Category Archives: High-Fat Diet

Study Finds: “Short-Term Benefits Of Low-Carbohydrate Diets For Weight Loss Are Potentially Irrelevant”

BCA1D9Before I leave this topic, for now at least, here’s one more study* that found eating a low-carb diet leads to earlier death:

Low-Carbohydrate Diets And All-Cause Mortality: A Systematic Review And Meta-Analysis Of Observational Studies, PLoS One, January 2013

Low-carbohydrate diets were associated with a significantly higher risk of all-cause mortality.

These findings support the hypothesis that the short-term benefits of low-carbohydrate diets for weight loss are potentially irrelevant.

Given the facts that low-carbohydrate diets are likely unsafe and that calorie restriction has been demonstrated to be effective in weight loss regardless of nutritional composition, [36] it would be prudent not to recommend low-carbohydrate diets for the time being. Further detailed studies to evaluate the effect of protein source are urgently needed.

Interestingly, this was a similar mortality risk to the onestudy in my last post, 31% increased risk here, 33% in Harvard’s analysis of the large Nurses’ Health Study and Health Professional Follow‐Up Study cohorts:

The risk of all-cause mortality among those with high low-carbohydrate score was significantly elevated: the pooled RR (95% CI) was 1.31 (1.07–1.59).

There’s something about eating a lot of animal food that just isn’t good. I’ve said for years now that how we raise animals for food is contributing to chronic disease in humans. It’s more than saturated fat and cholesterol, although they play a part. Animals are higher up on our food chain. Being so, they bioaccumulate POPs (Persistent Organic Pollutants) which have been linked to a range of metabolic disorders. Since POPs are often hydrophobic or lipid soluble, there are higher levels in an animal’s body fat, including our own.

If you’re eating a high-fat diet and that fat is coming from cheese, eggs, bacon, butter, and other animal sources, you’re being exposed to more environmental pollutants than if you are eating either a low-fat diet or a plant-based diet.

* Thanks to @albie_cilliers who posted this in his Twitter stream.

High-Fat Diet, Especially High Saturated Fat, Increases Risk For Breast Cancer In Large Multicountry Study

Butter and knifeSeveral prominent news outlets have carried stories recently calling on us to eat more fat, especially more saturated fat, saying “fat is good for you.” Yet, in this large multicountry study, women who ate the most fat, and especially the most saturated fat, were more likely to develop breast cancer (BC) than women who ate the least:

Study: Dietary Fat Intake and Development of Specific Breast Cancer Subtypes, Journal of the National Cancer Institute, 9 April 2014

Press Release: Consuming a high-fat diet is associated with increased risk of certain types of BC, Journal of the National Cancer Institute, 9 April 2014

Researchers “prospectively analyzed data from 10,062 breast cancer (BC) patients from the EPIC study with 11.5 years of follow-up. The EPIC cohort study consisted of 337,327 women living in 10 European countries, which creates a heterogeneous cohort both in terms of geography-related dietary fat intake patterns and in terms of molecular subtype.”

The authors conclude, “a high-fat diet increases breast cancer risk and, most conspicuously, that high saturated fat intake increases risk of receptor-positive disease, suggesting saturated fat involvement in the etiology of receptor-positive breast cancer.”

News Summary: High-Fat Diet May Boost Breast Cancer Risk, Study Found Women Who Ate The Most Saturated Fat Were More Likely To Develop Tumors, HealthDay, 9 April 2014

One strength of the new study is its large numbers, said Mia Gaudet, director of genetic epidemiology at the American Cancer Society. The breast cancer subtypes linked with fat intake are common, she said. “The majority of breast cancers in the U.S. and Europe are ER-positive, PR-positive, HER2-negative,” she noted.

Lead author Sabina Sieri, PhD: It’s possible that the high-fat intake raises the levels of the body’s own estrogen, which can stimulate the growth of breast cancer cells.

Gaudet: “If you have a mainly plant-based diet, that is going to help you keep your fat intake low.”

So, dietary fat increases the risk for breast cancer. Yet Time Magazine’s Brian Walsh urges us to “Eat Butter” (7 grams of saturated fat in just 1 tablespoon) and New York Times’ Mark Bittman informs us that “Butter Is Back.” (“Butter is back, and when you’re looking for a few chunks of pork for a stew, you can resume searching for the best pieces — the ones with the most fat.”) Dietary fat has also been shown to increase the risk for prostate cancer. And we know it’s implicated in the development of insulin resistance and diabetes.  There must be some other motive working to push fat besides public health.

