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Dha (Docosahexaenoic Acid)

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What other names is Docosahexaenoic Acid known by?

Acide Docosahexaénoïque, Acide Gras d'Huile de Poisson, Acide Gras Oméga 3, Acide Gras N-3, Acide Gras W-3, Acido Docosahexaenoico, ADH, DHA, Fish Oil Fatty Acid, N-3 Fatty Acid, Neuromins, Omega 3, Oméga 3, Omega 3 Fatty Acids, Omega-3 Fatty Acids, W-3 Fatty Acid.

What is Docosahexaenoic Acid?

DHA (docosahexaenoic acid) is a fatty acid found in the meat of cold-water fish, including mackerel, herring, tuna, halibut, salmon, cod liver, whale blubber, and seal blubber. It can also be made by algae.

Don't confuse DHA with EPA (eicosapentaenoic acid). They are both in fish oil, but they are not the same. DHA can be converted into EPA in the body in very small amounts. See separate listings for fish oil and EPA.

DHA is used as a supplement for premature babies and as an ingredient in baby formula during the first year of life to promote better mental development. It is also used in infant formula to prevent lung diseases, allergic diseases such as eczema or hay fever, and diarrhea. This practice probably started because DHA is found naturally in breast milk. In some cases, DHA is used in combination with arachidonic acid.

DHA is also taken by mouth alone or along with EPA to improve mental function in healthy people or those with mental impairment. It is also used to improve mental function in people with dementia or age-related mental decline. It is also taken by mouth for attention deficit-hyperactivity disorder (ADHD), depression, aggressive behavior, Alzheimer's disease, autism, and to prevent relapse in schizophrenic patients who stop taking antipsychotic medication.

DHA is also taken by mouth for diabetes, coronary artery disease (CAD), stroke, high levels of cholesterol and fats in the blood, high blood pressure, and cancer including breast and prostate cancer. It is also used for a type of fatty liver not related to drinking alcohol, obesity, ear infections, and learning problems in children.

Some people use DHA is for improving vision, preventing an eye disease called age-related macular degeneration (AMD), treating an eye condition called retinitis pigmentosa, and increasing DHA levels in people with cystic fibrosis.

DHA is taken by mouth in combination with eicosapentaenoic acid (EPA) for a variety of conditions, including the prevention and reversal of heart disease, stabilizing heart rhythm, preventing abnormal heart beats after heart surgery, painful menstrual periods, lupus, and certain kidney diseases. EPA and DHA are also used in combination for preventing migraine headaches in teenagers, Behcet's syndrome, psoriasis, Raynaud's syndrome, rheumatoid arthritis, bipolar disorder, and ulcerative colitis.

It is also used in combination with evening primrose oil, thyme oil, and vitamin E (Efalex) to improve movement disorders in children with a condition called dyspraxia.

Possibly Effective for...

  • Clogged arteries (coronary artery disease). Increased consumption of DHA in the diet might lower the risk of death in people with coronary artery disease.
  • High cholesterol. Research suggests that taking 1.25 to 4 grams of DHA daily can lower triglyceride levels in people with high cholesterol or high triglyceride levels. It might also improve cholesterol levels in people with at least one risk factor for heart disease. However, DHA does not seem to lower total cholesterol in people with high cholesterol levels. Also, most research shows that it does not increase high-density lipoprotein (HDL or "good") cholesterol, although some conflicting research exists. DHA might increase low-density lipoprotein (LDL or "bad") cholesterol. But this effect might not be clinically significant. DHA does not seem to improve cholesterol in children with high cholesterol levels.

Possibly Ineffective for...

  • Age-related mental decline. Most research shows that taking DHA alone or with other ingredients does not improve memory, forgetfulness, or learning ability in people with age-related mental decline or mild mental impairment. Also, in elderly people without mental decline, taking DHA does not improve learning or memory. However, one large clinical study shows that taking DHA might improve visual and spatial learning in people with age-related mental decline. The effect seems to be greatest for people with a family history of dementia or those taking statins.
  • Attention deficit-hyperactivity disorder (ADHD). Many children with ADHD have low levels of DHA in their blood. However, taking DHA does not seem to improve ADHD symptoms, although some early research suggests that DHA might help children with ADHD become less aggressive and get along better with others.
  • Cancer. Research suggests that taking DHA along with eicosapentaenoic acid (EPA), with or without B vitamins, does not reduce the risk of getting any type of cancer in middle-aged and elderly people with heart disease. In fact taking the combination might increase the risk of cancer in women.
  • Mental performance. Research suggests that taking DHA does not improve mental performance in healthy children, young women, or healthy adults. Also, taking DHA along with eicosapentaenoic acid (EPA) does not improve mental function. One study shows that taking DHA can improve reading scores in children below the 20th percentile for reading. But it doesn't seem to improve reading scores in other children.
  • Depression. Taking DHA by mouth does not seem to relieve or prevent depression symptoms in most people. It also doesn't seem to prevent depression from developing in people with hepatitis C who are undergoing a treatment that is linked with depression. But taking DHA may delay the development of depression in these patients. Also, early research suggests that taking DHA along with eicosapentaenoic acid (EPA) might improve symptoms of depression in elderly people with mild mental impairment.
  • Diabetes. Taking DHA by mouth does not seem to lower blood sugar or cholesterol in people with type 2 diabetes. Also, levels of DHA in the blood of the pregnant mother do not appear to be associated with risk of type 1 diabetes in the child (90705).

