In this sequence, “Treatment Overkill,” Kaiser Health News investigates the causes and penalties of medical overtreatment, each for sufferers and the well being care system.
When she was a younger doctor, Dr. Martha Gulati observed that lots of her mentors had been prescribing vitamin E and folic acid to sufferers. Preliminary studies within the early 1990s had linked each dietary supplements to a decrease danger of coronary heart illness.
She urged her father to pop the capsules as effectively: “Dad, you should be on these vitamins, because every cardiologist is taking them or putting their patients on [them],” recalled Gulati, now chief of cardiology for the University of Arizona College of Medicine-Phoenix.
But just some years later, she discovered herself reversing course, after rigorous medical trials discovered neither vitamin E nor folic acid dietary supplements did something to guard the center. Even worse, research linked high-dose vitamin E to the next danger of heart failure, prostate cancer and death from any cause.
“‘You might want to stop taking [these],’” Gulati informed her father.
More than half of Americans take vitamin dietary supplements, together with 68 p.c of these age 65 and older, in response to a 2013 Gallup ballot. Among older adults, 29 p.c take 4 or extra dietary supplements of any variety, in response to a Journal of Nutrition study printed in 2017.
Often, preliminary research gasoline irrational exuberance a few promising dietary complement, main thousands and thousands of individuals to purchase in to the development. Many by no means cease. They proceed though extra rigorous research — which might take a few years to finish — virtually by no means discover that nutritional vitamins stop illness, and in some circumstances trigger hurt.
“The enthusiasm does tend to outpace the evidence,” mentioned Dr. JoAnn Manson, chief of preventive medication at Boston’s Brigham and Women’s Hospital.
There’s no conclusive evidence that dietary dietary supplements stop power illness within the common American, Manson mentioned. And whereas a handful of vitamin and mineral studies have had constructive outcomes, these findings haven’t been sturdy sufficient to recommend supplements to the general U.S. public, she mentioned.
The National Institutes of Health has spent greater than $2.four billion since 1999 learning nutritional vitamins and minerals. Yet for “all of the analysis we’ve performed, we don’t have much to show for it,” mentioned Dr. Barnett Kramer, director of most cancers prevention on the National Cancer Institute.
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In Search Of The Magic Bullet
A giant a part of the issue, Kramer mentioned, may very well be that a lot diet analysis has been primarily based on defective assumptions, together with the notion that individuals want extra nutritional vitamins and minerals than a typical weight loss program gives; that megadoses are at all times protected; and that scientists can boil down the advantages of greens like broccoli right into a each day capsule.
Vitamin-rich meals can remedy illnesses associated to vitamin deficiency. Oranges and limes had been famously proven to prevent scurvy in vitamin-deprived 18th-century sailors. And analysis has lengthy proven that populations that eat a lot of fruits and vegetables are usually healthier than others.
But when researchers tried to ship the important thing substances of a nutritious diet in a capsule, Kramer mentioned, these efforts almost at all times failed.
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It’s attainable that the chemical substances within the vegetables and fruit in your plate work collectively in ways in which scientists don’t totally perceive — and which might’t be replicated in a pill, mentioned Marjorie McCullough, strategic director of dietary epidemiology for the American Cancer Society.
More essential, maybe, is that almost all Americans get loads of the necessities, anyway. Although the Western weight loss program has plenty of issues — an excessive amount of sodium, sugar, saturated fats and energy, typically — it’s not quick on nutritional vitamins, mentioned Alice Lichtenstein, a professor on the Friedman School of Nutrition Science and Policy at Tufts University.
And though there are greater than 90,000 dietary supplements from which to decide on, federal health agencies and advisers nonetheless recommend that Americans meet their dietary wants with meals, particularly fruits and vegetables.
Without even realizing it, somebody who eats a typical lunch or breakfast “is essentially eating a multivitamin,” mentioned journalist Catherine Price, writer of “Vitamania: How Vitamins Revolutionized the Way We Think About Food.”
That could make learning nutritional vitamins much more difficult, Price mentioned. Researchers might have hassle discovering a real management group, with no publicity to supplemental nutritional vitamins. If everybody in a research is consuming fortified meals, nutritional vitamins might seem much less efficient.
The physique naturally regulates the degrees of many vitamins, akin to vitamin C and lots of B nutritional vitamins, Kramer mentioned, by excreting what it doesn’t want in urine. He added: “It’s hard to avoid getting the full range of vitamins.”
Not all consultants agree. Dr. Walter Willett, a professor on the Harvard T.H. Chan School of Public Health, says it’s affordable to take a each day multivitamin “for insurance.” Willett mentioned that medical trials underestimate dietary supplements’ true advantages as a result of they aren’t lengthy sufficient, typically lasting 5 to 10 years. It might take many years to note a decrease fee of most cancers or coronary heart illness in vitamin takers, he mentioned.
