Why Eating or Avoiding Dietary Cholesterol Has No Effect on Blood Cholesterol Levels

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Avoiding Cholesterol

Cholesterol synthesis and metabolism are tightly regulated within the human body. It turns out that when the cell senses low levels of cholesterol, our body initiates cholesterol synthesis (via the SREBP system) as well as processes to enhance the uptake of cholesterol. Thus, avoiding dietary cholesterol in an attempt to lower blood cholesterol levels doesn’t make much sense in light of this ability of our body to regulate cholesterol synthesis. Any attempt to lower cholesterol in the body would be counteracted by the body ramping up cholesterol production and uptake.

Eating Cholesterol

This is a quote from Metabolic Regulation: A Human Perspective by biochemist Keith N. Frayn (my emphasis added):

“Perhaps surprisingly, the amount of cholesterol in the diet is not a major factor affecting the blood cholesterol concentration. The amount of cholesterol we eat is not large in comparison with the body pool: we eat less than 1g per day whereas the amount of cholesterol in the body is more like 140g, of which about 8g is present in the plasma. Contrast this with glucose, where we eat several “plasma’s-worth” in a single meal. And cholesterol is not rapidly absorbed like glucose: it enters the plasma slowly, even more so than triacylglycerol. Further, cholesterol intake leads to cholesterol entering cells, which effectively suppresses cholesterol synthesis. The blood cholesterol concentration is related far more closely to the dietary intake of particular fatty acids, especially the ratio of saturated to polyunsaturated fatty acids.”

So, the cholesterol that we eat pales in comparison to that stored in our bodies. Again, cholesterol synthesis and transport in the body is a highly regulated process. As mentioned in this video by Dr. Peter Attia, cholesterol levels in the body are not that influenced by the cholesterol in our diet, since a majority of the cholesterol from our diet is in the form of cholesterol ester, which is the storage form of cholesterol which doesn’t get absorbed by our gut. The unesterified active version of cholesterol in our diet does get absorbed. And again, the amount of active absorbable cholesterol in the diet is very small in comparison to the amount stored and synthesized by our bodies; on a daily basis, we typically get ~300-500mg of cholesterol from our diet, whereas we synthesize ~800-1,200mg of cholesterol in our cells per day.

As Dr. Attia suggests in the video, the total store of cholesterol in the body is akin to a giant swimming pool, and there are two very small hoses that contribute to, and control, the swimming pool levels: an internal hose (cholesterol synthesis) and an external hose (cholesterol input from diet). Anything in biology that resembles this situation, with a large store of something with two very small contributing inputs, suggests that the system is highly regulated and that what is moving the “cholesterol needle” isn’t the small inputs (diet and internal synthesis) but something else…

Bottom Line

Avoiding cholesterol, or eating cholesterol, does not have a profound impact on blood cholesterol levels. Any cholesterol that is indeed present blood is carefully controlled by the cholesterol transport system. Furthermore, cholesterol isn’t “bad”, and avoidance of dietary cholesterol can be problematic. In fact, genetic deficiencies in cholesterol synthesis pathways can lead to conditions that can cause mental disabilities and skeletal muscle problems.

Cholesterol is vital, and cells need cholesterol to function (cholesterol is actually part of the structural makeup of cells). It’s not the presence of cholesterol in the blood that matters, it’s the type, amount, and size of that cholesterol that matters. “Cholesterol” in the blood only becomes “dangerous” if the LDL, which is a protein/cholesterol complex, increases in number, and decreases in particle size.

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NOTE: Nothing in this post is written or intended to be medical advice or to replace medical advice. We are not doctors. We are merely individuals with a passion for health, fitness, nutrition, and scientific research.

What Is The Paleo Diet (a.k.a. The Caveman Diet)?

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The Caveman Diet: The Original Human Diet

The Paleo Diet, also known as the “Caveman Diet”, is a nutritional protocol that is intended to mimic the diet of our ancestors, who were hunter-gatherers that lived during, and survived through, the Paleolithic era. Overall, it is a low-carb diet, but differs from other low-carb protocols in very specific ways, as well explain below.

