Role of DHA in human body

health-benefits Jul 28, 2021
Prawns with butter and Tahitian vanilla served with coconut rice from Mama's Fish House in Maui, Hawaii.
Photo by Alexandra Tran / Unsplash

Omega-3 fatty acid that has an important role in cognitive and neurological health at all ages is docosahexaenoic acid (DHA).
It is found in the brain, eyes and in the tissues present in the heart and cardiovascular system as a major structural and functional fat.
This Omega-3 fatty acid is necessary for human health, but the body cannot synthesise it, so we have to get them through food or supplementation.

This essential fatty acid is found in the meat of cold-water fish, including mackerel, herring, tuna, halibut, salmon, cod liver, whale blubber, seal blubber, seaweed and algae.
Eggs produced by hens fed with a diet containing flaxseeds also contain DHA. Plant-based foods that contain DHA are flaxseeds, leafy greens, beans, cauliflower, cabbage and squash. DHA is widely available in supplement form.
Those who don’t eat fish and seaweed in their diets can take it in supplement form.

DHA improves brain function, decreases inflammation, reduces the occurrence of fatal heart attacks and ischemic strokes, improves the effect of autoimmune diseases, and improves vision.
As DHA plays a crucial role in the development of eye and nerve tissues, its intake will prevent age-related macular degeneration (AMD).
DHA also helps in treating type 2 diabetes, rheumatoid arthritis, coronary artery disease (CAD), dementia, and attention deficit-hyperactivity disorder (ADHD). When a person is in stressful conditions, DHA helps in reducing aggressive behaviour.

If it is taken in higher doses, reduces the symptoms of Alzheimer’s disease, vascular dementia, and improves   memory in those affected by dementia.
It lowers the triglycerides levels of the blood and decreases the thickness of the blood. This will reduce the risk of heart disease.
DHA is treated as a natural remedy for allergies.

Intake of DHA in pregnant and nursing mothers helps adequate brain development in their children.

DHA can also be used in combination with Eicosapentaenoic acid (EPA), evening primrose oil, thyme oil, and vitamin E. These combinations help in the prevention and reversal of heart disease, stabilizing heart rhythm, prevention of asthma, lung diseases, cancer, certain kidney diseases, painful menstrual periods, hay fever, systemic lupus erythematosus (SLE), and improves movement disorders in children suffering from dyspraxia.

As DHA has a crucial role in the health of infants and adults, DHA supplement manufacturers are busy in incorporating DHA into infant recipes, baby foods, DHA fortified foods and beverages.


  • DHA deficiency can cause many psychiatric disorders such as depression, anger, mood swings and suicidal behaviour.
  • Dry skin and hair, rough patches on skin, small bumps on the back of upper arms and legs, dandruff and soft or brittle nails.
  • Eye sight problems such as macular degeneration, dry eye syndrome and glaucoma
  • Insomnia
  • Excessive thirst, frequent urination
  • Neurons functioning is inhibited leading to memory loss and difficulty in learning
  • Metabolism is lowered  leading to weight gain
  • Fatigue
  • blood pressure will be lowered, blood clotting will be reduced and other heart-related illness
  • inflammation and arthritis
  • Immune system functions will be inhibited

Side effects

DHA is generally considered to be safe but its intake in the supplement form may cause some side effects.

  • Fish oils containing DHA can cause fishy taste, bad breath, heartburn, nausea, loose stools, belching, intestinal gas, and bruising.
  • When taken in large amounts, more than 3 grams per day, (generally advised to take 1 gm per day) will increase the risk for bleeding because DHA causes thinning of the blood.
  • If a person is sensitive to aspirin, DHA may affect the breathing.
  • It lowers blood pressure too much in people who are also taking blood pressure medications. If a person has high blood pressure, consulting the physician is compulsory before combining DHA with medications.


A. Sandhya

M.Sc Zoology

Great! You've successfully subscribed.
Great! Next, complete checkout for full access.
Welcome back! You've successfully signed in.
Success! Your account is fully activated, you now have access to all content.