Does white wine give you skin cancer?

Many studies have shown that drinking wine, especially red wine, seems to have modest benefits for heart health, as long as you drink it in moderate amounts. A study published this week, though, offers a more worrisome message: white wine might increase your risk of skin cancer.

The bottom line: a daily glass of white wine carries a 13% increased risk of melanoma, one of the deadliest forms of skin cancer. Surprisingly, though, red wine did not carry the same risk. In fact, when the authors separated out beer, red wine, white wine, and other forms of alcohol, only white wine carried any risk for melanoma. 

Should you cut back on white wine based on this new finding? I read the study to find out more.

The new study, led by Eunyoung Cho from Brown University, appeared in the most recent issue of a journal published by the American Association for Cancer Research. It's a large, carefully-done analysis of survey information from over 210,000 health professionals, about two-thirds of them nurses, followed over an 18-year period. The 210,000 participants came from 3 studies: 2 studies of nurses and one of male health professionals. About three-quarters of the participants were female, and the vast majority were white (which means the findings might not apply to non-white populations).

One feature I always look for in an analysis like this is a dose-response effect. If the effect is genuine, then higher doses (in this case, more alcohol) should increase the risk. The authors here found that people who drank the most alcohol had the greatest increase in risk. The study also controlled for all the usual confounding factors, such as family history of cancer and smoking. 

In some subgroups–those who drank the most white wine–the increased in relative risk of melanoma was 50% or more. Keep in mind, though, that this is "relative risk." I'll get to that in a minute.

When the researchers looked at where the cancer occurred, they found that the risk of melanoma was "far greater" on areas of the body that don't receive regular sun exposure, such as the stomach and back, compared to the arms or neck where people get the most sun. This result suggests that the effect of alcohol is unrelated to sun exposure.

There are several important caveats about this study. Perhaps the biggest is that the mechanism is unclear: how does white wine cause melanoma? The authors suggest that the effect is due to acetaldehyde, a cancer-causing compound that is present in wine. However, both red and white wine contain this compound, so it's not clear why white wine would carry a greater risk. It's also not clear why acetaldehyde should cause skin cancer more than other cancers, and why it should be associated with skin cancer specifically on areas of the body that are not exposed to the sun. 

Before you panic, let's revisit the actual amount of risk here. The 13% increase in risk does not mean that you have a 13% chance of getting melanoma from drinking white wine. I looked at the raw numbers in the study, and the overall rate of melanoma in non-drinkers (about 71,000 people in this study) was 0.61%. About 26,000 people reported drinking 10-20 grams of alcohol per day (the equivalent of 1 or more glasses of wine), but the study didn't report how many of these people drank white wine. Nonetheless, in this group the rate of melanoma was 0.85%. So in raw numbers, the increased risk for melanoma was 0.24%.

That's a rather small number, but it's still worrisome. The National Cancer Institute warns that alcohol is linked to several types of cancer (although not melanoma), especially for those who drink excessively. The new study reinforces that warning, and suggests that for those who drink wine, red wine might carry fewer risks than white.

I'm still a bit skeptical, because we have no good explanation for why white wine–but not red wine, beer, or alcohol–would cause skin cancer.  But still, when you reach for a glass of wine this holiday season, perhaps you should choose red instead of white.


FTC steps in where FDA fears to tread - on homeopathy

Here's a label that the FDA should require.
The federal government is probably wincing right now from the after-effects of the election, but one agency deserves a robust round of applause: the Federal Trade Commission. This week, the FTC announced, in a strongly-worded report on homeopathic advertising, that homeopathic drugs should "be held to the same truth-in-advertising standards as other products claiming health benefits."

The FTC can't prevent homeopathic marketers from selling their products; only the FDA could do that. But starting very soon, they will require that homeopathic products include statements that:
  • There is no scientific evidence backing homeopathic health claims
  • Homeopathic claims are based only on theories from the 1700s that are not accepted by modern medical experts.
Admittedly, this might not effect sales very much. Over at Slate, Alan Levinovitz argues that these claims might even backfire, because some users of homeopathic drugs don't trust modern medicine, or because they might belief that hey, if it's been around that long, it must work. But old medicine is not good medicine. (And in the FTC's defense, they also recommended that the FDA "subject homeopathic drugs to the same regulatory requirements as other drug products," but they can't force the FDA to act.)

