed powder reduced triglycerides, total cholesterol, and LDL versus placebo.
22.SupplementDEX Database: High cholesterol — Flaxseed supplementation improves anthropometric measurements, metabolic, and inflammatory biomarkers in overweight and obese adults2019
In a 12-week RCT of 50 overweight/obese adults, 30 g/day milled flaxseed plus lifestyle advice produced greater weight loss, improved lipids, HOMA-IR, and hs-CRP than lifestyle advice alone.
23.SupplementDEX Database: High cholesterol — Dietary flaxseed independently lowers circulating cholesterol and lowers it beyond the effects of cholesterol-lowering medications alone in patients with peripheral artery disease2015
In a 12-month double-blind RCT of peripheral artery disease patients, 30 g/day milled flaxseed reduced LDL cholesterol by 15% within 1 month, including in those already on cholesterol-lowering medications.
24.SupplementDEX Database: High cholesterol — Flaxseed in pediatric hyperlipidemia: a placebo-controlled, blinded, randomized clinical trial of dietary flaxseed supplementation for children and adolescents with hypercholesterolemia2013
In an 8-week RCT of 32 children (ages 8–18) with hypercholesterolemia, 30 g/day ground flaxseed in muffins and bread did not significantly change fasting lipid profiles versus whole-wheat controls.
25.SupplementDEX Database: High cholesterol — Effects of flaxseed consumption on systemic inflammation and serum lipid profile in hemodialysis patients with lipid abnormalities2012
In an 8-week unblinded RCT of 30 hemodialysis patients with dyslipidemia, 40 g/day ground flaxseed improved serum lipids and reduced systemic inflammation versus usual diet.
26.SupplementDEX Database: High cholesterol — Meta-analysis of the effects of flaxseed interventions on blood lipids2009
A meta-analysis of 28 flaxseed trials found whole flaxseed and lignans reduced total and LDL cholesterol (~0.10–0.28 mmol/L), while flaxseed oil alone did not significantly change lipids.
27.SupplementDEX Database: High cholesterol — Fatty acids and lignans in unground whole flaxseed and sesame seed are bioavailable but have minimal antioxidant and lipid-lowering effects in postmenopausal women2009
In a crossover RCT of 16 postmenopausal women, 4 weeks of 25 g/day unground flaxseed or sesame seed increased serum n-3 or n-6 fatty acids and urinary lignans but did not change plasma lipids or antioxidant markers.
28.SupplementDEX Database: High cholesterol — Flaxseed reduces total and LDL cholesterol concentrations in Native American postmenopausal women2008
In an RCT of 55 Native American postmenopausal women with mild hypercholesterolemia, ~30 g/day dietary flaxseed for 3 months lowered total cholesterol by ~7% and LDL cholesterol by ~10%.
29.SupplementDEX Database: High cholesterol — Flaxseed and cardiovascular risk factors: results from a double blind, randomized, controlled clinical trial2008
In a 10-week RCT of 62 hypercholesterolemic adults, 40 g/day ground flaxseed in baked products reduced LDL cholesterol by 13% at 5 weeks versus wheat bran placebo on a low-fat diet.
30.SupplementDEX Database: High cholesterol — Flaxseed supplementation in hyperlipidemic patients2005
In 40 hyperlipidemic patients on a hypolipidic diet for 60 days, adding 20 g/day ground flaxseed reduced total cholesterol by 17% and LDL by 4% versus diet alone or diet plus statins.
31.SupplementDEX Database: High cholesterol — Flaxseed improves lipid profile without altering biomarkers of bone metabolism in postmenopausal women2002
In a 3-month double-blind RCT of postmenopausal women, 40 g/day ground flaxseed lowered total and LDL cholesterol versus wheat control without altering bone metabolism biomarkers.
32.SupplementDEX Database: High cholesterol — Flaxseed dietary supplement versus hormone replacement therapy in hypercholesterolemic menopausal women2002
In a crossover RCT of 25 hypercholesterolemic menopausal women, 40 g/day crushed flaxseed for 2 months lowered lipids comparably to hormone replacement therapy in this small trial.