This particular diet is actually our favorite dietary protocol here at HealthSnap, with the Ketogenic Diet being a close second (note: the Paleo Diet and Ketogenic Diets are actually quite similar). We strongly believe, and the research agrees with us, that the Paleo Diet is the healthiest way to eat because it is the only nutritional protocol that takes into consideration our genetic makeup.

So, why mimic the diet of our ancestors? How is the diet aligned with our genetics?

The theory behind the diet is that our genetic makeup today is virtually the same as that of our ancestors who lived 40,000 or so years ago during the Paleolithic era (genes are very slow to change, evolution takes place on VERY large timescales). The Paleolithic era was one of the harshest moments in time for the human species, and yet we are the only species of human to survive this era (the Neanderthals, for example, did not survive).

During this era, we experienced diverse environmental conditions, exposure to certain food sources, as well as variable food availability. We had to survive on the African savannah, as well as on the sea shoreline during the Ice Ages. We likely experienced periods of feast and famine, as food sources were scarce. We had to be hunter-gatherers (working in teams to hunt and gather food), we had to be fit, we had to be mobile, and we had to be smart in order to survive.

It’s obvious that we were genetically fit to survive this period because we are the only species TO survive this period. Our genetics must be something quite special. Thus, any lifestyle choice that closely aligns ourselves with our genetics would seem like a prudent one.

This doesn’t mean that we need to go the Arctic to experience the extreme cold to mimic the Ice Ages (although science is showing that there are many health benefits of periodic cold exposure), or that we need to starve (although science is showing the benefits of intermittent fasting, which is fasting for brief periods of time). What about dressing like a caveman, acting like a caveman, or giving up all modern technology? NO. What it does mean is that mimicking the energy (a.k.a. food) availability and density we experienced during that time may be a healthy thing to do. Why?

The advent of farming and agriculture occurred only approximately 10,000 years ago. If our genes are slow to change, and we carry the same genetic makeup of our ancestors, this means that the consumption of edible grains and dairy products through farming and modern agriculture is quite simply alien to our genes. In short, the only thing that has changed in 40,000 or so years is that the environment that our genes are expressed in.

So, what exactly did our ancestors eat? What should we eat on a Caveman Diet?

Since the diet is modeled after our hunter-gatherer ancestors, this means that we should aim to eat the foods that hunter-gatherers ate during that time period. Or rather, eliminate the foods that they likely never experienced. So let’s start with a list of what to NOT eat. A list of foods that they likely never experienced, and thus should be avoided on a caveman diet, is the following:

FOODS TO AVOID

Grains and refined carbohydrates (wheat, barley, rice, bread etc.)
Legumes (beans, lentils, peas, peanuts, etc.)
Dairy
Sugars, soda’s, candy
Alcohol

I know, all the fun things, right?

This leaves us with the following:

FOODS TO EAT

Grass-fed and free-range meat (ruminants like cows were meant to eat grass, not grains which they are fed today)
Wild-caught seafood (not farm raised salmon)
Fresh organic vegetables (not GMO-based vegetables; from a statistical and risk analysis point of view, messing with the genetics of mother nature by genetically modifying foods is a dangerous thing, and can have unforeseen consequences)
Fresh organic fruits (although sparingly because modern fruit is high in simple sugars)
Nuts, seeds, spices, and some tubers

How do we know cavemen ate this way?

Again, since the farming is a relativity recent invention in the context of the lifetime of our species, we likely never experienced edible grains or dairy (other than breast milk) in our diet. Furthermore, sugar consumption, if it took place at all in the ancient world, occurred via the consumption of fruits, which were only seasonally available.

We can also look at fossil evidence, which shows that our species utilized stone tools to cut meat and bone marrow. Not only that, but our large brain is also evidence of our diet. By consuming nutrient-dense meat, instead of large amounts of vegetation (like ruminants or gorillas), humans were able to trade stomach mass for brain mass, allowing us to become smarter. An added benefit to this is that, due to a smaller stomach, humans gained mobility advantages compared to other species. All of these things were critical to our survival as a species.

