I was surprised to see a chapter in Fish, Omega-3 and Human Health devoted to hypertension. Isn’t high blood pressure caused by too much salt and too much weight? Well, yes, but a special strain of rats used as an animal model of hypertension turned out to have a defect in their immune system. Perhaps high blood pressure is also caused by immune-system over-reaction.
A 1993 meta-analysis of studies of the effect of fish oil on blood pressure concluded:
Diet supplementation with a relatively high dose of omega-3 PUFA, generally more than 3 g/d, can lead to clinically relevant BP reductions in individuals with untreated hypertension.
The sizes of the blood pressure changes:
Weighted, pooled estimates of SBP [systolic blood pressure] and DBP [diastolic blood pressure] change (mm Hg) with 95% confidence intervals were -1.0 (-2.0 to 0.0) and -0.5 (-1.2 to +0.2) in the trials of normotensives, and -5.5 (-8.1 to -2.9) and -3.5 (-5.0 to -2.1) in the trials of untreated hypertensives.
A different meta-analysis reached essentially the same conclusion.
Note the use of fish oil. Fish oil has long-chain omega-3 fats, while flaxseed oil — which I have used in my self-experimentation — has only the short-chain omega-3 fat, which is converted to long-chain omega-3 after you eat it. Fish oil is often considered better because the omega-3s don’t need to be converted. But this way of thinking misses something. Because the omega-3s in flaxseed oil are converted to long-chain omega-3s by enzymes, the amount of long-chain omega-3 in the body rises more slowly (and thus lasts longer) than if you take fish oil supplying the same amount of long-chain omega-3. Flaxseed oil supplies a kind of time-release long-chain omega-3. A long low dose could easily be more potent than a short high dose.
Thanks to Dave Lull.
I’m sure something in Dr. Davis’ past education prompted his speculation about dose frequency, but he does not sound very convincing. The liver holds vitamins until needed, surely the body has some way of dealing with the oh-so-important omega-3 fats. His theory sounds more like pandering to our voodoo instinct: be sure to shake the bottle 7 times before it’s opened, too. It activates the molecules at their resonant frequency.
I agree that Dr. Davis is remarkably vague: “more frequent dosing may provide a larger effect. The least effective dosing is once per day; twice per day is far more effective. Three times per day, although cumbersome,provides even greater effect.” He never says what “effect” is being measured. Why not?
I think the “effect” that Dr Davis is looking for is a decrease of triglycerides to 60 mg/dl or less, and the elimination of “intermediate-density lipoprotein, or IDL, also called ‘remnant lipoproteins’ on a VAP panel.” *
*See “How much omega-3s are enough” here:
https://heartscanblog.blogspot.com/2007/05/how-much-omega-3s-are-enough.html
on an unrelated note, it seems to have an effect on Parkinson’s
https://www.sciencedaily.com/releases/2007/11/071126110453.htm
Igor.