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Posts Tagged ‘Energy Regulation’

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A LESSON IN TOXICOLOGY

Thursday, April 21st, 2011

Gary Taubes, author of, “Why we get fat” and “Good calories, bad calories” has a nice piece out in the NYT Magazine, which poses the question, “Is sugar toxic?” The question is an interesting one to ask and the article is worth reading in it’s entirety. However, as a faculty member in a Department of Pharmacology and Toxicology, there were a couple of statements that caught my attention.

1. A former FDA administrator who now consults with the Corn Refiners Association is quoted as saying that sugar and high-fructose corn syrup might be toxic, but so might any substance that is consumed in ways or quantities that are unatural for humans and that the key question is at what point does a substance go from being harmless to harmful.

This is a great point. A basic principle in pharmacology and toxicology is that you must study the entire dose-response function to really know what you are dealing with. It is always risky to draw strong conclusions from simply comparing two points or two doses to each other. As such, studies that examine a range of acute and chronic “doses” of fructose relative to sucrose or complex carbohydrates could be quite telling. A related point pertains to relative toxicity. It is true that all sorts of substances such as water or salt can be acutely toxic (i.e., fatal) in large enough quantities. So, we must ask how wide a margin of safety we can expect for various substances. Lastly, it is also important to define what we mean by acute and chronic “harm” or “toxicity,” especially when discussing biochemical measures such as glucose tolerance, insulin sensitivity, or LDL levels.

2. Robert Lustig, of YouTube “Sugar: the bitter truth” video/lecture fame, is quoted as saying that sugar and high-fructose corn syrup are certainly not acute toxins of the kind that FDA typically regulates, but are rather chronic toxins in which the detrimental effects occur over months to years.

This makes me think of cigarettes, which for a long time were regarded as different from the “intoxicating substances” such as alcohol and illicit drugs because of the relative lack of acute impairment from tobacco/nicotine. Typically, the predominant harms from cigarette smoking (cancer, emphysema, heart disease, COPD, etc. ) come with chronic exposure over months to years. And, guess what? FDA just got regulatory authority over tobacco products (about 45 years after the first major report on smoking and health from the Surgeon General). Could the regulation of fructose be in our future?  

COCONUT OIL: FRIEND OR FOE?

Monday, March 28th, 2011

It was about a year ago that a friend told me that coconut oil was not only good for you, but that it was poised to be the next big thing in the world of health foods. I remember reacting with surprise and incredulity – coconut oil? Isn’t that like, the most saturated of fats?

Yes, indeed, coconut oil is comprised of a lot of saturated fat (it is more than 90% saturated), which is why it has gotten a bad rap in the past. However, earlier this month the mainstream media outlet known as the NYT fulfilled my friend’s prophecy by publishing a story titled, “Once a Villain, Coconut Oil Charms the Health Food World.” So, what gives?

Well, one can categorize fatty acids on the basis of their saturation level (saturated, mono-unsaturated, poly-unsaturated), but fatty acids can also be categorized on the basis of their length. It is this latter issue that appears to be relevant to the purported health benefits of coconut oil. You see, although coconut oil is comprised of almost all saturated fatty acids, coconut oil is also predominantly comprised of medium chain triglycerides (a triglyceride contains three fatty acids). Medium chain triglycerides differ from long chain triglycerides (found in olive oil) in that they are more readily absorbed from the small intestine, they are rapidly metabolized in the liver for energy and not fat storage, and they do not contribute to the synthesis of cholesterol. This differs from long chain triglycerides, which require enzymes and vehicles (lipases and chylomicrons) for absorption and transport, and can be repackaged as triglycerides for fat stoage or cholesterol synthesis in the liver.

Ok, ok, you might say – so that is some interesting biochemistry (or you might not say that), but I have been raised to believe that saturated fat = bad and olive oil = good, so are you really suggesting that my body is going to burn coconut oil more efficiently than olive oil?

Yes. But, I’m not just suggesting it, folks have actually done the study (science is cool).