But wait: does this mean homeopathic drug makers didn't have to be truthful in the past? Well, yes. As the FTC report explains, in 1988 the FDA–the agency in charge of regulating drugs in the U.S–basically struck a deal where they agreed that homeopaths could be self-regulating, as long as they included a disclaimer that their claims haven't been evaluated by the FDA. To put this more bluntly: the FDA's agreement with homeopaths (you can read it here) is basically a license to lie.*

For example, the widely-sold homeopathic product Oscillococcinum, which is nothing more than a sugar pill, says on its packaging that it "Temporarily relieves flu-like symptoms such as body aches, headache, fever, chills and fatigue."

Helpful hint to potential victims customers: Oscilloco doesn't do anything of the sort. Oscilloco escapes having to prove their claims by a tiny asterisk, which (after much digging through the website) is attached to a disclaimer that '*these “Uses” have not been evaluated by the Food and Drug Administration.' Interesting how they place the word "uses" in quotation marks.

Homeopathy is the most obviously fake alternative medicine you're likely to see in your local pharmacy. This may seem like a pretty strong statement, but look at what homeopathy claims:
  • That infinite dilutions of a substance, to the point where not a single molecule remains, have a medical benefit
  • That water "remembers" the substances that were in it in the past
  • That a substance that causes a symptom will, when diluted, cure that same symptom. Thus (for example) poison ivy can cure itching.
These claims violate basic principles of physics, chemistry, and biology. The idea that water remembers what was in it is so confused that it's not even wrong–and it also implies that every sip of water you take "remembers" virtually every substance on the planet, although homeopaths appear not to recognize this. Yet homeopathic "drugs" are a multi-billion dollar business today; the FDA estimated that consumers spent $2.9 billion on homeopathic remedies in 2007, the last year for which they reported numbers.

The FDA held a public hearing last March, and the FTC held their public workshop in September. They solicited and received over 500 comments, both pro and con. Most of the pro-homeopathy comments boil down to "it worked for me" or "people have been using this stuff for years"; in other words, anecdotes and testimonials. The con-homeopathy comments described scientific studies showing that homeopathy simply doesn't work. These include a thorough review conducted by the Australian government last year, which concluded:
"There are no health conditions for which there is reliable evidence that homeopathy is effective."
Despite Alan Levinovitz's concerns that warning labels won't help, I'm with the FTC here. If the FDA won't (or can't) stop homeopaths from selling their modern snake oil, at least we can slap labels on them saying they don't work. If consumers want to buy a product that the government says doesn't work, well, it's their money.

*Well, they're not really lying if they include a disclaimer, are they? So I'm not really calling them liars.

Another dietary supplement to avoid: calcium

Despite the claims on the package, these
pills don't give you strong bones.
Dietary supplements and vitamins are a multi-billion dollar business, driven by heavy advertising and constant promises that supplements will somehow make you healthier. For most people, vitamins and other dietary supplements are useless, and when taken in large quantities they can even be harmful. (See my article, "The Top Six Vitamins You Should Not Take" for specifics.)

Now we can add another supplement to the list of those that you shouldn't take: calcium. Calcium supplements are often sold on the promise that they strengthen your bones or prevent osteoporosis. Given that calcium is a major component of our bones, it seems sensible to assume that extra calcium might help strengthen them.

What seems sensible, though, doesn't always turn out to be true. A large new study published recently in the Journal of the American Heart Association shows that taking supplemental calcium leads to an increased risk of heart disease, by increasing the calcification of your arteries. That's a bad outcome.

The new study, led by John J.B. Anderson of UNC Chapel Hill and Erin Michos at Johns Hopkins University, looked at changes in coronary artery calcification over a 10-year period in 2,742 adults. Calcification of the arteries is strongly associated with heart attacks and other life-threatening events; basically, a calcified artery is a dangerously unhealthy artery.

The study found some surprising results that seem at first to be contradictory: people who simply consumed the most calcium through their diet had a slightly lower risk of calcification of the arteries - about 27% lower than the group with the lowest amount of dietary calcium. However, people who took calcium supplements had a 22% higher risk of calcification.

Why are calcium supplements harmful when dietary calcium seems healthful? The authors explained:
"Little of the additional calcium provided by calcium supplements, however, is incorporated in bone by adults."
In other words, if you just take a pill of concentrated calcium, your body can't handle it, and some of it seems to end up in the linings of your arteries, where it makes them rigid and contributes to cardiovascular disease. So rather than strengthening your bones, supplemental calcium might "strengthen" your arteries, but in a bad way. As the study explains:
"Rather than promoting bone health, excess calcium from the diet and supplements is postulated to accrue in vascular tissues." 
You don't want more calcium in your arteries. That's too bad for supplement makers, whose claims that calcium supplements "promote healthy bones" (as claimed, for example, by Nature's Way "bone formula" calcium pills) are just not supported by science. You can, though, get plenty of calcium by eating these calcium-rich foods:

  1. Cheese
  2. Yogurt
  3. Milk
  4. Sardines
  5. Leafy greens such as spinach, kale, broccoli rabe, and bok choy

So if you're concerned about osteoporosis or just general bone health, skip the pills, save your money–and protect your heart–by eating a calcium-rich diet instead.

