Is there something fishy about fish oil?

To be sure, there's plenty of misinformation out there about fish oil. Take a look at the swill that passes for health information on Woman's Day: On Call with Dr. Sandy: Fish Oil and Mercury:



Reader Question: My doctor recommended that I take a fish oil supplement, but I'm concerned about mercury. Is there any way to tell which brands are lowest in mercury content?



On Call Response: When it comes to OTC supplements, the answer is no. Though most fish oil supplements sold by major brands are probably safe, there's really no way to tell what's in the bottle or how much mercury it might contain.




Perhaps Dr. Sandy should read the many independent analyses performed on nutritional supplement fish oil, including those at Consumer Lab and Consumer Report before she offers her blind criticisms.

Lovaza vs fish oil supplements?

Lovaza is the FDA-approved form of fish oil that is available only by prescription. It contains 842 mg of the omega-3 fatty acids, EPA and DHA, per capsule.

The FDA application for Lovaza is viewable here on the FDA website. Interestingly, while there is plenty of the usual regulatory gobbledy-gook about toxicology, dose escalation, and efficacy in the extensive documentation, there is little said about the issue of contamination.

In other words, critics of nutritional supplement fish oil harp on the possibility of contamination with mercury and pesticide residues, like dioxin and PCBs (polychlorinated biphenyls). Yet there is virtually nothing about these same issues in the FDA application for Lovaza.

Let's take a look at a sample over-the-counter fish oil product. Our friends at PharmaNutrients (a new Track Your Plaque partner for nutritional supplements) have a fish oil product called PharmaNutrients" Cardio. Here's an independent analysis of the Cardio product (per 1000 mg fish oil capsule):

EPA content: 566.1 mg
DHA content: 216.6 mg
(Total EPA + DHA 782.7 mg)

Cardio passed all tests for peroxides, PCBs, dioxin, furans, dioxin-like PCBs, and heavy metals (arsenic, cadmium, lead, mercury) using criteria at least 60% more stringent than European Commission (EC) standards (EC standard <2 picograms/gm for dioxins and furans, PharmaNutrients <1 picograms/gm; EC standard <10 picograms/gm for dioxin-like PCBs, PharmaNutrients <3 picograms/gm). PCBs levels in particular are less than 0.009 ppm, 90% below the industry-wide purity standard of 0.09 ppm. Likewise, mercury is >90% lower than European Commission standards.

In other words, this over-the-counter "pharmaceutical grade" fish oil has virtually nothing but omega-3 fatty acids.

Interestingly, the PharmaNutrients fish oil capsule also contains the third omega-3 fatty acid, docosapentaenoic acid (DPA), a neglected form that some authorities have proposed has superior cardiovascular protective properties over eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). If DPA is included in the analysis, PharmaNutrient's Cardio contains a total of 900 mg omega-3 fatty acids per capsule.

At some point, I'd like to see a head-to-head comparison not just on purity grounds, since I am convinced that high-quality products like Cardio can match or exceed the purity of prescription fish oil, but on efficacy in raising omega-3 blood levels, the omega-3 index. (The omega-3 index is a predictor of heart attack and sudden cardiac death--the higher, the better.) My prediction: High-quality fish oil supplements will match or exceed prescription fish oil.

More on blood sugar

Take any of the following foods:

One chicken breast
Quarter-pound ground beef
6 oz salmon steak
½ cup raw almonds
3 eggs scrambled in olive oil

How much is blood sugar increased by any item in the above list?

If you said virtually zero, you’re correct. Eat any of these foods, regardless of portion size, and blood sugar won’t change substantially. If you started with a blood sugar of, say, 90 mg/dl, 1-2 hours later it would be 90 mg/dl. It might go up or even down a few milligrams, but for all practical purposes it remains substantially unchanged.