So, Is The Paleo Diet Healthy?

A plethora of research in biology, biochemistry, and other disciplines indicate that the Standard American Diet (SAD), or any other similar diet which contains large amounts of refined foods, sugar, and unhealthy trans fats, is the root of modern disease and health complications such as cancer, diabetes, heart disease, obesity, Parkinson’s, Alzheimer’s, depression and autoimmune disease. Some reasons why the SAD is detrimental to our health?

1) Chronic consumption of high carbohydrate foods leads to metabolic dysfunction

Our genetics are not adapted to consumption of large quantities of carbohydrates. As mentioned above, we were never continuously exposed to high carbohydrate foods. Consuming large amounts of carbohydrates leads to elevated blood sugar levels and thus elevated levels of insulin (insulin helps bring glucose into cells so that it may be used for energy). If we consistently consume large amounts of carbohydrates over time, chronic insulin release can make us become insulin resistant (resistant to the action of insulin). This leads to the development of metabolic syndrome. Not only that, but chronic insulin signaling (i.e. the effects that insulin has on other cellular processes) can impact the expression of oncogenes and thus the increased risk of cancer development. Higher carbohydrate diets have also been associated with higher mortality rates. By consuming lower levels of carbohydrates, we can improve our blood-sugar and insulin sensitivity, help prevent the expression of oncogenes, and potentially improve our lifespan.

2) Grains, legumes, and dairy, which are common staples in the Standard American Diet, are immunogenic foods

Grains are seeds of grass and don’t have fight-or-flight mechanisms. Anything without a fight-or-flight mechanism of protection evolutionarily develops other means of defense. In plants and seeds of grass, these are chemicals called lectins. Research is starting to show that all autoimmune diseases are linked to the gut somehow. The reason for this is that lectins from grains and legumes can, over time, punch holes through the gut, resulting in what’s known as a “leaky gut”. Our gut houses the largest concentration of immune cells in the body because the gut is the only area where the outside world can come into contact with our insides. Once the gut is penetrated, large particles of undigested food can pass through the intestinal lining where they don’t belong. These large particles of food show a striking resemblance to our own bodies proteins, but are just ever so slightly different that they trigger an immune response. And because the immune system is triggered, antibodies are formed. But, since these large particles show resemblance to our own bodies proteins, these newly made antibodies not only target these large foreign particles, but they can also go on to attack our own bodies proteins.

Finally, microRNA’s and certain peptides found in dairy and milk (other than breast milk), are foreign to the human body and are also recognized by our immune system, triggering inflammation.

By adopting a Paleo Diet lifestyle, we automatically remove these offending items from our Standard American Diet, putting us in a better position to improve our healthspan and lifespan. A brief outline of all of the health benefits of the Paleo Diet are listed below (there are a ton of references & stated benefits of the diet, too many to list in this one post, so we will list some of the most important and relevant ones here, and save the others for a more in-depth analysis in another post):

BENEFITS OF THE PALEO DIET

Promotes healthy insulin levels, metabolism, and improves metabolic syndrome
Protects against autoimmunity and can improve autoimmune symptoms
Promotes a healthy gut: a strong gut wall and healthy gut microbiome diversity
Decreases inflammation
Promotes cardiovascular health: improves blood lipids, cholesterol, and omega-3:omega-6 ratios
Can help prevent and reverse
May help prevent and treat cancer

Wait, but didn’t our ancestors live brutal lives and die young?

Yes, they led brutal lives, and most died quite young, but this is not due to what they ate. The ones that did survive youth were free from modern degenerative disease in old age and had strong bones (as evidenced by fossil records), and likely lived quite long.

For a simple explanation, check out this video by John Durant on The Colbert Report.

For a more detailed explanation, check out this paper by Dr. Loren Cordain.

