FAMILY MEDICINE® COLUMN

By John C. Wolf, D.O.Associate Professor of Family Medicine Ohio University College of Osteopathic Medicine

FLAXSEED OIL MAY HELP REDUCE LEVELS OF "BAD CHOLESTEROL"

Question: Is flaxseed oil good to take every day, and if so, are there any side effects? Should I be concerned about omega-6 fats in my diet, too?

Answer: Nutrition and its relationship to health is a confusing area for every one -- physicians, dietitians and other folks. Therefore, I'm not surprised that you have questions. Flaxseed oil has been advertised as the next great triumph of health care. As I'm sure you know, but my other readers may not, flaxseed oil is high in one of the omega-3 fatty acids. Its presence is the basis for the health claims made by the proponents of flaxseed oil. 

Research about the effects of nutrition on human health is hard to do because we humans are true omnivores. We can survive fairly well by eating almost any plant or animal source of food. Consequently, it takes a carefully designed study with a large number of participants to show with certainty the impact of excess or absence of any type of food. 

I'm sure you recall that a high level of HDL (so-called "good cholesterol") and a low level of LDL ("bad cholesterol") have been associated with a reduced risk of heart disease. A diet high in animal fats tends to raise total cholesterol primarily by increasing the amount of bad LDL in your blood. That's why it's recommended that we restrict our fat consumption to no more than 30 percent of our total daily calories. 

Further, its been shown that vegetable oils generally have less detrimental effect on our cholesterol than animal fats. But, the story is actually a bit more complicated. The process of manufacturing vegetable oils can change their desirable properties. Even cooking at high temperatures can do this. 

Another factor that must be considered in determining the health effects of various oils and fats involves the question you raised about omega-3 fatty acids. These fatty acids have been linked to lower total cholesterol and higher amounts of good HDL cholesterol. Flaxseed oil has one of the three omega-3 fatty acids, and thus may have some health benefit. But, to add just a bit more confusion, it is apparently not the mere presence of omega-3 fatty acids in the diet but the ratio of these fatty acids to another fatty acid (omega-6) that is the key to the possible health benefits. 

Omega-3 fatty acids are found in salmon, tuna, sardines, walnuts and flaxseed. The omega-6 fatty acids are found in cold pressed corn, olive, safflower and sunflower oils. So, those who believe the preliminary research that doesn't have the statistical power to convince skeptics, advocate the consumption of foods or supplements containing omega-3 fatty acids to "balance" with the easily available foods that are rich in omega-6 fatty acids. 

If you do not enjoy or can't afford cold-water fish as the source of your omega-3 fatty acids, then consider adding some flaxseed or flaxseed oil three times each week. The flax plant is an old friend of humans. We have used the fibers from the stalks of the plant to make linen for more than 3,000 years. The seeds are a food source. Unfortunately, flaxseed or its oil isn't very palatable. Walnut oil is somewhat better, but I still don't like it in my salad dressing. You should try them yourself because you may feel differently about their tastes. 

Remember that this omega-3 fatty acid information is currently only preliminary. While we await the results of better research, I'll eat fish -- which contain all three omega-3 fatty acids -- and keep my flaxseed oil as the finish on my wooden cutting board and olive oil in my salad dressing.

"Family Medicine" is a weekly column.

To submit questions, write to: John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.

Past columns are available online at http://www.FamilyMedicineNews.org.