Flaxseed's health benefits come from the fact that it's high in fiber and omega-3 fatty acids, as well as phytochemicals called lignans. One tablespoon (7 grams) of ground flaxseed contains 2 grams of polyunsaturated fatty acids (includes the omega 3s), 2 grams of dietary fiber and 37 calories.
The health benefits noted in the studies above were observed with just 1 tablespoon (10 grams) of ground flax seeds per day. However, it's recommended to keep serving sizes to less than 5 tablespoons (50 grams) of flax seeds per day. Summary: Ground flax seeds provide the greatest health benefits