The Bottom Line

Adopting a Paleo Diet can be a very wise and healthy lifestyle choice. To get started right away, here are a few pointers:

Eat meat (preferably grass-fed), fresh vegetables and fruit (preferably organic), nuts, and fish (preferably wild-caught).
Avoid grains, legumes, potatoes, carbs, and sugar. Limit alcohol consumption.
Skip one meal every now and then (perhaps once a week).
Add variation in everything you do:
- Don’t jog for hours, but go on walks with bursts of sprinting in between.
- Exercise briefly with varying intensity. Lift weights, and go to the gym a few times a week (30 minutes – 1 hour each time is more than enough)
Relax, keep stress low, and get plenty of sleep.

Final Parting Thoughts

There is something important to be said about Paleo. We are human. We should align our lives with our genetics. We should work with nature rather than against her. And it just so happens that nature did not intend for us to eat sugar in high quantities. And a high quantity doesn’t just mean the candies, sodas, etc. in addition to our base diet. It also means the carbs, because carbs by definition are sugar (i.e., multiple sugar units linked together). Nature also didn’t intend for us to eat immunogenic foods like grains (which are seeds of grass), or large amounts of grassy foods for that matter (humans can’t digest cellulose, one of the primary components of grassy foods, while ruminants like cattle can do this, as they have specialized machinery in their gut to do this).

Finally, while by nature the Paleo Diet is low carb and aims to minimize carbs and sugar, it’s also important to recognize that you can’t avoid carbs and sugar altogether. You invariably get some carbs and sugar from vegetables and from fruits (especially modern fruits which are bred to be very high in sugar). The point here is that quality and quantity matter. Keep the carb/sugar intake very low (to prevent chronic insulin release and blood sugar spikes), and get the carbs (and fiber) you need from non-starchy vegetables and fruits (note: fiber is an important staple of a healthy diet, but it is a common misconception that you need grains to get fiber).

Even if you did try to avoid all carbs, it turns out your body compensates by making sugar! It does this by breaking down glycogen stores in muscle, and by synthesizing glucose from other building blocks in a process known as gluconeogenesis, but more on these topics in another post! For now… Peace, Love… and Paleo!

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What Is The Ketogenic Diet?

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This will be the first post in a series of posts about the ketogenic diet. We hope you enjoy!

The Ketogenic Diet: Low Carb + High Fat

The ketogenic diet has been around for quite some time now, one could argue as early as 400 BC when the physicians of ancient Greece noticed that epilepsy could be treated by altering diet and by fasting. Over recent years, it has become increasingly popular due to its health benefits (from treating epilepsy to starving cancer), thus prompting scientists to study it more in depth.

In a nutshell, the ketogenic diet is a diet that is low in carbohydrates, high in fat, and moderate in protein. When consumed in this particular ratio, the body is forced to burn fats for energy instead of carbohydrates. This is a process known as ketosis. The ketogenic diet essentially mimics fasting (which also induces ketosis), but you don’t actually have to fast. [Note: the ketogenic diet induces ketosis, NOT ketoacidosis, which is a very different condition. You can learn more about the differences in this article by Dr. Peter Attia.]

How does the ketogenic diet work?

There are three main macronutrients that each of our cells utilize for energy: 1) sugar (a.k.a. glucose), which comes from the breakdown of carbohydrates, 2) amino acids, which come from the breakdown of protein, and 3) ketones, which come from the breakdown of fat. Our cells are metabolically flexible, which means that they can use any of these three compounds for energy at any time, depending on their availability (which turns out to be an incredibly useful feature, but we’ll save this for another post). Normally, our cells primarily utilize glucose and fat for energy, while amino acids are used as building blocks to make other vital things like enzymes and muscle protein.

When we consume a diet with large amounts of carbohydrates (like the Standard American Diet), we end up becoming heavily reliant on burning carbohydrates for energy. As we’re now discovering, this is not so good. Consumption of large amounts of carbohydrates leads to elevated blood sugar levels and thus elevated levels of insulin (insulin helps bring glucose into cells so that it may be used for energy). If we consistently consume large amounts of carbohydrates over time, chronic insulin release can make us become insulin resistant (resistant to the action of insulin). Not only that, but chronic insulin signaling (i.e. the effects that insulin has on other cellular processes) can result in the expression of oncogenes and thus the increased risk of cancer development.

