This article provides an extensive review of the health benefits of flaxseed as well as a review of safety. The authors indicate that the supplementation of the diet with milled flaxseed has many health benefits to the body. Although cardiovascular disease and cancer are probably the best researched areas that have shown convincing evidence of a beneficial action for dietary flaxseed, other areas like gastro-intestinal health and diabetes have also been receptive to the beneficial effects of dietary flaxseed.
The main bioactive compounds in flaxseed include alpha-linolenic acid (ALA), lignans and fiber. Four common forms of flaxseed available for human consumption include whole flaxseed, ground flaxseed, flaxseed oil and partially defatted flaxseed meal.
Flaxseed has been incorporated into foods for human consumption at concentrations of 5–28% of total ingredients (by weight) before baking. The amount of flaxseed ingested daily over an extended period of time has been as much as 40 to 50 g. Clinical trials having patients ingesting a food each day for up to one year have been successfully completed with drop-out rates of approximately 20% in both placebo and flax groups. This demonstrates that it is not the flaxseed that induces non-compliance per se, but instead a great number of different flax-containing foods are needed to allow variety in the daily choices if one is to maintain subjects in a trial with an extended duration.
Each food matrices can influence the stability of the flaxseed. Processing of the seed, storage temperature and duration as well as the form of flaxseed (milled flaxseed versus whole seed versus flax oil) will also influence the stability of the product. Milling, grinding or crushing flaxseed will destroy the hard protective seed coat on flaxseed, exposing the ALA and SDG to oxidation. However, this process is required to render these bioactive ingredients bioavailable. ALA is more bioavailable to the body if it is in oil or milled form. The incorporation of milled flaxseed into baked products may actually protect the ALA and SDG from degradation. Cooler storage temperatures and a shortened storage duration, particularly for flax oil, will also result in a better preservation of the ALA and SDG.
Dietary Flaxseed and Cardiovascular Disease
The health effects of flaxseed on parameters of cardiovascular disease have become one of the most intensely studied areas and are fully described in this paper. Flaxseed also impacts another major disease that is growing in incidence across the globe: diabetes. Flaxseed has been used in animal studies to treat a variety of cancers with the most studied being breast cancer.
The authors suggest that increasing our understanding of the value of dietary flaxseed, flax oil and SDG in this field and its efficacy in human trials may be a profitable avenue of future study. As in the case of the effects of flaxseed and its bioactive constituents in cardiovascular disease, it would appear that sufficient data already exists for the institution of these dietary therapies in specific cases of cancer prevention and treatment.
The paper also provides a review of research suggesting that dietary flaxseed may also improve aspects of normal brain function and also during conditions of neural disease. Dietary flaxseed may also exhibit a protective effect against menopausal symptoms. In addition, studies in healthy female volunteers with sensitive skin reported a positive improvement in skin properties with the ingestion of flaxseed oil.
The understanding of the impact of dietary flaxseed on the gut microbiome in either healthy or diseased populations is limited. It was known that the lignans that are unusually high in content within flaxseed need to be metabolized by intestinal bacteria in order to gain access to the systemic circulation in humans. The authors also note that is important to recognize that no definitive scientific data have been produced to support the concept of toxicity from dietary flaxseed.
Numerous areas in human health require further research to make definitive conclusions but the preliminary data is encouraging. With little or no evidence of toxicity for dietary supplementation with flaxseed, there appears to be a clear argument to support its inclusion in the daily diet and little reason to oppose it.
Key Points
This article provides an extensive review of the health benefits of flaxseed as well as a review of safety. The authors indicate that the supplementation of the diet with milled flaxseed has many health benefits to the body. Although cardiovascular disease and cancer are probably the best researched areas that have shown convincing evidence of a beneficial action for dietary flaxseed, other areas like gastro-intestinal health and diabetes have also been receptive to the beneficial effects of dietary flaxseed.
The main bioactive compounds in flaxseed include alpha-linolenic acid (ALA), lignans and fiber. Four common forms of flaxseed available for human consumption include whole flaxseed, ground flaxseed, flaxseed oil and partially defatted flaxseed meal.
Flaxseed has been incorporated into foods for human consumption at concentrations of 5–28% of total ingredients (by weight) before baking. The amount of flaxseed ingested daily over an extended period of time has been as much as 40 to 50 g. Clinical trials having patients ingesting a food each day for up to one year have been successfully completed with drop-out rates of approximately 20% in both placebo and flax groups. This demonstrates that it is not the flaxseed that induces non-compliance per se, but instead a great number of different flax-containing foods are needed to allow variety in the daily choices if one is to maintain subjects in a trial with an extended duration.
Each food matrices can influence the stability of the flaxseed. Processing of the seed, storage temperature and duration as well as the form of flaxseed (milled flaxseed versus whole seed versus flax oil) will also influence the stability of the product. Milling, grinding or crushing flaxseed will destroy the hard protective seed coat on flaxseed, exposing the ALA and SDG to oxidation. However, this process is required to render these bioactive ingredients bioavailable. ALA is more bioavailable to the body if it is in oil or milled form. The incorporation of milled flaxseed into baked products may actually protect the ALA and SDG from degradation. Cooler storage temperatures and a shortened storage duration, particularly for flax oil, will also result in a better preservation of the ALA and SDG.
Dietary Flaxseed and Cardiovascular Disease
The health effects of flaxseed on parameters of cardiovascular disease have become one of the most intensely studied areas and are fully described in this paper. Flaxseed also impacts another major disease that is growing in incidence across the globe: diabetes. Flaxseed has been used in animal studies to treat a variety of cancers with the most studied being breast cancer.
The authors suggest that increasing our understanding of the value of dietary flaxseed, flax oil and SDG in this field and its efficacy in human trials may be a profitable avenue of future study. As in the case of the effects of flaxseed and its bioactive constituents in cardiovascular disease, it would appear that sufficient data already exists for the institution of these dietary therapies in specific cases of cancer prevention and treatment.
The paper also provides a review of research suggesting that dietary flaxseed may also improve aspects of normal brain function and also during conditions of neural disease. Dietary flaxseed may also exhibit a protective effect against menopausal symptoms. In addition, studies in healthy female volunteers with sensitive skin reported a positive improvement in skin properties with the ingestion of flaxseed oil.
The understanding of the impact of dietary flaxseed on the gut microbiome in either healthy or diseased populations is limited. It was known that the lignans that are unusually high in content within flaxseed need to be metabolized by intestinal bacteria in order to gain access to the systemic circulation in humans. The authors also note that is important to recognize that no definitive scientific data have been produced to support the concept of toxicity from dietary flaxseed.
Numerous areas in human health require further research to make definitive conclusions but the preliminary data is encouraging. With little or no evidence of toxicity for dietary supplementation with flaxseed, there appears to be a clear argument to support its inclusion in the daily diet and little reason to oppose it.