Posts Tagged ‘Vitamins’
Men who take vitamin C supplements could develop kidney stones. Calcium supplements may increase the risk of heart disease and even death. There is no scientifically proven evidence that multivitamins improve people’s health. These are just a few headlines that lately appeared in the press. Behind those stories are a series of clinical studies that question a widespread habit among Americans, namely to add one or more daily supplements to their diet to ensure their nutritional needs are covered.
Nearly half of American adults use supplements regularly, generating over $30 billion a year in sales, according to the National Institute of Health (NIH). A new study tried to find out why so many people put their trust in supplements despite of much uncertainty that they have any significant health effects.
“People have very strong beliefs about these products and I don’t know where they are getting their information,” said Dr. Regan Bailey, a nutritional epidemiologist at NIH and lead author of the study report, in an interview with HealthDay. “The majority of scientific data available does not support the role of dietary supplements for improving health or preventing of disease.”
What’s even more puzzling is that many supplement users don’t think of supplements as related to nutrition but rather to overall health. It’s almost like a lifestyle issue, according to the study. Typical users are older, eat well, are physically active, manage their weight, don’t smoke, and usually have a higher educational and social status than non-users. They consider themselves to be in very good or excellent health, and they also have health insurance.
Multi-vitamin-mineral products are among the most popular choices, followed by calcium and fish oil supplements. Many older women use calcium supplements for bone health. Some believe that vitamins are good for heart health or to lower cholesterol levels. Others think certain vitamins help preserve their eyesight.
The popularity of supplements has not been generated by the medical community. “Less than a quarter of supplements used by adults were recommended by a physician or health care provider,” said Dr. Bailey.
There may also be safety concerns. The Food and Drug Administration (FDA) regulates dietary supplements under a different set of regulations than conventional foods and prescription drugs. Under current laws, the responsibility for the safety of supplements lies with the manufacturers. The FDA can only take action against unsafe products after they have been put on the market. Generally, manufacturers of supplements do not need to have their products approved by the agency.
Because of dietary deficiencies many Americans suffer from due to poor eating habits, I still would recommend taking a daily multi-vitamin-mineral supplement from reputable sources. However, it is crucial that users are aware of potential risks, i.e. overdosing. While it is unlikely for a healthy person to overdose on water-soluble vitamins like vitamin C and B-complex, since excessive amounts get eliminated in the urine, the fat-soluble varieties like vitamins A, D, E and K are stored in fat cells and can build up to toxic levels. So can a number of minerals. Some supplements can also interfere with certain medications and cause metabolic problems.
Most importantly, taking supplements should never be considered as a substitute for a healthy diet. Essential nutrients from real foods like fresh fruits, vegetables, lean meats, dairy products and whole-grains cannot easily be provided by a few pills. Those are just – well, supplements.
Timi Gustafson R.D. is a registered dietitian, newspaper columnist, blogger and author of the book “The Healthy Diner – How to Eat Right and Still Have Fun”®, which is available on her blog and at amazon.com. For more articles on nutrition, health and lifestyle, visit her blog, “Food and Health with Timi Gustafson R.D.” (www.timigustafson.com). You can follow Timi on Twitter and on Facebook.
Two independent studies suggest that taking a daily dose of vitamin supplements may not be as health-promoting as previously believed and may even be harmful. Their findings are only the latest in a series of clinical study reports that have questioned the benefits of the popular nutrition-enhancers.
In one study, researchers from the University of Minnesota followed over 38,000 women in an still ongoing survey called the “Iowa Women’s Health Study.” The participants were in their early 60s when the project was started in 1986. The focus of this study was on the women’s use of vitamin supplements for about 18 years on average.
As it turns out, the women who took daily doses of supplements had a higher mortality rate by two and a half percent compared to those who didn’t take any.
“Our study, as well as other similar studies, have provided very little evidence that commonly used dietary supplements would help to prevent diseases,” said Dr. Jaako Mursu, an epidemiologist at the University of Minnesota School of Public Health and lead author of the study report, which was published in the Archives of Internal Medicine (10/11/2011). “We would advise people to reconsider whether they need to use supplements, and put more emphasis on a healthy diet instead,” he added.
Dr. Mursu admitted that the study was not designed to determine if there was a specific cause for the increased mortality risk of the supplement users. The study did however distinguish between the different kinds of supplements the participants took. For example, the women who took iron supplements had a four percent higher probability of dying. Others who used multivitamins, folic acid, vitamin B6, magnesium and zinc also showed higher rates. Only calcium seemed to have a positive effect, decreasing the risk for most women who took it.
A second study, sponsored by the National Cancer Institute (NCI), found that men who took daily a high dose of vitamin E ran a 17 percent greater risk of developing prostate cancer. These results, which were published in the Journal of the American Medical Association (JAMA), came as a surprise, considering that vitamin E was believed to be actually helpful in the prevention of prostate cancer.
The vitamin E study, named the “SELECT” trial, began in 2001. It was designed as a double-blind, placebo-controlled research project, the highest standard in scientific testing. The initial goal was to find out how vitamin E and selenium (a mineral mostly found in soil) can reduce the risk of prostate cancer.
