Written by Alexa Heathorn, MS, CNS. Daily supplementation with 20 mg of astaxanthin for 8 weeks significantly increased antioxidant capacity (TAC, SOD), reduced oxidative stress (MDA) and uric acid levels, and improved fatigue and dyspnea in patients with heart failure, supporting its potential role as an adjunct therapy for cardiometabolic and symptom management.

Heart failure (HF), a condition characterized by the heart’s inability to pump blood effectively, leading to fluid retention, shortness of breath, fatigue, and reduced exercise tolerance, remains a significant global health burden.¹ It represents the final common pathway of many cardiovascular diseases and is strongly driven by oxidative stress.¹ Several biomarkers are used to assess oxidative stress, including malondialdehyde (MDA), a marker of lipid peroxidation; superoxide dismutase (SOD), a key antioxidant enzyme; total antioxidant capacity (TAC), which reflects overall antioxidant status; and uric acid (UA), which is associated with adverse cardiac outcomes.¹ Targeting oxidative stress may therefore help improve clinical outcomes and quality of life in patients with HF.¹

Astaxanthin (ASX) is a naturally occurring carotenoid with potent antioxidant properties found in foods such as microalgae, shrimp, and salmon.¹ It is highly stable, can integrate into cell membranes, and is capable of crossing the blood–brain barrier, allowing it to effectively protect cells from oxidative damage.¹ While previous studies have demonstrated beneficial effects in conditions such as diabetes and chronic inflammatory disorders, clinical evidence in patients with heart failure remains limited.¹ To address this gap, a randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the effects of ASX supplementation on oxidative stress biomarkers, serum UA levels, and clinical outcomes in patients with HF.¹

Participants included 80 adults (≥18 years) with a confirmed diagnosis of heart failure.¹ They were randomly assigned to receive either 20 mg of astaxanthin (ASX) daily in its non-esterified, cis-isomer form (n = 40) or an identical placebo containing 20 mg of maltodextrin (n = 40).¹ Participants were instructed to take the capsule with lunch for 60 consecutive days. Oxidative stress markers including total antioxidant capacity (TAC), malondialdehyde (MDA), and superoxide dismutase (SOD), as well as serum uric acid (UA) and clinical symptoms (dyspnea, fatigue, appetite), were assessed before and after the intervention.¹

The results following 60 days (8 weeks) of supplementation were as follows:

Oxidative Stress Markers:

• TAC increased significantly in the ASX group compared to placebo (0.12 vs. −0.04 mmol/L, P = 0.002).
• SOD levels increased significantly (156.92 vs. 36.14 U/mL, P < 0.001).
• MDA levels decreased significantly (−2.19 vs. −0.68 nmol/L, P < 0.001).

Uric Acid:

• Serum UA levels decreased significantly in the ASX group compared to placebo (−1.82 vs. −0.63 mg/dL, P = 0.003).

Clinical Symptoms:

• Dyspnea and fatigue improved significantly in the ASX group compared to placebo (P < 0.001).
• Appetite increased, but this change was only marginally significant between groups (P = 0.071).

Several limitations should be considered when interpreting these findings. The sample size was relatively small (80 participants), and the study was conducted at a single center in Iran, which may limit the generalizability of the results to broader populations.¹ The intervention period was relatively short (8 weeks), making it unclear whether the observed improvements in oxidative stress markers, uric acid, and clinical symptoms would be sustained over time.

Additionally, while key biomarkers were assessed, the study did not include more comprehensive measures of inflammation or cardiac function, limiting insight into the full clinical impact of ASX supplementation. Blood levels of astaxanthin were also not measured, preventing evaluation of dose–response relationships and individual variability in absorption. Finally, the study population included patients with varying degrees of heart failure severity without subgroup analysis, which may have influenced the overall outcomes.

This study suggests that astaxanthin supplementation may improve oxidative stress balance and clinical symptoms in patients with heart failure. Significant increases in antioxidant markers (TAC and SOD), along with reductions in MDA and uric acid, indicate a meaningful shift toward improved cellular and metabolic function.¹ These changes were accompanied by reductions in fatigue and dyspnea, highlighting potential benefits for quality of life.

The effects of astaxanthin are likely driven by its potent antioxidant activity, including its ability to reduce lipid peroxidation, enhance endogenous antioxidant defenses, and support mitochondrial function.¹ While these findings are promising, longer-term studies are needed to determine whether these improvements translate into sustained clinical benefits and reduced disease progression.

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Posted May 1, 2026.

Alexa Heathorn, MS, CNS-c, is a clinical nutritionist specializing in metabolic health, hormonal balance, and gastrointestinal restoration through root-cause functional nutrition. She earned her master’s degree in Nutrition from Bastyr University and is currently a Certified Nutrition Specialist (CNS) candidate. Alexa also works as a research writer and functional health consultant, translating complex science into actionable strategies for practitioners and wellness companies. Learn more at www.bloomedwellness.com.

References

1. Mohammadi SG, Shafie D, Feizi A, Bagherniya M, Ahmadi AR, Kafeshani M. Impact of astaxanthin on oxidative markers, uric acid, and clinical symptoms in heart failure: a randomized clinical trial. BMC Cardiovasc Disord. 2025;25(1):779. Published 2025 Oct 29. doi:10.1186/s12872-025-05260-z