Updated: Jun 15, 2019
Cholesterol, Fat Burning, Ketosis, and Metabolic Flexibility
Okay, we are on to the first aspect of an animal-based diet that will prevent heart attacks. That concept is the idea that humans evolved to what they are today because they ate and burned fat for fuel and are much more efficient when we do. Our heart is especially reliant on this aspect of evolved metabolism. But before we get into this let’s review where we are.
In Part 1 of this series we laid the foundation for what really causes heart attacks and as we saw it has nothing to do with saturated fat or cholesterol getting clogged in an artery. If you didn’t read that post go back and read it now. The following posts will make much more sense once you have the concepts in that post running through your head. Here is the outline of this series.
Part 1 – The Foundational Imbalances That Cause Heart Attacks
Part 2 – (This post) Cholesterol, Fat Burning, Ketones, and Metabolic Flexibility
Part 3 – The Autonomic Nervous System Imbalance
Part 4 – Toxins, Oxidative Stress, and Nitric Oxide
Part 5 – The Evolutionary Mismatch Behind It All
As promised in Part 1 we are going to go a little deeper into debunking the cholesterol hypothesis, or lipid hypothesis, of heart attacks. It’s obvious that an animal-based diet is high in cholesterol and saturated fat. Should we be scared of these foods in our diet? No, we should not be.
In Part 1 we talked about Ancel Keys and the study he did that got the ball rolling on the cholesterol hypothesis. We also showed how his study was very bad science. In the archeological record we see that humans have been eating meat and saturated fat through millions of years of our evolution. (1,2) Since our epidemic of heart disease and heart attacks are a relatively new thing, the last 100 years or so (3), it doesn’t make sense to say that animal products in the diet are the cause. Further, the modern research just doesn’t back it up.
A study in 2009 looked at 136,905 hospital admissions for heart disease from 2000 to 2006. Cholesterol was measured in the patients soon after admission to the hospital and to everyone’s surprise 75% of the patients had normal cholesterol levels. (4) How could cholesterol be causing the heart disease if it wasn’t elevated in 75% of those with heart disease? Another study in 2016 showed that 92% of elderly people with cholesterol levels considered high lived longer! (5)
Considering that cholesterol plays a vital role in nourishing our brain and nervous system, making our hormones, and driving cell to cell communication this makes sense. Cholesterol is not the enemy. Makes you wonder why statin drugs (cholesterol lowering medications) are the most commonly prescribed drug most years. (6)
There are actually many interesting findings in studies of statins. One study showed that healthy women with high cholesterol get no benefit from statins as far as reducing risk of heart attack or death. Further, it showed that in men and women over sixty-nine years of age with high cholesterol there was also no benefit to taking statins. (7) Another study showed that treatment with two statins lowered cholesterol more than one alone but also showed no change in the number of heart attacks and lead to more plaque in the arteries. (8)
Statistically statins have very little clinical effect. In people who already had heart disease they prevent death in 1 in 83 people, nonfatal heart attack in 1 in 104 people, and prevented stroke in 1 in 154 people. (9) Even if cholesterol was the cause of heart disease there is even evidence that statins aren’t very good at lowering it. (10) All this does not give you confidence in statin therapy, and what makes it worse are the side effects statins can cause. Statins cause diabetes in 1 in 50 people and muscle damage in 1 in 10 people. (9) It has also been shown that statins can cause memory problems, (11) sexual dysfunction (12) and muscle pain. (13) As a practicing Chiropractor I see many patients who come to me for treatment of muscle pain who are also on statins and did not have this pain before they started taking them.
So, the research makes it very clear that saturated fat and cholesterol are not bad for our hearts and that depriving our body of these things with statins can be dangerous. If we eat fat freely, like we would on an animal-based diet, what would happen to us? How would our health change? Turns out that research shows it would change for the better.
