FREQUENTLY ASKED QUESTIONS ON DHA

FAQ'S - ABOUT FOODS WITH HIGH DHA CONTENT

Docosahexaenoic acid (DHA) is an omega–3 fatty acid which is an essential fatty acid and an important part of the brain and the eye. Essential fatty acids cannot be synthesized in the body. They are also called polyunsaturated fatty acid (PUFA). These PUFA must be obtained from dietary food. There are 2 types of PUFA – omega 6 and omega 3. Omega 3 fatty acids are also known as Long Chain polyunsaturated fatty acids (LC PUFA’s). The most important omega 6 (n-6) fatty acid is arachidonic acid (ARA) that is formed from linoleic acid (LA) while most important omega 3 (n-3) fatty acid is DHA which is formed from alpha – linolenic acid (ALA). Throughout most of life, there is a very limited metabolic capacity to convert ALA to DHA. Thus, DHA should be acquired from dietary sources to maintain optimal health.

Question:
What are the food sources of DHA?

Answer:
In infants, breast milk is a good source of DHA. Breast milk content of DHA depends on intake of DHA and its stores in the mother. Fish oils are rich in DHA. Most of the DHA in fish and other organisms originate from microalgae. ALA is present in vegetable oils such as flaxseed or linseed oil, rapeseed or canola oil, peanut oil, olive oil, soya oil, walnut oil, green leafy vegetables, fenugreek seeds, kidney beans and dry fruits. DHA is also manufactured from microalgae in vegetarian form for commercial use. Inadequate intake of n-3 PUFA decreases DHA and increase n-6 PUFA in the brain. Western diets as well as diet in developing countries are low in n-3 PUFA (7) whereas consumption of n-6 fatty acids is higher. The ideal ratio of n-6 and n-3 PUFA in diet should be 5-10:1 for optimal health benefits.

The DHA content in various foods is depicted in Table 1.

Table 1: Dietary sources of DHA (7)

Source	Grams of omega - 3 fatty acid
Fish  • Tuna  • Pollock  • Salmon  • Cod  • Catfish  • Flounder  • Grouper  • Halibut  • Mahi mahi  • Orange roughy  • Red snapper  • Shark  • Sword fish  • Tile fish  • King mackerel Botanical sources  • Chia  • Kiwifruit  • Perilla	(per 3 oz serving) 0.21 - 1.1 0.45 1.1 - 1.9 0.15 - 0.24 0.22 - 0.3 0.48 0.23 0.60 - 1.12 0.13 0.028 0.29 0.83 0.97 0.90 0.36 Percentage of omega - 3 in seed oil 64 62 58
Flaxseed	55(18% of omega-3 in the whole food
Cow berry	49
Camelina	36
Purslane	35
Black raspberry	33
Hemp seed	19 (8.7% of omega 3 in the whole food)

Question:
What should be the daily intake of DHA?

Answer:
While exact dose of DHA to be consumed is not known, the following are recommended amounts:

	Pregnant and Nursing women – A workshop sponsored by the National Institutes of Health and International Society for the study of fatty acids and lipids (NIH/ISSFAL) recommended an intake of 300mg/day of DHA
	Children and Healthy Adults – NIH/ISSFAL have recommended an intake of 220 mg/day of DHA.