Large-Scale Study Proves High-Fat Diet Promotes Health and Longevity – Quackery?

Lew Rockwell recently published an article by Dr. Joseph Mercola, who seems enamored with ketogenic diets for some reason.  In the article, Mercola advocates for eating a high fat diet and regularly putting oneself into a state of ketosis.  Mercola claims this will promote longevity and “boost mitochondrial function.”

It’s true that a properly done ketogenic diet can cause weight loss, and strictly because of that weight loss, it can lower markers of inflammation, improve blood lipid profiles and improve blood glucose levels… in people who were previously eating the standard American diet (ie. people who are already unhealthy and overweight.)  However, that doesn’t mean it’s the ideal diet or even one that will promote long term health.

Heavy methamphetamine use will also cause weight loss, which leads to improved blood glucose levels, improved blood lipid profiles and lower markers of inflammation.  Obviously that doesn’t mean we should all start doing meth.  As with a meth habit, there are unhealthy side effects associated with ketogenic diets that Mercola doesn’t like to talk about too much.

There are so many misleading and flat-out incorrect statements made in Mercola’s article that it’s hard to even know where to start, so I guess I’ll just work my way down the article.

Mercola states,

The benefits of a cyclical ketogenic diet are detailed in my latest best-sellingg book, “Fat for Fuel.”3 While the book was peer-reviewed by over a dozen health experts and scientists, a new large-scale international study (known as the international Prospective Urban Rural Epidemiology, or PURE, study4,5 ) adds further weight to the premise that high intakes of healthy fats — especially saturated fats — boost health and longevity.

Given that other major epidemiological studies have reached opposite conclusions, perhaps that’s a clue that the PURE study’s data should be interpreted with some skepticism?

The PURE study took food questionnaires from 135,335 individuals aged 35-70 from 18 countries.  Three were high income countries, eleven were middle income and four were low income.  Of the eleven “middle” income, ten are considered developing by the IMF, so this study is mostly based on the developing world.

The study found that total fat intake was associated with lower total mortality risk (ie. accidents, homicides, and every other form of death put together).  The study also found that higher carb intake was associated with an increased risk of total mortality.   Given that this study is based mostly on the developing world, this inverse relationship is entirely explained by socio-economic factors, not diet.  Fat intake is merely a proxy for socio-economic status.  The more developed a nation is, the higher its fat intake becomes.

Dr. David L. Katz, Director of Yale University Prevention Research Center, writes,

“In other words, past the hype and headlines, the apparent paradoxes and puzzles, what PURE means is that: poor people with poor diets and barely enough to eat, and living in places with limited if any modern medical care- are more likely to get sick and die than people living in better circumstances. With all due respect to the researchers, and none to the promulgators of massively misleading media coverage- we knew that already.”

Here’s a great video that explains the PURE study results in detail.

Mercola goes on to state, “In related news, another recent study found a reduced-sugar diet lowered liver fat by more than 20 percent in just nine days.”  What Mercola fails to mention is that the experimental diet they used swapped out sugar for starch based whole plant foods.  In other words, not all carbs are created equal.  Sugar is bad, whole food carbs like rice and beans are good.

Then Mercola goes on to say the AHA “has it all wrong” saying:

In June, the American Heart Association (AHA) shocked health conscious individuals around the world by declaring coconut oil dangerous and urging people to switch from butter to margarine to protect their heart health.9 According to the AHA, replacing saturated fats with polyunsaturated fats such as margarine and vegetable oil might cut your heart disease risk by as much as 30 percent.

This is a remarkable statement when you consider that margarine and refined polyunsaturated vegetable oils10 have been scientifically identified as the fats that actually DO cause heart disease and other health problems, whereas saturated fats have been exonerated.

Mercola cites a Weston A. Price foundation (WAPF) article as his official source for this claim, not a scientific study.  Science Based Medicine lists the WAPF as one of the worst sites on the internet. The WAPF article in question is a tour-de-force of cherry-picked misinformation, hand-waving and red herring arguments that deserves it’s own response, but here’s an article I did on a Peter Attia presentation that pretty much destroys the saturated fat = good pseudoscience.  Saturated fat impairs endothelial function and is directly responsible for inflammation.  Notice that he just boldly proclaims “saturated fats have been exonerated” without any reference material at all.

Mercola goes on to ask, “Why is the AHA clinging to outdated science?” Claiming that, “If people would simply eat healthy saturated fats like coconut oil and butter, there would be no need for a [cholesterol lowering] vaccine strategy.”

Perhaps he’s not aware that epidemiological studies don’t have the statistical power to show an association between saturated fat intake and serum cholesterol levels, which means only dietary change or comparative studies can tell us about the impact of saturated fat intake.

Perhaps he’s not aware of the 395 dietary change experiments that prove eating saturated fat raises serum cholesterol levels so consistently that there is actually a mathematical formula that will tell you exactly how much saturated fat you need to consume to raise your cholesterol by a given number of points.

