Fat Head: Tom Naughton's manifesto for low-carb eating

12. March 2010 William Davis (16)
I just got back from Jimmy Moore's low-carb cruise to the Bahamas.

Among the many interesting people I met on the cruise was the creator of the documentary film, Fat Head, Tom Naughton.

Tom brings both creative insights into low-carbohydrate eating as well as humor. Low-carb eating can be a pretty contentious issue, but Tom made it fun. He will make you laugh about many of the odd notions we have about diet.

Among the best parts of Fat Head is Tom's portrayal of the effects of carbohydrates on insulin and fat metabolism:






Fat Head joins the ranks of films like Food, Inc, that make nutrition information entertaining. For anyone interested in a unvarnished look at diet, weight loss, along with a few laughs along the way, Tom Naughton's Fat Head is worth viewing.

Oatmeal: Good or bad?

11. March 2010 William Davis (67)

You've heard it before: oatmeal reduces cholesterol. Oatmeal producers have obtained permission from the FDA to use a cholesterol-reducing claim. The American Heart Association provides a (paid) endorsement of Quaker Oats.

I've lost count of the times I've asked someone whether they ate a healthy breakfast and the answer was "Sure. I had oatmeal."

Is this true? Is oatmeal heart healthy because it reduces LDL cholesterol?

I don't think so. Try this: Have a serving of slow-cooked (e.g., steel-cut, Irish, etc.) oatmeal. Most people will consume oatmeal with skim or 1% milk and some dried or fresh fruit. Wait an hour, then check your blood sugar.

If you are not diabetic and have a fasting blood sugar in the "normal" range (<100 mg/dl), you will typically have a 1-hour blood glucose of 150-180 mg/dl--very high. If you have mildly increased fasting blood sugars between 100 and 126 mg/dl, postprandial (after-eating) blood sugars will easily exceed 180 mg/dl. If you have diabetes, hold onto your hat because, even if you take medications, blood sugar one hour after oatmeal will usually be between 200 and 300 mg/dl.

This is because oatmeal is converted rapidly to sugar, and a lot of it. Even if you were to repeat the experiment with no dried or fresh fruit, you will still witness high blood sugars in these ranges. Do like some people and pile on the raisins, dried cranberries, or brown sugar, and you will see blood sugars go even higher.

Blood sugars this high, experienced repetitively, will damage the delicate insulin-producing beta cells of your pancreas (glucose toxicity). It also glycates proteins of the eyes and vascular walls. The blood glucose effects of oatmeal really don't differ much from a large Snickers bar or bowl of jelly beans.

If you are like most people, you too will show high blood sugars after oatmeal. It's easy to find out . . . check your postprandial blood sugar.

In past, I recommended oat products, specifically oat bran, to reduce LDL, especially small LDL. I've changed my mind: I now no longer recommend any oat product due to its blood sugar-increasing effects.

Better choices: eggs, ground flaxseed as a hot cereal, cheese (the one dairy product that does not excessively trigger insulin), raw nuts, salads, leftovers from last evening's dinner.

Mustard: Super health food?

6. March 2010 William Davis (32)
Could mustard--yes, the yellow condiment you smear on hot dogs--be a super heart healthy food in disguise?

Consider that mustard contains:

Vinegar

Turmeric

No appreciable sugar


The vinegar slows gastric emptying, resulting in slower absorption of any carbohydrates and a reduced glucose area-under-the-curve. Of the little fats contained (about 3 grams per 1/4 cup), most are desirable monounsaturates. Mustards are relatively rich in selenium, with 20 mcg per 1/4 cup, helpful for protection against cancer and thyroid disease, and magnesium, 31 mg per 1/4 cup.

Turmeric is added to most mustards. One of the constituents of turmeric, curcumin, the substance that confers the bright yellow color, has been a focus of interest for its anti-inflammatory effects. Curcumin has been documented to reduce activity of the inflammatory enzymes cyclooxygenase-2 (COX-2), lipoxygenase, and reduce activity of inflammatory signal molecules, tumor necrosis factor-alpha (TNF-a), interleukin (IL)-1,2,6,8, and 12, and monocyte chemoattractant protein (MCP). Curcumin also has been shown to reduce LDL oxidation, a potentially important step in atherosclerotic plaque formation. Turmeric is used as a tea by Okinawans. (Hmmmm . . . )

Turmeric content of mustard can vary, of course. Likewise, sugar content. Look for mustards that are not sweetened, so avoid honey mustard in particular. Look for hot, brown, horseradish, Dijon, etc. If there is a downside to mustard, it's sodium content, though the 709 mg per 1/4 cup should only be a problem for those who are sodium-sensitive (African Americans, in particular).

