Dispelling nutrition myths, ranting, and occasionally, raving


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Are food cravings the result of nutrient deficiencies?

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Image by John Hain on pixabay. Used under a Creative Commons Licence

One of the most pervasive myths in the nutrition realm is that food cravings are caused by nutrient deficiencies. I came across this article by self-proclaimed nutrition guru David Wolfe the other day. In it he lists a number of food cravings and then tells you what nutrient deficiency each may be linked to.

While there has actually been very little research done exploring the relationship between food cravings and nutrient deficiencies the evidence is mixed at best. Most of the research investigating cravings has been done with pregnant women and has looked at both food cravings and pica (cravings for non-food substances such as dirt, chalk, and soap). Some researchers have found that pica is linked to nutrient deficiencies. However, some studies have shown that pica is a result of a nutrient deficiency while others have shown the reverse; i.e. consuming non-food substances may cause nutrient deficiencies. To date there is no clear evidence to support the notion that specific food cravings can be linked to specific nutrient deficiencies.

Wolfe asserts that chocolate cravings are a result of magnesium deficiency. Therefore, instead of chocolate, you should snack on leafy greens, fish, nuts, seeds, beans, and molasses. Sugar cravings may be the result of a deficiency in any of five nutrients: chromium, sulfur, tryptophan,  or serotonin (by my count, that’s four so the fifth is anyone’s guess). His advice: “revitalize your diet”. Carb cravings may be a result of a nitrogen deficiency. To remedy this? Eat more fish. Cravings for oily and fatty foods are blamed on a calcium deficiency. Instead of some fries, try having some milk (but not just common pasteurized milk, no you should risk ingesting potentially deadly bacteria and drink raw milk) or turnip greens. And finally, salty food cravings are likely a result of your body wanting chloride or silicon. Instead of chips, grab yourself a plate of fish, nuts, and seeds (aka the new party mix).

Many of us could benefit from including more wholesome foods in our diets. However, if you’re craving chips, it’s unlikely that you’re going to be satisfied with a tin of sardines instead (power to you if you are). At least at this point, there is no evidence to support that specific food cravings equate to specific nutrient deficiencies. Rather than trying to satisfy your cravings with turnip greens, try to eat a balanced, varied, nutritious diet and let yourself have a little of what you’re craving when you’re craving it.


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Parasites for gluten!

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A friend alerted me to this article last week. Before we look at the actual research study, I need to say this is terrible reporting. The headline proclaims: Gluten allergies may be reduced using hookworms. No. Well, maybe. But probably not, and that’s certainly not what the study was looking at. No wonder people are confused about gluten. The study looked at the effect of hookworms on gluten tolerance in individuals with celiac disease. Which, we know, is not an allergy. Celiac disease is an autoimmune disease in which consumption of gluten results in the destruction of microvilli in the small intestine in sufferers. Gluten allergy is a hypersensitivity of the immune system to the gluten (or one of its component proteins) protein. So… if you are allergic to gluten, don’t go infect yourself with hookworms and eat a sandwich. I wouldn’t recommend doing this if you have celiac disease either.

Looking at the actual study… It was very small (12 people, two of whom withdrew from the study before completion). When a study is so small, it’s impossible to say if the results would extend to the majority of those with celiac disease. Setting aside the fact that I’m doubtful that the majority of celiac disease sufferers would willingly ingest hookworms in order to be able to consume gluten again. That being said, it’s quite interesting that the study participants were able to gradually increase their gluten intake to 3 g of spaghetti a day without experiencing any overt, nor covert (i.e. intestinal damage) symptoms of celiac disease. Of course, that’s not a lot of gluten (about one cup of pasta a day) and the study took place over 12 weeks, with the largest quantity of pasta being consumed over the final two weeks. It would be interesting to see if intestinal damage was visible after an extended period of time or if greater quantities of gluten could be consumed.

Something else that I wondered about when reading the article was any potential complications from the use of hookworms. According to the Centre for Disease Control, most people with hookworms experience no symptoms. However, some many experience gastrointestinal distress and the most serious complication is blood loss leading to anemia, and protein loss.

Essentially, celiac disease leads to nutritional deficiencies when gluten is consumed. Introducing hookworms may allow celiac disease sufferers to consume gluten but may also lead to nutrient deficiencies. Alternatively, celiac disease sufferers can follow a nutritious gluten-free diet.


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Vitamin supplements: deadly or life saving?

