Joseph Mercola, D.O., founded one of the most-visited health websites in the world.
And his enormous number of newsletter subscribers gives his views very wide reach and influence.
His latest book, “Fat for Fuel”, focuses on the ketogenic diet, and its potential for enhancing brain health, giving us more energy, and fighting cancer.
Ketogenic diets strictly limit foods high in carbohydrates — sugars and starches — and rely instead on fats to provide most daily calories.
Dr. Mercola promotes ketogenic diets because he believes they improve metabolic health, partly by protecting the tiny “energy factories” in our cells called mitochondria (my-toe-kon-dree-ah).
That’s why he calls his unique new program Mitochondrial Metabolic Therapy (MMT).
Our mitochondria are vulnerable to damage by the unstable molecules called free radicals.
And producing cellular energy from glucose — which the body makes from carbohydrates — generates many more free radicals, versus production of energy from ketones, which the body makes from dietary fats.
Accordingly, Dr. Mercola’s MMT program combines a “high-fat, low-carb, adequate-protein” diet designed to generate ketones in the body, and minimize free radicals.
His program also calls for periodic but mild fasting, and use of food-weight scales and at-home blood sugar and ketone tests.
Dr. Mercola advises adherence to the full program for people who either have or run higher risks of cancer, type 2 diabetes, dementia, obesity, and cardiovascular disease.
But he stresses that his program — which is rather rigorous if followed to the letter — can be adjusted (and relaxed) to fit your needs or goals.
What are ketogenic diets?
As we said, ketogenic diets avoid most sugars and starches, limit protein to modestly adequate amounts, and rely on fats to provide most calories.
When the body lacks enough blood sugar (glucose) for energy, it burns fats instead, and this results in a build-up of acids called ketones.
Very-low-carb diets are “ketogenic”, and force the body to rely on fat as fuel, making it much less reliant than usual on carbohydrates.
Ketogenic diets were first used to treat people with epilepsy, but gain much greater fame with the popularity of Dr. Atkins’s famed low-carb diet.
Under pressure from critics who warned (inaccurately) about the dangers of ketogenic diets, Dr. Atkins later changed his plan to rely more heavily on protein than fat.
Growing evidence shows that ketogenic diets can enhance metabolic and brain health while reducing inflammation and discouraging cancer growth — the key reasons why Dr. Mercola promotes reliance on fat for fuel.
And, as he points out in his new book, a truly ketogenic diet provides considerably less protein and more fat than the Atkins Diet or the typical Paleo-style diet.
Dr. Mercola critiques Atkins- and Paleo-style diets, saying that most Americans already pack in too much protein, and that these high-protein diets exacerbate that excess.
Let’s examine three claims that Dr. Mercola makes for his Mitochondrial Metabolic Therapy program, which rests on a ketogenic foundation.
Ketones versus cancer
The apparent ability of ketogenic diets to curb cancer growth is another proposed benefit of Dr. Mercola’s MMT program.
The idea that tumors can be curbed by starving their cancerous cells of glucose was first proposed early in the 20th century by Nobel Prize-winning biochemist Otto Warburg, M.D.
His hypothesis is backed by growing evidence that tumors struggle to thrive or even survive on a ketogenic diet, which is by definition very low in the carbs and sugars that the body converts into glucose.
This does not mean ketogenic diets can necessarily cure or even curb the growth of any given cancer.
But mainstream cancer doctors are increasingly excited about ketogenic diets as important allies (Allen BG et al. 2014; Vergati M et al. 2017; Zahra A et al. 2017).
Ketogenic diets for energy?
Dr. Mercola asserts that a ketogenic diet can make you more energetic.
That makes intuitive sense, given the energy roller-coaster induced by carb-rich diets.
Eating rapidly digested starches and sugars causes a spike in blood sugar, followed by an insulin-induced plunge that leaves you feeling fatigued.
However, the medical literature doesn’t seem to support the idea that ketogenic diets increase people’s perception of energy, or consistently enhance their athletic performance (Burke LM. 2015; Paoli A et al. 2015; Chang CK, et al. 2017).
That said, there’s some evidence that — after a period of adaptation — endurance athletes may perform better on a ketogenic diet.
