DPA on the rise

The health benefits of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) fatty acids are among the most documented in nutrition research. However, a third key fatty acid, docosapentaenoic acid (DPA)an intermediary between EPA and DHA, has been shown to play a powerful role in key health outcomes. DPA, an elongated version of EPA, has drawn the attention of scientists because it is present in relatively high levels in the diet of Greenland Inuits, a population with exceptionally low incidence of cardiovascular disease (CVD).

Generally, Americans do not consume Inuit dietary stapleswhale and seal meat and blubber. However, USDA National Nutrient Database indicates DPA is present in marine oils, with menhaden oil documented as the richest fish oil source of the compound. In the last three decades, scientific studies focused on oils that contained mixtures of fatty acids, or on purified EPA and DHA, while the amount of research focused on DPA was limited. Nevertheless, a careful review of the published literature indicates inadequate dietary intake and low circulating blood levels of DPA may serve as a predictor and indicator of a broad range of diseases.

Among the many health conditions DPA addresses, heart health has received considerable scientific attention. A recent Harvard study, which involved more than 30,000 participants, showed higher plasma concentrations of DPA were associated with lower risk of heart attack. Similarly, another study showed people with evidence of CVD had lower levels of EPA, DHA and DPA as compared to healthy control subjects. Most importantly, the largest difference in fatty acid profiles was attributed to DPA, and only DPA showed an independent negative association with the disease after the adjustment for smoking habits.

Indeed, DPA has a good potential as a therapeutic compound. A large epidemiological trial showed dietary intake of DPA was significantly and inversely related to hardening of the arteries in Japanese adults. A separate study showed oral supplementation with purified DPA increased tissue concentrations of DPA, DHA and EPA in rats, while decreasing levels of arachidonic acida pro-inflammatory fatand restoring a healthy, critical balance of omega-3s to omega-6s.

Other studies examined the role of DPA in neurological health. For instance, it was demonstrated that DPA concentrations in blood of schizophrenic patients were significantly lower than those in blood of individuals from a matched control group. A separate study showed DPA supplementation may restore age-related decline in cognitive functions in an animal model.

Besides the role of DPA in cardiovascular, neurological and cognitive health, the compound may serve as a biomarker for other diseases. Human studies indicated a range of other potential health benefits, namely that DPA was the only EFA to have a positive effect on the aggressiveness of prostate cancer; and that omega-3/DPA levels are shown to be lower for alcohol-exposed subjects as compared to control groups.

Numerous studies indicate insufficient levels of DPA in diets and blood circulation may serve as a predictor and indicator of a broad range of health conditions. In addition, existing evidence points to DPA as a distinct and powerful nutritional and therapeutic supplement.

Alex Byelashov, Ph.D., is the manager of research and development at Omega Protein Corp. He holds a doctorate in food science safety from Colorado State University, and masters degrees from Iowa State University and Yale Universitys School of Public Health.  Byelashov has authored/coauthored multiple research papers, press articles, scientific reports and book contributions, and serves as an active member of GOEDs scientific committee.

References

1. Herold PM, Kinsella JE. Fish oil consumption and decreased risk of cardiovascular disease - a comparison of findings from animal and human feeding trials. Am J Clin Nutr. 1986;43(4):566-598.

2. Paganelli F et al. Altered erythrocyte n-3 fatty acids in Mediterranean patients with coronary artery disease. Int J Cardiol. 2001;78(1):27-32.

3. Sun Q et al. Blood concentrations of individual long-chain n-3 fatty acids and risk of nonfatal myocardial infarction. Am J Clin Nutr. 2008;88(1):216-223.

4. Leng GC et al. Plasma essential fatty-acids, cigarette-smoking, and dietary antioxidants in peripheral arterial-disease - a population-based case-control study. Arteriosclerosis Thrombosis. 1994;14(3):471-478.

5. Assies J et al. Significantly reduced docosahexaenoic and docosapentaenoic acid concentrations in erythrocyte membranes from schizophrenic patients compared with a carefully matched control group. Biological Psychiatry. 2001;49(6):510-522.

6. Milte CM et al. Erythrocyte polyunsaturated fatty acid status, memory, cognition and mood in older adults with mild cognitive impairment and healthy controls. Prostagland Leukotriene Essen Fatty Acids. 2011;84(5-6):153-161.

7. Ritch CR et al. Dietary fatty acids correlate with prostate cancer biopsy grade and volume in Jamaican men. J Urol. 2007;177(1):97-101.

8. Pawlosky RJ, Salem N. Ethanol exposure causes a decrease in docosahexaenoic acid and an increase in docosapentaenoic acid in feline brains and retinas. Am J Clin Nutr. 1995;61(6):1284-1289.

9. Hino A et al. Very long chain n-3 fatty acids intake and carotid atherosclerosis: An epidemiological study evaluated by ultrasonography. Atheroscler. 2004;176(1):145-149.

10. Kaur G et al. Short-term docosapentaenoic acid (22:5n-3) supplementation increases tissue docosapentaenoic acid, DHA and EPA concentrations in rats. Br J Nutr. 2011;103(1):32-37.

11. Akiba S, Murata T, Kitatani K, Sato T. Involvement of lipoxygenase pathway in docosapentaenoic acid-induced inhibition of platelet aggregation. Biol Pharmaceutical Bull. 2000;23(11):1293-1297.

12. Kanayasu Toyoda T, Morita I, Murota S. Docosapentaenoic acid (22:5, n-3), an elongation metabolite of eicosapentaenoic acid (20:5, n-3), is a potent stimulator of endothelial cell migration on pretreatment in vitro. Prostaglandins Leukotriene Essent Fatty Acids. 1996;54(5):319-325.

13. Kelly L et al. The polyunsaturated fatty acids, EPA and DPA exert a protective effect in the hippocampus of the aged rat. Neurobiology of Aging; In Press, Corrected Proof.