How to treat the flu: a shopping guide

Flu season is upon us, and your local pharmacy may feature special displays with products claiming to cure or treat the flu (which is caused by the influenza virus). The array of products, and the claims featured on their packaging, can be bewildering. Which of them should you buy? Here is a quick guide. (Spoiler: if you want to know what really works, skip to the end.)

This photo from a local RiteAid shows their display of "alternative" treatments. Let's consider a few of them.
Alternative pills that claim to treat the flu. 
1. Across the top we have vitamin C drops, helpfully labelled "Defense" in large letters. You might think these would defend you against the flu virus, but you'd be wrong. Vitamin C has no effect whatsoever on the flu, and it doesn't prevent colds either. People have been taking it for decades, but popularity is no substitute for evidence.

2. The shelves include 11 different formulations of Airborne, with the phrase "helps support your immune system" prominently displayed. Does this product help your immune system fight off the flu? Not even a tiny bit. Airborne is nothing more than an overpriced vitamin supplement (including vitamin C), and it's on the shelf because of clever and misleading marketing. Back in 2008, Airborne settled a $23.3 million lawsuit over false advertising, which was filed because they called their product a "miracle cold buster." After the lawsuit, they simply re-labeled it as an "immune booster," which is vague enough that they've been getting away with this claim ever since. Save your money.
3. Several of the products here, notably Zicam, are basically sugar pills supplemented with zinc. Some time ago, there was preliminary evidence that zinc might reduce the duration of a cold, but there was never any evidence that it could work for the flu. (Aside: colds are caused by completely different viruses.) Once scientists looked at it a little harder, they discovered that zinc doesn't work for colds either, as I explained in a 2012 column. Zicam is marketed as homeopathic, a clever ploy that allows it to escape government regulation. Their marketing constantly dances around what is permitted, usually by claiming it provides "immune support." Sound familiar?
Very expensive sugar pills.
4. On the bottom shelf you might notice Oscillococcinum, a homeopathic remedy that is just a sugar pill. Oscillo's claims to treat anything are almost laughably ridiculous: its "active" ingredient is supposed to be an extract from the heart and liver of a duck, which is then diluted until even that ingredient is no longer present.  As you can see in the close-up picture here, it's not cheap: $31 for 30 pills.
The box also claims that it "reduces duration and severity of flu symptoms," a completely false claim. The FDA has issued warning letters about this before, pointing out that "These products have not been approved or otherwise authorized by FDA for use in the diagnosis, mitigation, prevention, treatment (including treatment of symptoms), or cure of the H1N1 Flu Virus." Apparently the manufacturers of Oscillo (and the numerous places that sell it) are just ignoring the FDA.

These are just the "alternative" treatments. Most pharmacies have an even larger selection of flu treatments with real medicine in them. Here's a photo from the same RiteAid, right next to the alt-med selections.  
Medicines that try to treat the flu.
The selection here includes pills and liquids in many shapes and sizes, and all of them have active ingredients that do indeed have some effects. But they don't actually treat the flu itself: instead, they treat some of the symptoms, such as pain and congestion. None of them work very well, although those that contain ibuprofen or acetaminophen do help reduce pain.


So what does work? The latest medical science offers only two options:
1. Vaccination. Get your flu shot! The flu vaccine isn't perfect, and it varies in efficacy from year to year, but it usually provides some protection. In the best years it can reduce your chance of getting the flu by 75% or more. It's far better to avoid getting the flu in the first place.

2. Oseltamavir (Tamiflu), available only by prescription, is the only anti-viral medication that has been shown to have some effectiveness against the flu. It's not great, but it can reduce the severity of symptoms and maybe shorten the duration of the illness by about 1 day. You have to see a doctor to get it, which means taking your (sick) child or self to a doctor's office and exposing other people to the flu. 

The bottom line: none of the treatments that you can buy without a prescription will cure the flu. The "alternative" treatments are completely useless, and the real medicines might help a little bit with symptom control. 

Your best choice, by far, is the flu vaccine. Unfortunately, the internet is filled with misinformation such as claims that the vaccine doesn't work, or that it can give you the flu, or (worst of all) the utterly discredited notion that preservatives in the vaccine cause autism. Some of the anti-vaccine nonsense has even been promoted by presidential candidates, namely Donald Trump, Ben Carson, and Jill Stein. By spreading these false stories, Trump and Stein are doing real harm to the public health.