Vitamin Users Start Out Healthier
For Charlsa Bentley, 67, maintaining with the newest diet analysis may be irritating. She stopped taking calcium, for instance, after research discovered it doesn’t defend in opposition to bone fractures. Additional research counsel that calcium dietary supplements enhance the risk of kidney stones and heart disease.
“I faithfully chewed those calcium supplements, and then a study said they didn’t do any good at all,” mentioned Bentley, from Austin, Texas. “It’s hard to know what’s effective and what’s not.”
Bentley nonetheless takes 5 dietary supplements a day: a multivitamin to forestall dry eyes, magnesium to forestall cramps whereas exercising, pink yeast rice to forestall diabetes, coenzyme Q10 for total well being and vitamin D primarily based on her physician’s advice.
Like many people who take dietary supplements, Bentley additionally workout routines repeatedly — taking part in tennis three to 4 occasions every week — and watches what she eats.
People who take nutritional vitamins are usually more healthy, wealthier and higher educated than those that don’t, Kramer mentioned. They are most likely much less prone to succumb to coronary heart illness or most cancers, whether or not they take dietary supplements or not. That can skew analysis outcomes, making vitamin capsules appear simpler than they are surely.
Preliminary findings may lead researchers to the flawed conclusions.
For instance, scientists have lengthy noticed that individuals with excessive ranges of an amino acid called homocysteine usually tend to have coronary heart assaults. Because folic acid can decrease homocysteine ranges, researchers as soon as hoped that folic acid dietary supplements would stop coronary heart assaults and strokes.
In a sequence of medical trials, folic acid capsules lowered homocysteine ranges however had no total profit for coronary heart illness, Lichtenstein mentioned.
Studies of fish oil additionally might have led researchers astray.
When research of enormous populations confirmed that individuals who eat a lot of seafood had fewer coronary heart assaults, many assumed that the advantages got here from the omega-Three fatty acids in fish oil, Lichtenstein mentioned.
Rigorous studies have failed to point out that fish oil dietary supplements stop coronary heart assaults. A medical trial of fish oil pills and vitamin D, whose outcomes are anticipated to be launched inside the 12 months, might present clearer questions on whether or not they stop illness.
But it’s attainable the advantages of sardines and salmon don’t have anything to do with fish oil, Lichtenstein mentioned. People who’ve fish for dinner could also be more healthy because of what they don’t eat, akin to meatloaf and cheeseburgers.
“Eating fish might be an excellent factor, however we haven’t been able to point out that taking fish oil [supplements] does something for you,” mentioned Dr. Steven Nissen, chairman of cardiovascular medication on the Cleveland Clinic Foundation.
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Too Much Of A Good Thing?
Taking megadoses of nutritional vitamins and minerals, utilizing quantities that individuals might by no means eat by way of meals alone, may very well be much more problematic.
“There’s something appealing about taking a natural product, even if you’re taking it in a way that is totally unnatural,” Price mentioned.
Early research, for instance, instructed that beta carotene, a substance present in carrots, would possibly assist stop most cancers.
In the tiny quantities supplied by vegetables and fruit, beta carotene and comparable substances seem to guard the physique from a course of known as oxidation, which damages wholesome cells, mentioned Dr. Edgar Miller, a professor of drugs at Johns Hopkins School of Medicine.
Experts had been shocked when two massive, well-designed research within the 1990s discovered that beta carotene capsules truly elevated lung most cancers charges. Likewise, a medical trial printed in 2011 discovered that vitamin E, additionally an antioxidant, elevated the chance of prostate most cancers in males by 17 p.c. Such research reminded researchers that oxidation isn’t all dangerous; it helps kill micro organism and malignant cells, wiping them out earlier than they will develop into tumors, Miller mentioned.
“Vitamins are not inert,” mentioned Dr. Eric Klein, a prostate most cancers knowledgeable on the Cleveland Clinic who led the vitamin E research. “They are biologically active agents. We have to think of them in the same way as drugs. If you take too high a dose of them, they cause side effects.”
Gulati, the doctor in Phoenix, mentioned her early expertise with recommending dietary supplements to her father taught her to be extra cautious. She mentioned she’s ready for the outcomes of enormous research — such because the trial of fish oil and vitamin D — to information her recommendation on nutritional vitamins and dietary supplements.
“We should be responsible physicians,” she mentioned, “and wait for the data.”
KHN’s protection associated to getting older and enhancing care of older adults is supported partly by The John A. Hartford Foundation.
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