Then he cites a Nina Teicholz article entitled, “The Big Fat Surprise: Why Butter, Meat, and Cheese Belong in a Healthy Diet:” that accuses the AHA of bias.  In actuality, the AHA has beef and pork based diets featured prominently on their web site.  They are heavily sponsored by the meat and dairy industry, as well the processed food industry.  Frankly, I’m amazed that the AHA isn’t fully in support of a high saturated fat diet given the insane recipes they feature on their site.

Then Mercola goes on to discuss the benefits of water fasting.  While I agree that water fasting can have medicinal benefits, I wouldn’t recommend it for anyone who is in relatively good health!  Perhaps periods of fasting wouldn’t be needed if people ate a calorically dilute plant based diet all the time.  The average person can consume five pounds of potatoes a day without gaining weight!  There are only 26 calories in an ounce of potatoes, for a total of 2080 calories in five pounds.

The rest of the article is a promotion for his particular brand of keto diet.  Mercola says,

The MMT diet is a CYCLICAL or targeted ketogenic diet, high in healthy fats and fiber, low in net carbs with a moderate amount of protein. This targeted component is important, as long-term continuous ketosis has drawbacks that may actually undermine your health and longevity. One of the primary reasons to cycle in and out of ketosis is because the “metabolic magic” in the mitochondria actually occurs during the refeeding phase, not during the starvation phase.

Whoa!  He said something half-way truthful!  Well call me Sally.  Let’s go over his bullet points of benefits.

-Weight loss

Yep, you can lose weight on a keto diet.  But you also can lose weight on all sorts of other diets. At the end of the day it’s always calories in vs. calories out.  To me, it’s much easier to eat pounds of potatoes every day and loose weight without having to starve myself into ketosis.  Studies show weight loss on keto diets is no better or worse than any other diet.

-Reduced inflammation

Mercola cites no studies showing reduced biomarkers of inflammation for people on keto diets. While it’s possible that this might occur for people who are eating the standard American diet and then switch to a keto diet, that doesn’t mean the keto diet is good for you.  As I pointed out earlier, saturated fat is a direct causal agent of inflammation.

Reduced cancer risk

Mercola cites no studies for his claim that keto diets reduce cancer risk.  Meat based diets are known to increase cancer risk.  Processed meat actually has the same level of confidence in carcinogenicity as cigarettes – both are class 1 carcinogens.  While I suppose it’s possible to do a keto vegan diet, I somehow doubt that’s what Mercola is referring to.

-Increased muscle mass

I love the disclaimer he gives for this one.  “Chronic ketosis may eventually result in muscle loss as your body is impairing the mTOR pathway, which is important for anabolic growth.”   Just an FYI, vegans have set world records for strength.  In fact, Roman Gladiators were also known as the “Barley Men of Rome” because of the predominately barley based diet they ate.  All carbs – total power.

-Lowered insulin levels

This one irks me because it’s not the keto diet that reduces the blood glucose levels per se, it’s the weight loss it induces that lowers the blood glucose levels.  If you were to take an already healthy person and put them on a keto diet, their blood glucose levels would most likely worsen.  Intramyocellular lipids (fats in the muscle tissues) are at the root of type II diabetes. This is why losing body fat will improve blood glucose readings.

In these studies, we can see that a whole food plant based diet was able to lower blood glucose levels WITHOUT caloric restriction.

Increased longevity

Mercola claims that keto diets reduce IGF-1 levels and mimic the life extending properties of caloric restriction.  Again, this might be true compared to people who eat the standard American diet, but not to healthy people.  Animal protein is known to increase IGF-1.  When we compare meat eaters to vegans and vegetarians, the vegans have the lowest levels.

Mercola then finishes up his article with more craziness saying, “The evidence is clear: Excessive net carbohydrate intake is the No. 1 culprit behind skyrocketing obesity, diabetes and chronic disease rates, primarily by decimating your mitochondrial function.”

This is patently wrong.

Historically in the US, total caloric intake has increased, overall fat intake has increased, thereby any statement blaming carbs alone for the obesity epidemic is wrong. Fat as a percentage of calories decreased, but fat intake in terms of total calories consumed increased since the 1970s.

Looking at a graph of the percent change in consumption, we can see added fats top the list.

Common sense says fat is behind the obesity epidemic. One gram of fat contains 9 calories compared to 4.5 for carbs or protein. A person would have to eat twice as many carbs by weight as fat to get the same number of calories.  Whole food carbs, such as potatoes, beans, rice, etc.. are also bound with fiber and water, which further dilutes their caloric density.  Randomized control trials tell us conclusively that reductions in fat intake lead to lower body weights. This is the strongest type of evidence available.

How many fat rice eating Asians on a traditional Asian diet do you know?  The lowest obesity rate nations in the world are almost exclusively rice based Asian nations.

Hopefully Lew Rockwell will eventually see Mercola for the quack that he is.  Feel free to share this article or republish it as you wish.  The more people who see this the better.