Flu advice from a future doctor.
Finally, I want to give props to RiteAid for trying to get people vaccinated. In front of the same store at which I took these pictures were two large signs saying "Get your flu shot today." Inside the store, they had a special table with science-based information about the flu vaccine, which featured artwork from local children (one of them shown here) encouraging other kids to get vaccinated. Well done.

Better diagnosis of infections

This week I'm not posting an article here because I wrote a piece for BloombergView, the online magazine published by Bloomberg, the company founded by Michael Bloomberg. The article is titled "Make Way for Better Germ Tests." Check it out here.

NIH will spend $37 million to study discredited treatment that may harm patients

What do you do when you've spent $30 million to study a highly controversial, possibly harmful treatment, only to learn that it doesn't work?

If you're NIH's alternative medicine center, you double down. More than double, actually: NIH's NCCIH* just announced they will spend another $37 million to study chelation as a treatment for heart disease. Or to be more specific, Mount Sinai of Florida and Duke University issued a press release this past week proudly announcing that they'd won a $37 million grant to launch TACT2, the second Trial to Assess Chelation Therapy. TACT2 will be a followup study from TACT, which ended in 2012 after largely failing, as I'll explain below.

Chelation is a harsh chemical treatment, using a chemical called disodium EDTA, that is sometimes used to treat lead poisoning, because it can help to remove heavy metals from the blood. Some people think that this can somehow remove plaques from arteries, a sort of Roto-Rooter for your circulation, which in turn might improve cardiovascular health. This turns out to be wrong.

(Chelation is also promoted, tragically, as a treatment for autism. Anti-vax doctors who think that mercury causes autism have been pushing this for years. In 2014, the FDA issued a warning for parents to beware of this dangerous and ineffective therapy.)

Let's briefly review what TACT was, and some of its problems. There are far too many to list here, but I'll refer readers to a lengthy article published in 2008 by Dr. Kimball Atwood and colleagues for details. That article, which called for a halt to TACT, explained that:

  • a series of randomized trials in the 1990s found no evidence that chelation worked for coronary artery disease
  • most of the early advocates of chelation (in the 1960s) were also outspoken advocates for Laetrile and other ineffective therapies
  • at least 30 deaths have been report associated with EDTA, but the doctors pushing its continued usage deny that any deaths have occurred.
  • the scientific literature has shown that the underlying "heavy metals" hypothesis is implausible
  • the TACT study includes "nearly 100 co-investigators who, in our opinion, are unsuitable to care for human subjects or to report trial data ... several have been disciplined, for substandard practices, by state medical boards; several have been involved in insurance fraud; at least 3 are convicted felons."
  • "The researchers failed to inform the subjects that one risk of the treatment was death." (from The Chicago Tribune.)

Atwood and colleagues called for a halt to the TACT study, saying it was "pointless, dangerous, unethical, and wasteful."

The TACT study was indeed halted in 2008 for these and other ethical concerns, but it was quietly resumed about a year later. Then in 2012, the final results were reported. Although the results were almost entirely negative, the lead investigator, Gervasio Lamas, claimed that there was a benefit for a sliver of patients: people with diabetes who had a prior heart attack. That's the group he plans to focus on in the new TACT2 trial.

As Forbes writer Matt Herper explained in 2012, most doctors were highly skeptical of these results. Cardiologist Steve Nissen of the Cleveland Clinic said "It would be tragic if the result of this was a widespread use of chelation." Science blogger (and cancer doctor) Orac provided a detailed analysis of the results at the time, explaining why the study essentially failed to prove any benefit for chelation. Most of the results were not statistically significant, and the best the study could claim was very marginal significance for a small benefit, a result that could easily be explained by bias, which was rampant in this study.

TACT2 is being run by the same doctor, Gervasio Lamas, who recruited questionable practitioners into the first trial. There's no reason to think the second trial will be run any better. The new trial will subject 1,200 diabetic heart attack survivors to chelation therapy in an effort to prove that chelation helps prevent a second heart attack. Not only is this extremely unlikely to provide any benefit, it also exposes the patients to serious risks that Lamas and his colleagues don't seem to acknowledge, and probably won't tell the patients about.

NIH should pull the plug on this enormous ($37 million) and dangerous trial before it begins. If potential patients are informed correctly that there is a serious risk of harm with virtually no chance of benefit, then hopefully they will simply refuse to enroll. That would be the best outcome for everyone.

