People love to talk about cholesterol – as they should! It’s an important topic to discuss as high levels of LDL-cholesterol in the blood can increase our risk of developing coronary heart disease. While our bodies need some cholesterol to function, our bodies can make all the cholesterol we need! We don’t need to eat additional cholesterol; in fact, consuming excess cholesterol may even have a detrimental impact on our cardiovascular risk by raising our LDL-cholesterol levels.1, 2
LDL-Cholesterol and Heart Disease
LDL (low-density lipoprotein) particles are made of protein and fat and can carry cholesterol and other fats through the blood. When it’s carrying cholesterol, it is known as LDL-cholesterol (LCL-C), which is often referred to as ‘bad cholesterol’. This is due to the link between LDL-C and certain cardiovascular diseases, particularly coronary heart disease.3
Why? Research has consistently found that higher LDL-C concentrations in the blood – even when comparing higher to lower values within the “normal” range – are associated with a greater degree of atherosclerosis (plaque in the arteries).4, 5 These atherosclerotic plaques can develop over several decades, and eventually a plaque may rupture and cause a clot, resulting in a heart attack or stroke. Furthermore, it’s been shown that when LDL -C concentrations are in the range of 50-70mg/dl (1.3-1.8mmol/L), atherosclerosis doesn’t appear to develop to any significant degree. This may suggest that our idea of “normal” LDL-C levels is too high to begin with.6 Interestingly, vegans are often the only diet group that maintains average LDL-C levels near or below 70mg/dl in some of the research we currently have on the topic. 7, 8
Beyond research looking at LDL-C and atherosclerosis, the link between LDL-C values and cardiac events, such as heart attacks, is incredibly consistent. In addition, lowering LDL-C by nearly any means (eg. diet, medications) can result in a predictable reduction in risk of atherosclerotic cardiovascular disease. And those with lower lifelong LDL-C values due to genetics have a significantly lower risk than those with higher values.9, 10
Does Eating Cholesterol Raise Our Cholesterol?
This is a popular question with a not-so-straightforward answer as it does and it doesn’t. If we keep a high cholesterol diet, adding some extra cholesterol (ie. an extra egg per day) probably won’t have much of an effect.11, 12 However, if we follow a plant-based diet that is low in cholesterol, adding high-cholesterol foods may have a more significant impact.
To confirm the effect of dietary cholesterol on serum cholesterol levels, we have a meta-analysis of controlled feeding experiments; which are often considered the gold standard of diet interventions. These experiments show that eating cholesterol raises cholesterol levels with a plateau happening at higher intakes.13, 14 This phenomenon is known as the cholesterol plateau, where LDL-cholesterol levels stop increasing after cholesterol consumption reaches approximately 400mg/day.15 To give some perspective, a single large egg contains about 185mg of cholesterol. Because of this phenomenon, it may be more difficult to ascertain a link between dietary cholesterol and disease amongst many populations. Unless of course, the given studies encompass individuals with a wide range of intake levels. Of course, when we do that, we do see that higher dietary cholesterol intakes are associated with cardiovascular disease risk.16, 17
Which Foods Contain Cholesterol?
So which foods have cholesterol? Meat, dairy, seafood, and eggs. Fortunately, plants are not a source of dietary cholesterol. However, high saturated fat oils like coconut and palm can raise LDL-cholesterol levels in the body. Of course, our liver can make all the cholesterol our bodies need, as mentioned previously; therefore, we do not require additional cholesterol or cholesterol-raising foods in our diet! It’s worth noting that while seafood does contain cholesterol, seafood consumption is typically associated with a lower risk of cardiovascular disease compared to meat. It also appears to be relatively neutral compared to many plant-based foods. Therefore, the healthful components appear to outweigh the addition of cholesterol.
Does Saturated Fat Raise Cholesterol Levels?
