Calcium and Vitamin D Supplements Still Don't Work, New Study Says

I think I’ll have to add calcium to my list of the Top Six Supplements You Should Not Take. Here’s why.

A year and a half ago, I reported on a very large study of 26,000 men and women that asked if vitamin D helps to prevent bone fractures, as many people (including some doctors) believe.

Well, it doesn’t. That study found that people who took vitamin D had exactly the same risk of bone fractures as those who didn’t. It didn’t matter how much vitamin D they took, nor did it help if they also took supplemental calcium: either way, vitamin D had no effect.

(Aside: everyone needs vitamin D, but most people get all they need from a normal diet. Alternatively, just 10 minutes of sunlight gives you about 4 times your daily recommended vitamin D requirement.)

Well, now there’s a huge new study, just out in the Annals of Internal Medicine, that followed over 36,000 older women, looking at the effects of a combination of vitamin D and calcium over a 22-year period. (That’s a really long time for a study, and kudos to the authors for their determination and effort.) The scientists leading the study looked not only at the effects of supplements on hip fractures, but also whether supplements changed the risk of dying from cancer or heart disease.

The results? Well, the study found no reduction in the risk of hip fractures, which isn’t surprising given that earlier studies found the same thing. But because it was such a lengthy study, following people for more than 20 years, they could ask something else: did vitamin D and calcium have any effect on mortality? Or to put it more bluntly, did the supplements prevent death?

Well, no. But the report was a bit more nuanced than that. It turns out that deaths from cancer went down a tiny bit, and deaths from heart disease went up a tiny bit.

First, though, let me explain the overall experiment. Approximately half the women in the study, just over 18,000, were assigned to take both vitamin D and calcium every day. They were given pills with 1000 mg of calcium carbonate (400 mg of elemental calcium) and 400 IU of vitamin D3 daily. The other half of the participants took placebo pills, but neither group knew whether their pills were placebos or not.

Over the course of 22 years, 1817 women taking supplements died of cancer, compared to 1943 women in the placebo group who died of cancer. That sounds kind of good, right? The study authors report that this result – 126 fewer deaths – was statistically significant (just barely), but there are good reasons to be skeptical of this “significance” claim.

On the other hand, 2621 women taking supplements died of heart disease, versus 2420 women in the placebo group. So there were 201 more deaths from heart disease among women taking vitamin D and calcium: not so good.

Combining both causes of death, we see that in the women taking supplements, there were 75 more deaths from either cancer or heart disease. The study also reported numbers for all causes of death, and there were still very slightly more deaths in the supplement group. (The annual death rate increased from 2.14% to 2.15% for those taking supplements, a non-significant change.)

So on the whole, taking supplements didn’t seem to provide any benefit at all, and it certainly didn’t reduce the risk of death.

Why would supplemental vitamin D and calcium increase the rate of heart disease, or decrease the rate of cancer? Well, first I should emphasize that it’s entirely possible that these supplements have no effect at all, and the difference in death rates must just be random variation. There have been multiple studies speculating on how vitamin D might help to prevent cancer, but the effect, if any, is very small. And as for heart disease, maybe, as the authors of the new study speculate, long-term calcium supplements create calcifications in coronary arteries, which would be a bad thing. For now, this is merely a hypothesis.

So here is my new list of the top 7 (no longer 6) supplements that you should not take:

1. Vitamin C
2. Vitamin A and beta carotene
3. Vitamin E
4. Vitamin B6
5. Multi-vitamins
6. Vitamin D
7. Calcium

You can read more about the first five, some of which can be downright bad for you, in The Top Five Vitamins You Should Not Take.

What’s left? Well, if you don’t have a deficiency, there’s no reason to take any supplemental vitamins at all. If you want to spend a little more money at the grocery, buy some fresh fruit instead. You’ll be healthier for it.

As a final caveat, I should point out that although routine supplementation is worthless and megadoses of vitamins can be harmful, if you think you have a vitamin deficiency, consult with your doctor. Serious vitamin deficiencies might be the result of other health problems that your doctor can help you address, and treatments for specific conditions or diseases may include vitamins.

