No, You Still Don’t Need Vitamin D Supplements!

The NY Times this week ran a story under the headline “Am I Getting Enough Vitamin D During the Winter?” I’ll give you one guess how they answered that one.

Yes, the days are at their shortest right now. (The shortest day of the year will be Wednesday, December 21.) And yes, your body synthesizes vitamin D when you’re out in the sun, so you make less of it this time of year.

You also get vitamin D from a variety of foods. The Times story quoted a skin cancer expert from NYU School of Medicine, Dr. Deborah Sarnoff from, who said “you don’t need to get it [vitamin D] from sunshine.”

So you don’t need to run out and take vitamin D supplements. as I pointed out emphatically in a column I wrote back in August, and in several earlier columns too. Scientists have conducted multiple major studies of vitamin D supplements, as I wrote before, and those studies–involving thousands of subjects and running for many years–showed that

• Vitamin D supplements do not improve bone density, and they do not reduce the risk of osteoporosis.
• Vitamin D supplements don’t prevent heart disease, weight gain, mood disorders, multiple sclerosis, or metabolic disorders.
• Vitamin D supplements (in the most recent study, involving 26,000 men and women followed for more than five years) don’t do anything to prevent bone fractures.

But the NY Times reporter (Rachel Peachman) really wanted to recommend supplements, it appears. She apparently wasn’t able to get a doctor to say that, so instead she quoted a dietitian nutritionist, who provided the quote, saying “Especially as we’re entering the winter months, most people would benefit from taking a supplement.”

Not surprisingly, the Times doesn’t quote an actual study that supports this recommendation, because that’s not what the science says. (To be fair, the dietitian also included some caveats, which are paraphrased in the article, including the point that “it’s difficult to suggest one blanket recommendation for everyone.”)

So no, NY Times, most people wouldn’t benefit from taking a supplement. As Drs. Steven Cummings and Clifford Rosen wrote last summer in the New England Journal of Medicine, “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.” And as five of my Hopkins colleagues wrote in a 2013 review in The Annals of Internal Medicine, “stop wasting money on vitamin and mineral supplements.” The science just doesn’t support it.

Cummings and Rosen also pointed out that more than 10 million blood tests for vitamin D levels are conducted in the US each year, with the vast, vast majority of these being unnecessary. These tests aren’t free, and our costly health care system doesn’t need the extra burden.

Finally, let me offer a caveat that I’ve written before: 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.

Should we all take aspirin? Not so fast.

I thought we'd put this one to bed. A large-scale study showed that low-dose aspirin (one quarter of a standard 325 mg pill, or about 81 mg) taken once a day can prevent heart attacks and some common types of cancer, including colon cancer.

I wrote about this topic just over a year ago, and I've followed my own advice, taking daily 81mg aspirins since then. The US Preventative Services Task Force recommends this too: regular, low-dose aspirin for people between the ages of 50 and 69 helps to prevent heart attacks, strokes and some types of cancer.

But now, a new study just published in The Lancet upends that advice. It's not that the previous study was wrong–it wasn't. It's just that the effects of aspirin vary significantly based on body weight. Essentially, the new study finds, almost all of the benefits accrue to people who weigh 70 kilograms (154 pounds) or less.

The study, a re-analysis by Peter Rothwell and colleagues of ten large trials that included 117,279 participants, is too long and complex to summarize here, so I'll just highlight a few key points. (Because the paper is open access, anyone can read it for free, just by clicking here.)

The good news, for people who weigh between 50 and 70 kg (110-154 lbs), is that the benefits of daily low-dose aspirin are quite good, possibly even better than we thought. The relative risk of a heart attack, stroke, or other major heart-related event is about 25% lower for people in this group.

The bad news, for the rest of us, is that we seem to get no heart-related benefits from taking a daily low-dose aspirin.

So perhaps those of us who weigh more than 70 kg just need a slightly larger daily aspirin pill. There is some good news here: Rothwell and colleagues found that, indeed, higher doses of aspirin are effective at reducing the risk of heart attacks for people who weigh more than 70 kg. This makes sense: adjusting the dosage based on weight is how most drugs are given. The problem is that aspirin generally comes in only 3 pill sizes: 81, 325, and 500 mg. So the studies have only looked at these 3 doses, and 325 mg is likely too large a dose for most people, because it increases the risk of bleeding events.

