New evidence is shifting health recommendations around cholesterol and triglycerides. 05/10/2021
Cholesterol is often the first thing that comes to mind when people think about heart health and their diet. Traditionally, high cholesterol levels are associated with poor cardiovascular fitness and a higher chance of cardiovascular illness such as heart attacks.
And while it’s still probably a good idea to keep an eye on your cholesterol – more on that below - researchers are now realizing that it’s also far from the whole story when it comes to taking care of your ticker. Many factors play into a healthy heart, and recent research indicates we may need to be paying more attention to one in particular: triglycerides (Wan et al., 2015) (Nichols et al., 2018) (Puri et al., 2016).
These fatty molecules are among the body’s main ways of storing energy. When triglyceride levels are high, they pile up in our bloodstreams in increasingly larger concentrations, something that can be bad for our hearts.
High triglycerides levels are also often tied to other signs of poor health like diabetes, obesity and high blood pressure. The good news is that there are a few simple, evidence-backed ways to keep your triglyceride levels in check. Adding more fish to your diet may be the easiest — studies have long shown that omega-3 fatty acids found in seafood actively suppress triglycerides in our bodies. A healthy diet that limits carbohydrates and regular exercise are also powerful tools against triglyceride build-up in our bodies.
Triglycerides and Fats
With triglycerides, we’re really talking about fat. Triglycerides come directly from our diets. They’re the most common way our bodies store excess energy from food to be used later. Thousands of years ago, when our next meal wasn’t always assured, that was a good thing. But in today’s screen-filled, sedentary and relatively prosperous world, it can be difficult to keep the pounds off as we battle the allure of ever-present and often unhealthy food.
Those extra calories usually end up as triglycerides stored in our bodies, where they eventually find their way into our bloodstreams. In fact, measuring blood levels is how doctors typically assess a patient’s triglyceride range. The American Heart Association estimates almost one-third of Americans have higher than normal triglyceride levels, defined as more than 150 milligrams per deciliter of blood (Miller et al., 2011).
Those little circulating bits of fat can cause a range of problems. The fatty molecules can harden the arteries, a condition known as arteriosclerosis, which is also a risk factor for cardiovascular disease (Libby, 2007). A number of studies also links triglycerides to cardiovascular disease in general. At very high levels, triglycerides can even lead to pancreatic disease (Kota et al., 2012).
While doctors have known for decades that high triglyceride levels are an issue, health guidance has tended to focus more on cholesterol. In particular, a often-quoted studies have shown that especially LDL, or “bad” cholesterol, was associated with cardiovascular disease and a higher risk of mortality (Domanski et al., 2020).
But recent research has painted a more complex picture of cholesterol in our bodies, while simultaneously highlighting the harms that triglycerides can pose to health. The result is a reckoning with the true causes of heart disease, as well as a shift in the way we approach our diets.
Is Cholesterol Really ‘Bad’?
Cholesterol is a ubiquitous molecule in our diets, and it comes largely from animal-derived foods, like meat and dairy. Our bodies use cholesterol for a number of basic functions, including building cell membranes and producing vitamin D.
If you know one thing about cholesterol, it’s probably that it comes in both “good” and “bad” forms. LDL, the “bad” cholesterol, is said to clog up arteries and lead to heart attacks. Meanwhile, HDL, or “good” cholesterol helps clean the LDL from our bloodstream (Barter, 2005). As it turns out, there’s much more nuance to cholesterol than a simple good/bad dichotomy.
Recent studies, for example, indicate that other forms of cholesterol aside from LDL may be causing harms in our bodies (Varbo and Nordestgaard, 2016). It’s led many researchers to simply refer to “non-HDL” levels when they talk about cholesterol.
And other surprising research shows that dietary cholesterol may not even have that much of an effect on bodily cholesterol levels at all (Blesso and Fernanda, 2018).
High cholesterol levels are typically managed with a class of drugs called statins, which reduce how much cholesterol our livers produce. These drugs have helped millions of people lower their cholesterol levels. But as statins became ubiquitous, some researchers began to notice that heart disease rates weren’t dropping like they should have been thanks to all the drug prescriptions (Libby, 2005). That led scientists to theorize that something else besides cholesterol levels was responsible for heart disease. Eventually, that line of inquiry led to triglycerides.
In the last few years, studies examining the relationship between triglyceride levels and heart health have found strong ties between the two. In general, high triglyceride levels — especially in relationship to low HDL levels — are associated with worse cardiovascular outcomes.
A 2015 study of acute coronary syndrome patients — people who had suffered a sudden loss of blood to their hearts, like a heart attack — found that the triglyceride-to-HDL ratio in their bloodstreams was a powerful predictor of mortality, as well as a risk factor for cardiovascular issues (Wan et al., 2015). Another study found that elevated triglycerides increased the risk of heart problems in diabetic patients, even when their LDL levels were under control (Nichols et al., 2018). And a 2016 study concluded that both non-HDL cholesterol and above-normal triglyceride levels were associated with the buildup of fatty deposits in the arteries (Puri et al., 2016).
To find your triglyceride to HDL ratio, just put your blood triglyceride value over your blood HDL level as measured by lab blood test. There’s no firm consensus on ideal values, but according to less than 2 is ideal, above 4 is too high (Sigurdsson, 2014). There are variables to consider, however – discuss with your physician or cardiologist.