How much is blood sugar increased by the foods in this list:

2 slices multigrain bread
1 whole wheat bagel
4 oz high-fiber breakfast cereal
2 whole grain pancakes, 2 oz maple syrup

The foods in this list are a different story from the first. Depending on your body weight, exercise habits, and other factors, a typical blood sugar response in an otherwise healthy non-diabetic person would be 120 mg/dl to 160 mg/dl. In someone with diabetes, it could easily exceed 200 mg/dl.

That isn’t good. Large blood sugar excursions to 140 mg/dl have been clearly associated with greater risk for heart attack, progression to diabetes, inflammatory responses, and other adverse health effects. In fact, blood sugars as low as 100 mg/dl after eating have been associated with increased cardiovascular risk.

Then why are the USDA, American Heart Association, the American Dietetic Association, and the American Diabetes Association telling us to eat more of the foods that shoot blood sugar up to such high levels? “Eat more healthy whole grains”?

To see how much the issue of exaggerated blood sugars after eating applies to you, a simple blood sugar check 1-2 hours after eating can show you. Either your doctor can have the test drawn or you can purchase your own inexpensive glucose meter (e.g., Walmart, Wagreens).

My prediction: You will be very surprised at blood sugar responses after common foods, including “healthy whole grains.” And, by the way, keeping blood sugar excursions to a minimum will facilitate weight loss.

Postprandial blood sugar: Almonds vs. whole wheat bread

Here's my postprandial (after-eating) blood glucose demonstration.



I tested raw almonds vs. 100% whole wheat bread, matched for calories. (Full nutritional composition below.)



Blood sugars:

Raw almonds

Start:

One-hour after eating:





2 slices 100% whole wheat bread

Start:

One-hour after eating:





100% whole wheat bread, 2 large slices

Water (g) 24.69

Energy (kcal) 158

Protein (g) 8.29

Fat, total (g) 2.14

Carbohydrate (g) 26.43

Sugars, total (g) 3.56

Fiber, total dietary (g) 4.4

Cholesterol (mg) 0

Saturated fatty acids, total (g) 0.478

Monounsaturated fatty acids, total (g) 1.022

Polyunsaturated fatty acids, total (g) 0.384





23 almonds, raw



Energy (kcal) 159

Protein (g) 5.86

Fat, total (g) 13.64

Carbohydrate (g) 5.98

Sugars, total (g) 1.07

Fiber, total dietary (g) 3.4

Cholesterol (mg) 0

Saturated fatty acids, total (g) 1.03

Monounsaturated fatty acids, total (g) 8.525

Polyunsaturated fatty acids, total (g) 3.331



To get low-carb right, you need to check blood sugars

Reducing your carbohydrate exposure, particularly to wheat, cornstarch, and sucrose (table sugar), helps with weight loss; reduction of triglycerides, small LDL, and c-reactive protein; increases HDL; reduces blood pressure. There should be no remaining doubt on these effects.

However, I am going to propose that you cannot truly get your low-carb diet right without checking blood sugars. Let me explain.

Carbohydrates are the dominant driver of blood sugar (glucose) after eating. But it's clear that we also obtain some wonderfully healthy nutrients from carbohydrate sources: Think anthocyanins from blueberries and pomegranates, vitamin C from citrus, and soluble fiber from beans. There are many good things in carbohydrate foods.

How do we weigh the need to reduce carbohydrates with their benefits?

Blood sugar after eating ("postprandial") is the best index of carbohydrate metabolism we have (not fasting blood sugar). It also provides an indirect gauge of small LDL. Checking your blood sugar (glucose) has become an easy and relatively inexpensive tool that just about anybody can incorporate into health habits. More often than not, it can also provide you with some unexpected insights about your response to diet.

If you’re not a diabetic, why bother checking blood sugar? New studies have documented the increased likelihood of cardiovascular events with increased postprandial blood sugars well below the ranges regarded as diabetic. A blood sugar level of 140 mg/dl after a meal carries 30-60% increased (relative) risk for heart attack and other events. The increase in risk begins at even lower levels, perhaps 110 mg/dl or lower after-eating.

