February is National Heart Health Month. So, we thought we'd do our part in spreading awareness by bringing you a three-part heart health blog series. First up? The ever-ominous "total cholesterol."
As one of the most ordered lab tests, total cholesterol can provide a high level glance at how your body is handling lipids, or fats. According to the CDC, roughly nine percent of all doctor’s visits include a cholesterol test.1 So, how should you interpret your total cholesterol value? Is the whole greater than the sum of its parts?
A quick overview of total cholesterol
- Total cholesterol can be determined in two ways. It can either be directly measured in the blood, or more commonly, it can also be calculated. The calculation takes into account the two main forms of cholesterol – HDL (high density lipoprotein) and LDL (low density lipoprotein) – as well as a small fraction of triglycerides. Any one of these three components can skew total cholesterol values. Here's a brief definition of each:
- HDL: High density lipoprotein is a protective form of cholesterol that helps to remove harmful particles from circulation before they can cause damage to blood vessels. This process earned it the nickname "good cholesterol."
- LDL: Low density lipoprotein is a potentially dangerous type of cholesterol that can become oxidized (a process that makes it unstable and capable of causing damage), which can lead to the hardening of arteries. If LDL builds up, it can lead to blockages – which can cause serious cardiovascular incidents. LDL is therefore aptly referred to as the "bad cholesterol."
- Triglycerides: A form of stored fat that circulates in the bloodstream usually from excess weight, calories, alcohol, lack of exercise, liver damage, or genetics.
How to interpret your results
To answer the question posed in the title of this post, knowing which biomarker (or combination of the three) is responsible for the skew of your total cholesterol number is more important than the total cholesterol value itself. Three scenarios can account for high total cholesterol:
1. High total cholesterol, high LDL cholesterol, low HDL cholesterol, and high triglycerides
High alert! This is the most dangerous combination of lipid markers. Roughly 32% of Americans have elevated LDL cholesterol, according to the CDC.1 In this ratio, where high LDL is coupled with low HDL, the risk of developing cardiovascular disease is high. It is very important here to bring down LDL cholesterol and increase HDL cholesterol to help combat the “bad” LDL. The ratio of HDL to LDL is very important.
2. High total cholesterol, normal LDL, high HDL, normal triglycerides
In this case, the high total cholesterol is less troublesome since it's largely due to elevated HDL (remember, that's the "good" kind). The fact that HDL is high and LDL is normal also makes for a favorable HDL:LDL ratio. Although, extremely high levels of HDL cholesterol can be due to genetics. Generally, HDL levels shouldn't exceed 116 mg/dL for men and 135 mg/dL for women.2
3. High total cholesterol, normal LDL cholesterol, normal HDL cholesterol, very high triglycerides
Even though triglycerides only contribute a small fraction to the total cholesterol value, very high levels can drastically skew this value and are very dangerous. High levels of triglycerides, especially without high levels of HDL or LDL, may indicate issues in the liver, where triglycerides are made. Testing your liver enzymes can help you identify whether there is in fact a problem – levels of these enzymes would be high if this were the case. Elevated triglycerides can be damaging to your cardiovascular system, but can also lead to acute pancreatitis (inflammation of the pancreas), which requires immediate medical attention.3
What about LDL particle size?There is a lot of buzz in the health community about LDL particle size. If you recall, LDL is low density lipoprotein. Its “low” density is due to its high proportion of fat, which is not a very dense substance (think of salad dressing when it separates – the oil floats to the top). HDL, on the other hand, has a lower fat-to-protein ratio than LDL, making it more dense.
LDL is particularly troublesome due to its capacity to oxidize, which makes it more likely to become implanted in blood vessels and harden. This can eventually cause blockages. This is where the particle size becomes important: smaller LDL particles can become lodged in the arteries more easily. The larger LDL particles appear to be less dangerous.
Unfortunately, LDL particle size is still new science. While it is promising, it should not yet be used to determine and manage someone's risk of cardiovascular disease (CVD).4
Because of this need for further research, InsideTracker doesn’t include LDL particle size in our lipid panels just yet. In the meantime, it appears that there is an association between small LDL particle size and high triglycerides coupled with low HDL.4
How to make the “bad” a little bit better
As mentioned above, the oxidation and hardening of LDL is largely responsible for the development of heart disease. Accordingly, lowering your LDL value is the first hurdle to tackle when prioritizing your heart health (hint: increase soluble fiber and limit saturated fat intake).
Once you have reached an optimal level, protecting the LDL from oxidation is just as important. Free radicals (yep, the same ones that cause inflammation) are the main stimulant for oxidization.5 They're also counteracted by antioxidants, hence the name. Therefore, it follows that in order to reduce the potential for LDL to cause damage in the body, you should eat anti-inflammatory foods.
Common antioxidants include vitamins A, C, and E, as well as selenium. These are plentiful in dark leafy greens, bright red, orange or yellow fruits and vegetables, citrus, berries, broccoli, bell peppers, and nuts and seeds – get a serving of at least one of these foods every day. Dark chocolate and red wine in moderation are also high-antioxidant foods.
Already have your total cholesterol values? Let us help you interpret them by adding them to the InsideTracker platform. Haven’t had your values checked before? Perhaps it's been a while? We can help with that, too. Your lifestyle choices might also be influencing your cholesterol number; if it needs a fine tune, let us build you a personalized plan to improve!
Ashley Reaver, MS, RD, CSSD
Ashley is the Lead Nutrition Scientist at InsideTracker. As a registered dietitian and educator, Ashley enjoys cooking and teaching individuals the power that food has on their health. You’ll find Ashley hiking, eating, and spending time with her family. Follow her on Instagram @lower.cholesterol.nutrition.
-  High Cholesterol Fact Sheet. 17 March 2015. https://www.cdc.gov/cholesterol/facts.htm
-  Madsen, Christian M., Anette Varbo, and Børge G. Nordestgaard. "Extreme high high-density lipoprotein cholesterol is paradoxically associated with high mortality in men and women: two prospective cohort studies." European Heart Journal (2017): ehx163.
-  Murad, M. Hassan, et al. "The association of hypertriglyceridemia with cardiovascular events and pancreatitis: a systematic review and meta-analysis." BMC endocrine disorders 12.1 (2012): 2.
-  Allaire, Janie, et al. "LDL particle number and size and cardiovascular risk: anything new under the sun?." Current Opinion in Lipidology 28.3 (2017): 261-266.
-  Amiot, M. J., C. Riva, and A. Vinet. "Effects of dietary polyphenols on metabolic syndrome features in humans: a systematic review." Obesity Reviews 17.7 (2016): 573-586.