New Diet Advice on Triglycerides
The recent swell of evidence implicating triglycerides over cholesterol as a significant heart risk suggests a few tweaks to dietary recommendations. Foods like eggs, cheese and shellfish, long maligned for their high cholesterol levels, may not pose a threat to our health, for example, and may even be heart-protective. When such foods are eaten, the liver simply produces less cholesterol, and blood levels remain stable.
And when it comes to shellfish and other seafoods, there’s actually a powerful reason to eat more of them. The omega-3 fatty acids in seafood are well known to help lower triglyceride levels and help prevent heart disease. For example, a 2012 study found that taking 3.4 grams of omega-3 fatty acid supplements a day for just a month reduced triglyceride levels by between 25 and 50 percent (Shearer et al., 2012). And we’ve also reported on how diets rich in seafood can help raise HDL levels.
You can find omega-3 in most seafood, but fish like salmon, sardines and cod have the highest levels of these healthy fats. (It’s worth noting that omega-3 fatty acids, while technically fats, behave very differently in our bodies than unhealthy fats like triglycerides.) A diet rich in omega-3 helps counteract the deleterious effects of triglycerides.
Another, powerful way to keep triglyceride levels low and steady is to limit carbohydrate consumption. It may seem counterintuitive, but when carb consumption goes up and fat consumption goes down, triglycerides rise. The phenomenon is known as carbohydrate-induced hypertriglyceridemia (Parks, 2012).
In other words, to keep “trigs” low, eat your fish and watch your carbs!
The research on triglycerides, cholesterol and health is likely to continue for years, and we’ll keep reporting on the latest science. But the basic facts are unlikely to change anytime soon: Triglycerides are a significant risk to our health, but also a manageable one. Eat well, exercise regularly and you’ll be on the path to a healthy life.
- Barter, Philip. The role of HDL-cholesterol in preventing atherosclerotic disease, European Heart Journal Supplements, Volume 7, Issue suppl_F, July 2005, Pages F4–F8, https://doi.org/10.1093/eurheartj/sui036
- Blesso CN, Fernandez ML. Dietary Cholesterol, Serum Lipids, and Heart Disease: Are Eggs Working for or Against You?. Nutrients. 2018;10(4):426. Published 2018 Mar 29. doi:10.3390/nu10040426
- Domanski, M. J., Tian, X., Wu, C. O., Reis, J. P., Dey, A. K., Gu, Y., . . . Fuster, V. (2020). Time course of ldl cholesterol exposure and cardiovascular disease event risk. Journal of the American College of Cardiology, 76(13), 1507-1516. doi:10.1016/j.jacc.2020.07.059
- Kota S, Kota S, Krishna SVS, Modi K, Jammula S. Hypertriglyceridemia-induced recurrent acute pancreatitis: A case-based review. Indian Journal of Endocrinology and Metabolism. 2012;16(1):141. doi:10.4103/2230-8210.91211
- Libby P. The forgotten majority: unfinished business in cardiovascular risk reduction. J Am Coll Cardiol. 2005 Oct 4;46(7):1225-8. doi: 10.1016/j.jacc.2005.07.006. PMID: 16198835.
- Libby, Peter. Fat Fuels the Flame: Triglyceride-Rich Lipoproteins and Arterial Inflammation. Circulation Research. 2007;100:299–301 https://doi.org/10.1161/01
- Miller M, Stone NJ, Ballantyne C, et al. Triglycerides and Cardiovascular Disease. Circulation. 2011;123(20):2292-2333. doi:10.1161/cir.0b013e3182160726
- Nichols GA, Philip S, Reynolds K, Granowitz CB, Fazio S. Increased residual cardiovascular risk in patients with diabetes and high versus normal triglycerides despite statin-controlled LDL cholesterol. Diabetes, Obesity and Metabolism. 2018;21(2):366-371. doi:10.1111/dom.13537
- Parks, E. J. (2001). Effect of dietary carbohydrate on triglyceride metabolism in humans. The Journal of Nutrition,131(10). doi:10.1093/jn/131.10.2772s
- Puri R, Nissen SE, Shao M, et al. Non-HDL Cholesterol and Triglycerides. Arteriosclerosis, Thrombosis, and Vascular Biology. 2016;36(11):2220-2228. doi:10.1161/atvbaha.116.307601
- Shearer GC, Savinova OV, Harris WS. Fish oil — How does it reduce plasma triglycerides? Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids. 2012;1821(5):843-851. doi:10.1016/j.bbalip.2011.10.011
- Sigurdsson A. 2014. The Triglyceride/HDL Cholesterol Ratio. The Doc’s Opinion.
- Varbo, Anette and Nordestgaard, Børge G. Remnant Cholesterol and Triglyceride-Rich Lipoproteins in Atherosclerosis Progression and Cardiovascular Disease. Arteriosclerosis, Thrombosis, and Vascular BiologyVolume 36, Issue 11, November 2016, Pages 2133-2135 https://doi.org/10.1161/ATVBAHA.116.308305
- Wan K, Zhao J, Huang H, et al. The Association between Triglyceride/High-Density Lipoprotein Cholesterol Ratio and All-Cause Mortality in Acute Coronary Syndrome after Coronary Revascularization. Bursill C, ed. PLOS ONE. 2015;10(4):e0123521. doi:10.1371/journal.pone.0123521