Gary Taubes’ Typical Low-Carb Diet, And Lab Results

SteakEggs3Gary Taubes, author of “Good Calories, Bad Calories,” and “What If It’s All Been A Big Fat Lie?” is an advocate of low-carbohydrate diets. He posted the results of his blood test on his site about 3 years ago, along with this description of his usual diet:

“Keep in mind as you go through these that I do indeed eat three eggs with cheese, bacon and sausage for breakfast every morning, typically a couple of cheeseburgers (no bun) or a roast chicken for lunch, and more often than not, a ribeye or New York steak (grass fed) for dinner, usually in the neighborhood of a pound of meat. I cook with butter and, occasionally, olive oil (the sausages). My snacks run to cheese and almonds. So lots of fat and saturated fat and very little carbohydrates. A deadly diet, according to Dr. Oz.”

I don’t want to post his lab results here; I feel that’s invasive, even though he made them public. The only values that fell out of the lab’s “reference range” were his total cholesterol (204 mg/dl) and carbon dioxide (19 mmol/L, should be below 21). His LDL was 116.

This is the diet he purports will turn around the epidemics of obesity and diabetes. It is the diet he recommends for avoiding heart disease and cancer. Keep in mind that over 100 million people in this country have diabetes or prediabetes, more than a third of the entire US population. Can you imagine how things would change if suddenly millions of people started eating mostly animal food? No grains, no beans, no potatoes, no fruit?

Taubes’ foundation NUSI has already raised $40 million and is on track to raise $190 million. There’s a lot of funding behind this diet. I think that’s one reason we’re seeing it advanced more in the media.

High-Fat Diet Linked To Loss Of Smell

OlfactoryNerveAccording to Dr. Perlmutter, author of the book Grain Brain, a high-fat diet should protect neurons from damage. In this new study, researchers show that a high-fat diet damages neurons, particularly those involved in the sense of smell:

Hyperlipidemic Diet Causes Loss of Olfactory Sensory Neurons, Reduces Olfactory Discrimination, and Disrupts Odor-Reversal Learning, Journal of Neuroscience, May 2014

We report marked loss of olfactory sensory neurons and their axonal projections after exposure to a fatty diet.

Mice maintained on fatty diets learn reward-reinforced behaviors more slowly, have deficits in reversal learning demonstrating behavioral inflexibility, and exhibit reduced olfactory discrimination

When obese mice are removed from their high-fat diet to regain normal body weight and fasting glucose, olfactory dysfunctions are retained.

New Research Links Bad Diet To Loss Of Smell, Florida State University Press release, 21 July 2014

The research was conducted over a six-month period where mice were given a high-fat daily diet, while also being taught to associate between a particular odor and a reward (water).

Mice that were fed the high-fat diets were slower to learn the association than the control population. And when researchers introduced a new odor to monitor their adjustment, the mice with the high-fat diets could not rapidly adapt, demonstrating reduced smell capabilities.

“Moreover, when high-fat-reared mice were placed on a diet of control chow during which they returned to normal body weight and blood chemistry, mice still had reduced olfactory capacities,” [lead author] Fadool said. “Mice exposed to high-fat diets only had 50 percent of the neurons that could operate to encode odor signals.”

It was the first time researchers had been able to demonstrate a solid link between a bad diet and a loss of smell.

An unfortunate part of this story is that once the mice returned to a regular low-fat diet and lost weight, they didn’t fully regain their sense of smell.

Some Thoughts On Dr. Perlmutter’s “Grain Brain”

GrainBrainCover2I finally went to yesterday and skimmed through the book Grain Brain. The author, Dr. Perlmutter, is an award-winning, practicing neurologist. The book was a number one New York Times bestseller. Perhaps he has something to say.

Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar – Your Brain’s Silent Killers, by David Perlmutter and Kristin Loberg, September 2013

With “grain” in the title, I assumed the book was about avoiding gluten, a protein found in some grains. Was Perlmutter going to argue that gluten impacts neurological function? The full title, which I just saw now, is telling me it isn’t about gluten, not exclusively. It’s about carbohydrate.  So, is he arguing that dietary carbohydrate impacts neurological function? Any food with carbohydrate in it? Quinoa? Rice? Beans? Apples? Carrots? Lemons? Potatoes? Just about all plant foods contain carbohydrate.