We use a one-hour after eating blood sugar to gauge the effects of a meal. If, for instance, your dinner of baked chicken, asparagus brushed with olive oil, sauteed mushrooms, mashed potatoes, and a piece of Italian bread yields a one-hour blood sugar of 155 mg/dl, you know that something is wrong. (This is far more common than most people think.)

Doing this myself, I have been shocked at the times I've had an unexpectedly high blood sugar from seemingly "safe' foods, or when a store- or restaurant-bought meal had some concealed source of sugar or carbohydrate. (I recently had a restaurant meal of a turkey burger with cheese, mixed salad with balsamic vinegar dressing, along with a few bites of my wife's veggie omelet. Blood sugar one hour later: 127 mg/dl. I believe sugar added to the salad dressing was the culprit.)

You can now purchase your own blood glucose monitor at stores like Walmart and Walgreens for $10-20. You will also need to purchase the fingerstick lancets and test strips; the test strips are the most costly part of the picture, usually running $0.50 to $1.00 per test strip. But since people without diabetes check their blood sugar only occasionally, the cost of the test strips is, over time, modest. I've had several devices over the years, but my current favorite for ease-of-use is the LifeScan OneTouch UltraMini that cost me $18.99 at Walgreens.

Checking after-meal blood sugars is, in my view, a powerful means of managing diet when reducing carbohydrate exposure is your goal. It provides immediate feedback on the carbohydrate aspect of your diet, allowing you to adjust and tweak carbohydrate intake to your individual metabolism.

Food sources of vitamin K2: Reprint

For some reason, my December, 2007, Heart Scan Blog post, Food sources of vitamin K2, has been receiving a lot of traffic.

I therefore reprint the vitamin K2 post below.





Vitamin K2 is emerging as an exciting player in the control and possible regression of coronary atherosclerotic plaque. Only about 10% of dietary vitamin K intake is in the K2 form, the other 90% being the more common K1.

The ideal source of K2 is natto, the unpalatable, gooey, slimy mass of fermented soybeans that Japanese eat and has been held responsible for substantial decreases in osteoporosis and bone fractures of aging. Natto has an ammonia-like bouquet, in addition to its phlegmy consistency that makes it virtually inedible to anyone but native Japanese.

I say that the conversation on vitamin K2 is emerging because of a number of uncertainties: What form of vitamin K2 is best (so-called MK-4 vs. MK7 vs. MK-9, all of which vary in structure and duration of action in human blood)? What dose is required for bone benefits vs. other benefits outside of bone health? Why would humans have developed a need for a nutrient that is created through fermentation with only small quantities in meats and other non-fermented foods?

Much of the developing research on vit K2 is coming from the laboratories of Drs. Vermeer, Geleijnse, and Schurgers at the University of Maastricht in the Netherlands, along with several laboratories in Japan, the champions of K2.

MK-7 and MK-8,9,10 come from bacterial fermentation, whether in natto, cheese, or in your intestinal tract; MK-4 is naturally synthesized by animals from vitamin K1. While natto is the richest source of the MK-7 form, egg yolks and fermented cheeses are the richest sources of the MK-4 form.

Chicken contains about 8 mcg MK-4 per 3 1/2 oz serving; beef contains about 1 mcg. Egg yolks contain 31 mcg MK-4 per 3 1/2 oz serving (app. 6 raw yolks). Hard cheeses contain about 5 mcg MK-4 per 3 1/2 oz serving, about 70 mcg of MK-8,9; soft cheeses contain about 30% less. Natto contains about 1000 mcg of MK-7, 84 mcg MK-8, and no MK-4 per 3 1/2 oz serving.




All posts by william-davis

Indian buffet

I took my family to a local all-you-can-eat Indian buffet. It was delicious.

I confined my food choices mostly to vegetables and soups. Within about 30 minutes, I started to get that odd buzz in my head that usually signals a high blood sugar.

When I got home, my fingerstick blood glucose: 173 mg/dl. Darn it! Must have been cornstarch or other sugars in the sauces.

