A Focus on Fibre
What makes flax stand out above other whole grains is its mix of fibre. Rather than containing large amounts of one type of fibre, flax seeds contain generous quantities of both soluble and insoluble fibre. Flax tastes good and adds all the fibre of whole grains to foods: 1 Tbsp of milled flax contains as much total dietary fibre as 1 slice of whole wheat bread or 1/4 cup of cooked oat bran.
Flax is also one of the richest sources of lignans in the plant kingdom. Researchers are particularly interested in the cancer-fighting ability of lignans.
Soluble fibre – Most of the soluble fibre in flax seeds is mucilage, a thick, sticky substance. Few studies have looked at the direct effects of mucilage on health. But studies show that eating flax (baked into muffins and breads) can lower blood cholesterol levels.
Since it is well known that soluble fibres — fruit pectin, oat bran or mustard seed mucilage — are effective cholesterol-lowering agents, it’s likely that the soluble fibre in flax seeds is no exception.
Insoluble fibre – Not surprisingly, studies show that the insoluble fibre in flax, like that in wheat bran, is helpful for regulating bowel movements and preventing constipation. Because flax’s insoluble fibre components have the capacity to hold water, they help soften the stool and allow it to move through the colon more quickly.
Lignans – When bacteria in the digestive tract act on plant lignans these compounds are converted into potent hormone-like substances. Research with animals suggests that the newly formed compounds may be capable of blocking the action of certain cancer-causing substances in the body, substances that can contribute to the formation of tumours.
Currently , scientists are trying to determine how effective lignans and other chemicals in foods (phytochemicals) are at preventing cancer. They are also looking over evidence that suggests the omega-3 fatty acids in flax are potential anticarcinogens.