Articles

Docosahexaenoic Acid (DHA)

Introduction

DHA is a member of the omega-3 group of fatty acids. DHA is also one of the most abundant fatty acids in the brain. In the fetus and young infants, DHA is essential for proper growth and development of the brain, (1) , (2) nervous system, and the retina of the eye. Because DHA is present in breast milk and not in cow’s milk, many physicians recommend breast-feeding or the use of infant formula that contains DHA.

The richest dietary sources of DHA are the oils from cold water fish such as salmon, mackerel, herring, sardines, and other marine animals. DHA is also produced in the body, but it must be derived from alpha-linolenic acid, which is found in flaxseed oil.

Dosage Info

Dosage Range

250-1,000mg daily.

Most Common Dosage

500mg daily.

Dosage Forms

Capsules and tablets.

Interactions and Depletions

Interactions

Reported Uses

Scientists think DHA is primarily involved in the growth and development of the brain and nervous system, (3) as well as the retina. However, these functions may make it useful for the treatment and support of a number of health conditions.

Studies suggest that children with attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD) may be deficient in DHA. (4) However, DHA supplementation in ADHD individuals may not be as effective as once thought. (5) People with schizophrenia may also be deficient (6) , (7) and DHA has improved some of the symptoms associated with the disease. (8) Other studies suggest that omega-3 fatty acids like DHA may exhibit mood-stabilizing properties in patients with bipolar disorder, also known as manic-depressive illness. (9) Researchers found that bipolar mood disorder patients had lower levels of DHA than control subjects and that supplementation may be beneficial to the patients. (10)

DHA and other omega-3 fatty acids may help reduce the risk of breast cancer. They may also suppress factors that can contribute to the growth of breast tumors. (11) Animal and cell studies have demonstrated decreased tumor size and decreased cancer cell growth with DHA use. (12) Animal studies also suggest that supplementation with DHA can make several types of chemotherapy, including mitomycin C and cyclophosphamide, both more effective and less toxic. (13) , (14)

The importance of DHA for pre-term and full-term infants cannot be overemphasized. Studies suggest that infants receiving supplemental DHA in their infant formulas scored significantly higher in mental development, as gauged by memory, problem solving, and related skills. (15) , (16) DHA is also essential for the development of the brain (17) and eyes in infants and has shown benefit in vision studies. (18) Physicians stress that pre-term infants should be supplemented with DHA since these infants are often incubated and not breast-fed. (19) It is also important that mothers breast-feeding their infants be educated about the importance of obtaining optimal intakes of DHA. DHA may also help ease the symptoms for women who experience painful menstruation. (20)

A study evaluated a group of patients suffering from sickle cell disease while providing them with a fish oil that contained 12% EPA and 18% DHA. This treatment decreased the number of pain episodes requiring hospitalization by almost one-half. (21)

Results from several studies indicated that supplementation of DHA may be of benefit to X-linked retinitis pigmentosa patients. (22) , (23) Also, a study provided information as to the safety of DHA supplementation over a long period of time. (24)

Individuals with a genetic disorder known as Zellweger syndrome are known to have low levels of DHA. (25) Patients treated with DHA had improved vision and muscle function, as well as MRI-documented improvements in myelination, a coating found on nerves that enhances the conduction of nerve impulses. Treatment has been most successful when initiated before 6 months of age. (26)

As with other omega-3 fatty acids, DHA may support long-term health of the cardiovascular system. More specifically, DHA may help prevent heart disease and help lower harmful fat levels in the blood stream. (27) , (28) , (29) , (30) One study noted that DHA not only lowered the harmful fat and cholesterol levels in the body, but also improved the elastic nature of the arteries. (31) Arteries that have poor elasticity may indicate cardiovascular disease.

Toxicities & Precautions

Introduction

[span class=alert]Be sure to tell your pharmacist, doctor, or other health care providers about any dietary supplements you are taking. There may be a potential for interactions or side effects.[/span]

General

People who take supplemental DHA are advised to take additional antioxidants, especially vitamin E, to protect against free radical damage to DHA in the body.