I got on my supine stationary bike and pedaled for 40 minutes at a moderate pace while I played Modern Warfare on XBox. (A great way, by the way, to fit in some low- to moderate-intensity exercise while occupying your brain. My wife often has to yell at me to get off, it's so much fun.)

Blood glucose at the conclusion of exercise: 93 mg/dl-- a nice 80 mg/dl drop.

This is a useful strategy to use in a pinch when you've either been inadvertently exposed to more carbohydrate than you can tolerate, or if you'd like to blunt the adverse glucose effects of a bowl of ice cream or other carbohydrate indulgence.

Should we explore the idea of a "morning-after" pill, or actually a "meal-after" pill, a supplement pill or liquid that blunts or eliminates the blood glucose rise after a meal? I've considered such an idea, but have been fearful that people would start to use it habitually. Thoughts?

American Heart Association diet makes a monkey out of you

Heart Scan Blog reader, Roger, brought this New York Times article to my attention.

In an effort to develop a better experimental model for obesity than mice, scientists have turned to monkeys and other primates. The emerging observations are eerily reminiscent of what you and I witness just by going to the local grocery store or fast food outlet:

"'It wasn’t until we added those carbs that we got all those other changes, including those changes in body fat,' said Anthony G. Comuzzie, who helped create an obese baboon colony at the Southwest National Primate Research Center in San Antonio."

"Fat Albert, one of her monkeys who she said was at one time the world’s heaviest rhesus, at 70 pounds, ate “nothing but American Heart Association-recommended diet,” she said."

Yes, indeed: The American Heart Association diet makes monkeys fat. Extrapolate this a little higher on the evolutionary ladder and guess what?

This is one of the many reasons why, when I have a patient who is counseled by the hospital dietitian on the American Heart Association diet, I advise them to 1) ignore everything the dietitian told them, and then 2) follow the wheat-free, cornstarch-free, sugar-free, whole food diet I advocate.

Not unexpectedly, much of this primate research is not being devoted to just manipulating diet to achieve weight loss and health, but to develop new drugs to "treat" obesity.

Would you like a banana?

Construct your glucose curve

In a previous Heart Scan Blog post, I discussed how to make use of postprandial (after-meal) blood sugars to reduce triglycerides, reduce small LDL, increase HDL, reduce blood pressure and inflammatory measures, and accelerate weight loss.

In that post, I suggested checking blood glucose one hour after finishing a meal. However, this is a bit of an oversimplification. Let me explain.

A number of factors influence the magnitude of blood glucose rise after a meal:

--Quantity of carbohydrates
--Digestibility of carbohydrates--The amylopectin A of wheat, for example, is among the most digestible of all, increasing blood sugar higher and faster.
--Fat and protein, both of which blunt the glucose rise (though only modestly).
--Inclusion of foods that slow gastric emptying, such as vinegar and fibers.
--Body weight, age, recent exercise

Just to name a few. Even if 10 people are fed identical meals, each person will have a somewhat different blood glucose pattern.

So it can be helpful to not just assume that 60 minutes will be your peak, but to establish your individual peak. It will vary from meal-to-meal, day-to-day, but you can get a pretty good sense of blood glucose behavior by constructing your own postprandial glucose curve.

Say I have a breakfast of oatmeal: slow-cooked, stoneground oatmeal with skim milk, a few walnuts, blueberries. Blood glucose prior: 95 mg/dl. Blood glucose one-hour postprandial: 160 mg/dl.

Rather than taking a one-hour blood glucose, let's instead take it every 15 minutes after you finish eating your oatmeal:


In this instance, the glucose peak occurred at 90-minutes after eating. 90-minute postprandial checks may therefore better reflect postprandial glucose peaks for this theoretical individual.

I previously picked 60-minutes postprandial to approximate the peak. You have the option of going a step better by, at least one time, performing your own every-15-minute glucose check to establish your own curve.

Why is type 1 diabetes on the rise?

Type 1 diabetes, also called "childhood" or "insulin-dependent" diabetes, is on the rise.