33.SupplementDEX Database: High cholesterol — Health aspects of partially defatted flaxseed, including effects on serum lipids, oxidative measures, and ex vivo androgen and progestin activity: a controlled crossover trial1999
In a 3-week crossover RCT of 29 hyperlipidemic subjects, muffins with ~50 g/day partially defatted flaxseed (~20 g fiber) on a Step II diet did not significantly change serum lipids versus wheat bran control.
SupplementDEX Database · Mastalgia
1 reference34.SupplementDEX Database: Mastalgia — Effects of Vitex agnus and Flaxseed on cyclic mastalgia: A randomized controlled trial2016
In an RCT of 159 women with cyclical mastalgia, 25 g/day flaxseed powder and Vitex agnus both reduced breast pain over 2 months versus placebo, with no significant difference between active groups.
SupplementDEX Database · Obesity
3 references35.SupplementDEX Database: Obesity — Flaxseed Mucilage (IQP-LU-104) Reduces Body Weight in Overweight and Moderately Obese Individuals in a 12-week, Three-Arm, Double-Blind, Randomized, and Placebo-Controlled Clinical Study2022
In a 12-week double-blind RCT of 108 overweight adults (BMI 25–<35), flaxseed mucilage (IQP-LU-104) on a hypocaloric diet reduced body weight versus placebo in a dose-dependent manner.
36.SupplementDEX Database: Obesity — Gene-diet interaction in response to defatted flaxseed flour supplementation on obesity-related traits in Chinese overweight and obese adults: A randomized controlled trial2022
In an 8-week RCT of 51 overweight Chinese adults, defatted flaxseed-flour biscuits at breakfast reduced body weight and waist circumference versus control biscuits, with gene-diet interactions on some traits.
37.SupplementDEX Database: Obesity — The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials2017
A meta-analysis of 45 flaxseed RCTs found supplementation reduced body weight 0.99 kg, BMI 0.30 kg/m², and waist circumference 0.80 cm versus control, with larger effects at ≥30 g/day whole flaxseed.
SupplementDEX Database · Weight loss
1 reference38.SupplementDEX Database: Weight loss — The effects of flaxseed (Linum usitatissimum) supplementation on anthropometric indices: An updated systematic review and meta-analysis of randomized clinical trials2024
A meta-analysis of 64 RCTs found flaxseed supplementation significantly reduced body weight, BMI, and waist circumference, though effects varied by flaxseed form and dose.
SupplementDEX Database · Osteoporosis
1 reference39.SupplementDEX Database: Osteoporosis — A randomized controlled trial of the effects of flaxseed lignan complex on metabolic syndrome composite score and bone mineral in older adults2009
In a 6-month double-blind RCT of 100 older adults on a walking program, 543 mg/day flaxseed lignan complex did not significantly improve metabolic syndrome composite score or bone mineral density versus placebo.
40.SupplementDEX Database: Benign prostatic hyperplasia — Effects of dietary flaxseed lignan extract on symptoms of benign prostatic hyperplasia2008
In an RCT of 87 men with BPH, 600 mg/day flaxseed lignan (SDG) for 4 months significantly improved International Prostate Symptom Score and quality of life versus placebo.
SupplementDEX Database · Breast cancer
9 references41.SupplementDEX Database: Breast cancer — Enterolactone is differently associated with estrogen receptor beta-negative and -positive breast cancer in a Swedish nested case-control study2008
In a Swedish nested case-control of 366 breast cancer cases and 733 controls, plasma enterolactone above the median was associated with lower breast cancer risk, especially for ERalpha-positive and ERbeta-negative tumors.
42.SupplementDEX Database: Breast cancer — Dietary phytoestrogens are not associated with risk of overall breast cancer but diets rich in coumestrol are inversely associated with risk of estrogen receptor and progesterone receptor negative breast tumors in Swedish women2008
In a Swedish cohort of 45,448 women with 1,014 breast cancers, dietary coumestrol—but not lignans or isoflavonoids—was inversely associated with ER-/PR- breast tumors.
43.SupplementDEX Database: Breast cancer — Dietary lignans and postmenopausal breast cancer risk by oestrogen receptor status: a prospective cohort study of Swedish women2008
Among 51,823 postmenopausal women in the Swedish Mammography Cohort, highest-quartile dietary lignan intake was associated with a 17% lower overall breast cancer risk, particularly among hormone therapy users.
