Benefits of flax in the diet

Flaxseed benefits and healing effects in the diet are familiar since the old Egyptians times. Nowadays flaxseed is popular due to high concentration of omega-3 unsaturated alpha-linolenic acid (ALA). The concentration of ALA in the cold pressed flaxseed oil is over 50%. Other fatty acids present in flaxseed oil besides the above mentioned are: palmitic (to 6%), stearic (to 4%), oleic (to 18%) and linoleic (to 14%). Flaxseed oil has highest concentration of unsaturated fatty acids. ALA is very important in the diet because this fatty acid is a “parent” to the essencial omega 3 unsaturated fatty acids.
In table No. 1 the percentage of fatty acids in flaxseed oil is shown

Table No.1. Most common fatty acids in flaxseed oil
Fatty acids - Percentage
Palmitic acid 5 to 6%
Stearic acid 3 to 4%
Oleic acid 15 to 18%
Linoleic acid 13 to 14%
Alpha-linolenic acid (ALA) 55 to 65%

Even back in 1920, scientists have discovered that excluding oil from rats’ diet leads to growth failure, dry skin and wounds. However, at that time people were not familiar with all the fatty acids and they didn’t know which fatty acids are essential for proper growth and development. Nowadays, it is well known that three types of fatty acids: linoleic, arachidonic and alpha-linolenic acids are crucial to people’s diet because these acids are “essential” due to the fact that the human body cannot synthesize them, i.e. they must be obtained through food [1]. The lack of ALA causes lack of omega 3 fatty acids in the human body leading to neurological symptoms, such as stiffness, muscle pain and blurry vision [2].
Flaxseed oil may have an impact on kidneys’ functioning
Regular use of flaxseed in the diet has an important impact on the functioning of the liver and the kidneys. Alpha-linoleic acid (ALA) induces a shift to 3-series prostanoids and omega 6 fatty acids to 2-series prostanoids. 3 series prostanoids are known as inhibitors of inflammatory processes. This is why flaxseed has an anti-inflammatory benefit and is recommended to heal kidneys inflammation [3].

Besides unsaturated fatty acids, flaxseed is rich in lignin phytoestrogen with a concentration of 75 to 800 more than other 66 types of vegetable food. Lignans are similar to the female hormone estrogen. Secoisolariciresinol diglucoside (SDG)and its mammalian lignin metabolically turn into enterodiol and into enterolactone afterwads. The effect of the flaxseed has an important role in the functioning of the sex hormones level in the blood. Namely, if women in menopause consume flaxseed on a regular basis, the lignins may cause estrogen effect. Phipps and his associates have made a research on the effect flax has (from 0 to 10g of flax per day) on 18 premenopause women and have concluded that the luteal phase had been prolonged of which the progesterone is responsible [4].

Brzezinski and his associates have conducted a research on 165 postmenopause women during a 12 weeks period and have concluded that diet rich in lignins reduces the symptoms of cold and hot flashes [5].
Lignans have anti-cancer effect because they reduce the risk of different types of cancer. Lignans are broken down in the intestines microflora and are converted into enterodiol and enterolactone. Adlercreutz and his associates have conducted a research on the effect these substances from the flax have on the breast cancer. He noticed that the excretion of lignans in the patients’ urine and the non-vegetarian ones is lower than the one in the vegetarians [6]. According to the latest research, prostate cancer and the thyroid gland cancer depends on the phytoestrogens.
Carcinogenesis is a process divided into four stadiums: initiation, promotion, progression and metastasis. Regular use of flax may inhibit any stadium in carcinogenesis. Previous studies on rats have demonstrated that diet rich in flax lowers the risk of initiation and promotion of cancer for 46% [7].
The cardiovascular effects of flaxseed
Healthy nutrition enriched with fats and oil is very important for heart disease prevention. One of the most important reasons for heart disease growth is mainly animal products based diet. It contains high percent of saturated fats such as palmitic and stearic fatty acid which cause increased plasma total cholesterol and LDL cholesterol, which in turn are closely related to mortality caused by cardiovascular diseases [8].
Regular Ala consumption causes metabolic synthesis of omega 3 fatty acids in the body regulating the systolic and diastolic blood pressure. This conclusion has been scientifically proven by Morris’s experiment and his associates. Namely, 1356 patients were included in this experiment. The results have proven that the systolic blood pressure lowered in3,4 mmHg whilest the diastolic blood pressure lowered in 23,4 mmHg with the regular use of 5,6 g/daily of oil rich in ALA to patients with chronical hypertension [9].
Flaxseed beneficial effects on the Immune system
Regular use of flaxseed and flaxseed oil in the diet significantly affects the inflammatory diseases associated with improper functioning of the immune system. Unsaturated omega-3 fatty acids act as AA antagonists, lowering their concentration in the cell membranes thus lowering the inflammatory mediators such as prostaglandins, leukotrienes responsible for the inflammatory process in the human body. Kelley And his associates have studied the effect of flaxseed oil on the immune system on 10 volunteers in the period of 56 days. The research has proven that flaxseed significantly lowers the immune system hypersensitivity to several types of antigens[10]. Also, by regular flaxseed and flaxseed oil consumption the risk of arteriosclerosis to 46% without lowering the total cholesterol in the blood serum [11].
Flaxseed’s effect on diabetes
The effect flaxseed and its oil have on the diabetes isn’t completely clear yet. However, some conducted researches indicate that although it does not directly lower the glucose level in the patients with diabetes – type 2’s blood it slows down the formation rate of glucose after meal.
Flaxseed and flaxseed oil are a rich source of vitamins group E. these are especially important in the skin age protection and the functioning of the sexglands [12].
Table No2 Vitamis goup E with highest concentration in the flaxseed oil
Table No2 Vitamis goup E with highest concentration in the flaxseed oil
Vitamis goup E mg/kg oil
α-tokoferolto 2 mg
γ-tokoferolto 450 mg
Plastochromanol-8 to 200 mg
δ-tokoferolto 4 mg

Phytosterols are a minor group of substances present in the flaxseed oil with a similar chemical structure to cholesterol. These substances are of a great importance nowadays due to the way they are absorbed in the body and the fact that they lower the blood cholesterol. Latest research conductedby Harward’s scientists have proven that although phytosterols have similar structure to the cholesterol, it differs from the cholesterol in the fact that it is more suitable for absorption in the intestines than the cholesterol. That way the cholesterol is not absorbed in the intestines when there are phytosteroles present, it only passes through them.Since the bile needs cholesterol for synthesis of the bile acid, the bile uses the LDL cholesterol and leaves the HDL cholesterol unused in the blood, thus lowering the total blood cholesterol [13].
The percent of phytosterols concentration in flaxseed oil is given in Table No.3.
Table No.3. the most concentrated phytosterols in flaxseed oil
Phytosterolsmg/kg oil
Brassicasterol 20-30mg
24-Methylene cholesterol 60-80 mg
Campesterol 600-800 mg
Campestanol 40-50 mg
Stigmasterol 200-300 mg
Δ7-Campesterol40-50 mg
Clerosterol 20-30 mg
β-Sitosterol 1200-1600 mg
Sitostanol 20-30 mg
Δ5-Avenasterol 300-400 mg
Δ5,24-Stigmastadienol 50-70 mg
Δ7-Stigmastanol 20-30 mg
Δ7-Avenasterol 20-30 mg

Bibliography
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