One of the biggest myths in the nutrition world is that eating saturated fat doesn’t raise cholesterol levels and doesn’t impact cardiovascular disease risk. However, this couldn’t be further from the truth. Furthermore, adding cholesterol to a high saturated fat meal may amplify the cholesterol raising effects of the saturated fat too.18
In controlled feeding experiments, in which participants are fed saturated fat-rich foods and having their LDL-cholesterol values measured, we clearly see that saturated fat has a very consistent LDL-C raising effect.19 The increase is so predictable that there’s even an equation called the “Keys Equation,” which can calculate how much cholesterol levels will increase with added saturated fat (and other fatty acids).20 It’s important to note that along with many animal products (ie. meat, high fat dairy), coconut and palm oil-rich foods can also significantly raise cholesterol levels since they can be very high in saturated fats.21, 22
Perhaps the more dangerous argument is that some research suggests that replacing saturated fats with other foods doesn’t reduce heart disease risk. For example, replacing saturated fat with refined grains may not result in a lower risk. Rather, the American Heart Association Presidential Advisory report suggests shifting away from saturated fat to unsaturated fats, which has shown to reduce risk of CHD by a substantial degree. A focus should be placed on substituting food high in saturated fat with healthier options. Think fruits, vegetables, legumes, whole grains, nuts/seeds, etc.23 For example, carbohydrate-rich whole foods (e.g., whole grains) are consistently linked to a lower risk of cardiovascular disease, while refined carbs (e.g. white bread, pastries) may increase risk, depending on what they’re replacing.24 This further supports the idea that what we replace the saturated fat with matters.25, 26
What Should We Eat?
Here are some ways we can lower cholesterol through dietary modifications:
Limit Foods with Saturated Fat and Cholesterol
One of the most impactful ways to lower our LDL-C is to limit our intake of foods that raise LDL-C. Go figure! That means limiting saturated fat and/or cholesterol-rich foods, including meat, full-fat dairy, egg yolks, coconut oil, and palm oil. Embracing a more plant-based diet will almost guarantee a shift away from most of these foods.
Eat Plenty of Soluble Fibre
When we consume foods that are high in soluble fiber, we help prevent absorption of cholesterol in our digestive tracts.27 Some examples include whole grains (e.g., oatmeal), fruits (e.g., apples, bananas, prunes, oranges, pears), legumes (e.g., chickpeas, lentils, kidney beans), and okra and eggplant as they are very high in soluble fibre.
Include More Nuts
Nuts are a heart healthy food as they can lower LDL-C levels, reducing our risk of developing cardiovascular heart disease. We can have nuts as snacks between meals or spread a nut butter on top of whole wheat toast. By adding one handful of nuts per day to our diet, we can reduce our LDL-cholesterol levels and ultimately our cardiovascular disease risk.28, 29 Almonds in particular are a great addition to a heart-healthy diet due to their potent LDL-C lowering effect.30
Eat More Plant Protein
We can obtain lower LDL-C levels by adding a variety of plant protein sources.31 Beans and other legumes are typically inexpensive, versatile, and a great source of heart-healthy protein. Some common varieties to try would be soybeans (more on this below), lentils, split peas, pinto beans, kidney beans, black beans, white beans, navy beans, and lima beans. Legume-based pastas may also be a very nutrient rich and high plant protein option.
Introduce More Soy
There are so many meatless options on the market nowadays. Many of which hold a bevy of health benefits and contain unique cholesterol-lowering properties.32, 33, 34 Tofu, edamame, textured vegetable protein, soy nuts, soy curls and soy milk are great sources of plant-based protein that can leave us feeling satiated and are heart healthy to boot.
Find a Plant-Based Doctor to Lower Cholesterol
Embracing a plant-based diet can do wonders for our health. Along with disease prevention, it can also help treat certain diseases while providing the nutrition your body needs. For an added level of guidance and support, Dr. Nagra is a plant-based doctor with the knowledge, expertise, and training to help his patients through this transition. Get in touch today!
Matthew Nagra is a Naturopathic Doctor and is a passionate advocate for evidence-based nutrition as medicine. I have a particular passion for plant-based/vegan nutrition, physical medicine, and chronic disease. With additional training in nutrition, I hold a Plant-Based Nutrition Certification from Cornell University and the T. Colin Campbell Center for Nutrition Studies where I’ve authored multiple articles on the subject.