*In case you're wondering what NCCIH is, it's the new acronym for the former National Center for Complementary and Alternative Medicine, NCCAM. Last year it was renamed. The new name is the National Center for Crackpot and Implausible Hypotheses, Or maybe it's the National Center for Complementary and Integrative Medicine, you decide.

Is being a little bit obese unhealthy?

Everyone knows that being obese is very bad for your health. But how overweight do you have to be before you should worry? A new study covering millions of people attempts to answer this question.

The short answer: being a little bit fat isn't so bad, especially if you're already a senior citizen, but the fatter you are, the shorter your life expectancy. Let's dive into the details.

The new study, published in The Lancet, is a combined evaluation (a meta-analysis) of 239 studies that included over 10 million people from four continents: Asia, Australia, Europe and North America. All the studies followed their subjects for a long time, averaging nearly 14 years of observation. The authors (a large consortium called "The Global BMI Mortality Collaboration") wanted to exclude people who might have already been sick, so their study only looked at people who (a) had never smoked, and (b) who lived at least five years after the study began.

This left them with nearly 4 million people, of whom 385,879 died at some time during the course of the study. From this large data set, the researchers computed the risk of death as a function of body mass index (BMI).

[Aside: BMI is a simple function of your height and weight. For example, someone who stands 5'11" and weights 170 has a BMI of 23.7. A height of 5'6" and weight of 150 gets you a BMI of 24.2. You can calculate your own BMI using this calculator.]

The study divided people into six groups:

  • underweight, BMI 15–18.5
  • normal, BMI 18.5–24.9
  • overweight, BMI 25–29.9
  • obesity grade 1, BMI 30–34.9
  • obesity grade 2, BMI 35–39.9
  • obesity grade 3, BMI 40 or above

The main outcome that they studied was mortality (death) from any cause. Of course, one can argue that this is too simplistic, since if someone dies from, say, an auto accident, it probably wasn't due to their weight. But the results were consistent across all four continents, which argues that the study design was probably good. Here are the main findings for each group:
  • BMI 15–18.5: 47% increased risk of death
  • BMI 18.5–24.9: no increase (normal)
  • BMI 25–29.9: 11% increased risk of death
  • BMI 30–34.9: 44% increased risk of death
  • BMI 35–39.9: 92% increased risk of death
  • BMI 40 or above: 171% increased risk of death
Another way to describe these hazard ratios is this: with a BMI above 40, people are 2.71 times as likely to die during any particular time period as people with a normal BMI. 

If these numbers seem scary, keep in mind that this is relative risk, not absolute risk. So an 11% increase in risk might mean that your chance of dying increases from 1% to 1.11%; it certainly doesn't mean you have an 11% risk of dying. 

To put some real numbers on this risk, consider this comparison: out of 1,075,894 people with a near-optimal BMI between 22.5–25.0, 98,833 died during the course of the study, or 9.2%. (Remember that these data come from 239 different studies, and the average length of followup is 14 years. So fewer than 1% of this group died per year.) Compare this group to people with obesity grade 1, or BMI from 30–35. That group had 330,840 people, of whom 37,318 died, or 11.3%. After various adjustments, this translates into a 44% relative increase, but the actual mortality rate, per year, was about 0.66% versus 0.81% in the two groups.

One mildly positive note: if you're already 70 or older, having a BMI from 25–30 has almost no effect; in other words, it's okay to be a little plump when you're older.

A word of warning to men: the ill effects of obesity are much stronger in men than in women. The study breaks down those hazard ratios by sex, and in each range the risk is higher for men than for women. So for example, if you're a woman with a BMI of 30–35, your hazard ratio is 1.37 (37% higher risk of death), but for men it is 1.70 (70% increase). 

There are many, many more details in the study, including a breakdown of how BMI is associated with four major causes of death (heart disease, cancer, respiratory disease, and stroke), and if you're interested in those, you should read the study

Of course, one can think of many caveats to these findings: people die from all sorts of illnesses, and many of them are not caused by being overweight. For any individual case, we might not be able to say whether someone's weight had anything to do with their illness. Nonetheless, this very large study shows clearly that the more obese you are, the greater your risk of dying. That's precisely what we would expect if obesity was causally linked to mortality.

So is it okay to be a little bit fat? The answer is probably yes: people with a BMI of 25 might view themselves as "a bit" fat, even though they are not overweight. But very high BMIs (and very low BMI, below 18.5) are definitely unhealthy. Unfortunately, no one has an easy answer to the problem of losing weight (despite what you might have heard from Dr. Oz), but if you do have a dangerously high BMI, reducing it will likely be good for your health.