Type 2 diabetes, or "adult," diabetes, is also sharply escalating. But the causes for this are easy-to-identify: overconsumption of carbohydrates and resultant weight gain/obesity, inactivity, as well as genetic predisposition. A formerly rare disease is rapidly becoming the scourge of the century, expected to affect 1 in 3 adults within the next several decades.

Type 1 diabetes, on the other hand, generally occurs in young children, not uncommonly age 3 or 4. Type 1 diabetes also shares a genetic basis to some degree. But the genetic predisposition should be a constant. Obviously, lifestyle issues cannot be blamed in young children.
Then why would type 1 diabetes be on the rise?

For instance, this study by Vehik et al from the University of Colorado documents the approximate 3% per year increase in incidence in children with type 1 diabetes between 1978 and 2004:


(From Vehik 2007)

(For an excellent discussion of the increase in type 1 diabetes in the 20th century, see this review.)

This is no small matter. Just ask any parent of a child diagnosed with type 1 diabetes who, after recovering from hearing the devastating diagnosis, then has to stick her child's fingers to check glucose several times per day, mind carefully what he or she eats or doesn't eat, watch carefully for signs of life-threatening hypoglycemic episodes, not to mention worry about her child's long-term health. Type 1 diabetes is a life-changing diagnosis for both child and parents.

Various explanations have been offered to account for this disturbing trend. Some attribute it to the increase in breast feeding since 1980 (highly unlikely), exposure to some unidentified virus, or other exposures.

I'd like to offer another explanation: wheat.

Lest you accuse me of becoming obsessed with this issue, let me point out the four observations that lead me to even consider such an association:

1) Children diagnosed with celiac disease, i.e., the immune disease of wheat gluten exposure, have 10-fold greater likelihood of developing type 1 diabetes.

2) Children diagnosed with type 1 diabetes are 10-fold more likely to have abnormal levels of antibodies (e.g., transglutaminase antibodies) to wheat gluten.

3) Experimental models, such as in these mice genetically susceptible to type 1 diabetes, showed a reduction of type 1 diabetes from 64% to 15% with avoidance of wheat.

4) The increase in type 1 diabetes corresponds to the introduction of new strains of wheat that resulted from the extensive genetics research and hybridizations carried out on this plant in the 1960s. In particular, unique protein antigens (immune-provoking sequences) were introduced with the dwarf variant attributable to alterations in the "D" genome of modern Triticum aestivum.

Proving the point is tough: Would you enroll your newborn in a study of wheat-containing diet versus no wheat, then watch for 10 years to see which group develops more type 1 diabetes? It is a doable study, just a logistical nightmare. Perhaps the point will be settled as more and more people catch onto the fact that modern wheat--or this thing we are being sold called "wheat"--is a corrupt and destructive "foodstuff" and eliminate it from their lives and the lives of their young children from birth onwards. Then a comparison of wheat-consuming versus non-wheat-consuming populations could be made. But it will be many years before this crucial question is settled.

Yet again, however, the footprints in the sand seem to lead back to wheat as potentially underlying an incredible amount of human illness and suffering. Yes, the stuff our USDA puts at the bottom, widest part of the food pyramid.

Apo E4 and sterols: Lethal combination?

Phytosterols, or just "sterols" to its friends and neighbors, are a group of cholesterol-like compounds that are abundant in the plant world. Lately, however, sterols have proliferated in the processed food supply, thanks to the observation that sterols reduce LDL cholesterol when ingested by humans.

This must mean that sterols are good for you.

Uh oh. Wait a minute: There is a rare disease called sitosterolemia in which there is unimpeded intestinal absorption of all sterols ingested through diet. They must have really low LDL cholesterols! Nope. They develop coronary disease--heart attacks, angina, etc.--in their late teens and 20s. In other words, if sterols gain access to your bloodstream, they are bad. Very bad.

Conventional thinking is that only a modest quantity of dietary sterols gain access to the bloodstream. But there are two potentially fatal flaws in this overly simplistic line of thinking:

1) What happens when you load up your diet with "heart healthy" sterols, such as those in "heart healthy" margarines, mayonnaise, and yogurt, effectively increasing sterol intake 10-fold?