Side Effects

People who take a fish oil form of DHA may experience belching that causes a “fishy" odor. (32)

Pregnancy / Breast Feeding

To date, the medical literature has not reported any adverse effects related to fetal development during pregnancy or to infants who are breast-fed. Yet little is known about the use of this dietary supplement while pregnant or breast-feeding. Therefore, it is recommended that you inform your healthcare practitioner of any dietary supplements you are using while pregnant or breast-feeding.

Age Limitations

To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Since young children may have undiagnosed allergies or medical conditions, this dietary supplement should not be used in children under 10 years of age unless recommended by a physician.

References

  1. View Abstract: Helland IB, et al. Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children's IQ at 4 years of age. Pediatrics. Jan2003;111(1):e39-44.
  2. View Abstract: Colombo J, Kannass KN, Jill Shaddy D, et al. Maternal DHA and the Development of Attention in Infancy and Toddlerhood. Child Dev. Jul2004;75(4):1254-67.
  3. View Abstract: Khedr EM, Farghaly WM, Amry Sel-D, Osman AA. Neural maturation of breastfed and formula-fed infants. Acta Paediatr. Jun2004;93(6):734-8.
  4. View Abstract: Burgess JR, et al. Long-chain polyunsaturated fatty acids in children with attention-deficit hyperactivity disorder. Am J Clin Nutr. Jan2000;71(1 Suppl):327S-30S.
  5. View Abstract: Voigt RG, Llorente AM, Jensen CL, et al. A randomized, double-blind, placebo-controlled trial of docosahexaenoic acid supplementation in children with attention-deficit/hyperactivity disorder. J Pediatr. Aug2001;139(2):189-96.
  6. View Abstract: Laugharne J, et al. Fatty Acids and Schizophrenia. Lipids. 1996(Suppl.);31-S-163 - S-165.
  7. View Abstract: Ranjekar PK, Hinge A, Hegde MV, et al. Decreased antioxidant enzymes and membrane essential polyunsaturated fatty acids in schizophrenic and bipolar mood disorder patients. Psychiatry Res. Dec2003;121(2):109-22.
  8. View Abstract: Peet M, Laugharne JD, Mellor J, Ramchand CN. Essential fatty acid deficiency in erythrocyte membranes from chronic schizophrenic patients, and the clinical effects of dietary supplementation. Prostaglandins Leukot Essent Fatty Acids. Aug1996;55(1-2):71-5.
  9. View Abstract: Stoll AL, et al. Omega 3 fatty acids in bipolar disorder; A preliminary double-blind, placebo-controlled trial. Archives of General Psychiatry. May1999;66:407-412.
  10. View Abstract: Ranjekar PK, Hinge A, Hegde MV, et al. Decreased antioxidant enzymes and membrane essential polyunsaturated fatty acids in schizophrenic and bipolar mood disorder patients. Psychiatry Res. Dec2003;121(2):109-22.
  11. View Abstract: Noguchi M. The Role of Fatty Acids and Eicosanoid Synthesis Inhibitors in Breast Cancer. Oncology. 1995;52:265- 271.
  12. View Abstract: Colquhoun A, Ramos KL, Schumacher RI. Eicosapentaenoic acid and docosahexaenoic acid effects on tumour mitochondrial metabolism, acyl CoA metabolism and cell proliferation. Cell Biochem Funct. Jun2001;19(2):97-105.
  13. View Abstract: Shao Y, Pardini L, Pardini RS. Dietary menhaden oil enhances mitomycin C antitumor activity toward human mammary carcinoma MX-1. Lipids. Nov1995;30(11):1035-45.
  14. View Abstract: Shao Y, Pardini L, Pardini RS. Intervention of transplantable human mammary carcinoma MX-1 chemotherapy with dietary menhaden oil in athymic mice: increased therapeutic effects and decreased toxicity of cyclophosphamide. Nutr Cancer. 1997;28(1):63-73.
  15. View Abstract: Birch EE, et al. A randomized controlled trial of early dietary supply of long-chain polyunsaturated fatty acids and mental development in term infants. Dev Med Child Neur. 2000;(42):174-181.
