Evidence Level
Flaxseed oil is notable for its high content of alpha-linolenic acid (ALA), an omega-3 fatty acid, and has been studied for its cardiovascular, anti-inflammatory, and dermatological benefits. A meta-analysis by Pan et al. (2009) involving 28 studies demonstrated that flaxseed supplementation significantly lowers total cholesterol and LDL levels, attributed to its ALA and lignan content. Khalesi et al. (2014) conducted a meta-analysis of 11 randomized controlled trials (RCTs) and found that flaxseed consumption reduces systolic blood pressure by 2.85 mmHg, with greater effects observed in longer studies.
Recent studies have further explored the benefits of flaxseed oil. McNabb et al. (2024) systematically reviewed 17 RCTs and found no significant impact on blood pressure or inflammatory markers in healthy or at-risk adults. However, Tabrizi et al. (2024) analyzed 8 RCTs involving hemodialysis patients and reported that flaxseed oil significantly reduced triglycerides (-85.78 mg/dL) and CRP levels (-2.66 mg/L). Additionally, Mahmudiono et al. (2022) meta-analyzed five RCTs and found a significant reduction in systolic blood pressure (-3.86 mmHg) among patients with metabolic syndrome.
Flaxseed oil also exhibits anti-inflammatory properties. Tamtaji et al. (2020) reviewed 12 RCTs and found that flaxseed oil supplementation reduced IL-6 and malondialdehyde (MDA), while increasing total antioxidant capacity (TAC). Furthermore, Musazadeh et al. (2024) analyzed 64 RCTs and reported that flaxseed supplementation significantly decreased body weight, BMI, and waist circumference.
Despite these benefits, flaxseed oil has limitations. Burdge & Calder (2005) highlighted its low conversion rate to EPA (5-10%) and DHA (<1%), making it insufficient as a sole omega-3 source for conditions requiring high EPA/DHA levels, such as severe hypertriglyceridemia. Overall, flaxseed oil offers meaningful cardiovascular and anti-inflammatory benefits, particularly in plant-based diets and as a complementary omega-3 source.