How about flax seed or flax seed oil for Omega-3? Do we also need to keep a ratio of Omega-6?

One hundred grams of ground flax seed supplies about 450 kilocalories, 41 grams of fat, 28 grams of fiber, and 20 grams of protein.

Flax seed sprouts are edible, with a slightly spicy flavor. Excessive consumption of flax seeds with inadequate water can cause bowel obstruction.

Flax seed
Nutritional value per 100 g (3.5 oz)
Energy	2,234 kJ (534 kcal)
Carbohydrates	28.88 g
Sugars	1.55 g
Dietary fiber	27.3 g
Fat	42.16 g
Protein	18.29 g
Thiamine (Vit. B1)	1.644 mg (126%)
Riboflavin (Vit. B2)	0.161 mg (11%)
Niacin (Vit. B3)	3.08 mg (21%)
Pantothenic acid (B5)	0.985 mg (20%)
Vitamin B6	0.473 mg (36%)
Folate (Vit. B9)	0 μg (0%)
Vitamin C	0.6 mg (1%)
Calcium	255 mg (26%)
Iron	5.73 mg (46%)
Magnesium	392 mg (106%)
Phosphorus	642 mg (92%)
Potassium	813 mg (17%)
Zinc	4.34 mg (43%)

Flaxseed oil is good for the heart because it is the richest source of alpha-linolenic acid. Flaxseed itself (ground or whole) also contains lignans, which may have antioxidant actions and may help protect against certain cancers, though not everyone agrees on this issue.
Flaxseeds and flaxseed oil may help to:

- Lower cholesterol, protect against heart disease and control high blood pressure. Several studies indicate that flaxseed oil, as well as ground flaxseeds, can lower cholesterol, thereby significantly reducing the risk of heart disease. Flaxseed oil may also have a protective effect against angina (chest pain) and high blood pressure. In addition, a 5-year study done recently at Boston's Simmons College found that flaxseed oil may be useful in preventing a 2nd heart attack. It may also help prevent elevated blood pressure by inhibiting inflammatory reactions that cause poor circulation andartery-hardening plaque.

Ground flaxseed or flaxseed oil?

Liquid flaxseed oil is the easiest form to use, although it must be kept refrigerated. It is available either in liquid form, or in capsules.
If you prefer to use ground flaxseeds, just add 1 or 2 tablespoons of to an 8-ounce glass of water and mix. Flaxseeds have a pleasant, nutty flavor and taste good sprinkled on salads, cooked vegetables, or cereals.
I recommend you grind the seeds (or buy ground flaxseed) because whole seeds simply pass through the body. Grinding the seeds just before using them best preserves flavor and nutrition, but pre-ground seeds are more convenient. Keep them refrigerated. There are no nutritional differences between brown and yellow seeds.
For best absorption, take flaxseed oil with food. It is easily mixed into juices and other drinks, and its nutty, buttery flavor complements cottage cheese, yogurt and many other foods. You can also use it instead of olive oil in a salad dressing. Don't cook with it, however, as this will deplete the oil's nutrient content.