Here’s what I found from Amazon’s “Look Inside”

Modern grains are silently destroying your brain. … I’m referring to all the grains that so many of us have embraced as being healthful – whole wheat, whole grain, multigrain, seven-grain, live grain, stone-ground, and so on.

I will demonstrate how fruit and other carbohydrates could be health hazards.

… An extremely low-carbohydrate but high-fat diet is ideal (we’re talking no more than 60 grams of carbs a day – the amount in a serving of fruit). This may also sound preposterous, but I’ll be recommending that you start swapping out your daily bread with butter and eggs. You’ll soon be consuming more saturated fat and cholesterol and re-thinking the aisles in your grocery store.

In the days leading up to your new way of eating, you’ll want to take an inventory of your kitchen and eliminate items that you’ll no longer be consuming. Start by removing the following … All forms of processed carbs, sugar and starch: corn, yams, potatoes, sweet potatoes.

The following can be used in moderation (“moderation” means eating small amounts of these ingredients once a day or, ideally, just a couple times weekly):
– Carrots and parsnips.
– Legumes (beans, lentils, peas).
– Non-gluten grains. (Avoid oats entirely.)
– Whole sweet fruit: Berries are best; be extra cautious of sugary fruits such as apricots, mangoes, melons, papaya, prunes, and pineapple.

I’m going to rescue you from a lifetime of trying to avoid eating fat and cholesterol and prove how these delicious ingredients preserve the highest functioning of your brain. … Our bodies thrive when given “good fats,” and cholesterol is one of these. And we don’t do so well with copious amounts of carbohydrates, even if those carbs are gluten-free, whole grain, and high in fiber.

Eating high-cholesterol foods has no impact on our actual cholesterol levels, and the alleged correlation between higher cholesterol and higher cardiac risk is absolute fallacy.1

You will be starting a daily supplement regimen for life. [Perlmutter sells supplements on his site.]

Yes, Perlmutter is saying that any intake of carbohydrate, beyond the 60 or so grams in a piece of fruit, impairs brain function. It’s evident that Dr. Perlmutter’s food journey and mine have led to drastically different diets. (At least he allows small amounts of beans. On a Paleo diet, you have to avoid them at all costs, even fresh green beans.)

Here’s a comment by srj, who claimed to be a physician. It’s representative of other comments which call into question Perlmutter’s treatment of the evidence:

“I quit reading about half way through the book because in almost every case he badly misinterpreted the studies he quoted. As an example, reference 25 in Chapter 4 (Title: Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance) compared people on a high glycemic diet, a low glycemic diet (whole grain) and a very low carbohydrate (high fat/meat) diet. This study did show a slight improvement in metabolic syndrome components in the low carb diet over the low glycemic diet, but the low carb diet raised cortisol and CRP (C-Reactive Protein) levels considerable. Previous studies have shown a 5-fold (that’s 500%!) increase in cardiovascular mortality with the higher levels of cortisol and CRP and thus the conclusion of the study authors was that the low carb diet was too dangerous to recommend. The only part of the study reported by Dr. Perlmutter was that that the metabolic syndrome parameters were better – nothing about the cortisol and CRP elevation which was far more important.”

I’m surprised at the assurance with which Perlmutter advances his ideas. Dr. David Katz, founding director of Yale University’s Prevention Research Center, criticized Grain Brain, saying many of its claims were “wildly preposterous,” particularly the one where Perlmutter says the ideal diet “is close to that of the Paleo diet: 75% fat, 20% protein, and 5% carbs.” Katz, citing work of researcher and “The Paleo Diet” author Lorin Cordain, said that humans during the Paleolithic Era ate mostly plants with a scattering of seeds and nuts. … “What the hell could they possibly have eaten that would be that fatty?”2

Maybe we’re all a little guilty of focusing on science that supports our preconceptions and glossing over that which challenges them. It’s our prerogative. Most of us aren’t writing books, selling products, and collecting consulting fees. Don’t you think that someone who is presenting himself as an authority, who claims to be science-based, who is urging millions of people to adopt a controversial diet, would be more even-handed with the evidence? I do. The reason I support eating a whole-food, plant-based diet is because I’ve read the studies, not because I’ve read a book by someone claiming to have read the studies for me.

