Dietary flaxseed: Cardiometabolic benefits and its role in promoting healthy aging.

2025-01-16
GeroScience 47(3)
- Setor K Kunutsor
- Davinder S Jassal
- Amir Ravandi
- Andrea Lehoczki

PubMed: 39821819
DOI: 10.1007/s11357-025-01512-0

Study Design

Type: Review

Flaxseed, a rich source of omega-3 polyunsaturated fatty acid alpha-linolenic acid (ALA), lignans, and soluble fiber, has attracted attention for its potential to improve multiple cardiometabolic risk factors. While its benefits are well-recognized, comprehensive evaluations of its direct impact on clinical outcomes, such as the prevention or progression of cardiometabolic diseases, remain limited. Additionally, its potential to support healthy aging and longevity through fundamental biological mechanisms has not been fully elucidated. This review synthesizes existing research on flaxseed supplementation, highlighting its effects on cardiometabolic risk factors and outcomes, the underlying biological mechanisms, and its broader implications for health promotion and aging. Findings demonstrate that flaxseed supplementation significantly improves several cardiometabolic risk factors, including body weight, body mass index, lipid levels, blood pressure, glycemic measures, markers of inflammation (e.g., C-reactive protein and interleukin-6), oxidative stress, and liver enzymes. Blood pressure reductions range from approximately 2 to 15 mmHg for systolic blood pressure and 1 to 7 mmHg for diastolic blood pressure, with the magnitude influenced by dose, duration, and baseline risk profiles. While direct evidence linking flaxseed to the prevention of hypertension, metabolic syndrome, metabolic dysfunction-associated steatotic liver disease, type 2 diabetes, chronic kidney disease, and cardiovascular disease is limited, its bioactive components-ALA, lignans, and fiber-are strongly associated with reduced risks of these conditions. The benefits of flaxseed are mediated through multiple pathways, including anti-inflammatory and antioxidant effects, improved lipid levels, improved glucose metabolism and insulin sensitivity, modulation of gut microbiota, and enhanced vascular health. Beyond cardiometabolic outcomes, flaxseed may influence key biological processes relevant to aging, underscoring its potential to promote healthy aging and longevity. Optimal cardiometabolic benefits appear to be achieved with ground whole flaxseed at doses of ≥ 30 g/day for at least 12 weeks, particularly among individuals at high cardiometabolic risk. Future research should focus on elucidating flaxseed's mechanisms of action, clarifying its role in disease prevention, and refining dietary recommendations to harness its potential for cardiometabolic health and aging interventions.

Research Insights

flaxseed→Improved Insulin Levels
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including ... glycemic measures
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Prevented Cardiovascular Disease
While direct evidence linking flaxseed to the prevention of ... cardiovascular disease ... is limited
Effect
Neutral
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Prevented Chronic Kidney Disease
While direct evidence linking flaxseed to the prevention of ... chronic kidney disease ... is limited
Effect
Neutral
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Prevented Hypertension
While direct evidence linking flaxseed to the prevention of hypertension ... is limited
Effect
Neutral
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Prevented Metabolic Dysfunction-Associated Steatotic Liver Disease
While direct evidence linking flaxseed to the prevention of ... metabolic dysfunction-associated steatotic liver disease ... is limited
Effect
Neutral
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Prevented Metabolic Syndrome
While direct evidence linking flaxseed to the prevention of ... metabolic syndrome ... is limited
Effect
Neutral
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Prevented Type 2 Diabetes
While direct evidence linking flaxseed to the prevention of ... type 2 diabetes ... is limited
Effect
Neutral
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced Blood Pressure
Blood pressure reductions range from approximately 2 to 15 mmHg for systolic blood pressure and 1 to 7 mmHg for diastolic blood pressure
Effect
Beneficial
Effect size
Moderate
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced Body Mass Index
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including body weight, body mass index
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced Body Weight
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including body weight
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced C-Reactive Protein Levels
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including markers of inflammation (e.g., C-reactive protein and interleukin-6)
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced Interleukin-6 Levels
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including markers of inflammation (e.g., C-reactive protein and interleukin-6)
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced Liver Enzyme Levels
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including ... liver enzymes
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced Low-Density Lipoprotein Level
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including ... lipid levels
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks
flaxseed→Reduced Oxidative Stress Marker
Flaxseed supplementation significantly improves several cardiometabolic risk factors, including ... oxidative stress
Effect
Beneficial
Effect size
Small
Dose
≥ 30 g/day for at least 12 weeks