Fish Oil*Friend or Foe?

[JacquelineL]

This throws a monkey wrench into my plans to lower both triglycerides and LDL by taking fish oil supplements. It is more important to me to get my LDL down as my triglycerides are barely over the norm.

These patients were on a diet rich in saturated fat. A change in diet to lower saturated fat intake at the same time will effect a decrease in LDL.
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Effects of Omega-3 Fatty Acids and Lipoproteins
The addition of omega-3 fatty acids to the diet lowers triglyceride levels, an effect that is pronounced in those with marked hypertriglyceridemia.3 The triglyceride-lowering effect is not seen with plant sources of n-3 PUFA.4 In those patients with type V hyperlipidemia, the use of fish oil supplements is an important therapeutic option.5 Connor6 listed the following putative mechanisms of dietary n-3 PUFA on lipoprotein metabolism in humans: (1) inhibition of VLDL triglyceride synthesis, (2) decreased apoprotein B synthesis, (3) enhancement of VLDL turnover with an increased fractional catabolic rate of VLDL, (4) depression of LDL synthesis, and (5) reduction of postprandial lipemia.

A critical review by Harris2 has clarified the discrepancy among fish oil studies reporting effects on LDL cholesterol (LDL-C). He noted that in the majority of studies reporting reductions in LDL-C levels, the saturated fat intake was lowered when subjects switched from the control diet to the fish oil diet. When fish oil is consumed and saturated fat intake is constant, LDL-C levels either do not change or may increase.

Although fish oil is not recommended in the treatment of hypercholesterolemia, it does have a role in the treatment of lipoprotein disorders characterized by severe hypertriglyceridemia. It can be quite useful in those severely hypertriglyceridemic (triglyceride >1000 mg/dL) patients for whom attempts to correct secondary causes (through diet, exercise, and gemfibrozil) have proved inadequate.7 Although a negative aspect is the concomitant elevation in LDL-C that occurs when fish oils are given to these patients with lower plasma levels of triglyceride, this is usually not a problem for those with severe hypertriglyceridemia, because LDL-C values are usually quite low. It can be a problem for those with more modest elevations of triglycerides in whom the elevation of LDL-C will actually move the patient away from the desired LDL-C goal.

[ARIZONA73]

I think that an elevated triglyceride level poses a significant risk, since it contributes towards LDL as VLDL. This can result in a shift in LDL particle size towards that of Pattern B, a predominantly smaller particle size which carries significantly higher risk. While we all have LDL which is composed of varying particle sizes, some people are predominantly Pattern A (large particle size), while others may be Pattern B. It has been said that Pattern B can carry as much as 3 times the risk as Pattern A. That tells me that someone who is Pattern B and has an LDL of 70 may carry as much risk as someone else who has an LDL of 210, but is Pattern A. Generally speaking, Pattern A is more strongly correlated with high HDL and low triglycerides, while Pattern B is more common with low HDL and high triglycerides. But a calculated LDL tells us essentially nothing. A measured LDL provides a much clearer picture of actual risk.

[zip2play]

Originally Posted by ARIZONA73

But a calculated LDL tells us essentially nothing. A measured LDL provides a much clearer picture of actual risk.

I have been thinking about this for several months and have come to the conclusion that you have hit the nail SQUARE on the head, Arizona.
Back in the dark ages they got themselves a way to easily measure CHOLESTEROL. But then they found that there are several components to it such as HDL and LDL....hmmm but these didn't add up so they threw in triglycerides as a fudge factor....oops tpoo high, but if we divide by 5, hmmmm.

OK, so now they had a first approximation analysis. BUT then turning it backwards (as if it could be dealt with in pure numbers like A +B =C) to determine LDL by working in the TRI/5 is pure hokum.

In your bloodstream there are PARTICLES of LDL....if your vision was good enough you'd SEE them. Adding some extra triglyceride molecules won't make these particles of matter disappear, only SEEM to disappear on paper because the "equation" fiddling is bad science.

So for several weeks now, everytime I saw LDL = TC - HDL -(T/5) my eyes just glazed over


This same line of reasoning goes to VLDL's as well....they are VERY REAL MOLECULES: triglycerides/5 is NOT REAL just a convenience that's probably CHEAPER to measure.

[arkie6]

Originally Posted by pcovers

Using the means by which 99% of all lipid profiles numbers are determined, the rule, not the exception, but the rule states that if trigs go down ldl goes up. No wonder studies would show this. Thre is nothing else hey could possibly show except this. Simple math:

LDL=TC(minus)HDL(minus)(Trigs/5)

Anyway you look at it, if trigs go down, ldl goes up...

I've seen that statement made before, but I don't see how you can come to that conclusion by just looking at a simple mathematical equation. The equation doesn't mean that if triglycerides go down that LDL must go up. HDL and total cholesterol can also change resulting in no direct correlation between LDL and triglycerides. And no studies that I am aware of support this statement either. Now LDL particle size and triglycerides are closely related, but not the total amount of LDL.

The LDL equation starts with the following equation:

Total Cholesterol = HDL + LDL + VLDL

Solving for LDL and substituting trig/5 for VLDL results in the common form of the equation shown above:

LDL = Total Cholesterol - HDL - triglycerides/5.

This equation is just used as a convienence and cost saving measure since LDL is more difficult to directly measure than the total or any of the other subcomponents.

As an example, if triglycerides went down 50 points and HDL went up 10 points and total cholesterol remained unchanged, then the LDL number would not change. And this is a fairly common response to a low carbohydrate diet (reduces triglyceride levels) that includes plenty of red meat and animal fats (natural saturated fat promotes elevated HDL levels).

Back to the LDL particle size and triglyceride connection. I have read several study abstracts on Medline and other sources that show a close correlation between low triglyceride levels (in general <100 mg/dl) and the predominate LDL particle size being the larger pattern A which is not considered harmful. And high triglyceride levels have been shown to be strongly associated with the predominate LDL size being the smaller denser pattern B with is highly subject to oxidation and most often associated with atherosclerosis. This may be related to what is happening with the fish oil/triglycerides/LDL studies. Anyone note the LDL particle size associated with the fish oil supplementation?

[pcovers]

Originally Posted by arkie6

I've seen that statement made before, but I don't see how you can come to that conclusion by just looking at a simple mathematical equation. The equation doesn't mean that if triglycerides go down that LDL must go up. HDL and total cholesterol can also change resulting in no direct correlation between LDL and triglycerides.

I think one reason for your confusion over my position is that you left out the key qualifying statement I made. To restate, I said:

So, it would be a correct statement to say that if fish oil reduces trigs, all else being equal, ldl will of a certainty go up.

I am not saying that ldl will go up in reality, I am stating that using the accepted equation for determining calculated ldl, the number reported to doctor and patient for LDL will be higher. I say, "all else being equal" because we can play if's and but's all day with TC and HDL. If HDL goes up, if TC goes down, if this or if that occurs. The bottom line remains the same, if HDL and TC remains the same (that is the "all else being equal" part) and trigs goes down, calculated LDL goes up...and this seems to be an odd notion that to lower trigs will necessarily cause ldl to increase.