Actiflax Flax Lignan
Also known as: SDG, Flax lignan, Flaxseed lignan, Actiflax Flax Lignan, Secoisolariciresinol diglucoside
Overview
Secoisolariciresinol diglucoside (SDG) is the primary lignan compound found predominantly in flaxseed (Linum usitatissimum). Actiflax Flax Lignan is a branded, standardized extract rich in SDG. As a phytochemical supplement, flax lignans are polyphenolic compounds that are converted by gut microbiota into enterolignans, specifically enterodiol and enterolactone. These metabolites exhibit weak estrogenic and antioxidant activities, which are believed to mediate their health benefits. Flax lignans are primarily researched for their potential to support cardiovascular health, including blood pressure regulation and improvement of lipid profiles. While research is ongoing, multiple randomized controlled trials and meta-analyses have explored its effects, indicating a moderate level of research maturity. The evidence quality is generally good, with several systematic reviews and meta-analyses available, though some heterogeneity exists in study designs and outcomes.
Benefits
Flax lignans, particularly when consumed as whole flaxseed, have demonstrated several evidence-based benefits. Meta-analyses indicate that flaxseed powder supplementation can significantly reduce systolic and diastolic blood pressure, with stronger effects observed with whole flaxseed compared to lignan extracts alone. For instance, one meta-analysis reported significant reductions in SBP and DBP with flaxseed powder (p < 0.001). Flax lignans and whole flaxseed also significantly reduce total cholesterol and LDL cholesterol concentrations. A meta-analysis found reductions of approximately 0.10 mmol/L in total cholesterol and 0.08 mmol/L in LDL cholesterol, with more pronounced effects in females and individuals with higher baseline cholesterol levels. It's important to note that flaxseed oil alone does not show significant lipid-lowering effects. While observational studies suggest a link between higher serum or urinary enterolactone (a flax lignan metabolite) and lower cardiovascular disease-related and all-cause mortality, these are associative data and not from randomized controlled trials. Conversely, a meta-analysis found no significant effect of flaxseed or lignan supplementation on plasma C-reactive protein (CRP), a marker of systemic inflammation.
How it works
Flax lignans, primarily SDG, are not directly absorbed in significant amounts. Instead, they undergo metabolism by intestinal bacteria in the gut. This microbial conversion transforms SDG into bioactive metabolites known as enterolignans, specifically enterodiol and enterolactone. These enterolignans are then absorbed systemically. Once absorbed, enterolignans exhibit weak estrogenic activity by binding to estrogen receptors, and they also possess antioxidant properties. The cardiovascular benefits, such as blood pressure reduction, are thought to be related to improved endothelial function and these antioxidant effects. The cholesterol-lowering effects may involve the modulation of lipid metabolism pathways within the body. The health of an individual's gut microbiota plays a crucial role in the efficient conversion of flax lignans into these active metabolites.
Side effects
Flax lignan supplementation is generally considered well tolerated, with no serious adverse events reported in clinical trials. The most common side effects, though uncommon, are mild gastrointestinal symptoms such as bloating and flatulence. Due to the weak estrogenic activity of its metabolites, caution is advised for individuals on hormone-sensitive therapies, and it is not recommended for those with hormone-sensitive cancers without direct medical supervision. No significant drug interactions have been definitively documented, but given its biological activity, it's prudent to consult a healthcare professional if taking other medications. Safety in special populations, such as pregnant or lactating women, has not been well established, and therefore, its use in these groups should be approached with caution. Postmenopausal women may experience more pronounced lipid-lowering benefits.
Dosage
Clinical trials investigating flax lignan extracts have typically used doses ranging from 360 mg to 600 mg of SDG per day. For whole flaxseed, effective doses ranged from 13 g to 60 g per day, as whole flaxseed contains varying amounts of lignans along with fiber and other components. An optimal daily range for lignan extracts is approximately 300-600 mg of SDG. If consuming whole flaxseed, higher quantities may be necessary to achieve a similar lignan intake. Supplementation is typically taken daily, with study durations ranging from 2 weeks to 12 months. Longer durations may be required to observe sustained effects on blood pressure and lipid profiles. Both powdered flaxseed and standardized lignan extracts have been used in studies; however, flaxseed oil alone is less effective for lignan-related benefits as it contains minimal lignans. The efficacy of flax lignans is also influenced by the health and composition of an individual's gut microbiota, which is responsible for converting SDG into its active metabolites.
FAQs
Does Actiflax Flax Lignan lower blood pressure?
Yes, particularly when consumed as whole flaxseed powder, which has shown significant reductions in blood pressure. Lignan extracts alone may show less consistent effects on blood pressure.
Is it safe for long-term use?
Current evidence suggests good safety for up to 12 months of use. However, data on longer-term safety and efficacy are limited, and ongoing research is needed.
How quickly can I expect to see results?
Changes in blood pressure and lipid profiles have been observed within weeks to months of consistent supplementation, depending on the individual and dosage.
Can flax lignans replace my prescribed medications?
Flax lignans may complement existing treatments but should not replace prescribed cardiovascular medications without explicit medical advice and supervision from a healthcare professional.
Research Sources
- https://www.archivesofmedicalscience.com/A-systematic-review-and-meta-analysis-of-clinical-trials-investigating-the-effects,74141,0,2.html – This meta-analysis of 17 randomized controlled trials, involving 1256 participants, investigated the effects of flaxseed or lignan supplementation on C-reactive protein (CRP). The study found no significant effect on plasma CRP levels, indicating no significant anti-inflammatory effect as measured by this marker. Limitations included heterogeneity among studies, small sample sizes, and short durations.
- https://pubmed.ncbi.nlm.nih.gov/26071633/ – This meta-analysis of randomized controlled trials examined the effect of flaxseed supplementation on blood pressure. It concluded that flaxseed powder significantly reduced both systolic and diastolic blood pressure, while lignan extracts alone showed less consistent effects. The study highlighted the importance of the form of flaxseed used and its dosage in achieving blood pressure benefits.
- https://pubmed.ncbi.nlm.nih.gov/19515737/ – This meta-analysis of 28 randomized controlled trials investigated the effects of flaxseed and its components on cholesterol levels. It found that both whole flaxseed and lignan supplements significantly reduced total and LDL cholesterol concentrations. However, flaxseed oil alone did not demonstrate significant lipid-lowering effects, and the study noted that sex and baseline lipid profiles influenced the results.
- https://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/lignans – This comprehensive review from the Linus Pauling Institute provides an overview of lignans, including their metabolism, sources, and health effects. It discusses the conversion of flax lignans by gut microbiota into enterolignans and their potential roles in cardiovascular health and cancer prevention, citing observational studies linking enterolactone levels to reduced mortality.