Does Taurine Really Extend Life? Maybe.

 Readers of this column will know that I’m highly skeptical of dietary supplements. So you might imagine my reaction when I saw headlines a few days ago about “Taurine, the elixir of life?” (at CNN) and “Supplement slows aging in mice and monkeys” (NY Times).

Unlikely, I thought. But I read the scientific article behind these reports, and now I’m intrigued.

What is taurine? And could it really slow down aging? Well, it seems like it could, just maybe. A new study published last week in Science (one of the top journals in all of science) seems to show, for the first time, that taking large doses of taurine, an essential amino acid, might provide a host of benefits that include slowing down the aging process.

First question first: what is taurine? It’s an amino acid, but it’s not one of the 20 amino acids that comprise all the proteins in your body. It’s a slightly different one, and our bodies naturally produce it in small amounts. We need more than our bodies produce when we’re very young, but we get it from breast milk, and it’s added as a supplement to infant formula.

We also get extra taurine from our diet: the best foods for taurine are meats, especially shrimp and other shellfish, but also beef and the dark meat in chicken and turkey.

What did the new Science paper show? Well, first the authors (from Columbia University, India’s National Institute of Immunology, and the Sanger Institute in the UK) describe how taurine levels clearly decline with age in humans and other mammals. Now, just because taurine declines doesn’t mean that replacing it will reverse the aging process, but at least it establishes plausibility.

They then describe a series of experiments, mostly in mice but also in monkeys, where they fed the animals relatively large amounts of taurine each day, and the results were pretty darned impressive:

1. Life span in the mice increased by 10-12%.
2. In mice that started taurine supplements in middle age, life span increased by 18-25%.
3. Bone density increased in female mice and osteoporosis seemed to be cured.
4. Muscle strength increased in both males and females compared to mice who didn’t get taurine.
5. The number of senescent cells–cells that don’t do much except emit damaging inflammatory signals–seemed to be reduced.

Of course, there’s always a big caveat with results in mice: they’re mice, not humans! And many, many times we’ve seen results in mice that just don’t carry over into humans. So the scientists also did a study (a smaller one) in monkeys, which are much closer to humans genetically. This also had some very good results:

1. Bone density increased in the spine and legs.
2. Body fat was lower than it was in monkeys that didn’t get taurine.
3. Several measures of inflammation decreased.

Monkeys live a lot longer than mice, so the scientists don’t yet know if taurine increases the monkeys’ life span, but all the signs are promising. I was skeptical going into this article, but I couldn’t find any obvious flaws.

In an accompanying article in Science, U. Penn’s Joseph McGaunn and Joseph Baur point out that we don’t know for sure what the risks of long-term supplementation with taurine would be, but it is already widely taken as a supplement in baby formula and in energy drinks, with no known ill effects.

However, the amounts used in the Columbia study were very high, much higher than you’d get from energy drinks or even from standard taurine supplements. I looked up a few, and typical formulations offer 1000 or 2000 mg (which is 1-2 grams) per day. The doses given to monkeys in the study, if converted to a 150-pound person, is equivalent to about 5500 mg (5.5 grams) per day. That’s not very much by weight, and it would be easy enough to take this much taurine, but no one knows the effects in humans of such high doses.

The bottom line: this study is really intriguing. More studies are needed, especially to measure the effects of taurine on humans, but all the signs are positive. I’ll be watching closely to see if the effects in mice and monkeys carry over, and if they do, we may all be taking taurine supplements one day. And I just ordered some taurine powder for myself–why not?

Herbal extracts that cure an enlarged prostate? Not likely.

Saw palmetto, which is NOT effective for

treating enlarged prostates.

(Note: see the brief update at the bottom of this post for a response from the manufacturer.)

I haven’t looked at medical scams recently, and I thought I’d venture back into that world just a little bit this week, to see what is happening.