2) What happens in people with the genetic pattern, apo E4, that is carried by 25% of the general population that permits much greater intestinal absorption of sterols?

My prediction: Despite the fact that sterols reduce LDL, they may, in certain genetically-susceptible people, such as those with apo E4, increase risk for heart disease: heart unhealthy.

Here are two studies that suggest that greater sterol absorption in people without sitosterolemia are at higher risk for heart disease:

Alterations in cholesterol absorption/synthesis markers characterize Framingham offspring study participants with CHD

Plasma sitosterol elevations are associated with an increased incidence of coronary events in men: results of a nested case-control analysis of the Prospective Cardiovascular Münster (PROCAM) study

Glucomania

As I suggested in a previous Heart Scan Blog post, a glucose meter is your best tool to:

1) Lose weight
2) Cure diabetes
3) Reduce or eliminate small LDL particles
4) Achieve anti-aging or age-slowing effects


But it means getting hold of a glucose meter and applying it in a very different way.

Diabetics typically check fasting morning glucose and again several times during the day to assess medication effects. But you and I can measure blood glucose to assess the immediate effects of food choices--two very different approaches.

The concept is simple: Check a blood glucose just prior to a food or meal of interest, then one hour after finishing.

Let's take two hypothetical breakfasts. First, oatmeal, a so-called "low-glycemic index" food. Slow-cooked, stone ground oatmeal with skim milk, a handful of walnuts, just a few blueberries.

Blood glucose just prior: 95 mg/dl
Blood glucose one hour after finish: 175 mg/dl

I made those numbers up, but this is a fairly typical response for many adults. (This is why "low-glycemic index" is an absurd notion.) This kind of response causes 1) glycation, the adverse effects of glucose modification of proteins that leads to cataracts, kidney disease, cartilage damage and arthritis, atherosclerosis, skin wrinkles, etc., 2) high insulin response that cascades into fat deposition, especially visceral fat ("wheat belly"), and 3) glucotoxicity, i.e., direct damage to the pancreas that can, over years, lead to diabetes.

Next day, let's try a breakfast of 3-egg omelet made with green peppers, sundried tomatoes, and olive oil.

Blood glucose just prior: 95 mg/dl
Blood glucose one hour after finish: 93 mg/dl

This is a meal of virtually zero-glycemic index. This kind of response triggers none of the effects experienced following the oatmeal. Repeated over time and you fail to trigger glycation, you stop provoking insulin, and visceral fat mobilizes rather than accumulates: you lose weight, particularly around the middle.

We therefore aim to keep the one-hour blood glucose 100 mg/dl or less. If you start with a high fasting blood glucose of, say, 118 mg/dl, then we aim to keep the one-hour after-eating blood glucose no higher than the pre-meal.

It works. Plain and simple.

This makes the primary care docs crazy: "How dare you check your blood sugar! You're not diabetic." In truth, blood glucose meters are relatively simple devices to use. The test strips and lancets will cost a few bucks. (The meters themselves are either low-cost or free, just like Gillette sometimes sends you a beautiful new razor for free but expects you to buy the blades). These are direct-to-consumer products. While a prescription written by your doctor for a glucose meter and supplies helps insurance cover the costs, you can easily get these devices without a prescription. Some stores, like Target, keep their devices out on the shelves with the shampoo and bath soap.

Warning: Anyone taking diabetes drugs will have to consult with their doctors about the safety of such an approach. Because this approach can actually cure diabetes in some people, if you are taking some diabetes drugs, especially glyburide, glipidize, and glimepiride, you can experience dangerously low blood sugars, just as any non-diabetic taking these drugs would.