What about the cancer risk? As I wrote in 2017, the biggest benefit from daily low-dose aspirin is its reduction in the risk of colon cancer, breast cancer, and prostate cancer. Here, the new study doesn't quite give the whole picture, because it didn't look at breast cancer or prostate cancer. For colon cancer, low-dose aspirin reduces the risk significantly for people who weigh less than 70 kg. For heavier people, low-dose aspirin had little to no effect on colon cancer risk, but regular-sized aspirin (325 mg) worked for people up to 80 kg (176 lbs).

What to do now? The new study concludes that:

"The one-dose-fits-all strategy for daily aspirin use is unlikely to be optimal."

 In other words, you will probably benefit from daily aspirin, but the amount you should take depends on your weight. If you weigh less than 70 kg, the 81-mg tablets that you can find almost anywhere will do nicely. 

But what if you weigh more (as most men and many women do)? The science doesn't yet give us an answer: you could simply take 2 low-dose pills a day, but too much aspirin increases the risk of serious bleeding events. You could instead take a few extra pills per week, depending on your weight, which is what I'm going to do, at least until we get better data and more precise guidelines.

(Final note: as always, before you make any changes in your medication, ask your physician.)

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.

Stem cell therapy offers hope for “irreversible” heart damage

In December 2011, I reported on one of the first attempts to inject stem cells into damaged hearts. In that study, published in The Lancet, scientists grew stem cells from patients’ own hearts after the patients had suffered serious heart attacks. These were patients who had serious, irreversible heart damage. As the study leader, Dr. Roberto Bolli, said at the time, 

“Once you reach this stage of heart disease, you don’t get better. You can go down slowly, or go down quickly, but you’re going to go down.”

Amazingly, in that study, the patients got better. 14 of the 16 patients had improved heart function after 4 months, and the results were even better after one year. The stems cells grew into new, functioning heart cells.

That was just one study. Now there have been more, and the results continue to be very encouraging. Just last week, the Cochrane Collaboration published a review of 23 trials, all of them attempting stem cell therapy for heart disease. These trials looked at the use of bone marrow stem cells in patients whose hearts were failing. Unlike the 2011 study, which looked at heart attack patients, these studies looked at patients with advanced heart disease who had not suffered a heart attack. The results: overall, stem cell treatments reduced the risk of death and improved heart function, though the benefits were not as dramatic as in the patients with heart attacks. 

What is most exciting in the newest studies is the long-term reduction in the risk of death. Six of the studies reported long-term results (more than one year) on mortality. In these studies, 8 patients died out of 241 who received stem cell therapy (3.3%). In contrast, 30 patients died out of 162 (18.5%) who did not receive stem cells. The numbers are small, but this is a huge benefit: patients were about 5 times less likely to die. The Cochrane review concluded that

“The risk of mortality over long-term follow-up was significantly lower for those who received BMSC [bone marrow stem cell] therapy.”

An important caveat is that this is still “low quality” evidence, meaning that we need to see more data, on many more patients, before we can have confidence in the results. But it is still very encouraging, especially when no other treatment offers anything remotely this promising for advanced heart disease.

The evidence continues to build that stem cells can repair heart tissue damaged by heart attacks. Just a couple of months ago, Britain launched the largest study yet of stem cell treatments for heart attacks, involving 3,000 patients in Europe. This new review shows that they can help repair some of the damage from other types of heart disease as well.

Heart disease is the leading cause of death in the United States, and we should be pursuing every plausible treatment, though very few exist. Stem cells offer the hope that, for the first time ever, we might be able to reverse heart damage that was previously thought to be irreversible. Stem cell treatments are a true breakthrough, and rather than cutting medical research, as we have been doing for the past five years, we should be pouring resources into this remarkable new medical technology and the therapies that it makes possible.

Those fish oil supplements might cause cancer

Eating fish is good for you, especially fish that contain omega-3 fatty acids.  So I was surprised last week to read a new study in the Journal of the National Cancer Institute that found that omega-3 fatty acids increase the risk of prostate cancer.  The risk for both high-grade and low-grade cancer was increased with higher levels of omega-3 fatty acids.  This is a carefully done study, and the results should make anyone who is taking fish oil pills reconsider.

One reason this study caught many people off guard is that there has been much evidence showing that a diet rich in fish that contain omega-3 oils is good for you.  The Mayo Clinic says that  "eating fish helps your heart", especially fish like salmon that contain omega-3 fatty acids.  The American Heart Association (AHA) elaborates:

"Omega-3 fatty acids benefit the heart of healthy people, and those at high risk of — or who have — cardiovascular disease. Research has shown that omega-3 fatty acids decrease risk of arrhythmias (abnormal heartbeats), which can lead to sudden death. Omega-3 fatty acids also decrease triglyceride levels, slow growth rate of atherosclerotic plaque, and lower blood pressure (slightly)."