In a paper published in the International Journal of Obesity in 2003, investigators gave two groups of men diets that were matched on fat, carb, and protein ratios (40:55:15). However, 67% of the fats that the medium chain triglyceride group received had chain lengths of 8-10 (compared to 0% in the long chain group), whereas 84% of the of the fats in the long chain triglyceride group had chain lengths of 18 (compared to 24% in the long chain group). Over the next month (28 days), the medium chain group exhibited greater energy expenditure and lost significantly more weight (specifically, fat tissue) as compared to the long chain group, even though the saturated fat makeup of the medium chain group was 76% saturated fat, 14% mono-unsaturated, and 10% poly-unsaturated and the long chain group was 17% saturated fat, 71% mono-unsaturated, and 10% poly-unsaturated.

These data provide some convincing evidence in humans that the biochemical differences between medium and long chain triglycerides appear to translate into physiologically meaningful differences in metabolism and energy regulation.

So, is coconut oil a friend or foe? Let’s just say that it is a welcome guest in our house.

THAT DUDE IS AN AWESOME SLEEPER!

Friday, January 28th, 2011

P1011937

(Guinness, my Siberian Husky who sure knows how to sleep)

Have you ever said the title of this post out loud or have you even thought it to yourself? Of course you haven’t. Sleep is underrated. It is easy to fail to connect the dots between the amount and quality of our sleep and the effects that it has on our productivity, choices, appetite, exercise, weight, and overall happiness. Unfortunately, we also tend not to think that one can become significantly better at sleeping. This is simply not true.

In the 2008 book “Talent is overrated: what really separates world class performers from everybody else” the authors describe some of the key components to self-improvement. For example:

“The best performers observe themselves closely. They are in effect able to step outside themselves, monitor what is happening in their own minds, and ask how it’s going…Top performers do this much more systematically than others do; it’s an established part of their routine.”

“Excellent performers judge themselves differently from the way other people do. They’re more specific, just as they are when they set goals and strategies. Average performers are content to tell themselves that they did great or poorly or okay. The best performers judge themselves against a standard that’s relevant for what they’re trying to achieve. Sometimes they compare their performance with their own personal best; sometimes they compare with the performance of competitors they’re facing or expect to face; sometimes they compare with the best known performance by anyone in the field.”

“If you were pushing yourself appropriately and have evaluated yourself rigorously, then you will have identified errors that you made. A critical part of self-evaluation is deciding what caused those errors. Average performers believe their errors were caused by factors outside their control: My opponent got lucky; the task was too hard; I just don’t have the natural ability for this. Top performers, by contrast, believe they are responsible for their errors. Note that this is not just a difference of personality or attitude. Recall that the best performers have set highly specific, technique-based goals and strategies for themselves; they have though through exactly how they intent to achieve what they want. So when something doesn’t work, they can relate the failure to specific elements of their performance that may have misfired.”

In my experience, I have found these statements to be absolutely true. For example, it is quite common if not ubiquitous among serious athletes to record videos of their performance for subsequent review. This is important because 1) the tape doesn’t lie and 2) it is easier to see what is going wrong when you are not engaged in the activity. Both of these things point to objective assessment and improvement. I experienced this first-hand in a college course in which the professor taped our presentations and reviewed them with us. It was a really useful exercise to be able to see yourself say “um” about 200 times or to realize how much your had been fidgeting and how distracting it could be.

So, back to sleep. Have you ever tried to analyze or track how you have been sleeping? If sleep is important to you, consider how you might try to become the Michael Jordan, Tiger Woods, or Michael Phelps of sleeping. You might seek out information, training, or coaching on sleeping well. You might purchase some high quality sleep equipment (i.e., comfortable bedding, heavy drapes). You might keep track of how you are sleeping, what and where things are going wrong, and try to trouble-shoot those areas. I find that when I think of sleep as a sport or an activity at which I can improve, I approach sleep in a completely different way that gives it the importance that it truly deserves.

Sleep well,

Larry

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