Tag Archives: fatty acids

Your Heart Works Fine on a Low-Carb Diet

Amber Wilcox-O’Hearn explains why.

Paleobetic diet, low-carb,paleo diet, Steve Parker MD, cabbage soup, diabetic diet

This cabbage soup only has 9 grams of digestible carbohydrate per 2-cup serving

Your heart beats 100,000 times a day, every day, without rest. You’d think it needs a reliable energy source, and you’d be right. One of Amber’s references (#4) reminds me that, “Fatty acids are the heart’s main source of fuel, although ketone bodies as well as lactate can serve as fuel for heart muscle. In fact, heart muscle consumes acetoacetate in preference to glucose.”

Steve Parker, M.D.

PS: Paleo-compliant Cabbage soup recipe

Dr. Roy Taylor on the Cause of Type 2 Diabetes and What To Do About It

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Warning: this is a sciencey post

According to Roy Taylor, M.D., “type 2 diabetes is a potentially reversible metabolic state precipitated by the single cause of chronic excess intraorgan fat.” The organs accumulating fat are the pancreas and liver. He is certain “…that the disease process can be halted with restoration of normal carbohydrate and fat metabolism.” I read Taylor’s article published last year in Diabetes Care.

(Do you remember that report in 2011 touting cure of T2 diabetes with a very low calorie diet? Taylor was the leader. The study involved only 11 patients, eating 600 calories a day for eight weeks.)

Dr. Taylor says that severe calorie restriction is similar to the effect of bariatric surgery in curing or controlling diabetes. Within a week of either intervention, liver fat content is greatly reduced, liver insulin sensitivity returns, and fasting blood sugar levels can return to normal. During the first eight weeks after intervention, pancreatic fat content falls, with associated steadily increasing rates of insulin secretion by the pancreas beta cells.

bariatric surgery, Steve Parker MD

Band Gastric Bypass Surgery (not the only type of gastric bypass): very successful at “curing” T2 diabetes if you survive the operation

Taylor’s ideas, by the way, dovetail with Roger Unger’s 2008 lipocentric theory of diabetes. Click for more ideas on the cause of T2 diabetes.

Here are some scattered points from Taylors article. He backs up most of them with references:

  • In T2 diabetes, improvement in fasting blood sugar reflects improved liver insulin sensitivity more than muscle insulin sensitivity.
  • The more fat accumulation in the liver, the less it is sensitive to insulin. If a T2 is treated with insulin, the required insulin dose is positively linked to how much fat is in the liver.
  • In a T2 who starts insulin injections, liver fat stores tend to decrease. That’s because of suppression of the body’s own insulin delivery from the pancreas to the liver via the portal vein.
  • Whether obese or not, those with higher circulating insulin levels “…have markedly increased rates of hepatic de novo lipogenesis.” That means their livers are making fat. That fat (triglycerides or triacylglycerol) will be either burned in the liver for energy (oxidized), pushed into the blood stream for use elsewhere, or stored in the liver. Fatty acids are components of triglycerides. Excessive fatty acid intermediaries in liver cells—diglycerides and ceramide—are thought to interfere with insulin’s action, i.e., contribute to insulin resistance in the liver.
  • “Fasting plasma glucose concentration depends entirely on the fasting rate of hepatic [liver] glucose production and, hence, on its sensitivity to suppression by insulin.”
  • Physical activity, low-calorie diets, and thiazolidinediones reduce the pancreas’ insulin output and reduce liver fat levels.
  • Most T2 diabetics have above-average liver fat content. MRI scans are more accurate than ultrasound for finding it.
  • T2 diabetics have on average only half of the pancreas beta cell mass of non-diabetics. As the years pass, more beta cells are lost. Is the a way to preserve these insulin-producing cells, or to increase their numbers? “…it is conceivable that removal of adverse factors could result in restoration of normal beta cell number, even late in the disease.”
  • “Chronic exposure of [pancreatic] beta cells to triacylglycerol [triglycerides] or fatty acids…decreases beta cell capacity to respond to an acute increase in glucose levels.” In test tubes, fatty acids inhibit formation of new beta cells, an effect enhanced by increased glucose concentration.
  • There’s a fair amount of overlap in pancreas fat content comparing T2 diabetics and non-diabetics. It may be that people with T2 diabetes are somehow more susceptible to adverse effects of the fat via genetic and epigenetic factors.
  • “If a person has type 2 diabetes, there is more fat in the liver and pancreas than he or she can cope with.”
  • Here’s Dr. Taylor’s Twin Cycle Hypothesis of Etiology of Type 2 Diabetes: “The accumulation of fat in liver and secondarily in the pancreas will lead to self-reinforcing cycles that interact to bring about type 2 diabetes. Fatty liver leads to impaired fasting glucose metabolism and increases export of VLDL triacylglcerol [triglycerides], which increases fat delivery to all tissues, including the [pancreas] islets. The liver and pancreas cycles drive onward after diagnosis with steadily decreasing beta cell function. However, of note, observations of the reversal of type 2 diabetes confirm that if the primary influence of positive calorie balance is removed, the the processes are reversible.”
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Figure 6 from the article: Dr. Taylor’s Twin Cycle Hypothesis of Etiology of Type 2 Diabetes

  • The caption with Figure 6 states: “During long-term intake of more calories than are expended each day, any excess carbohydrate must undergo de novo lipogenesis [creation of fat], which particularly promotes fat accumulation in the liver.”
  • “The extent of weight gloss required to reverse type 2 diabetes is much greater than conventionally advised.” We’re looking at around 15 kg (33 lb) or 20% of body weight, assuming the patient is obese to start.  “The initial major loss of body weight demands a substantial reduction in energy intake. After weight loss, steady weight is most effectively achieved by a combination of dietary restriction and physical activity.”

