Algal oil, a marine-derived source of the omega-3 fatty acid docosahexaenoic acid (DHA), has been suggested to influence cardiovascular risk factors. However, its precise relationship with such factors has not been thoroughly examined. This systematic review and meta-analysis aimed to scrutinize the available evidence on the effects of algal oil supplementation on serum triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in individuals free from coronary heart disease.

Our systematic review encompassed randomized controlled trials published from 1996 to 2011, focusing on the impact of algal oil DHA on the aforementioned blood lipids. Eleven trials involving 485 participants met our inclusion criteria, revealing a median algal DHA dose of 1.68 g per day. The pooled estimates indicated a decrease in TG concentration by 0.20 mmol/L, an increase in LDL-C by 0.23 mmol/L, and an increase in HDL-C by 0.07 mmol/L. These findings suggest that algal oil, an alternative to fish-derived sources of omega-3, may positively modulate blood lipid profiles in a healthy population.

Introduction

The benefits of consuming EPA and DHA, particularly from fatty fish, are well-documented for individuals with hypertension, elevated TG levels, and those at risk of coronary heart disease (CHD). However, the sustainability of wild marine fish as a food source is under threat due to overexploitation, and aquaculture practices have raised ecological concerns.

Algal oil presents an intriguing alternative, as certain algae species are now cultivated to produce oil rich in DHA. Despite previous narrative reviews, a systematic examination of the link between algal oil supplementation and CHD risk factors was lacking, prompting this review and meta-analysis.

Materials and Methods

Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a comprehensive search of multiple databases for relevant randomized controlled trials. Our search was unrestricted by language, and we excluded non-human and pediatric studies, as well as those involving conditions that could affect algal oil absorption or metabolism.

Study Selection and Data Extraction

Our search strategy yielded 756 articles, from which we identified 11 eligible studies for final analysis. We extracted data on participant demographics, study design, intervention details, and lipid concentration measurements. The quality of each study was assessed using a validated scoring system, with attention to randomization, blinding, and reporting standards.

Statistical Analysis

Employing a fixed-effects meta-analysis, we calculated pooled estimates for changes in serum lipid concentrations due to algal oil DHA supplementation. Heterogeneity between studies was assessed using the Q statistic and I-squared statistic. Sensitivity analyses and publication bias assessments were conducted to ensure the robustness of our findings.

Results

The 11 trials provided data on 485 participants and demonstrated a significant reduction in TG and increases in both LDL-C and HDL-C with algal DHA supplementation. The observed changes in lipid profiles were similar in magnitude to those reported with fish oil supplementation.

Discussion

This systematic review and meta-analysis provide novel insights into the effects of algal oil DHA on blood lipid profiles. The findings suggest that algal oil may be a viable alternative to fish oil for supporting cardiovascular health. However, the limited number of studies, potential industry bias, and the need for further research to assess long-term cardiovascular outcomes are acknowledged limitations.

Conclusion

Algal oil, as a sustainable and pure source of DHA, shows promise for reducing serum triglycerides and increasing HDL-C and LDL-C in individuals without CHD. Further research is warranted to fully elucidate its potential impact on cardiovascular health.

Acknowledgments

The research was designed and conducted by a collaborative team, with data analysis and manuscript preparation handled by dedicated researchers. All authors contributed to the final content and approved the manuscript.

Supporting Information

Additional data and details are available in the supplementary materials.

Cited by

The impact of algal oil supplementation has been recognized in various fields, as evidenced by citations in multiple peer-reviewed journals.

This review adds to the body of evidence supporting the cardiovascular benefits of omega-3 fatty acids, offering a sustainable alternative to traditional fish oil sources. Future research directions should aim to explore the long-term effects of algal oil on cardiovascular health and compare its efficacy with fish oil supplementation.