As always, the scams are everywhere, with products claiming to cure just about everything. What surprised me, though, is how blatant some of them have become. Some sites have no caveats or disclaimers at all, despite the fact that their claims are utterly false. They don’t even pretend that they are worried about a regulatory agency objecting to their false claims. The boldness can be startling–or, if you’re not sufficiently skeptical, convincing.

Let’s look at one site that strikes me as particularly egregious, which sells a dietary supplement called Prostoxalen as a cure for prostate problems. I was directed to this site by another site, ShopBodyVibes, that sells an even wider range of bogus cures (more on that below).

The marketers of Prostoxalen, which they sell for $40 for a bottle of 60 pills, are nothing if not direct. At the top of their website, they promise that Prostoxalen will “get rid of the constant pressure on the bladder, unpleasant pain and all other ailments related to prostate enlargement! Once and for all!”

Nowhere do they provide even a shred of evidence for this claim.

And there’s more: they also claim that Prostoxalen will cure erectile dysfunction: “if you've noticed erection problems, our capsules will fix that issue as well,” the site states.

Again, no evidence at all.

I was expecting at least a citation to a poorly-done study published in a low-quality journal - after all, even homeopathic treatments, which are laughably ineffective, can find some bad science to support their claims.

But no, not for Prostoxalen. Maybe its marketers think that the testimonials alone (which appear to be fake) are sufficient.

So what on earth is in these pills? Well, it turns out that they’re just plant extracts and vitamins. The main ingredients are extracts of saw palmetto, pumpkin seeds, cranberries, tomatoes, nettles, and willowherb, along with a couple of common vitamins.

Great! So all you need is cranberries, tomatoes, and pumpkin seeds, and your prostate problems will go away. I’m surprised that anyone has an enlarged prostate, if this is all it takes to cure it.

But here’s the problem: there is no good scientific evidence that any of these ingredients will cure or relieve the symptoms of enlarged prostate. Not even a tiny bit.

(If you want to dig deeper, you can find multiple scientific studies of saw palmetto, which is widely marketed as a treatment for enlarged prostates. A carefully-done randomized trial out of Washington University, back in 2013, show that it simply doesn’t work, even at high doses.)

The name Prostoxalen sounds just a little bit like they might want you to think it’s a drug, doesn’t it? Maybe something to do with the prostate? Fortunately, the website answers this question in a FAQ list, which says: “No, Prostoxalen is not a drug. It is a food supplement in the form of capsules.”

Aha, that explains it. Dietary supplements aren’t regulated by the FDA, unless you claim that they’re a drug or that they can treat a medical condition.

What I expected to see on the website, but didn’t, was this disclaimer: “these statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.” That’s the small-print language that appears on thousands of websites and products, and that allows supplement makers to make all kinds of hints and suggestions while avoiding regulation. Typically they use phrases like “supports prostate health,” as one saw palmetto product puts it.

It appears that Prostoxalen is manufactured and sold by a company in Poland, identified on the website only as PLT Group. So I guess they just don’t care what the FDA thinks–even though they are marketing this in the U.S. (I contacted them through their website, but they didn’t respond.)

So no, there is no magic pill that cures or relieves the symptoms of enlarged prostates, and any such cure is almost certain to require more than a few plant extracts.

Finally, about that site that directed me to Prostoxalen: that was ShopBodyVibes, a site that sells products to “make the penis longer” (Eroxel), “cleanse the body of toxins” (BurnBooster), “reduce varicose veins” (Variforce), “eliminate knee pain” (Ortezan), and a “breast enlargement serum” called BooUp. I’m not making this up. Needless to say (but I’ll say it), none of these products works–and yet the site has no disclaimers, nor does it provide any evidence for the claims.

The ShopBodyVibes site repeats all the claims from the Prostoxalen website (see here), again with no disclaimers. If you wonder what is in this product, (as I did), ShopBodyVibes suggests that “Everyone who is interested in learning the detailed composition of the product can read the list of ingredients, which is available on the manufacturer’s official website.”