Diarrhea, runny noses, and rage: Poll results

Here are the results of the week-long poll asking the question:

Have you experienced a wheat re-exposure syndrome?
Yes, undesirable gastrointestinal effects 223 (41%)

Yes, asthma or sinus problems 51 (9%)

Yes, joint pains and/or swelling 85 (15%)

Yes, emotional or other nervous system effects 59 (10%)
No, nothing, nada  107 (19%)

No. Wheat is sacred and you're all nuts  13 (2%)


There are several interesting observations to make from this informal poll. First, as I have observed, the most common wheat re-exposure syndrome is gastrointestinal, usually involving cramps, diarrhea, and lame explanations to your dinner partner.

Second most common: joint pains and/or swelling.

Third: asthma or sinus congestion.

The incidence of emotional or nervous system effects surprised me a bit. I didn't expect 10% of people to share this effect. This is an effect I also experience personally, along with the gastrointestinal consequences.

To be sure, this is a skewed poll, since many people likely come to this blog in the first place because of such issues. But I was nonetheless impressed with the relatively modest proportion of people who did not share such a re-exposure syndrome: only 19%.

Beyond the interesting numbers provided by readers, a good many also provided some fascinating and graphic comments. Here's a sample:




Sassy said:

Reflux -- starts a day later and goes for up to a week. And Bloat:2-5 inches on my waistline in a day, lasting up to three. Miserable. And why, having experienced this once, have I done it often enough to verify the connection with certainty? I am working on that one.



Anonymous said:
Wheat increased hunger with even with only a small amount. Crackers in soup was enough to set it off.

Also, when I was trying to get off wheat, I noticed that 2 eggs and 2 bacon and I could go 5 hours before hunger, or 2 eggs and 2 bacon and toast was good for three hours before hunger. That was the final step to giving up wheat. Now three years and 59 Kg [130 lbs!] loss later, there is no doubt in my mind that wheat is evil, and I do not regard it as suitable for human food. I speculate that it increases ghrelin or cortisol.

Anna said:
For me, in the two years since I began eating Gluten-Free (Low Carb for 6 years), the few times I've had re-exposure to wheat, I've experienced fast onset and intense abdominal pain (known exposure during the daytime) and heartburn, indigestion, intense nausea, and disrupted sleep (exposures during evening meal not discovered until the next day).

My husband wants to think he's fine with wheat (though I know that he has at least one gene that predisposes to celiac), but IMO, he isn't. He eats no wheat at home because that's the default, and he's OK with that. But if he goes out to dinner at a restaurant that serves "good" artisan bread, he will indulge in a few bites (he does restrict his carb intake, so it's still a limited amount). More often than not, he will sleep fitfully on those nights, snore more, and wake in the night with indigestion. He wants to bury his head in the sand and will only acknowledge the discomfort being due to eating too many carbs, not the wheat itself. I notice he sleeps fine if he eats a small amount of potato or rice. Go figure.

Our 12 yo son has been eating GF for two years also. About 6 months into GF, he unknowingly ate wheat a number of times (licorice candy laces at a friend's house), which resulted in outbreaks of canker sores in his mouth each time. He also exhibits mood and behavior changes when he eats wheat, which is what prompted me to test him for gluten intolerance in the first place.

Mark said:
If I go for 3-4 days without wheat, grains or sugar and then go out and binge on a pizza and ice cream or something like that I become explosive within 20 minutes to an hour. It's like a wheat and sugar rage.(I'm not saying this is an excuse for rage, I'm saying it has happened to me and I believe partly do to re-exposure) It seems the combination of the wheat plus sugar can be the worst.

I get red rashes around my neck sometimes right away and sometimes up to a day or later and sometimes get bad diarrhea. 
I think it can be almost dangerous to cut things like gluten and sugar suddenly out of the diet without being very serious about keeping them out. I have found it very hard to cut out wheat without binging on it later after 4 or 5 days. I don't believe that my symptoms are just psychological either.

I was also diagnosed with ADHD as a young kid and then rediagnosed with adult ADHD by 3 different doctors. I also have bouts of mania at times too. I am considering trying to go completely gluten/refined carbohydrate free to see if it helps with the symptoms and gives me some relief.