However, when we consume a diet that is low in carbohydrates, high in healthy fats, and moderate in protein, our body is forced to burn fat for energy. When fat is burned, ketones are produced. Ketones are miracle molecules. Our cells can use them for energy in a much more efficient manner than glucose (for the science fans, ketones are directly imported into the mitochondria and used for energy, and don’t need to go through the Krebs cycle preparation process like glucose does). In a sense, we get more bang for our buck when using ketones instead of glucose, in terms of energy.

Eating low carb and high fat is not the only way to produces ketones, however. Anytime we fast, we actually trigger the production of ketones, since in a fasted state our blood levels of glucose are low which triggers the body to mobilize stored fat for energy. This is the process that keeps us alive in times of starvation. This is also why we stated above that the ketogenic diet mimics fasting.

What are the health benefits of a ketogenic diet?

There are a plethora of health benefits of ketones and thus a ketogenic diet. Research has shown that ketones can suppress oncogenes, decrease inflammation, promote healthy cell metabolism & cell signaling, promote healthy body weight and physiology, improve good cholesterol and other cardiovascular markers, and enhance cognitive ability. The famous Hollywood producer Jim Abrahams successfully treated his son who had severe epilepsy with a ketogenic diet and started a foundation about ketogenic diet therapies as a result of this. The ketogenic diet has also been shown to reverse cancerous tumors (see Dr. Dominic D’Agostino’s website for a plethora of resources and references).

In conclusion, the ketogenic diet is a very healthy diet with many benefits. It is also a very promising therapeutic regime for certain diseases and health conditions. Here at HealthSnap, we actually follow a ketogenic diet (we cycle between Paleo diets and Ketogenic diets, and have been doing so for the past 5 years or so).

What about the fat? I’ve always heard fat was bad for me?

If you’re worried about eating fat, don’t be. We will go into more detail on this in another post, but for decades, fat has been demonized as a culprit for obesity and cardiovascular disease for no good reason as there is no good scientific evidence to support these claims. Only recently has the mainstream science and nutrition community started to recognize that fat isn’t the issue, sugar is. Here are some resources to check out in case you are worried about fat:

A major scientific study released last year in 2017 found these results: “High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings.”
An excellent review article highlights that there is no link between saturated fat and heart disease.
A talk by Dr. Peter Attia – “The Straight Dope on Cholesterol”.
Gary Taubes on “Why We Get Fat”.
Gary Taubes on “Fat & Sugar”.

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Diving Into Cancer Metabolism: Is It Possible To Starve Cancer?

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What Is Cancer Metabolism?

Cancer metabolism is the process of how cancer cells process nutrients and use them for energy. It is well known that cancer metabolism is a deviation from normal cell metabolism. When becoming cancerous, cells switch their metabolism from a normal utilization of glucose and fats (glucose and fatty acid oxidation) to an abnormal, less efficient but more rapid, utilization of glucose.

Glycolysis in itself doesn’t cause cancer per se, but it is a necessary consequence (i.e. necessary for cancer to develop). For example, our immune cells, red blood cells, cells lining the gut, and fast twitch muscle fibers, are all glycolytic, and they aren’t cancerous. They are glycolytic in order to rapidly proliferate (immune cells in response to infection, or gut cells to continuously be an effective barrier in the stomach), or in order to provide rapid energy when oxygen isn’t available in an adequate amount of time (e.g. sprinting or high intensity exercise which requires rapid energy where you aren’t able to get oxygen to the cells to make energy in such a short time frame).

Cancer cells want to reproduce and grow, and to avoid death. Glycolysis is therefore a mechanism to provide energy in a rapid enough manner in order to proliferate quickly, as well as provide building blocks for its new cells (this is called glutaminolysis, which is a pathway that is activated in parallel with glycolysis in cancer).

Otto Warburg, a German scientist, and doctor, first noticed this some 50 years ago: “Cancer, above all other diseases, has countless secondary causes. But, even for cancer, there is only one prime cause. Summarized in a few words, the prime cause of cancer is the replacement of the respiration of oxygen in normal body cells by a fermentation of sugar.”