And while non-obese people may respond differently, the results of some trials suggest that ketogenic diets may be unhelpful with regard to exercise and weight loss in obese people (McClernon FJ et al. 2007; Rankin JW et al. 2007; Brinkworth GD et al. 2009).
Ketogenic diets fight brain fog
Three years ago, we reported the encouraging results of a small clinical study from UCLA.
The UCLA team tested a low-carb, high-fat diet in 10 men and women who suffered from memory and/or thinking problems:
- More fat, fewer carbs.
- More vegetables, fruits, and wild fish
- No starchy carbohydrates (white flour goods; potatoes)
- More antioxidant-rich foods (berries, cocoa, coffee, tea, colorful veggies, greens)
Nine of 10 participants showed “marked” improvement, providing preliminary evidence that memory loss can be reversed through diet changes. (For more details, see Can Dementia be Defeated Naturally?.)
This result echoed positive indications seen in earlier studies, and have since been affirmed by several others.
There’s growing evidence that Alzheimer’s disease is either caused or accelerated by a decline in the brain’s ability to use glucose as fuel, which leads to the death of brain cells (Ciavardelli D et al. 2016; Ohnuma T et al. 2016; Cunnane SC et al. 2016).
So, researchers have been testing the effects of dietary ketones — or ketogenic diets — on people with dementia — with remarkably encouraging results.
It turns out that the aging brain is more than happy to burn ketones instead of glucose as fuel, which appears to help keep it functioning.
Encouraging results were obtained from several studies that tested the brain-performance effects of medium chain triglycerides or MCTs, which the body typically and readily converts into ketones.
Likewise, the primary ketones the body makes from MCTs — beta-hydroxybutyrate (β-HBA) and acetoacetate (ACAC) — have also been tested in people with mild cognitive impairment (“brain fog”) and in people at various stages of Alzheimer’s disease.
Most studies found that MCTs and ketones improved brain performance in people with mild cognitive impairment or Alzheimer’s.
However, most studies detected substantial differences between people who carry the APOE4 gene variant (a major risk factor for Alzheimer’s) and those who don’t, with the former benefiting the most.
Where can you get MCTs?
Coconut oil is the best commonly available source of MCTs — specifically, lauric, caprylic, and capric fatty acids.
The other rich source of MCTs is palm kernel oil, which is harder to find, and many if not most palm plantations employ unsustainable methods that wreak havoc on tropical forests.
Lauric acid constitutes about half the fat in coconut oil. In contrast to caprylic and capric acid, lauric acid produces fewer ketones and it’s metabolized in the liver.
That’s why many advocates — such as Dave Asprey of Bulletproof Coffee fame — recommend “MCT oils” formulated to contain primarily caprylic and capric acid.
However, a recent study showed that coconut oil produced more ketones than either caprylic or capric acid alone, which makes sense, given the very large amount of lauric acid in coconut oil (Cunnane SC et al. 2016).
MCTs are saturated fats, the category commonly — albeit controversially — blamed for raising cardiovascular risks.
But the results of a recent study found that consuming 30 grams (about one ounce) of MCTs for 30 days did not adversely affect blood sugar, insulin, triglyceride, or cholesterol levels (Courchesne-Loyer et al. 2013).
Beyond MCTs: Caffeine and omega-3s also yield ketones
MCTs are not the only way in which diet can produce more ketones.
It turns out that caffeine and the plant source omega-3 called ALA both generate ketones.
This may be a partial explanation for the demonstrated ability of coffee, tea, and omega-3s to enhance brain performance.
A final note on “Fat for Fuel”
We recommend Dr. Mercola's new book, with one caveat.
As he says in the book's introduction, research is constantly advancing, and could make some of his points obsolete.
But we think it’s better to act on what's known now, rather than wait for health authorities to issue firm opinions.
Official guidance is equally vulnerable to obsolescence, and it's much harder for high-profile agencies to admit error.
We should note that Dr. Mercola’s website presents controversial positions on topics like vaccines and fluoridation of water.
Unsurprisingly, his more controversial views are disputed vigorously by scientists active in those fields.
That said, he beneficially focuses people's attention on diet and lifestyle as first-line strategies for preventing and treating our most common health conditions.
And we admire his willingness to explore the frontiers of science to help people achieve optimal health.
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