Perhaps unsurprisingly, the ShopBodyVibes site has no indication of where it is located. It appears to be outside the U.S., which explains its stunning lack of any attempt to qualify its many bogus claims. It also has enough similarity to the Prostoxalen site to suggest that both sites might be owned by the same group in Poland. They didn’t respond to my inquiries.

And if you’re wondering how I stumbled upon BodyVibes: they were promoted by an article on Goop (yes, that’s Gwyneth Paltrow’s lifestyle company) about “wearable stickers that promote healing.” Yes, BodyVibes sells those too. I wrote about these magic stickers back in 2017, and my advice then still applies: they still don’t work, but if you like stickers, you can get a sheet of 50 for a couple of bucks.

Update: the manufacturer of Prostoxalen replied to my inquiry after this post appeared. Their message, in full, said: “our product has passed all the required tests before being launched on the market. It has proven to be highly effective, safe and legally introduced. We are a Polish company - the product is on the list of the National Sanitary Inspectorate at the Ministry of Health in Poland.” They did not provide any evidence or citations to support these claims, particularly the “highly effective” claim.

For Pete's Sake, Stop Taking Vitamin D Supplements!

Way back in 2014, I wrote a column about vitamin D supplements, explaining that they don’t work. I added vitamin D to my previous list, the Top 5 Vitamins That You Should Not Take, to create a list of 6 useless vitamin supplements.

Together, these two columns had well over 1,000,000 views. And yet it seems the message didn’t get through. Well, now a massive new study published in the New England Journal of Medicine reports that I was right all along: taking vitamin D pills isn't good for you. Let’s review the findings, shall we?

In 2014, I wrote about two studies, both published in The Lancet. The first paper, a massive review of 462 other studies, concluded that taking supplemental vitamin D did not help to prevent heart disease, weight gain, mood disorders, multiple sclerosis, and metabolic disorders, all of which had been linked to lower vitamin D. Nope, they said: it appears that low levels of vitamin D are a result of bad health, not the cause.

Ah, you might be thinking, but vitamin D is mostly about bone health, right? Well, the second study that I wrote about in 2014 looked precisely at that question. That paper concluded that vitamin D supplements do not improve bone density, and they do not reduce the risk of osteoporosis.

In other words, vitamin D supplements are a complete waste of money.

Nonetheless, people keep taking vitamin D, and doctors in the U.S. continue to recommend it (based on published guidelines that urgently need revision), on a very large scale.

So now we’ve spent millions of dollars on a huge new trial, which followed nearly 26,000 men and women for more than 5 years, to see if vitamin D supplements would do anything to prevent bone fractures. (And by “we” I mean U.S. taxpayers, who funded this study through grants from the National Institutes of Health.)

The result: people who took vitamin D had exactly the same risk of bone fractures as those who didn’t. It didn’t matter how much vitamin D they took, nor did it help if they also took supplemental calcium at 1200 mg per day. And it didn’t help people who had relatively low levels of vitamin D either. Taking vitamin D supplements just didn’t make any difference to anyone.

So we should stop taking vitamin D–but there’s more. In an editorial accompanying the new study, Steven Cummings and Clifford Rosen point out that “More than 10 million serum 25-hydroxyvitamin D tests are performed annually in the United States.” These tests add costs to our already exorbitant health care system, and they don’t provide patients with any benefit.

Cummings and Rosen put it bluntly: “providers should stop screening for 25-hydroxyvitamin D levels or recommending vitamin D supplements, and people should stop taking vitamin D supplements to prevent major diseases or extend life.” Or as my Hopkins Eliseo Guallar, Lawrence Appel, and Edgar Miller wrote back in 2013, “Enough is enough: stop wasting money on vitamin and mineral supplements.”