When we eat lots of fat it teaches our bodies how to burn fat rather than sugar. There can be a bit of a transition period when we are teaching our bodies to do this. When we start eating lots of fat we start to deprive our body of glucose and it is forced to convert to burning fat, but it does this gradually. While doing this we also start to make ketones as a by-product of fat burning, which your body can also use as fuel. Your brain likes to use ketones as fuel and after about 3 days your brain starts burning about 25% ketones, (14) and after about 4 days this can go up to about 70%. (15) The point is that it can take a week, for some people longer, for your body to make the switch over to burning fatty acids and ketones.
Ketogenic diets, or high fat diets that produce ketones, are all the rage these days in the health world and rightfully so. The benefits people are seeing from these diets cannot be ignored. Ketogenic diets have been shown to increase your internal production of antioxidants, (16) decreased pain in those with arthritis, (17) significantly improve symptoms in neurodegenerative diseases, (18) and increase overall longevity! (19,20)
More relevant to our discussion, when we look at the effects of a ketogenic diet on the heart we continue to see the benefits. This is no surprise as 70% of our hearts fuel comes from fat burning (21) and the efficiency of the heart muscle is increase by 28% once we convert to fat burning and our body is providing the heart ketones as well. (22) We have discussed how the research on high fat diets show no correlation to heart disease, but high fat diets are actually protective against heart disease.
One study that looked at cardiac function and health of people eating a high fat Mediterranean diet concluded that the recommendations for low fat and high carbohydrate were “severely challenged” and they urged organizations who advocate this type of diet to “strongly reconsider their recommendations”. (23) There are many other studies showing that saturated fat is actually protective against heart disease. (24,25,26) Therefore, an animal-based diet would in fact protect us against heart attacks. But how could it do this?
Recall the study we discussed above where a large portion of people admitted to the hospital for a heart attack had normal or low cholesterol levels at the time of their admittance. (4) Not only does this help debunk the idea that high cholesterol causes heart attacks, but could the fact that they didn’t have enough cholesterol have contributed to the cause of the heart attack?
The heart, and most of the body, is metabolically flexible and can burn fatty acids or sugar but remember that predominantly burning fat is what the heart prefers. This is for a very important reason. If the heart was ever forced to burn more sugar than fat then the burning of sugar in heart cells would create a build-up of lactic acid (27). When we exercise our skeletal muscles can start to burn sugar as well and it creates the burn you feel in the muscles because of lactic acid build up. This is not dangerous for them because the pain eventually makes you stop using the muscle so intensely and then the lactic acid is pumped out. The reason the heart gets first dibs on the fat you eat, and burns fatty acids for at least 70% of its fuel, is because if it doesn’t have that fat available and it is forced to burn primarily glucose then lactic acid will build up in the heart cells. (28) This can happen chronically from eating a high carbohydrate diet and therefore creating lactic acid burn in the heart, we call this angina (29). Or this can happen acutely, during a stress response, and cause a sudden and intense build up of lactic acid in heart cells that cause tissue death, which we call a heart attack.
The more we allow our body to use fat for fuel by eating a high fat diet, of which and animal-based diet is, then the more we are decreasing the chances that our heart will ever have to burn glucose chronically and give us angina. We are also increasing the resilience the heart has against converting to burning glucose in an acute stress response situation (the topic of Part 3).
By default, a high fat animal-based diet will keep your heart in a predominantly fat burning state. This will keep your heart healthy and more efficient as well as steer it far clear of the dangers of a heart that is forced to burn primarily glucose.
So, don’t be scared of fat. Just make sure it is of the animal variety (meat, tallow, lard, butter, fish, egg yolks) and not the vegetable variety (corn oil, canola oil, soy oil, rapeseed oil).
In Part 3 we are going to discuss the imbalanced stress response that can put us at risk of forcing a heart to burn glucose in an acute situation. We will also discuss the fascinating characteristics of an animal-based diet that can protect us against developing this imbalanced stress response.
See you next time. Stay healthy out there!