Which vitamins and supplements actually work?
By Julia Belluz - Thursday, December 6, 2012 - 0 Comments
Jon Feingersh/Blend Images/Getty
There’s a tendency to divide the world of pills in two: evil pharmaceuticals and nice supplements. When we’re looking at the outrageous claims on the labels of supplements—that they’ll help us lose weight, clear-up acne, live long lives—we somehow forgot that the natural-health business is a business like any other, and that in Canada, while there are loose regulations around these products, they are not necessarily safe or effective.
Unlike pharmaceuticals—which admittedly have their own evidence problems—”natural” pills don’t undergo rigorous testing before they reach the market. So some of the claims about them are simply lies or not based in good science. As Dr. Edzard Ernst, one of the world’s foremost experts on the evidence for alternative complementary medicine, told Science-ish: “It is a myth to assume that the supplement industry behaves any differently from any other industry. It is about making money, and all too often people are less than responsible in the pursuit of this aim.”
The good news is that there is strong evidence to either back or refute some common notions about supplements. Science-ish sifted through the research to identify indications for capsules that have compelling science behind them. Here’s the Science-ish guide to supplements:
Antioxidants for preventative health
Don’t mean to be alarmist here but the evidence suggests antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) may actually kill you quicker.
Vitamin C for colds
This is a myth. As Science-ish has explained in the past, this regularly updated Cochrane review on vitamin C and the common cold shows that popping these pills every day does nothing to prevent colds and only maybe shortens their duration.
Vitamin D for a range of indications
From combating chronic pain to staving off cancer, this celebrated supplement seems to be recommended for everything. Unfortunately, the evidence for most vitamin D-related claims is weak. It doesn’t help reduce the risk of a range of cancers. There’s little evidence that these pills can alleviate chronic pain. As well, no link has been found between vitamin D and reductions in blood pressure, improved cardiovascular outcomes, and the prevention of fractures in older women. People whom vitamin D can help: those who have tested positive for a deficiency.
Evening primrose oil for a range of indications
In a word: useless. Read here about uses for menopausal symptoms, here about eczema, and here about premenstrual syndrome.
Glucosamine for osteoarthritis
According to high-quality studies, these supplements appear to help manage pain and improve physical function in people suffering with this joint disorder.
Melatonin for jet lag
Melatonin supplements are the closest thing we have to a cure for jet lag. As a 2009 systematic review pointed out, “Melatonin is remarkably effective in preventing or reducing jet lag, and occasional short-term use appears to be safe.” What’s more, melatonin may also be effective for treating a number of sleeping problems, as well as cluster headaches.
Probiotics for gut health
For some very specific indications—managing diarrhea in hospital settings or antibiotic-induced diarrhea—probiotics seem to be helpful. But despite their popularity for improving gut health, the jury is still out.
St. John’s wort for depression
The use of this stuff to manage depression is actually backed by strong evidence. A synthesis of 29 studies in over 5,000 patients from several countries found that those who took the plant extract in the trials “were superior to placebo, similarly effective as standard antidepressants, and had fewer side effects than standard antidepressants.”
Weight loss supplements
Lies, damned lies. Raspberry ketones, green coffee beans: don’t waste your money! If there was a tablet that could help with weight loss, we would not be in the midst of an obesity epidemic. In fact, Science-ish has yet to come across claims about a weight-loss supplement that are backed by good evidence. As a general rule, when a study about one of these “fat busters” suggests it’s effective, that’s probably because the experiment was poorly designed or it was done in animals or cells but not in people.
Your supplement of choice isn’t listed here?
Check out this user-friendly, science-based website for more information about a range of supplements.
Science-ish is a joint project of Maclean’s, the Medical Post and the McMaster Health Forum. Julia Belluz is the associate editor at the Medical Post. Got a tip? Seen something that’s Science-ish? Message her at julia.belluz@medicalpost.rogers.com or on Twitter @juliaoftoronto
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The myth of Vitamin C and the common cold
By Julia Belluz - Friday, March 2, 2012 at 5:08 PM - 0 Comments
Flood G./Flickr
You’ve probably heard it a zillion times: take some vitamin C if you feel a cold coming on, and chase away illness with a gallon of orange juice. Even though we know there’s no cure for the common cold, many of us still believe in the sweet, orange elixir and don’t even question what the makers of the stuff guarantee: an 8 oz. glass delivers “100% of the vitamin C” needed to “maintain a healthy immune system.”