At the top of this article I mentioned that my list of useless vitamin supplements has 6 vitamins on it, so here they are:

1. Vitamin C
2. Vitamin A and beta carotene
3. Vitamin E
4. Vitamin B6
5. Multi-vitamins
6. Vitamin D

If you want to know the science behind the other 5, take a look at my column on The Top Five Vitamins You Should Not Take.

Finally, I should point out that although routine supplementation is worthless and megadoses of vitamins can be harmful, if you think you have a vitamin deficiency, consult with your doctor. Serious vitamin deficiencies might be the result of other health problems that your doctor can help you address, and treatments for specific conditions or diseases may include vitamins.

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.

The top 5 supplements you should not take

Ginkgo trees lining a path.

Dietary supplements are big business. They are promoted for all sorts of health benefits, including weight loss, memory enhancement, body building, and cancer prevention. Many of the claims featured on websites and product packaging are not true, but that doesn’t seem to stop supplement makers from promoting them.

Unlike drugs, supplements are not regulated by the FDA. With drugs, the FDA requires that they be both safe and effective, but with supplements, they can only take action when products are tainted in some way, or when supplement makers cross the line and make specific claims about curing disease. When they do cross that line, all the FDA can do (in most cases) is issue a stern warning and tell them to stop making false claims, which has little effect. In an effort to educate the public, the FDA regularly issues warnings such as this one, telling consumers to “beware of products promising miracle weight loss,” but supplements continue to sell briskly.

Many of the best-selling supplements have little or no evidence to back up their claims, and the vast majority of people will not benefit from taking them. So here are the top 5 dietary supplements that you should not take:

1. Ginkgo biloba. Ginkgo biloba extract is made from the leaves of a beautiful tree that is native to China. It is widely advertised as a supplement that can enhance memory, stave off dementia and Alzheimer’s, and treat other conditions. I found it available from many vendors, including Target, Whole Foods, CVS, Walgreens, and others.

Alas for any hopeful consumers, ginkgo biloba doesn’t work, as scientific studies have repeatedly shown. A recent meta-analysis of 28 different trials looked at its effect on memory, executive function, and attention, and found that it had zero effect on any of these functions.

Nonetheless, web vendors such as Zooscape.com continue to promote ginkgo as a treatment for dementia and Alzheimer’s, despite having received a warning notice from the FDA stating that their advertising violates the Food, Drug, and Cosmetics Act. The FDA letter, dating from 2010, stated that ginkgo biloba is “not generally recognized as safe and effective” for dementia or Alzheimers, but the Zooscape website still claims otherwise..

2. Garcinia cambogia. “Garcinia cambogia is hot,” says Consumer Reports. Also known as the tamarind fruit, garcinia cambogia is promoted as a near-magical weight loss treatment. It does contain a substance that was once thought to have promise in treating obesity, but it’s been studied in multiple trials, all of them negative. The first trial, in 1998, concluded that

“Garcinia cambogia failed to produce significant weight loss and fat mass loss beyond that observed with placebo.” 

According to Consumer Reports, multiple studies since then have all reached the same conclusion: it doesn’t work.

Garcinia cambogia’s popularity took off after Dr. Oz promoted it on his TV show in November 2012, where he called it a “revolutionary fat buster." This episode, which has now been removed from the Dr. Oz show website, was the subject of a U.S. Senate hearing led by Sen. Claire McCaskill, who sharply criticized Oz for promoting products that aren’t back by science. Said McCaskill, "I don't know why you need to say this stuff, because you know it's not true."

I had no trouble at all finding many sources for garcinia cambogia, all of them making strong weight loss claims. Amazon.com sells many brands, including Quality Encapsulations, which calls it a “powerful appetite suppressant” that will “block the formation of new fat cells” (there’s no evidence for this). A brand called Stay Healthy, also available from Amazon, claims you can “eat like a gorilla and lose belly fat fast!”

Sorry, but no: you can’t eat like a gorilla and lose weight. At least not like a healthy gorilla.

3. St. Johns wort is a flowering plant that some people use to treat depression. In this respect, it’s in a different category from the other supplements in this list, which are used for physical rather than psychological conditions.

