Clinical studies suggest that flaxseed oil and other omega-3 fatty acids may help treat a variety of conditions.
People who follow a Mediterranean diet tend to have an increased HDL (good) cholesterol level. The Mediterranean diet emphasizes fish and healthy fats, such as olive oil, and has a healthy balance between omega-3 and omega-6 fatty acids. Whole grains, root and green vegetables, daily portions of fruit, fish and poultry, olive and canola oils, and ALA (from flaxseed, flaxseed oil, and walnuts) are also part of the Mediterranean diet. Red meat and saturated fats are not part of the diet.
However, whether taking supplements of flaxseed or flaxseed oil helps lower cholesterol is up for debate. Some small studies show it has beneficial effects on cholesterol levels, but one double blind study found no evidence that it lowered cholesterol.
Eating a diet rich in fruits, vegetables, whole grains, nuts or legumes, and ALA-rich foods may substantially reduce the recurrence of heart disease. One of the best ways to help prevent and treat heart disease is to eat a diet low in saturated and trans fat and rich in monounsaturated and polyunsaturated fats (including omega-3 fatty acids from flaxseed and fish). Evidence suggests that people who eat an ALA-rich diet are less likely to suffer a fatal heart attack. ALA may reduce heart disease risk through a variety of ways, including making platelets less "sticky", reducing inflammation, promoting blood vessel health, and reducing risk of arrhythmia (irregular heart beat).
Several human studies also suggest that diets rich in omega-3 fatty acids, including ALA, may lower blood pressure.
However, it is not clear whether taking flaxseed oil as a supplement would have the same effect on heart health.
Preliminary evidence suggests that taking 1 to 2 g of flaxseed per day can improve the symptoms of dry eye in people with Sjogren's syndrome. Sjogren's syndrome is an autoimmune condition where the immune system attacks glands in the body that produce moisture like salivary and tear glands.
Studies suggest that flaxseed oil may help prevent the growth of breast tumors. In one Canadian Study, researchers discovered that flaxseed oil prevented breast tumor growth, likely through ALA content. People with breast cancer should not take any nutritional supplement without their doctor's approval.
Studies show that daily use of flaxseed and flaxseed oil are as effective as mineral oil in treating constipation.
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