So perhaps mustard isn't exactly a super health food. But it may have some bona fide health effects and should be used generously especially if you are concerned about blood sugar and inflammatory phenomena.

Exercise and blood sugar

5. March 2010 William Davis (30)
There is no doubt that exercise yields benefits across a spectrum of health: reduced blood pressure,  reduced inflammation, reduced blood coagulation, better weight control, stronger bones, less depression, reduced risk for heart attack.

Exercise also influences blood sugar. Diabetics understand this best: Exercise reduces blood sugar 20, 30, 50 or more milligrams. A starting blood sugar, for instance, of 160 mg/dl can be reduced to 80 mg/dl by jogging or riding a bicycle. (I recently had brunch at an Indian restaurant with my family. Blood sugar one-hour postprandial: 134 mg/dl. I was sleepy and foggy. I got on my stationary bike and pedalled at a moderate clip for 60 minutes. Blood sugar: 90 mg/dl.)

Could the reduction of blood sugar with exercise be THE reason that exercise and physical activity provide such substantial benefits?

Think about it. Reduced blood sugar:

1) Reduces risk for future cardiovascular events.
2) Reduces glycation of proteins, i.e., reduced glucose binding to proteins like the ones in artery walls and the lenses of your eyes.
3) Reduces blood coagulation
4) Reduces endothelial dysfunction (abnormal artery constriction that leads to atherosclerosis)

This might explain why it doesn't require high levels of aerobic activity to derive benefit from exercise, since even modest efforts (e.g., a 15-minute walk after eating) reduce blood sugar substantially.

The incredible 33-year, 18,000-participant Whitehall study tells us that a postprandial (after-eating) blood sugar of an impossibly-difficult 83 mg/dl is required to erase the excess cardiovascular risk of blood sugar. Could this simply be telling us that physical activity or exercise is required to suppress blood sugars to these low levels?

It makes me wonder if an index of the adequacy of exercise is your post-exercise blood glucose.

The most important weight loss tool

4. March 2010 William Davis (15)

Question: What is the most effective tool available to help you lose weight? 


A pedometer (walk 10,000 steps, etc.)?

A treadmill? 




A bicycle?






No. None of the above. 

The most important tool you can use to achieve weight loss is your glucose monitor:



Timing of blood sugars

3. March 2010 William Davis (5)
Because different foods generate different blood sugar (glucose) responses, the timing of your blood sugar is an important factor to consider.

This question has come up a number of times. Commenters have asked whether the one-hour postprandial glucose is timed with the start of the meal or the conclusion of the meal.

In my view, if we simply ignored all aspects of meal composition, then blood glucose should be obtained one hour after the conclusion of a meal. This is because most mixed meals (i.e., mixed in composition among proteins, fats, and carbohydrates) yield peak blood glucose levels at 60-90 minutes after consumption. Timing blood glucose to 60 minutes after the conclusion of a meal puts the sample right about at the peak.

But this is an oversimplification. For instance, here is the blood glucose behavior after so-called "complex" carbohydrates wheat bread, rye bread, rye made with beta glucan, and whole wheat pasta (50 grams carbohydrates each) in slender, healthy volunteers, mean age 29 years:


From Juntunen et al 2002

Note that blood glucose peaks at 35 minutes postprandial. (To convert glucose in mmol/L to mg/dl, multiple by 18. Thus, whole wheat bread increased blood glucose from 94 mg/dl to 122 mg/dl. Also note the lower peak glucose for pasta, but sustained higher glucose levels hours later.)

In another study, older (mean age 64 years), overweight (BMI 27.9) females with diabetes were given 50 grams carbohydrate, 50 grams carbohydrate with olive oil, or 50 grams carbohydrate with butter:


From Thomsen et al 2003. Control meal of soup plus 50 g carbohydrates ({blacktriangledown}), the control meal plus 80 g olive oil ({circ}), and the control meal plus 100 g butter (•).