  16. View Abstract: Willatts P, Forsyth JS, DiModugno MK, et al. Effect of long-chain polyunsaturated fatty acids in infant formula on problem solving at 10 months of age. Lancet. Aug1998;352(9129):688-91.
  17. View Abstract: Helland IB, et al. Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children's IQ at 4 years of age. Pediatrics. Jan2003;111(1):e39-44.
  18. View Abstract: Jorgensen MH, Hernell O, Hughes E, Michaelsen KF. Is there a relation between docosahexaenoic acid concentration in mothers' milk and visual development in term infants? J Pediatr Gastroenterol Nutr. Mar2001;32(3):293-6.
  19. View Abstract: Uauy R, Mena P. Requirements for long-chain polyunsaturated fatty acids in the preterm infant. Curr Opin Pediatr. Apr1999;11(2):115-20.
  20. View Abstract: Harel Z, et al. Supplementation With Omega-3 Polyunsaturated Fatty Acids in the Management of Dysmenorrhea in Adolescents. American Journal of Obstetrics and Gynecology. Apr1996;174(4):1335-8.
  21. View Abstract: Tomer A, Kasey S, Connor WE, et al. Reduction of pain episodes and prothrombotic activity in sickle cell disease by dietary n-3 fatty acids. Thromb Haemost. Jun2001;85(6):966-74.
  22. View Abstract: Hoffman DR, DeMar JC, Heird WC, et al. Impaired synthesis of DHA in patients with X-linked retinitis pigmentosa. J Lipid Res. Sep2001;42(9):1395-401.
  23. View Abstract: Hoffman DR, Locke KG, Wheaton DH, Fish GE, Spencer R, Birch DG. A randomized, placebo-controlled clinical trial of docosahexaenoic acid supplementation for X-linked retinitis pigmentosa. Am J Ophthalmol. Apr2004;137(4):704-18.
  24. View Abstract: Wheaton DH, Hoffman DR, Locke KG, Watkins RB, Birch DG. Biological safety assessment of docosahexaenoic acid supplementation in a randomized clinical trial for X-linked retinitis pigmentosa. Arch Ophthalmol. Sep2003;121(9):1269-78.
  25. View Abstract: Takemoto Y, Suzuki Y, Horibe R, Shimozawa N, Wanders RJ, Kondo N. Gas chromatography/mass spectrometry analysis of very long chain fatty acids, docosahexaenoic acid, phytanic acid and plasmalogen for the screening of peroxisomal disorders. Brain Dev. Oct2003;25(7):481-7.
  26. View Abstract: Martinez M. Restoring the DHA levels in the brains of Zellweger patients. J Mol Neurosci. Apr2001;16(2-3):309-16.
  27. View Abstract: Simon J, et al. Serum Fatty Acids and Risk of Coronary Heart Disease. American Journal of Epidemiology. 1995;142(5):469-476.
  28. View Abstract: Davidson M, et al. Effects of docosahexaenoic acid on serum lipoproteins in patients with combined hyperlipidaemia: a randomized, double-blind, placebo-controlled trial. J AM Coll Nutr. 1997;16:236-243.
  29. View Abstract: Stark KD, Holub BJ. Differential eicosapentaenoic acid elevations and altered cardiovascular disease risk factor responses after supplementation with docosahexaenoic acid in postmenopausal women receiving and not receiving hormone replacement therapy. Am J Clin Nutr. May2004;79(5):765-73.
  30. View Abstract: Lovegrove JA, Lovegrove SS, Lesauvage SV, et al. Moderate fish-oil supplementation reverses low-platelet, long-chain n-3 polyunsaturated fatty acid status and reduces plasma triacylglycerol concentrations in British Indo-Asians. Am J Clin Nutr. Jun2004;79(6):974-82.
  31. View Abstract: Nestel P, Shige H, Pomeroy S, Cehun M, Abbey M, Raederstorff D. The n-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid increase systemic arterial compliance in humans. American Journal of Clinical Nutrition. Aug2002;76(2):326-330.
  32. View Abstract: Healy DA, et al. Effect of low-to-moderate amounts of dietary fish oil on neutrophil lipid composition and function. Lipids. Jul2000;35(7):763-8.