This all sounds great.  Because of the evidence about the benefits of fatty fish, supplement manufacturers have been marketing and selling fish oil pills for years, with great success.  As I described back in 2010, GlaxoSmithKline even created a high-dose omega-3 fatty acid pill called Lovaza that has FDA approval.

But the evidence for that you can get the same benefit from supplemental omega-3 fatty acids — taking a pill, that is — is much weaker.  In fact, a large review published last year in the Journal of the American Medical Association found no connection at all between supplemental omega-3 and a lower risk of heart attacks, strokes, or death in general.  Other studies have reported similarly negative results.  So it appears that fish oil pills may not have any heart benefits.

And now, with this new study, we learn that supplemental fish oil might increase the risk of prostate cancer.

The bottom line: the AHA recommendations about eating fish are probably still good ones.  The AHA website says:

"We recommend eating fish (particularly fatty fish) at least two times (two servings) a week. Each serving is 3.5 oz. cooked, or about ¾ cup of flaked fish.  Enjoy fish baked or grilled, not fried." 

But popping a fish oil pill is not going to cut it. As we've seen before, supplements often fail to show the benefits that a healthy diet offers.  So save your money and stop buying those fish oil pills — and fire up the grill and throw on a few salmon fillets for this weekend's barbecue.

Stem cell hopes for damaged hearts

As the holiday season begins, I decided to discuss some good news about real science.

The promise of stem cell research just got a lot brighter.

There was some very good news from the world of medicine just a couple of weeks ago. For the first time, stem cells were injected into the hearts of humans who had suffered serious heart damage, and patients improved dramatically. It appears that, as everyone hoped, the stem cells grew into new heart cells to replaced the damaged tissue. This is the promise of all stem cell research: to repair or replace damaged organs that otherwise would never recover. In principle, we can someday use the same technique to replace damaged livers, kidneys, spinal cords, cartilege, and virtually all other tissues in the human body.

In the new study, just published in The Lancet, a group of researchers led by Robert Bolli grew stem cells from patients' own hearts, after the patients had suffered serious heart attacks, leaving their hearts permanently damaged. Bolli explained to CNN reporter Caleb Hellerman:

"Once you reach this stage of heart disease, you don't get better. You can go down slowly, or go down quickly, but you're going to go down."

In an effort to repair the patients' hearts, Bolli and colleagues collected a small amount of tissue from each patient's own heart, and purified stem cells from that tissue. By using the patient's own cells, there is no danger of rejection as there would be with cells from an unrelated donor.

They measured the patients' heart function by how much blood was being pumpled through the left ventricle. The patients had an average Left Ventricular Ejection Fraction (LVEF) of 30.3% at the beginning of the study, an indication of very severe heart disease. Four months later, the 16 patients who received the stem cells had an average LVEF of 38.5%, while patients in the control group (who didn't get the stem cells) showed no change. Even more dramatically, after one year the patients LVEF had improved further, to 42.5%.

Thus, remarkably, the cardiac stem cells seem to have "taken" in these patients, growing back into healthy cardiac cells in these severely ill patients. The researchers used MRI to measure the damaged heart tissue in 7 of their patients, and found that it had actually decreased by 30% after one year. In a companion trial at Cedars-Sinai Heart Institute in Los Angeles, Dr. Eduardo Marbán reported similarly positive results. Marbán told CNN that the patients grew approximately 600 million new heart cells after the procedure, comparable to the number of cells that die in a serious heart attack.

One reason these findings are especially dramatic is that they show convincingly that the human heart contains stem cells that can re-grow into new heart cells. It is entirely possible that heart damage that has always been thought to be irreversible can be completely repaired - someday.

The results are very preliminary, and only a few patients have been treated so far, but this is a major triumph for stem cell research. The research in question used adult stem cells, but embryonic stem cells may prove even more effective, and may be easier to obtain because they don't have to come directly from someone's heart.* Heart disease is the leading cause of death in the U.S., and we need to pursue every possibility for new treatments. Those who oppose stem cell research - including embryonic stem cell research - should wake up and take notice: many lives are at stake.

*Disclaimer: Until June 2011, I was a member of the Maryland Stem Cell Research Commission, a state commission established by the legislature and the governor to promote human stem cell research through state-funded grants. The views expressed here, as always, are my own, and do not represent the Commission.

Should we all be on statins?

Well, probably not.