Science-ish looked at high-quality studies on the subject of vitamin C and sickness, starting with this recent Cochrane systematic review (the highest form of evidence) on the supplement for prevention and treatment of the common cold. The lead author, Dr. Harri Hemilä, of the department of public health at the University of Helsinki, told Science-ish he has spent much of his career exploring this very question—with some interesting results.
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The Falcon and the snowman
By Colby Cosh - Friday, October 8, 2010 at 10:42 AM - 0 Comments
It is exciting to see the octogenarian Roland Huntford fighting back against the three decades of revisionism and carping that followed upon the publication of his 1979 book Scott and Amundsen. The book may be more familiar as The Last Place on Earth, which is the title it was given after a mini-series by that name was produced from it. When Scott and Amundsen was published, in the face of threats from imperial nostalgiacs and family members of Robert Falcon Scott, it was seen as the final nail in the coffin of Scott’s reputation.
It had long been obvious to students of polar-expedition lore that Scott had been, as Huntford was to put it, a “heroic bungler”. The Worst Journey in the World, published in 1922 by Scott expedition officer Apsley Cherry-Garrard, scattered cautious hints about Scott’s quality as a commander—and more or less gave the game away with its title. (It is generally thought to be the best single account written by any member of the Shackleton-Scott-Amundsen South Pole race.) But when Huntford was finished with Scott, even the “heroic” part of his reputation was really no longer tenable.
Huntford’s book was followed by a concerted effort to pry loose that coffin nail he had hammered in so firmly. Scott supporters tried to revive the argument, made in Leonard Huxley’s coyly sanitized 1913 edition of Scott’s diaries, that Scott and his South Pole party had run into unforeseeably horrible weather conditions—conditions confined only to Scott’s route; conditions which, by some terrible magic, failed to impede the nearly contemporaneous, geographically parallel Amundsen journey. Huntford has sometimes been derided in Britain as a vaguely treasonable Norwegian partisan—he speaks and reads the language, which is the sort of intellectual attainment that tends to invite suspicion amongst superpatriots—but if Huntford is a psychic traitor, how fortunate for him that the case against Scott was so easy to make.
Scott made dozens of inexcusable, baffling errors and openly irrational judgments in expedition planning, and much of the time, energy, and expenditure involved was consumed with what can only be called screwing around. The commander messed about with motor sledges and ponies when he should have been seeing to the integrity of his fuel tins and the ski education of his men. Later, when both fared poorly on the trail, he blamed everyone but himself.
Weather may have pushed Scott further and further behind Amundsen, extending the Norwegian’s 11-day head start to 34 days by the time Scott reached the pole. But it can’t really explain why Amundsen’s team, with its efficient “eat the dog teams and dash to the Pole” approach, suffered no casualties while Scott’s sledge-hauling wretches suffered falls, snow blindness, scurvy, and delirium. Cherry-Garrard was aware in the ’20s that Scott’s energy budgeting had been Enron-esque, and came as close to success as it did only through inhuman prodigies of effort. In a time before the discovery of Vitamin C, Amundsen took the possibility of scurvy seriously and used knowledge of Inuit and Viking dietary practices to formulate a completely effective prevention plan. Scott, forced by his financial backers to bring a doctor with Arctic experience along on the expedition, stubbornly ignored evidence-based advice to hunt for and consume as much fresh meat as possible.
When the time came to choose a three-man party to accompany him on the run to the Pole, Scott improvised a new supply arrangement and took four instead. These included the jovial, enormous petty officer Edgar Evans, who felt the effects of poor nutrition most and died first, and the famous Captain Oates, whose Boer War wound left him especially vulnerable to scurvy and fatigue. Oates, as every good Anglo-Saxon child knows, had to commit suicide to give the last three survivors even a miserably slender chance at making it back to camp.
It is hard to see Scott as anything but criminally negligent unless one possesses some prior, arbitrary emotional commitment to his legend. He wrote the story of his own last days, and it is hard to find any reason to admire him that doesn’t depend on blind faith in that account, which was written with reputation foremost in mind. He was a great believer in morale and élan, an inexhaustible lugger of grudges, and a self-promoter unto the last strokes of his pen. It is difficult to imagine that he could have been of much comfort to his disillusioned charges in their final frigid days. Long may his self-appointed vindicators continue to feel Huntford’s coolly apportioned wrath.
