Omega-3 fatty acids are polyunsaturated fatty acids. They have a double bond three atoms away from the end methyl group.
The most common sources for plant oils are walnuts, hemp oil and flaxseed oil. Sources of animal omega-3 fats include eggs, squid oils and fish.
Dietary supplementation does not affect the risk of cancer, heart disease or death.
They are not a main treatment for attention deficit hyperactivity disorder (ADHD), autism and other developmental disabilities. However, omega-3 supplements are often given to children with these conditions.

{{cite journal}}: Cite journal requires |journal= (help)