But a new review published earlier this month in the Cochrane Reviews looked at 14 different trials, with a total of 34,272 patients, in an attempt to answer this question, and came out with conflicting results. Scientific and medical experts looked at the review and have already reached diametrically opposed conclusions, reported in their blogs and in commentaries in several leading journals.

Everyone has heard of statins: they are a class of cholesterol-lowering drugs that offer clear benefits in people who already have suffered heart attacks or other serious cardiovascular problems. But what about the rest of us? If you have slightly elevated cholesterol, or even normal cholesterol, should you take statins? Drug companies would certainly like you too, and they have been pushing statins (such as Levacor, Zocor, Pravachol, Lipitor, and Crestor) for years in the U.S., through ad campaigns in print and on television. I wrote about a study of Crestor back in 2008, and I found serious problems with the study's design and conclusions.

First, what did this large-scale review find? All of the studies ran for at least a year, and all were randomized controlled trials, the most rigorous type of study. Overall risk of death was reduced by 17%, and the risk of a heart attack was reduced by 28%, which seem to be very positive results. None of the patients had previous history of cardiovascular disease, although most of the studies recruited patients with other risk factors such as high cholesterol, diabetes, or high blood pressure.

But - and this is a big but - the authors of the Cochrane review had big problems with the way these studies were run. They wrote in their conclusion that

"there was evidence of selective reporting of outcomes, failure to report adverse events and inclusion of people with cardiovascular disease. Only limited evidence showed that primary prevention with statins may be cost effective and improve patient quality of life. Caution should be taken in prescribing statins for primary prevention among people at low cardiovascular risk."

So the review authors were not convinced that people without previous heart disease should all go on statins, even though their own numbers showed a decreased risk. I think their skepticism is justified, because the benefits they observed were very small. This means that subtle biases such as including people who did have cardiovascular disease, could create the appearance of a benefit even if there wasn't one. And 9 of the 14 studies were funded by pharmaceutical companies, which hints at possible bias.

Writing in the journal BMJ, Susan Mayor highlighted the skeptical interpretation. She quoted one of the study's authors, Shah Ibrahim, who said "Absolute benefits were small, and evidence of selective reporting of outcomes makes the evidence less robust.”

Over at Science-Based Medicine, neurologist and skeptic Steven Novella has a more positive interpretation. He concluded that

"there is solid evidence that statins have a real benefit for primary prevention. This benefit is small, which is exactly what I would predict for a preventive measure in a low-risk population. The data also show that statins are safe. ... For interventions that prevent death – that lower mortality – I think even small benefits are worthwhile."

However, he goes on to say that "it is still unclear where to draw the line in terms of which patients should receive statins."

I would love to believe that statins will reduce everyone's risk of heart disease, but I couldn't ignore one statistic: the "number needed to treat." Based on the new study's findings, you'd have to treat 1000 low-risk patients for one year to prevent one death. To put that another way, if you are at low risk of heart disease, then there is a 99.9% probability that taking statins for a year will give you no benefit. Even so, given that statins have minimal side effects, you might think it's a reasonable preventative treatment, even with such a small benefit. The skeptic in me says that if there was even a tiny amount of bias in some of the trials, that apparent benefit might actually be zero.

On this question, we need more data from completely unbiased studies. In an editorial for the Cochrane Reviews, Carl Heneghan wrote that "Interventions targeting CVD risk reduction in low-risk population should be undertaken in the context of a randomised controlled trial; preventing scarce healthcare resources going to waste."

He's right. Statins might have a small benefit, but before we start prescribing them to tens of millions of people - and before I start taking them myself - I'd like to see unbiased studies conducted exclusively in low-risk populations.

Fish oil salesmen

Well, they’re not quite the modern-day equivalent of snake-oil salesmen, but the parallels are irresistible. In the 19th century, snake oil was promoted as a cure for joint pain and other ills, and the figure of the snake-oil salesman was widely ridiculed. (Ironically, snake oil is still used as a treatment in China today, despite the lack of any evidence for its efficacy.)

Today we have a new figure: the fish oil salesman. This modern figure, though, is no joke: he is a polished, sophisticated figure with the full weight of the FDA behind him. Should we buy his product?

Last week, while watching a major sports event, I was treated to a new commercial for a product called Lovaza, which I learned “helps to lower very high triglycerides in adult patients.” It’s a beautiful commercial, with an actor in a lab coat (am I supposed to think he’s a scientist?), carrying a clipboard and walking through a lab surrounded by blue aquariums. (Apparently the lab is under water.) You can see the ad here.