Reduce the risk of stroke

Up the mainstream without a paddle

I shouldn’t be amazed anymore, but sometimes I still am.

I read quite a few new studies every week, and every now and then one of them will jump out as particularly promising. For instance, last week I came across an article on the Healthnotes Newswire with this headline: “Linoleic Acid Reduces Risk of Stroke.”

This looks good, no? Up your intake of linoleic acid – reduce your risk of stroke. Beautiful. If only it were true.

The study in question was reported in “Stroke,” the journal of the American Stroke Association, which is a division of the American Heart Association. And, in theory, their credibility should translate as seriously dependable. But, unfortunately, we know better than that by now.

The study was conducted by a group of researchers associated with universities and research institutions throughout Japan. Over a seven-year period, 7,450 men and women (ages 40 – 85) participated in the study, submitting periodic blood samples to measure levels of essential fatty acids (EFAs). Strokes were reported with 197 subjects. As a group, these subjects had significantly lower levels of linoleic acid in their blood than the subjects who did not record any strokes.

The Japan team concluded: “A higher intake of linoleic acid may protect against ischemic stroke.” But they also allowed that the lower levels of linoleic acid in the stroke group may NOT have been the result of dietary deficiency. They cited either poor absorption or the increased breakdown of the fatty acid as other possible factors.

They also called for additional studies to determine if a supplement of linoleic acid might prevent strokes. But I hope that their research does not press forward to that goal, because the average diet already contains more linoleic acid than it should.

Last month I sent you an e-Alert (“What the Squeaky Wheel Gets” 9/18/02) with a discussion about dietary oils, and a more specific look at the relationship of oils to the balance of omega-3 and omega-6 – two groups of essential fatty acids.

The body does not make EFAs. We have to get them through our diets. And for optimum performance of the immune system and the cardiovascular system, it’s important that our intake of omega-3 be higher than intake of omega-6. Unfortunately, omega-6 is easier to get than omega-3, so most people have a higher omega-6 intake. An omega balance that favors omega-6 promotes inflammation and has a negative impact on the body’s immune system. One that favors omega-3 promotes the proper regulation of several key cardiovascular functions such as heart rate, blood pressure, blood vessel dilation and blood clotting.

Now – here’s the kicker: the most common omega-6 fatty acid is none other than linoleic acid.

So why does the Japan study show that 197 stroke victims had low levels of linoleic acid, which, in theory, should have made them LESS likely to have a stroke? Good question. As I mentioned above, the researchers admit that their conclusion may be compromised by other factors. I believe they’re on the right track with that assessment. But their suggestion that further research should support the idea that linoleic acid supplements might prevent stroke would seem to be aiming a square peg at a round hole.

But let’s leave Japan and linoleic acid and omega-6 behind for now, and take a closer look at omega-3, which almost all of us could use more of in our diets.

The primary source of omega-3 is fish, especially dark-meat fish like salmon, swordfish and tuna. If you want to avoid mercury, a high quality fish oil supplement is a good source as well. Interestingly, both omega-3 and omega-6 are present in beef. But if the source cattle of your beef have been fed grain, omega-6 will be larger in the balance, and if the cattle have been fed grass, omega-3 will prevail.

Unfortunately, most of the commercial beef (especially in grocery stores) comes from grain-fed cattle. Even grass-fed cattle are usually fattened with grain feed in the days just before slaughter. When conscientious ranchers don’t fatten their livestock with grain, the result is called “grass-finished” beef. It may be difficult enough to find grass-fed beef, much less grass-finished beef, but if you do, you’ll be doing your immune and cardiovascular systems an omega-3 favor.

To Your Good Health,

Jenny Thompson
Health Sciences Institute