In this experience, note that postprandial glucose peaks 60-120 minutes after the meals (consumed within 10 minutes), delayed more when either oil is included. Blood glucose started at 144 mg/dl and peaked as high as 230 mg/dl with carbohydrates only; peaks were reduced (along with AUC) when oil was included. (Note the differential effect, olive oil vs. butter.)

These two sets of observations give you a range of blood glucose behavior. One side lesson: Carbohydrates should never consumed by themselves, else you will pay with a high blood sugar (not to mention the hypoglycemic response later for many).

Psssst . . . There's sugar in there

1. March 2010 William Davis (13)
You non-diabetics who check your postprandial blood sugars already know: There are hidden sources of sugar in so many foods.

By now, everybody should know that foods like breakfast cereals, breads, bagels, pretzels, and crackers cause blood sugar to skyrocket after you eat them. But sometimes you eat something you thought was safe only to find you're showing blood sugars of 120, 130, 150+ mg/dl.

Where can you find such "stealth" sources of sugars that can screw up your postprandial blood sugars, small LDL, inflammation, blood pressure, and cause you to grow visceral fat? Here's a few:

Balsamic vinaigrette
Many commercially-prepared balsamic vinaigrettes, especially the "light" varieties, have 3 or more grams carbohydrates per tablespoon. Generous use of a sugar-added vinaigrette can therefore provide 12+ grams carbs. (Some, like Emeril's and Wish Bone, also contain high-fructose corn syrup.)

Hamburgers
I learned this lesson the hard way by taking my blood sugar after having a hamburger, turkey burger, or vegetarian burger (without bun): blood sugar would go way up. The effect is due to bread crumbs added to the meat or soy.

Tomato soup
If it were just tomatoes, it would still be somewhat high in sugars. But commercially-prepared tomato soup often contains added high-fructose corn syrup, sucrose, and wheat flour, bringing sugar totals to 12 to 20+ grams per half-cup. A typical 2-cup bowl of tomato soup can have upwards of 80 grams of sugar.

Granola
Sure, granola contains a lot of fiber. But most granolas come packed with sugars in various forms. One cup of Kellogg's Low-fat Granola with Raisins contains an incredible 72 grams (net) carbohydrates, of which 25 grams are sugar.


Given modern appetites and serving sizes, you can see that it is very easy to get carried away and, before you know it, get exposed to extraordinary amounts of sugar and carbohydrates eating foods you thought were healthy.

And don't be fooled by claims of "natural" sugar. Sugar is sugar--Just check your blood sugar and you'll see. So raw cane sugar, beet sugar, and brown sugar have the same impact as white table sugar. Honey, maple syrup, and agave? They're worse (due to fructose).

How low should blood sugar be?

28. February 2010 William Davis (0)
What should your blood sugar (glucose) be after eating?

Take a look at the data from the Whitehall study reported in 2006. The Whitehall Study stands apart from other studies in that it was very large (over 18,000 participants) who were observed for an unusually long time (33 years). All participants were administered a 50 gram glucose "challenge" at the start with glucose levels checked after the glucose challenge.

Here's what they found:




From Brunner et al 2006.
Chicken Little

Chicken Little

11. August 2007 William Davis (1)
Clinical studies can be designed in a number of ways. The ease and cost of these studies differ dramatically, as does the confidence of the findings.

The most confident way to design a clinical study is to tell neither the participants nor the investigator(s) what treatment is being offered, then to administer treatment or placebo. Neither the people doing the research nor the participants know what they are receiving. Of course, there needs to be some way to find out what was given at the end of the study in order to analyze the outcome.

This is called a “double-blind, placebo-controlled” clinical study. While not perfect since it tends to examine a treatment phenomenon in isolation (e.g., the effects of a single drug in a select group of people), it is the best sort of study design that is most likely to yield confident results, both negative and positive. This sort of design is followed, for instance, for most prescription drugs.

There are pitfalls in such studies, of course, and some have made headlines lately. For instance, beyond tending to examine single conditions in a select group of participants, a double-blind, placebo-controlled study can also fail to uncover rare effects. If a study contains 5000 participants, for instance, but a rare complication develops in 1 person out of 20,000, then it’s unlikely such an ill-effect will be observed until larger numbers of people are exposed to the agent.

