Flaxseed or linseed, with its high levels of omega-3 fatty acid, good amount of fiber, mucilage, and cancer-fighting lignans, is a healthy food supplement. Flaxseed is being used in functional food markets, where seeds are being used for fortification of food products as a health benefit ingredient. Recently, there has been a growing interest in the nutraceutical and probiotic properties of linseed due to its beneficial effects on coronary heart disease, neurological and hormonal disorders, colon tumor, breast cancer, prostrate cancer and atherosclerosis. The present article is intended to appraise the readers about the potential health benefits of linseed consumption.
Linseed or Flax (Linum usitatissimum L.) is an annual, self-pollinated species belonging to family Linaceae. Itis one of the ancient crops known to be grown 6000 – 8000 years ago. Linseed is important for the seed oil, stem fibre, paper, wax, nutraceutical and food processing industries.Linseed oil has edible as well as industrial uses. Besides being popular as a drying agent in paints and varnishes, diverse uses of linseed oil include the manufacturing of hardboards, brake linings, printer’s ink, anti-spalling treatments for concrete, manufacturing of linoleum, oil cloth, soaps and patent leather whileits stems produce good quality fibers used in high value linen and thread/rope and packaging material. Although, the petroleum based products have replaced linseed oil in such application but they pose threat to the environment. Hence, the interest in linseed oil is rejuvenating in present era.
Origin and current cultivation:Linseed is believed to have originated in either the Middle East or Indian regions. Indian subcontinent is known to have high biological diversity of genus Linum. Flax is an important crop worldwide, the total world production of linseed reached approximately 2.5 million tons in 2014, with Canada (34%), Russian Federation (15%) and China (13.6%) being the main producers. India is an important linseed growing country in the world ranking fourth in area (13%) and sixth in production (5.5%), respectively (FAOSTAT, 2016).
Nutritional composition: Flaxseeds are a rich source of micronutrients, dietary fiber, manganese, vitamin B1, and the essential fatty acid alpha-linolenic acid, also known as ALA or omega-3.An analysis of brown flax averaged 41% fat, 20% protein, 28% total dietary fibre, 7.7% moisture and 3.4% ash, which is the mineral-rich residue left after samples are burned.Detailed nutritional composition of linseed is as follows:
Fatty acids: Flax is rich in polyunsaturated fatty acids, particularly ALA,the essential omega-3 fatty acid, and linoleic acid (LA), the essential omega-6 fatty acid. These two polyunsaturated fatty acids are essential for humans i.e. they must be obtained from the fats and oils in foods because our bodies cannot synthesize them. ALA constitutes 57% of the total fatty acids in flax while Linoleic acid constitutes 16% of total fatty acids. Due to occurrence of rancidity in the oil after storage, it is not desirable for cooking inspite of its health benefits. Hence, efforts have been made to lower the linolenic acid content in the oil to make linseed oil ‘premium’ cooking oil. ‘Solin’ (LinolaTM 947), a mutant strain of linseed having fatty acid profile suitable for culinary uses was developed for use in foods. LinolaTM 989 andLinolaTM 1084 areother low linolenic acid flax cultivars released for commercial use.
Protein and Carbohydrates: The amino acid pattern of flax protein is similar to that of soybean protein, which is viewed as one of the most nutritious of the plant proteins. These are the ones that must be included in the diet because the human body cannot make them. Flax is low in carbohydrates (sugars and starches), providing little contribution to total carbohydrate intake.
Gluten:Flax is gluten-free. Gluten is a protein found in wheat, oats, barley and rye. The specific agent in gluten that causes the condition known as celiac disease is gliadin, which is rich in the amino acids proline and glutamine. Fortunately, people who are sensitive to gluten can enjoy flax in their diets.
Dietary fibre:The major fibre fractions in flax consist of cellulose, mucilage gums andlignin. Dietary fibre acts as a bulking agent in the gut. It increases stool weight and the viscosity of digested material, while also decreasing the transit time of material through the gut. In this manner, dietary fibre helps control appetite and blood glucose, promotes laxation and reduces blood lipids. Diets rich in dietary fibre may help reduce the risk of heart disease, diabetes, colorectal cancer, obesity and inflammation.
Vitamins and minerals:Vitamin E, a fat-soluble vitamin, is present in flax primarily as gamma-tocopherol. Gamma-tocopherol is an antioxidant that protects cell proteins and fats from oxidation; promotes sodium excretion in the urine, which may help lower blood pressure; and helps lower the risk of heart disease, some types of cancer and Alzheimer disease. Flax also contains a small amount of vitamin K in the form of phylloquinone. Vitamin K plays an essential role in the formation of certain proteins involved in blood clotting and in building bone. Flax contains magnesium, potassium,phosphorus, calcium and low amount of sodium and zinc.
Flax – A Health and Nutrition Primer: Flaxseed, with its high levels of omega-3 fatty acid, good amount of fiber, mucilage (long chain carbohydrates), and cancer-fighting lignans, is a healthy food supplement. Nutraceutical properties offlax make itfavourable choice in the food industry in addition to the industrial and ancient food uses.As a rich source of soluble fibre, linseed mucilage constitutes an excellent alternative to inulin indispensable for food processing industry. Flax oil is widely recognized for its health benefits. Its oil is used in anti-hypercholesterolemic (for lowering blood cholesterol) drugs for cardiovascular diseases. Recently, there has been a growing interest in linseed as a functional food due to its probiotic and anticancer properties.Probiotic properties of linseed have beneficial effects on coronary heart disease, neurological and hormonal disorders, colon tumor, breast cancer and atherosclerosis. Consumption of ground seeds adds nutritional benefits because flax seeds are also a rich source of lignans, compounds that have anticancer properties. Mucilage gums extracted from flax seeds and added to laxatives and cough syrups are a functional fibre. Flavonoids and lignans are major constituents of flaxseed. Among lignans, Secoisolariciresinoldiglucoside (SDG) is known to have different biological activities, such as prevention of cancer and also its antioxidant property. Dietary intake of flaxseed can decrease the risk of hot flashes among postmenopausal women. According to a study published in Nutrition Research journal, linseed consumption improves glycemic control in obese men and women with pre-diabetes.In the pet food industry, flax is being used to solve the digestive and skin problems in cats and dogs.In poultry, laying hens, when fed with 10 to 20% flax in their rations, produce eggs with increased amount of omega-3 fatty acids and decreased amount of saturated fatty acids called “Omega eggs”.Because of various health benefits, the demand for whole and milled flaxseed, and cold pressed flaxseed oil is increasing;hence, the interest in linseed is rejuvenating in present era.