SaluGenecists Science Blog

I saw this article earlier today, and am not too surprised by it. It is part of an ongoing campaign by CSPI to act as a watchdog against dubious and illegal claims by supplement manufacturers.

There was a sentence half-way through the article that caught my attention, though. It reads: “Even the more general claim Bayer uses to promote that and another men’s supplement that selenium “supports prostate health” is deceptive and illegal since it is unsubstantiated by scientific evidence and implies that the product can reduce the risk of prostate cancer. ”

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Given that the incidence of iodine deficiency appears to be rising in the United States - about 12% of the population at last survey - reliable and easy screening tests would be very helpful for primary care clinicians.

The gold standard test is a 24-hour urine catch is the gold standard, but has a couple of significant drawbacks. First, a 24-hour urine catch is a hard test to perform. Second, this test really only looks at recent intake of iodine, which is especially problematic given that iodine intake can be quite sporadic, and urinary loss of iodine can be controlled by controlled by multiple factors.

The thyroglobuin test is a potential surrogate for iodine deficiency. While in the population, the correlation between elevated thyroglobulin and iodine deficiency holds up well, at an individual level, it has only been demonstrated to aid diagnosis in children at high risk. The predictive value in most adults hasn’t been established. Furthermore, pregnancy, thyroid cancer, and hyperthyroidism elevate thyroglobulin, eliminating its predictive value entirely.

Iodine is a tricky nutrient, in that too much of it can lead to the same problem as too little - low thyroid function. In addition, when large amounts of people are given extra iodine, the incidence of hyperthyroidism tends to go up.

I think for patients presenting with hypothyroidism, ruling out autoimmune thyroiditis - by far the most likely culprit - is the first goal. In other non-Hashimoto’s patients, especially if presenting with multinodular goiter or from a low iodine area (mountainous regions are especially prone), running a thyroglobuin test along with your dietary history might help target interventions appropriately.

Here’s a question that has nagged at me for a long time: how frequently, if at all, should I be following up with imaging for people diagnosed with osteoporosis? A new study published this week attempted to answer this question. Current standards of care in the U.S. suggest rechecking within two years of starting pharmacologic treatment, but are silent (at least as far as I can tell) in situations where non-pharmacologic management is used.

According to the researchers, there was no real value to following up people with DEXA scanning once the diagnosis of osteoporosis was made and the treatment with bisphosphonate was started. This conclusion, in part, was due to a large amount of measurement variability.

Here’s why this study was interesting to me: if there is so much variability in the test that it isn’t helpful as a monitoring device, why are we so reliant on such a hard measure (-2.5 SD below mean peak density) to make a diagnosis and initiate treatment. Unfortunately, the research group was silent on this important question.

We do know that reduced bone mineral density by DEXA correlates with increased risk of fracture at an individual level. But there are many other potential risk factors ignored in this manner of diagnosis that could fine tune a risk analysis. Our risk analysis calculator for fracture risk can have a several-fold variance even in individuals with low baseline bone density.

Look for this research result to affect an important national health care debate, as new Medicare cuts are restricting access to DEXA scans (and since most baseline DEXA tests occur after age 65, this is a Medicare issue). Ironically, the sponsors of this study (Merck, the manufacturers of Fosamax) have much to lose if its results affect the frequency of testing.

I try to ensure that I work through osteoporosis prevention recommendations in any routine annual appointment with a girl or woman older than 12. This includes interventional counseling about exercise, screening for mineral (including, but not limited to, calcium) intake, and vitamin D screening as appropriate.

….that it is Homeopathy Awareness Week? This, of course, is not to be confused with World Homeopathy Awareness Week, which was in April.

In the teaching clinic where I work, though, Homeopathy Awareness Week isn’t just for June and April. No, it is a year-round event, because homeopathy is a usual topic of fierce (yet goodnatured) debate.

There are two things that have always bothered me about homeopathy, so I’d like to celebrate the second awareness week of the year by airing them out.

First, by and large modern research has failed to find a consistent or reproducible effect of the homeopathic remedy in a blinded setting. In fact, research trials have been so unkind to homeopathic theory that even the most prominent scientists interested in homeopathy have trouble making a case that remedies are anything but placebo. In fact, it is fairly easy to construct an alternative theory where confounders like doctor-pleasing behavior, patient expectation, and the Hawthorne Effect are the reasons why homeopathy persists in popularity.

Second, although I have seen the homeopathic proving set out as proof that homeopathy is a true science, I would argue just the opposite - that the entire process is decidedly non-scientific. In science, an observer starts with a null hypothesis - e.g. this remedy has no effect - and tests against that. In homeopathy, the investigator starts with an assumption that a remedy has an effect, and only tries to list what that effect is.

This is an important distinction, because in blinded settings, it is difficult to distinguish a remedy from a placebo, even for trained homeopaths. I’ve seen some elaborate explanations for why this might be the case (why do homeopaths have so much fondness for quantum physics in their discussions? Is it because it is so hard to understand for non-physicists that their points go unchallenged?), usually involving some failure in the current scientific method.

Almost a hundred years ago, Ernest Rutherford said that any physics too complicated to explain to a barmaid is probably bad physics. Similarly, if it requires so many leaps of faith and complicated equations to explain why homeopathy might be a real phenomenon, shouldn’t we at least consider that the whole thing is just a mirage?

The FDA has issued a consumer advisory about Zicam, an over-the-counter homeopathic cold remedy. The advisory was triggered by more than one hundred reports of permanent loss of smell after using Zicam.

The three products in question are all for nasal application, and all contain low doses of zinc. The company, for their part, is compliant with the advisory, withdrawing the product and offering a refund.