A double-blind, randomized, placebo-controlled trial of St. John’s wort as a treatment for major depression was published in 2002. This type of study is the gold standard for science-based medicine, and produces the most reliable results. The conclusion was clear: St. John’s wort performed worse than placebo, and the authors concluded that St. John’s work is not effective for major depression.

This might have settled things, but studies continued, and in 2008 a review article came to a different conclusion, finding that St. John’s wort was better than placebo for major depression. Even more recently, a 2011 study looking at minor (rather than major) depression found, just like the 2002 study, that St. John’s wort offers no benefit.

Thus the evidence for St. John’s wort is confusing and contradictory. One thing that is clear, though, is that St. John’s wort can have dangerous interactions with other drugs. The NIH warns that

“Combining St. John’s wort with certain antidepressants can lead to a potentially life-threatening increase of serotonin, a brain chemical targeted by antidepressants. St. John’s wort can also limit the effectiveness of many prescription medicines.” (emphasis in original)

Despite these dangers, you can buy St. John’s wort anywhere: it took me mere seconds to find dozens of choices. If you’re thinking about trying it, follow NIH’s advice and consult your physician first.

4. Glucosamin and chondroitin. These two supplements have been promoted for years as a treatment for joint pain. Scientists have run many experiments to see if they work, and some of the experiments have been mildly positive, encouraging people to give them a try. Joint pain, especially in the knees, is very common, and we don’t yet have a real cure (unless you count knee replacement). (I have chronic knee pain myself, and I would love to find a pill that would cure it.)

To finally resolve the question, NIH conducted a large $12.5 million study called GAIT, which compared glucosamin, chondroitin, celecoxib (an NSAID), and placebo. The conclusion: the only treatment that worked was celecoxib (Celebrex). In a small subset of patients with moderate to severe pain, there was a hint of a benefit for glucosamine-chondroitin, but it wasn’t significant. For patients with mild pain, only celecoxib worked better than a placebo.

So the door isn’t completely closed for this supplement: it clearly doesn't work for mild pain, but for moderate to severe pain, it might offer a small benefit, although an NSAID is better.

Of course, there’s no hint of this uncertainty in the advertising I found. For example, Puritan’s Pride says their pill “nourishes joints to improve flexibility, supports connective tissue in and around the joints," and "promotes healthy cartilege." Of course, the very bottom of their web page has a disclaimer stating that "these products are not intended to diagnose, treat, cure or prevent any disease." Oh, so why exactly should anyone purchase them?

5. Echinacea. Echinacea is a flower, similar to a daisy, that is widely used to treat the common cold. Apparently this got its start when a Swiss herbal supplement maker was erroneously told that Native American tribes used it as a cure. Regardless of the source, the use of echinacea grew, and it has now been subjected to multiple scientific studies.

What does the science say? In 2003, a randomized, placebo-controlled, double blind trial published in JAMA – again, these are the gold standard for scientific evidence – found that echinacea was not effective for treating colds in children aged 2-11, and that it appeared to causes rashes in some of them. Another study, also a randomized, placebo-controlled, double-blind trial, looked at college students, and found again that echinacea didn't work for them either: "echinacea provided no detectable benefit or harm in these college students who had the common cold." More recently, a 2014 review concluded "Echinacea products have not here been shown to provide benefits for treating colds."

Not surprisingly, though, everyone sells echinacea. The NatureMade brand just says "supports immune system health" (a vague claim that the FDA doesn't restrict). Puritan's Pride's label says the same thing. The Dr. Oz website doesn't sell echinacea, but an article there by Tod Cooperman claims that "echinacea can help you get over a cold faster and reduce symptoms." Zooscape is even bolder: it sells an echinacea tea that it advertises with the phrase "colds and flu be gone!"

Save your money. If you have a cold, echinacea won't help. I have it on very good authority, though, that chicken soup works wonders.

[For a list of the top vitamins you don't need, see my 2014 article on that topic.]