Insufficient Evidence to Rate Effectiveness for...

  • Age-related macular degeneration (AMD). Increased intake of DHA as part of the diet is associated with a lower risk of developing vision loss due to aging. This may be related to the effects of DHA on color, or pigment, in a specific part of the eye, called the macula. However, when DHA is taken along with other vitamins and minerals known to prevent age-related vision loss, DHA does not seem to offer any improvement.
  • Alzheimer's disease. Some research suggests that people who get more DHA from their diet have a lower risk of developing Alzheimer's disease. However, research suggests that taking DHA supplement does not slow mental or functional decline in people with Alzheimer's disease.
  • Atopic dermatitis (eczema). Adding DHA and the fatty acid arachidonic acid to infant formula does not seem to prevent the development of eczema compared to regular formula.
  • Hypersensitivity. Research shows that giving hypersensitive women DHA supplements during pregnancy reduces the number of infants who experience nasal discharge and nasal congestion with or without fever after birth.
  • Abnormal heart rhythm. Having higher levels of DHA in fat tissue does not seem to be linked with a lower risk of abnormal heart rhythm. However, research suggests that taking DHA along with eicosapentaenoic acid (EPA) around the time of heart surgery reduces the risk of having abnormal heart rhythm after surgery.
  • Autism. Early research suggests that taking DHA does not improve most symptoms of autism. But it might help with specific symptoms like social withdrawal and communication.
  • Breast cancer. Early research suggests that taking DHA during chemotherapy treatment might help delay progression of the breast cancer and improve survival.
  • Crohn's disease. Increased intake of DHA as part of the diet is linked with a lower risk of developing Crohn's disease.
  • Cystic fibrosis. Early research suggests that taking DHA for up to one year does not improve lung function in people with cystic fibrosis.
  • Dementia. Early research suggests that taking DHA for one year improves symptoms of dementia caused by a condition related to blood clots in the brain (thrombotic cerebrovascular diseases).
  • Diarrhea. Early research shows that feeding infants formula with added DHA and the fatty acid arachidonic acid helps prevent the development of serious diarrhea compared to giving regular formula.
  • Dyslexia. Taking DHA by mouth seems to improve night vision in children with dyslexia.
  • Movement and coordination disorder (dyspraxia). Taking DHA by mouth together with evening primrose oil, thyme oil, and vitamin E (Efalex by Efamol Ltd.) seems to improve movement in children with dyspraxia.
  • Hypertension. Research shows that eating a specific canola oil rich in DHA might reduce blood pressure by a small amount in people with at least one risk factor for heart disease.
  • Improving infant development. Some research suggests that infants who do not receive DHA from breast milk or formula have delayed mental and visual development compared to those who receive enough DHA. Some researchers reasoned that giving DHA in formula might improve development. However, when they tested this theory, study results did not agree. The reason for the differences may be due to the way the studies were designed. For now, experts generally recommend breast-feeding instead of formula-feeding. However, if formula is used, some experts suggest a formula providing at least 0.2% of fats from DHA. Most research shows that taking DHA during pregnancy does not improve fetal development or infant development after birth. However, it might increase the weight and length of the baby at birth, as well as language development and ability to sleep after birth.
  • Liver disease (nonalcoholic fatty liver disease). Early research suggests that taking DHA for up to 2 years reduces the risk of severe fat accumulation in the liver in children with liver disease.
  • Obesity. Early research shows that taking DHA reduces the dietary intake of carbohydrate and fat in overweight or obese women. But it does not seem to help with weight reduction in these people.
  • Ear infection. Early research suggests that feeding infants formula with added DHA and the fatty acid arachidonic acid does not seem to prevent the development of ear infections compared to feeding regular formula.
  • Prostate cancer. Results of two population studies show that higher dietary intake of DHA is linked with a reduced risk of developing aggressive prostate cancer and advanced prostate cancer. However, analyses of several population studies show that higher intake of DHA is linked with an increased risk of prostate cancer.
  • Respiratory tract infections. Some research shows that giving preterm infants formula containing 1% DHA does not prevent serious respiratory tract infections compared to formula containing 0.35% DHA. However, some early research shows that giving full-term infants formula with added DHA and the fatty acid arachidonic acid reduces the risk of bronchitis, croup, stuffy nose, and cough compared to regular formula.
  • Inherited condition that causes vision loss (retinitis pigmentosa). Research on the effectiveness of DHA for people with retinitis pigmentosa is inconsistent. Some research suggests that taking DHA for 4 years does not improve eye function in people with retinitis pigmentosa who are also taking vitamin A. However, other research shows that taking DHA for 4 years improves eye function in some people with this condition. But visual function does not seem to improve.
  • Schizophrenia. Early research suggests that taking DHA, eicosapentaenoic acid (EPA), and alpha-lipoic acid for 2 years does not prevent symptoms from returning in people with schizophrenia who stop taking their medication.
  • Stroke. Higher blood levels of DHA are linked with a reduced risk of stroke.
  • Other conditions. word
More evidence is needed to rate DHA for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).


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