MYTH #11: “We need to eat cholesterol.” Nope. Cholesterol has important functions in our bodies, but we are capable of making all the cholesterol we need, even if we consume a zero-cholesterol diet. Virtually every human tissue is capable of making cholesterol, especially the liver, intestine, adrenal glands, & reproductive organs.
MYTH #2: “The cholesterol we eat doesn’t matter.” Actually, cholesterol in food does raise blood cholesterol, though not as predictably as do saturated & trans fats. The point may be moot, as most foods that contain cholesterol also contain saturated fats. The effect that dietary cholesterol has on your blood cholesterol depends in part on the rest of your diet: if your diet is already high in saturated fats and cholesterol, adding more cholesterol won’t have as much of an effect. But if your diet is overall healthy, more dietary cholesterol will cause a greater rise in your blood cholesterol. Also, independent of blood cholesterol levels, high-cholesterol foods such as eggs have been shown to promote LDL oxidation and increase cardiovascular risk.
MYTH #3: “Raising your HDL (‘good’) cholesterol protects against cardiovascular disease.” Not necessarily! Research shows that the FUNCTION of your HDL particles is probably more important for lowering cardiovascular risk than the HDL level reported on your blood test results. In its normal state, HDL is an anti-inflammatory, antioxidant particle that is responsible for cholesterol efflux- the removal of excess cholesterol from our tissues, especially the blood vessels. But HDL can become dysfunctional and pro-inflammatory in situations of oxidative (cellular) stress. For example, saturated fats, which are known to raise HDL, also have been shown to render HDL more inflammatory and atherogenic. So you shouldn’t celebrate a rise in your HDL cholesterol if you got there simply by eating more saturated fats.
THE BOTTOM LINE? Eating a diet rich in plant foods, and low in added sugars, animal foods, & ultra-processed foods, is a great way to optimize your cholesterol panel & dramatically reduce your cardiovascular risk.
Freeman, J Am Coll Cardiol 2017 (dietary cholesterol)
Spence, Can J Cardiol 2010 (eggs, dietary cholesterol)
Spence, Atherosclerosis 2012 (eggs)
Briel, BMJ 2009 (raising HDL doesn’t reduce risk)
Navab, Nat Rev Cardiol 2011 (HDL review)
Kosmas, Drugs Context 2018 (HDL review)
Nicholls, J Am Coll Cardiol 2006 (saturated fats & HDL)
This is a short text, written by Dr McMacken, that is easy to share with the people you care about.
Five reasons why physicians that read studies do not recommend the keto diet.
(Scientific references are below the article.)
1. That we know of, no population in history has ever thrived on a very-low-carb/high-fat diet. There is exactly zero scientific evidence that a keto diet is conducive to longevity & longstanding vitality – unlike a plant-centric diet, the foundation of the longest-lived people on earth.
2. A keto diet may cause short-term weight loss, but possibly at a serious price. A 2010 review found that low-carb, animal-based diets increased cardiovascular death by 14%, cancer death by 28%, & all-cause mortality by 23%- trends confirmed in other large studies.
3. A keto diet hasn’t been shown to prevent, control, or reverse type 2 diabetes in the long run. Avoiding carbs will temporarily lower your blood sugar if you have diabetes. But this simply masks the underlying problem, which is insulin resistance – ie, glucose in our blood can’t enter our cells & the liver overproduces sugar. This is NOT the fault of carbs from healthy foods – whole grains, legumes, fruit, or even starchy vegetables. In fact, a high-carb, high-fiber, plant-based diet is exceptionally protective against diabetes & can actually REVERSE insulin resistance & lower diabetes complications. In contrast, low-carb diets can promote diabetes over time, as they foster inflammation & fat buildup in our cells, causing insulin resistance.
4. Keto diet research is in its infancy, focusing on short-term blood results & body weight – not actual rates of disease or death. And some findings are concerning. LDL cholesterol levels tend to rise (or at best, stay the same) on keto diets. An overwhelming wealth of research shows that the higher the LDL, the higher the risk of cardiovascular disease.
5. A keto diet is low in refined grains & added sugar. But it also can be low in phytonutrients, antioxidants, & fiber, all of which have profound benefits, and it forbids some of the most powerfully health-promoting foods on earth – whole grains, legumes, & many fruits. To me, that’s just not good medicine.
Written by Dr. Michelle McMacken Board-certified internal medicine physician. Passionate about preventing & reversing chronic disease through evidence-based nutrition. Plant eater.