Exploiting Cancer Metabolism By Removing Dietary Glucose

If glucose (i.e. sugar) is cancer’s primary food, then is it possible to starve the cancer of its food in order to program the cancer cell to die? Of course, this is a bit simplistic. But it turns out that this theory might not be all that far off…

Approximately 95% of cancer is caused by epigenetic factors (i.e. your environment). Of this, ~35% is due to diet. To me, this is a huge sign. If diet can induce cancer than diet can potentially cure cancer.

It is well known that you can alter your metabolism based on the foods you eat. For example, a high carbohydrate diet will result in chronic insulin release which promotes fat storage at the expense of fat utilization. This has all sorts of signaling consequences. For example, chronically elevated levels of insulin thus can lead to “insulin resistance” and thus metabolic syndrome, type 2 diabetes, and other potential conditions such as heart disease (and as I’ll make the case, potentially cancer). In essence, you switch your body to rely primarily on glucose, as opposed to fat. And this has consequences.

Elevated sugar levels, either from dietary sugar or carbohydrate (because carbohydrate is a polymer of sugar and breaks down into sugar when digested in the body), triggers cells in the body to signal that they are “full” of energy (for those of a technical scientific bent, this is due to suppression of AMPK). Having energy is a good thing, but as recent evidence suggests… perhaps a consistent level of being “full” is not such a good thing. Let me explain…

A Spoon Full of Hormesis Helps the Cancer Metabolism Go Down

Your body needs a certain amount of stress in order to operate efficiently, and to survive and grow. Sometimes this is referred to as hormesis. Think of exercising. Our muscles grow stronger when we “stress” them. We are, what renowned statistician Nassim Taleb refers to as, “antifragile”. We are the opposite of fragile. We grow when we are exposed to stress (in reasonable amounts). This is present in virtually every aspect of our body. A small amount of “stress” is good: and let me clarify, I’m referring to acute stress, not chronic stress. Chronic stress is a recipe for disaster (you wouldn’t lift weights 24/7 would you? Your muscles couldn’t handle it…).

Even our cells need some stress to ensure proper functioning. On a cellular level, there is a communication pathway (a signaling pathway) that actively works to prevent tumor formation. On the one hand, it is activated by mechanisms not yet understood (the regulation of the cell “skeleton” and others), but what we do know is that it is also regulated by the body’s “energy gauge”. When we experience some metabolic stress (from lack of sugar), this pathway is active and works properly. When we are “full”, this pathway is suppressed, which leads to the expression of cancer genes (oncogenes), and the initiation of cancer metabolism.

As with all things, both too much and too little energy might not be a good thing (for example, too much energy is a good thing for fighting infections, since your immune cells need energy to combat the infection). But, as described above, it appears they aren’t equal: too much energy might be more harmful than too little energy, at least in the context of cancer development and cancer metabolism.

Thus, if sugar consumption is not beneficial because it leads to a consistent state of “being full”, with “too much” energy, then perhaps this suggests that we need to take a break every now and then from the consumption of sugar. In essence, we need a little bit of metabolic “stress”. For example, perhaps switching to a low carb diet (such as the Paleo Diet or the Ketogenic diet), fasting, or switching the fuel source of the body to a substance that does not elevate insulin, such as ketones,² may be beneficial.

Furthermore, evidence exists that lowering blood glucose may be beneficial as a cancer therapy. Type II diabetes patients, taking medications (specifically, metformin) to reduce blood glucose, generally get less cancer. Additionally, animal models on a caloric restricted diet also appears to improve cancer outcomes (since a primary component diets are glucose, caloric restricted diets are lower in glucose).

Of course, this is somewhat simplistic, and there are many factors. For example, there are a small amount of cancers that actually become more aggressive when “starved”. But what is exciting is that all this scientific evidence is pointing in the direction that dietary intervention may be able to cure or at the very least ameliorate symptoms of diseases like cancer.

Hippocrates may not have been all that far off: “Let food be thy medicine and medicine be thy food.”

Category: Science