44.SupplementDEX Database: Breast cancer — Dietary phytoestrogen intake--lignans and isoflavones--and breast cancer risk (Canada)2007
In an Ontario case-control study of 3,063 breast cancer cases and 3,430 controls (ages 25–74), highest-quintile lignan intake was associated with 19% lower breast cancer odds overall, with stronger protection in overweight women.
45.SupplementDEX Database: Breast cancer — Plasma phytoestrogens and subsequent breast cancer risk2007
In a Dutch nested case-control of 383 breast cancer cases matched to 383 controls, highest-tertile plasma genistein was associated with 32% lower breast cancer risk; lignan levels showed no association.
46.SupplementDEX Database: Breast cancer — Dietary lignan intake and postmenopausal breast cancer risk by estrogen and progesterone receptor status2007
In a French cohort of 58,049 postmenopausal women, dietary lignan intake showed no clear overall association with breast cancer risk, with inconsistent patterns across ER/PR subtypes.
47.SupplementDEX Database: Breast cancer — Dietary flavonoid intake and breast cancer risk among women on Long Island2007
In a Long Island case-control study of 1,434 breast cancer cases and 1,440 controls, higher flavonoid intake—especially in postmenopausal women—was associated with lower breast cancer risk.
48.SupplementDEX Database: Breast cancer — Adolescent dietary phytoestrogen intake and breast cancer risk (Canada)2006
In an Ontario case-control of 3,024 breast cancer cases and 3,420 controls (ages 25–74), higher adolescent phytoestrogen intake (isoflavones and lignans) was associated with reduced adult breast cancer risk.
49.SupplementDEX Database: Breast cancer — Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer2005
In an RCT of 19 postmenopausal women with newly diagnosed breast cancer, 25 g/day flaxseed in muffins for ~32 days before surgery reduced tumor cell proliferation (Ki-67) versus placebo muffins.
50.SupplementDEX Database: Burning mouth syndrome — Effect of a Homemade Salivary Substitute Prepared Using Chamomile (Matricaria chamomilla L.) Flower and Flax (Linum usitatissimum L.) Seed to Relieve Primary Burning Mouth Syndrome: A Preliminary Report2020
In an open trial of 40 women over age 40 with primary burning mouth syndrome, a chamomile-and-flaxseed salivary substitute used for 3 months improved symptom intensity and salivary flow versus baseline.
SupplementDEX Database · Cardiovascular disease
2 references51.SupplementDEX Database: Cardiovascular disease — Effect of flaxseed consumption on flow-mediated dilation and inflammatory biomarkers in patients with coronary artery disease: a randomized controlled trial2018
In a 12-week RCT of 44 coronary artery disease patients, 30 g/day flaxseed did not significantly improve flow-mediated dilation or inflammatory markers versus usual care.
52.SupplementDEX Database: Cardiovascular disease — Intakes of 4 dietary lignans and cause-specific and all-cause mortality in the Zutphen Elderly Study2006
In the Zutphen Elderly Study of 570 men (ages 64–84) followed 15 years, total dietary lignan intake was not associated with coronary heart disease, cancer, or all-cause mortality.
SupplementDEX Database · Colorectal cancer
3 references53.SupplementDEX Database: Colorectal cancer — Plasma enterolignan concentrations and colorectal cancer risk in a nested case-control study2008
In a Dutch nested case-control of 160 colorectal cancer cases and 387 controls, plasma enterodiol and enterolactone were not associated with colorectal cancer risk after adjustment for confounders.
54.SupplementDEX Database: Colorectal cancer — Dietary phytoestrogen intake is associated with reduced colorectal cancer risk2006
In an Ontario case-control study (ages 20–74), higher dietary phytoestrogen intake—particularly lignans common in North American diets—was associated with reduced colorectal cancer risk.
55.SupplementDEX Database: Colorectal cancer — Plasma enterolignans are associated with lower colorectal adenoma risk2006
In a Dutch case-control of 532 colorectal adenoma cases and 503 controls, higher plasma enterolignans were associated with lower adenoma risk, with stronger associations for incident cases.