1 This particular claim has been exhaustively researched by a blogger who goes by Plant Positive. He refers to people who reject the lipid hypothesis, as Perlmutter does here, as cholesterol deniers. He’s amassed a trove of evidence that defends the lipid hypothesis, that defends the correlation between serum cholesterol and heart disease, i.e. the lower your cholesterol, the lower your heart disease risk.
2 James Hamblin’s skepticism is wholly transparent in his Atlantic article, “This Is Your Brain On Gluten.“)

Low-Carb, High-Fat Diets Linked To Poor Artery Function


Angina pectoris is chest pain due to poor functioning of arteries supplying the heart.

The New York Times’ Mark Bittman and Time Magazine’s Bryan Walsh may be telling us to eat butter, suggesting that dietary fat is not a problem, carbohydrates are the problem. But researchers in Spain said there is a …

Negative effect of a low-carbohydrate, high-protein, high-fat diet on small peripheral artery reactivity in patients with increased cardiovascular risk, British Journal of Nutrition, April 2013 (pdf)

This was a cross-sectional analysis of 247 men and women.  Patients eating the least fat and the most carbohydrate (45% carb, 20% protein, 32% fat) had better small artery function than those eating the most fat and least carbohydrate (29% carb, 24% protein, 40% fat).

“Conclusion: In a cross-sectional study of patients with increased CV [cardiovascular disease] risk, a dietary pattern characterised by a high LCDS (high protein and fat, but low carbohydrate content) was associated with poorer peripheral small artery function compared with individuals consuming a diet with a lower LCDS. The association was strong in patients with two different metabolic diseases studied: the MS [Metabolic Syndrome] and T2D [Type 2 Diabetes].”

High-Fat, High-Fructose Combination Worse Than High-Fat Or Low-Fat Alone

I’ve been saying this for years1,2 … a diet that is both high in fat and high in refined carbohydrates is worse (that is, leads to more metabolic disorders such as weight gain, diabetes, fatty liver, cancer) than a diet high in one or the other. The combination is particularly deleterious. (Although diets high in fat alone come with their own risks related to their higher levels of fat-soluble environmental toxins, increased systemic inflammation, and, as this study found, promotion of insulin resistance and fatty liver.)

This new study found that:

Fructose Supplementation Worsens The Deleterious Effects Of Short Term High Fat Feeding On Hepatic Steatosis And Lipid Metabolism In Adult Rats, Experimental Physiology, 27 June 2014

RatsHighFat2014Adult male rats were fed either a low-fat, high-fat, or high-fat/high fructose diet for 2 weeks. The high-fat/high-fructose diet was worse than the high-fat diet, which was worse than the low-fat diet. Another way of saying that … the low-fat diet was the healthiest.

Some significant bits:

“From our results, it appears that hepatic mitochondrial impairment is an early event induced by increased lipid content of the diet, since it is already evident after 2 weeks of dietary treatment, and that the presence of fructose does not have a further impact on mitochondrial function.

Significantly lower mitochondrial oxidative capacity but significantly higher oxidative stress was found in rats fed high fat and high fat-high fructose diet compared to rats fed low fat diet.”

During high fat feeding an increased lipid supply to peripheral organs, and particularly to the liver, arises mainly from dietary lipids.”

They say that mitochondrial impairment is linked to insulin resistance, and that it is dietary fat which initiates insulin resistance. It occurs because there is a reduced capacity by mitochondria to deal with the increased lipid supply. The extraneous fat is deposited ectopically or outside of the cell, leading to a fatty liver, which exacerbates insulin resistance. Adding fructose to this impaired state compounds the problem.

This is exactly what Dr. McDougall says happens. (Insulin Resistance Is A Normal Adaptation To A Rich Diet)

By the way, the rats fed a low-fat, high-carbohydrate diet (from cornstarch) by the end of the study weighed less, had less body fat, less liver fat, fewer plasma free fatty acids, and lower plasma cholesterol than the rats fed a high-fat diet, even though they ate the same amount of food (in calories) as the high-fat rats.

1 High-Fat High-Sugar Dietary Pattern (“Meat & Potatoes”) Linked To Colon Cancer, Diabetes, Fanatic Cook, July 2010
2 “Meat And Potatoes” Dietary Pattern And Risk For Colon Cancer, Fanatic Cook, May 2010