Another pitfall (though not so much of study design, but of human greed) is that study outcomes that are not favorable can be suppressed by simply failing to publish the results. This has undoubtedly happened numerous times over the years. For this reason, a registry has been created for all human clinical trials as a means to enforce publication of outcomes, both favorable and unfavorable.

Despite its weaknesses, the double-blind, placebo-controlled study design remains the most confident way to show whether or not some treatment does indeed yield some effect. It is less prone to bias from either the participant or the investigator. Human nature being what it is, we tend to influence results just to suit our particular agenda or interests. An investigator who knows what you are given, drug or placebo, but owns lots of stock in the company, or is hoping for special favors from the pharmaceutical company sponsor, for instance, is likely to perceive events in a light favorable to the outcome of the study.

Now, most studies are not double-blind, placebo-controlled studies. These are notoriously difficult studies to engineer; raise lots of ethical questions (can you not treat a person with an aggressive cancer, for instance, and administer a placebo?); often require substantial numbers of participants (thousands), many of whom may insist on payment for devoting their time, bodies, and perhaps even encountering some risk; and are tremendously expensive, costing many tens of millions of dollars.

For this reason, many other study designs are often followed. They are cheaper, quicker, may not even require the active knowledge or participation of the group being studied. That’s not to say that the participants are being tricked. It may simply be something like trying to determine if there are more heart attacks in people who live in cities compared to rural areas by comparing death rates from heart attack from public records and population demographic data. Or, a nutritional study could be performed by asking people how many eggs they eat each week and then contacting them every month for 5 years to see if they’ve had a heart attack or other heart event. No treatment is introduced, no danger is added to a person’s established habits. Many epidemiologic studies are performed this way.

The problem is that these other sorts of study designs, because they generate less confident results, are not generally regarded as proof of anything. They can only suggest the possibility of an association, an hypothesis. For real proof to occur, a double-blind, placebo-controlled may need to follow. Alternatively, if an association suggested by a study of lesser design might, by reasons of a very powerful effect, be sufficient. But this is rare. Thalidomide and catastrophic birth defects are an example of an association between a drug and fetal limb malformation that was so clear-cut that no further investigation was required to establish a causative association. Of course, no one in their right mind would even suggest a blinded study.

Where am I going with this tedious rambling? Lately, the media has been making a big to-do about several studies, none of which are double-blind, placebo-controlled, but were cross-sectional sorts of observations, the sorts of studies which can only suggest an effect. This happened with Dr. Steve Nissen’s study of Avandia (rosiglitazone) for pre-diabetes and risk for heart attack and the recent study suggesting that cancer incidence is increased when LDL cholesterol is low. Both were observations that suggested such associations.

Now, those of you following the Heart Scan Blog or the www.cureality.com website know that we do not defend drug companies nor their drugs. In fact, we’ve openly and repeatedly criticized the drug industry for many of its practices. Drugs are, in my opinion, miserably overused and abused.

But, as always, I am in the pursuit of truth. Neither of these studies, in my view, justified the sort of media attention they received. They are hypothesis-generating efforts—that’s it. You might argue that the questions raised are so crucial that any incremental risk of a drug is simply not worth it.

Despite the over-reaction to these studies, good will come of the fuss. I do believe that heightened scrutiny of the drug industry will result. Many people will seek to avoid prescription drugs and opt for healthy changes in lifestyle, thus reducing exposure to costs and side-effects.

But beware of the media, acting as our Chicken Little, reporting on studies that prove nothing but only raise questions.
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Comments (1) -

  • jpatti

    9/11/2007 10:26:00 AM |

    There's another issue with double-blind studies, for things other than drugs or supplements, they're impossible.  

    Your example of the number of eggs in a person's diet is a good example; there's no "placebo" for eggs.  Similarly, if I increase my level of exercise, I notice that - it can't be blinded.  For diet and other lifestyle changes, we will never be able to gain the amount of evidence as for drug trials.

    I think this is why many doctors don't think so much about prescribing these types of things, except for a cursory instruction to "eat better, lose weight and exercise," they're just not as strongly convinced of the benefit of these changes because they can't be proven as strongly.  But... not being able to prove something doesn't mean it's not important to health!  

    As a diabetic, I measure my bg multiple times a day and make changes to my food intake, exercise and medication dosage to hit established bg goals.  While I think tightly-controlling bg is probably the number one thing I can do for my heart health, it can never be proven in a double-blind study.

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