SupplementDEX Database · Dysmenorrhea
1 reference56.SupplementDEX Database: Dysmenorrhea — The Effects of Chamomile and Flaxseed on Pelvic Pain, Dyspareunia, and Dysmenorrhea in Endometriosis: A Controlled Randomized Clinical Trial2024
In an RCT of 102 endometriosis patients, 1,000 mg chamomile or flaxseed capsules three times daily for 8 weeks reduced pelvic pain, dyspareunia, and dysmenorrhea versus placebo.
SupplementDEX Database · Endometrial cancer
1 reference57.SupplementDEX Database: Endometrial cancer — Circulating enterolactone and risk of endometrial cancer2006
In a nested case-control of 153 endometrial cancer cases and 271 controls across three cohorts, circulating enterolactone showed no association with endometrial cancer risk.
SupplementDEX Database · Fatigue
1 reference58.SupplementDEX Database: Fatigue — The effect of flaxseed on physical and mental fatigue in children and adolescents with overweight/obesity: a randomised controlled trial2020
In a 4-week RCT of 72 overweight/obese children and adolescents, 20 g/day flaxseed reduced mental fatigue versus puffed wheat control, with a significant between-group difference.
59.SupplementDEX Database: Irritable bowel syndrome — Effects of linseeds on the symptoms of irritable bowel syndrome: a pilot randomised controlled trial2012
In a pilot open RCT of 40 IBS patients for 4 weeks, whole or ground linseeds did not clearly outperform no-linseeds for IBS symptom relief in this underpowered trial.
SupplementDEX Database · Lung cancer
1 reference60.SupplementDEX Database: Lung cancer — Dietary phytoestrogens and lung cancer risk2005
In a U.S. case-control study of 1,674 lung cancer cases and 1,735 controls, higher dietary phytoestrogen intake was associated with lower lung cancer risk after adjustment for confounders.
SupplementDEX Database · Menopause
4 references61.SupplementDEX Database: Menopause — A phase III, randomized, placebo-controlled, double-blind trial of flaxseed for the treatment of hot flashes: North Central Cancer Treatment Group N08C72012
In a phase III RCT of 188 postmenopausal women, a flaxseed bar providing 410 mg lignans daily for 6 weeks did not significantly reduce hot flash activity versus placebo.
62.SupplementDEX Database: Menopause — Evaluation of the efficacy of flaxseed meal and flaxseed extract in reducing menopausal symptoms2012
In a 6-month RCT of 90 menopausal women, both flaxseed extract (1 g/day) and flaxseed meal (90 g/day) significantly reduced Kupperman menopausal index scores versus collagen placebo.
63.SupplementDEX Database: Menopause — Consumption of a flaxseed-rich food is not more effective than a placebo in alleviating the climacteric symptoms of postmenopausal women2009
In a 12-week double-blind RCT of 38 postmenopausal women, bread with 25 g/day flaxseed (46 mg lignans) did not reduce hot flashes, Kupperman index, or endometrial thickness versus wheat bran placebo.
64.SupplementDEX Database: Menopause — A randomized controlled trial of the effect of dietary soy and flaxseed muffins on quality of life and hot flashes during menopause2006
In a 16-week RCT of 87 postmenopausal women, daily muffins with 25 g flaxseed, soy, or wheat control did not show clear superiority of flaxseed for quality of life or hot flash frequency.
SupplementDEX Database · Metabolic syndrome
2 references65.SupplementDEX Database: Metabolic syndrome — Flaxseed and/or hesperidin supplementation in metabolic syndrome: an open-labeled randomized controlled trial2020
In a 12-week open-label RCT of 98 metabolic syndrome patients, hesperidin (1 g/day) reduced systolic BP and triglycerides versus control; flaxseed (30 g/day) showed smaller metabolic changes.
66.SupplementDEX Database: Metabolic syndrome — Lifestyle counseling and supplementation with flaxseed or walnuts influence the management of metabolic syndrome2010
In a 12-week RCT of 283 adults with metabolic syndrome, lifestyle counseling with or without 30 g/day flaxseed or walnuts all reduced MetS prevalence by 16–20%, without significant between-group differences.
67.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Flaxseed powder supplementation in non-alcoholic fatty liver disease: a randomized controlled clinical trial2025
In a 12-week RCT of 50 NAFLD patients, 30 g/day flaxseed powder plus health education reduced intrahepatic lipid content more than health education alone.