Dr. Taylor doesn’t specify how much calorie restriction he recommends, but reading between the lines, I think he likes his 600 cals/day for eight weeks program. That will have a have a high drop-out rate. I suspect a variety of existing ketogenic diets may be just as successful and more realistic, even if it takes more than eight weeks. I wonder how many of the 11 “cures” from the 2011 study have persisted.

Steve Parker, M.D.

Reference: Taylor, Roy. Type 2 diabetes: Etiology and reversibility. Diabetes Care, April 2013, vol. 36, no. 4, pp:1047-1055.

Update: Some wild and crazy guys tried the Taylor method at home. Click for results.

Why Everybody Should Eat Nuts

Nuts with more omega-3 fatty acids (compared to omega-6) may be the healthiest

Nuts with the lowest omega-6/omega-3 fatty acid ratios may be the healthiest. In other words, increase your omega-3s and decrease omega-6s.

Conner Middelmann-Whitney explains in her recent post at Psychology Today. In a nutshell, they are linked to longer life and better health. For example:

In the largest study of its kind, Harvard scientists found that people who ate a handful of nuts every day were 20% less likely to die from any cause over a 30-year period than those who didn’t consume nuts. The study also found that regular nut-eaters were leaner than those who didn’t eat nuts, a finding that should calm any fears that eating nuts will make you gain weight.

The report also looked at the protective effect on specific causes of death. “The most obvious benefit was a reduction of 29% in deaths from heart disease—the major killer of people in America,” according to Charles S. Fuchs, director of the Gastrointestinal Cancer Treatment Center at Dana-Farber, the senior author of the report and a professor of medicine at Harvard Medical School. “But we also saw a significant reduction—11% —in the risk of dying from cancer,” added Fuchs.

Read the whole enchilada.

Nuts are integral to my Advanced Mediterranean Diet, Low-Carb Mediterranean Diet, Paleobetic Diet, and Ketogenic Mediterranean Diet.

Walnuts seem to have the lowest omega-6/omega-3 fatty acid ratio of all the common nuts. That may make them the healthiest nut. The jury is still out. Macadamia nuts have a good ratio, too. Paleo dieters focus on cutting out omega-6s and increasing omega-3s. Julianne Taylor has a great post on how to do that with a variety of foods, not just nuts.

Steve Parker, M.D.

Omega-3 Supplements Fail to Prevent Age-Related Cognitive Decline

I like fish, but cold whole dead fish leave me cold

Consumption of omega-4 fatty acids, mainly from fish, is thought to prevent dementia and certain types of heart disease such as heart attacks and dangerous rhythm disturbances. For those who don’t like fish or can’t afford it, would taking omega-3 fatty acid supplements be just as effective?

Unfortunately, supplementation does not help prevent age-related cognitive decline and dementia, according to an article at MedPage Today.

The respected Cochrane organization did a meta-analysis of three pertinent studies done in several countries (Holland, UK, and ?).

The investigators leave open the possibility that longer-term studies—over three years—may show some benefit.

I leave you with a quote from the MedPage Today article:

And while cognitive benefits were not demonstrated in this review, Sydenham and colleagues emphasized that consumption of two servings of fish each week, with one being an oily fish such as salmon or sardines, is widely recommended for overall health benefits.

Consumption of cold-water fatty fish also helps return our dietary omega-6/omega-3 fatty acid ratio toward our ancestral level.

Steve Parker, M.D.

Reference:
Sydenham E, et al “Omega 3 fatty acid for the prevention of cognitive decline and dementia” Cochrane Database of Systematic Reviews 2012; DOI: 10.1002/14651858.CD005379.pub3.

What’s Our Preferred Fuel?

Dr. Jay Wortman has been thinking about whether our bodies prefer to run on carbohydrates (as a source of glucose) or, instead, on fats. The standard American diet provides derives about half of its energy from carbs, 35% from fats, and 15% from proteins. So you might guess our bodies prefer carbohydrates as a fuel source. Dr. Wortman writes:

Now, consider the possibility that we weren’t meant to burn glucose at all as a primary fuel. Consider the possibility that fat was meant to be our primary fuel. In my current state of dietary practice, I am burning fat as my main source of energy. My liver is converting some of it to ketones which are needed to fuel the majority of my brain cells. A small fraction of the brain cells, around 15%, need glucose along with a few other tissues like the renal cortex, the lens of the eye, red blood cells and sperm. Their needs are met by glucose that my liver produces from proteins. The rest of my energy needs are met with fatty acids and these come from the fats I eat.

Dr. Wortman, who has type 2 diabetes, in the same long post also writes about oolichan grease (from fish), an ancestral food of Canandian west coast First Nations people.

Drs. Jeff Volek and Stephen Finney have done research on athletes using a low-carb, high-fat diet.

Steve Parker, M.D.