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.