68.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — The efficacy of flaxseed and hesperidin on non-alcoholic fatty liver disease: an open-labeled randomized controlled trial2020
In a 12-week open-label RCT of 100 NAFLD patients, 30 g/day flaxseed with lifestyle modification improved liver fat and metabolic markers more than lifestyle modification alone.
69.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Flaxseed supplementation in non-alcoholic fatty liver disease: a pilot randomized, open labeled, controlled study2016
In a 12-week RCT of 50 NAFLD patients, lifestyle modification plus 30 g/day milled flaxseed produced greater reductions in liver enzymes, fibrosis score, and steatosis than lifestyle modification alone.
SupplementDEX Database · Osteoarthritis
1 reference70.SupplementDEX Database: Osteoarthritis — Effect of flaxseed poultice compress application on pain and hand functions of patients with hand osteoarthritis2019
In a 7-day RCT of hand osteoarthritis patients, flaxseed poultice compress reduced pain and improved hand function versus hot compress or control, alongside routine pharmacotherapy.
71.SupplementDEX Database: Peripheral arterial disease (PAD) — The effects of dietary flaxseed on cardiac arrhythmias and claudication in patients with peripheral arterial disease2018
In the 1-year FLAX-PAD trial, 30 g/day milled flaxseed did not significantly change cardiac arrhythmia prevalence or exercise capacity in peripheral artery disease patients versus placebo.
72.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — The effects of flaxseed supplementation on metabolic status in women with polycystic ovary syndrome: a randomized open-labeled controlled clinical trial2020
In a 12-week open-label RCT of 41 PCOS patients (ages 18–45), 30 g/day flaxseed powder plus lifestyle modification reduced body weight, insulin, and HOMA-IR versus lifestyle modification alone.
SupplementDEX Database · Prostate cancer
2 references73.SupplementDEX Database: Prostate cancer — Flaxseed supplementation (not dietary fat restriction) reduces prostate cancer proliferation rates in men presurgery2008
In a pre-surgery RCT of 161 prostate cancer patients, 30 g/day flaxseed for ≥21 days before prostatectomy reduced tumor proliferation rates; low-fat diet alone did not.
74.SupplementDEX Database: Prostate cancer — Pilot study to explore effects of low-fat, flaxseed-supplemented diet on proliferation of benign prostatic epithelium and prostate-specific antigen2004
In a 6-month pilot of 15 men awaiting repeat prostate biopsy, a low-fat (<20% kcal) diet with 30 g/day flaxseed was associated with reduced benign prostatic epithelial proliferation and PSA trends.
75.SupplementDEX Database: Radiation pneumonitis — Phase II Trial of Flaxseed to Prevent Acute Complications After Chemoradiation for Lung Cancer2021
In a single-arm phase II trial of 33 lung cancer patients receiving chemoradiation, daily 40 g flaxseed before and during radiotherapy was evaluated for reducing radiation pneumonitis and esophagitis.
76.SupplementDEX Database: Rheumatoid arthritis — The effect of flaxseed with or without anti-inflammatory diet in patients with rheumatoid arthritis, a randomized controlled trial2021
In a 12-week RCT of 120 rheumatoid arthritis patients, 30 g/day flaxseed with or without an anti-inflammatory diet improved DAS28, pain, and quality of life versus roasted wheat control.
SupplementDEX Database · Ulcerative colitis
2 references77.SupplementDEX Database: Ulcerative colitis — Effects of flaxseed and flaxseed oil supplement on serum levels of inflammatory markers, metabolic parameters and severity of disease in patients with ulcerative colitis2019
In a 12-week RCT of 75 ulcerative colitis patients, 30 g/day ground flaxseed or 10 g/day flaxseed oil reduced fecal calprotectin, inflammatory markers, blood pressure, and disease severity versus control.
78.SupplementDEX Database: Ulcerative colitis — The effects of flaxseed supplementation on metabolic syndrome parameters, insulin resistance and inflammation in ulcerative colitis patients: An open-labeled randomized controlled trial2019
In a 12-week open-label RCT of 70 ulcerative colitis patients, 30 g/day ground flaxseed improved some metabolic syndrome parameters, including insulin, versus control.