Triglycerides appear several times in Dr. Robert Lustig’s recent book, Metabolical: The Lure and the Lies of Processed Food, Nutrition, and Modern Medicine. He defines triglycerides as “a blood lipid that contributes to heart disease” and notes that “the role of triglycerides in heart disease always took a back seat to LDL [low-density lipoprotein cholesterol].”
In the chapter “Assembling the Clues to Diagnose Yourself,” Dr. Lustig highlights a relationship between triglycerides and another form of cholesterol:
The serum triglyceride (TG), when unloaded of its fat at the adipose tissue, becomes the small dense LDL. Therefore, the TG:HDL (high-density lipoprotein) ratio — the real ratio of bad to good cholesterol — is the best biomarker of small dense LDL, the best biomarker of cardiovascular disease, and the best surrogate marker of insulin resistance and metabolic syndrome.
Two of the five criteria for metabolic syndrome are high triglycerides (over 150)** and low HDL (under 40). What is the recommended ratio between the two? Dr. Lustig writes:
For reasons that are completely unclear, race matters with TG levels. If it’s over 2.5 in Caucasians or over 1.5 in African Americans, that’s a correlate of metabolic syndrome.
Dr. Peter Attia, host of The Drive podcast, has also emphasized the ratio:
The real whizzes on the topic actually suggest TG levels should be below 80. In fact, combining HDL-C and TG into a ratio (i.e., TG/HDL-C) is probably the single best predictor of cardiac risk you can derive from a standard cholesterol test. The lower the ratio, the lower your chances of having an “adverse cardiac event,” as the medical community describes it (e.g., a heart attack).
Contrary to what people think, eating saturated fat does not increase saturated fatty acid content in triglycerides. In fact, reduction in carbohydrate intake, coupled with increased saturated fat intake, actually lowers both circulating triglycerides and the amount of saturated fatty acid within triglycerides. Unfortunately, most doctors don’t realize this and they tell patients with elevated triglycerides to reduce fat intake. Ironically, this is the wrong treatment.
The importance of the TG:HDL ratio has been discussed in medical literature for over a decade. A study from 2008 concluded:
Nearly all routinely assessed lipid variables were associated with the extent of coronary disease, but only the ratio of triglycerides to HDL-cholesterol or to HDL-c were robustly associated with disease extent. Elevation in the ratio of TG to HDL-c was the single most powerful predictor of extensive coronary heart disease among all the lipid variables examined.
Another study from 2019 associated a high TG:HDL ratio with silent brain infarcts. And research this year on COVID-19 symptoms concluded “a severe outcome was associated with lower HDL cholesterol levels and higher triglycerides.”
Given such a wide range of impact, health-conscious individuals should consider monitoring this ratio at least once a year through a lipid panel.
**Dr. Thomas Dayspring recently stated:
The guidelines will tell you under 150. As a lipidologist, I’m going to tell you well under 100 if not under 80…So look very carefully at that triglyceride level. Sadly, it’s the least understood or the most neglected parameter.