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Last week everyone was getting worked up because an editorial in the Annals of Internal Medicine advised against taking vitamin supplements. I wish that I could unequivocally state that they were correct (or incorrect) in this assessment. Unfortunately, this is a complicated issue and I don’t think that we have all of the answers yet.

We know that there are problems with the supplement industry. It’s not well-regulated. Some herbal supplements were recently found to contain ingredients other than those stated on the label, some even contained none of the sole ingredient they claimed to contain. It’s not a stretch to presume that this issue extends to supplements beyond the herbal variety. Last year researchers found that vitamin D supplement often contained hugely variable quantities of vitamin D, even within the same bottle.

An issue unique to multivitamins is that some minerals impede absorption of other minerals when consumed together (for example, zinc and copper). Other vitamins and minerals actually work better together (think calcium, magnesium, and vitamin D). When we’re taking a multivitamin we’re almost certainly not absorbing many of the vitamins and minerals listed on the label (assuming the label is correct in the first place). Does this mean that we should give up on supplements altogether? Possibly not.

The editorial refers to three specific studies. The important thing to note if that these studies looked at people who were not nutrient deficient. The problem with this is that many of us are nutrient deficient. Canadians have difficulty meeting their nutrient needs for calcium, magnesium, and vitamin D through food alone. We also tend to fall short in consumption of potassium as well as EPA and DHA (essential omega-3 fatty acids). There is also the fact that individual nutrient needs vary and that increased nutrients are needed during specific life stages. For example, folic acid is needed early in pregnancy to prevent neural tube defects in infants (1) and many nutrient needs are increased during pregnancy and lactation. Smokers have increased vitamin C needs and athletes have increased needs for nearly everything. Infants require vitamin D supplementation to avoid rickets. Vegans and seniors need vitamin B12 supplements. Etc.

Another problem with the basis on which the authors of the anti-supplement editorial made their recommendation is that they were looking at extremes. They asked: Do multivitamins prevent cancer? Cognitive decline? Heart attacks? Just because vitamin supplements don’t seem to prevent these conditions doesn’t mean that there aren’t other potential benefits to supplementation. More “minor” aliments may be ameliorated by consumption of supplements. We also may have been simply too late to see benefit from supplementation in those involved in those studies. As with osteoporosis which is a pediatric disease with geriatric consequences, these diseases are likely a result of exposures and lifestyles starting in utero.

So, should we take vitamin and mineral supplements or not? I think that it’s a bit of a gamble either way. On one hand you may not be getting what you bargained for in a supplement. On the other hand, you might be risking nutrient deficiency by avoiding all supplements.

Obviously it’s best to try to meet your nutrient needs through food. Realistically, most of us do not do this. If you’re able to determine what specific nutrients you’re lacking in your diet then it’s best to supplement with only those nutrients. Try to select supplements that have an NHP number on them to ensure a minimal level of regulation. And, of course, too much of anything can be a bad thing. Unless advised by your MD or nurse practitioner to take a high dose (and even then, you might want to question them) of any supplement avoid reaching or surpassing the upper limit.


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The Internet is not a doctor

Many of the nutrition misconceptions I overhear are in the lunch room at work. I’ve heard people discussing the nutrient deficiencies causing their muscle twitches on a couple of occasions recently. The first time the individual was convinced that the twitching was caused by a magnesium deficiency. The second time it was due to a potassium deficiency. These individuals had self-diagnosed based on google searching their symptom. Magnesium deficiency has been linked to muscle spasms, among other concerns such as, an irregular heartbeat, disorientation, nausea, vomiting, and seizures. Potassium deficiency has been linked to muscle cramps as well as loss of appetite, confusion, constipation, and eventually, irregular heartbeat. These are serious concerns, and most of us do not consume enough potassium nor magnesium in our diets. However, most of us are not clinically deficient in these nutrients either. The most common cause of muscle twitching is anxiety. While it’s not going to hurt you to eat some more potassium and magnesium rich foods. It’s also important not to self diagnose. If you’re experiencing muscle twitches and they’re causing you concern, it’s best to go to your doctor to determine if the cause is anxiety, nutrient deficiency, or disease. The Internet contains a wealth of information and it can help you to enter your doctor’s office well-informed, but self-diagnosis can be dangerous. You may be correct, but you may also be causing yourself undue worry or delaying appropriate treatment. In the meantime, you can increase your potassium levels by consuming foods such as kidney beans, winter squash, plain yoghurt, and cantaloupe. You can increase your magnesium levels by eating more spinach, squash, wheat germ, and peanut butter.