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A Science Daily preview of research results to be presented at the June 18, 2009, annual meeting of the Endocrine Society in Washington, D.C., includes a summary of the key findings of a new study on Americans’ likely levels of exposure to bisphenol A (BPA). 

Found in polycarbonate plastic food and beverage containers, like those ubiquitous plastic water and baby bottles, and also in the epoxy resin lining of cans, this chemical can leach into food and beverages. Between 8 and 9 billion pounds of BPA are used in products every year. 

According to Frederick vorn Saal, PhD, one of the study’s co-authors , “BPA is now known to be a potent estrogen. Human and animal studies indicate it could be related to diabetes, heart disease, liver abnormalities, miscarriage and other reproductive abnormalities, as well as prostate and breast cancer.”

vorn Saal and colleagues fed five female adult monkeys a whopping dose of BPA. These monkeys chowed down an oral dose of BPA of 400 micrograms per kilogram of body weight   — an amount more than 400 times higher than the amount the U.S. Food and Drug Administration estimates human adults are exposed to and 8 times higher than that estimated to be safe to consume daily.

Here’s the kicker — 24 hours later, these monkeys’ blood levels of biologically active BPA were lower than the average levels typically found in people in the U.S.

Gee, looks like Americans’ exposure to BPA is not as minimal as the FDA  thought. Considering that FDA declared BPA as “safe” based on its estimates that people were only consuming tiny amounts each day in their food and water, this is worrisome news.

The researchers are going to study some more monkeys, but expect their findings will be the same since the data from the first group was “very consistent.” While humans are not monkeys, we share the way we metabolize BPA with the species of monkey (rhesus) used in this study.  

Our advice: switch to a stainless steel water bottle for yourself and a heavy duty glass baby bottle for your little ones. You’ll shrink both your BPA load and carbon footprint.

A few years ago, the National Dairy Council started running advertisements suggesting that regular intake of dairy foods could help improve the efficacy of a weight loss diet. A few years later, their message has softened some, but they still suggest that dairy foods have special qualities that help to maintain healthy weight.

The problem with this statement is that the research results that are in dairy’s favor have been almost exclusively funded by dairy interests. Independent researchers have been unable to replicate these results. Here’s a link to an NPR segment on this controversy.

The centerpiece of this “dairy helps weight loss” theory is that the calcium in dairy foods is the key ingredient, and that calcium either reduces absorption of dietary fat or has a hormonal effect that is beneficial. Since dairy is the key source of calcium in many American diets, the jump from a calcium mechanism to dairy in the diet would make intuitive sense.

A study published this week in the Annals of Internal Medicine casts more doubt on the calcium for weight loss theory. In this study, two years of calcium supplementation (1500 mg/day as calcium carbonate) showed no effect on weight maintenance compared to placebo.

There are some limitations to this new research. It only contained people who were overweight or obese at baseline, it was heavily biased toward women, and people with features of the metabolic syndrome (some of which are helped by calcium supplements) were excluded. Most importantly, the intervention with calcium supplements is not the same thing as a dairy food intervention. Even with these limitations, I would consider this study to be a pretty definitive statement about the lack of efficacy of calcium in weight loss.

Here’s an interesting thought experiment: what would happen to a supplement company that suggested in their advertising that their product would help with weight loss if used every day? Why, other than because of political power, do we let the dairy industry get away with these claims, whether or not they are true?

This news item caught my eye this morning. For those who don’t know, the U.S. government has a number of regulations about what can or cannot be said about foods.

I learned to appreciate this the hard way, when I product I was working on contained an ingredient called Eleutherococcus senticosus. This used to be referred to informally as Siberian ginseng until a May 2002 amendment of the Food, Drug and Cosmetic Act decreed that only Panax sp. plants could be referred to as ginseng.

Color me skeptical that the USDA will reverse this ruling about using federal funds to decrease soda intake. Why? Because the head of the USDA (this guy) is from this place where they produce a lot of this stuff.

By the way, if you stay around that last link long enough to watch the posted ads, you’ll see a worried mom stumped by the question “what’s so bad about high fructose corn syrup?” Let me take a crack at a simple answer to this. The USDA recommends no more than 40 grams of added sugars per day in a healthy diet. Most HFCS-containing soft drinks contain about 40 grams or more of sugar, putting an individual at or beyond the upper limit of the daily supply. There are some potential differences in the ways that HFCS and cane sugar are metabolized that might make HCFS a little worse, but the biggest problem is that HFCS is a cheap way to sneak an extra few hundred calories into an already calorie overloaded American diet.

A new paper in the American Journal of Medicine this month concludes that the health habits of American adults have become markedly worse over the past two decades. The authors compiled statistics from the definitive National Health and Nutrition Study (NHANES) in five key areas, comparing results from 1988-94 to 2001-6.

In four of these five important predictors of good health, habits and measures on average significantly worsened over this time period. These four areas were regular physical activity, BMI less than 30, five fruits and veggies per day, and moderation in alcohol use. The fifth measure, smoking, was unchanged.

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A new article in the journal Cancer is certain to rekindle the debate about the use of antioxidant supplements during cancer treatment. In this article, 663 women with breast cancer were surveyed about their use of nutritional supplements during cancer therapy. The research team (led by Bastyr University graduate Heather Greenlee) found that roughly 60% of these women used mega-dose antioxidant supplements during their treatment.

The reason this is a big deal is that nobody is really sure whether these antioxidants improve treatment outcomes, worsen them, or make no difference at all. Because many of the key breast cancer treatments (specifically chemotherapy and radiation) work by creating the very type of free radical damage that antioxidants prevent, many researchers have raised concern that nutritional supplements might silently dampen the effectiveness of conventional oncology interventions.

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