“I was surprised by the results of this trial,” said Dr. Eric Klein, an urologist at the Cleveland Clinic and the national coordinator of the study. “There really is not any compelling evidence that taking these dietary supplements above and beyond a normal dietary intake is helpful in any way, and this is evidence that it could be harmful.”
The increase in health risks could be derived from the high concentration of nutritional compounds that many supplements contain. Most of these micronutrients are present in much smaller amounts in regular foods, so they can become toxic when they are consumed over long periods of time and accumulate in the body, according to Dr. Mursu.
While vitamins and minerals are necessary for healthy nutrition, excess intake can create serious problems. It is also important that consumers understand the differences between the supplements they are taking.
For example, overdosing on water-soluble vitamins like vitamin C and B-complex is possible but unlikely. Excessive amounts pass through the system and get eliminated in the urine.
Fat-soluble vitamins like vitamins A, D, E and K, on the other hand, are stored in fat cells and can eventually build up to toxic levels. Minerals like calcium, chloride, chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium and zinc are absorbed in the body as well and can become harmful to the liver and kidneys. Some supplements can interfere with medications a person is taking and also negatively affect the metabolism of other nutrients.
For these reasons and others, many nutrition experts warn that supplements should not be considered as a substitute for a well-balanced diet, notwithstanding their enormous popularity. Over half of American adults take at least one supplement a day. It is estimated that vitamin and supplement sales in the U.S. amount to $20 billion plus per year.
It’s tempting to rely on supplements. In our fast-food culture, it may even sound reasonable to take extra vitamins to make up for nutritional deficiencies. Ironically, the people who use the most supplements are the ones who already eat the healthiest. So, they may want to reconsider. But for the millions of Americans who adhere to a less than perfect diet, it makes good sense to keep adding a basic multivitamin a day.
Timi Gustafson R.D. is a clinical dietitian and author of the book “The Healthy Diner – How to Eat Right and Still Have Fun”®, which is available on her blog, “Food and Health with Timi Gustafson R.D.” ( http://www.timigustafson.com), and at amazon.com. You can follow Timi on Twitter and on Facebook.
Blueberries have long been popular for their tangy flavor and multiple uses in desserts, yogurts, juices and baked goods. They also rank among the healthiest foods you can possibly eat. In fact, the list of possible health benefits from blueberries grows longer every year, as more medical studies uncover their incredible healing power.
Here is a short list of the more recent findings:
• Blueberries have been shown to shrink cancerous tumors and prevent the development and growth of cancer cells.
• Blueberries can slow down and even reverse age-related memory loss.
• Blueberries can help improve physical coordination and balance at an advanced age.
• Blueberries reduce cholesterol levels.
• Blueberries prevent urinary tract infections.
• Blueberries are low in calories and high in fiber, vitamin C and antioxidants, all of which makes them extremely nutritionally beneficial.
This seems a lot of punch to pack for such a plain little berry, but all these claims are backed up by growing evidence.
For example, a study conducted at Ohio State University in 2009 found that when lab rats with blood vessel tumors were fed blueberry extract, their cancer growth was halted and even reversed. The blueberry-fed rats lived on average twice as long as those that were given none. Blood vessel tumor is among the most common cancer types affecting young children and occurs in about three percent of all infants. Researchers hope that the use of blueberries may some day be part of the treatment of these usually inoperable tumors.
A separate study that was conducted in 2007 at Rutgers University in cooperation with the U.S. Department of Agriculture (USDA) found that a specific compound in blueberries, named pterostilbene, was able to inhibit the spread of cancer cells in the colon of lab rats. And in 2005, researchers at the University of Illinois reported that antioxidants in wild blueberries, called anthocyanins, could prevent certain cancers from forming and proliferating in the prostate and the liver. “Blueberries seem to have “cancer-fighting properties at all stages: Initiation, promotion and proliferation,” said Dr. Mary Ann Lila, the lead author of the study report. “Wild blueberry compounds offer a multi-pronged attack against cancer,” she added.
Blueberries have also been praised for their ability to reduce age-related deterioration of brain functions and memory. A research team from England concluded in 2008 that eating blueberries can actually reverse problems with memory and other cognitive functions. Almost ten years earlier, a USDA-sponsored study found that blueberries improved the physical coordination and balance in aging lab rats.
USDA researchers also reported findings of cholesterol-lowering properties in blueberries, based on animal studies they conducted in 2004. In fact, their experimentation showed that blueberries were more effective in lowering cholesterol levels than many widely prescribed cholesterol medications.
A 2004 study from Rutgers University confirmed that blueberries, like cranberries, can be helpful in preventing and healing urinary tract infections. A compound, called epicatechin, keeps infectious bacteria from attaching themselves to the bladder wall.
Besides these astounding health benefits, blueberries are also nutritional powerhouses. They are low in calories – one cup is 82 calories – high in fiber and loaded with vitamins, especially vitamin C. They rank among the top providers of antioxidants, which are essential to nutritional health. Antioxidants like anthocyanin, vitamin C, vitamin A, vitamin E and mineral selenium, and also copper (a highly effective anti-bacterial agent), zinc and iron (which raises hemoglobin and the concentration of oxygen in the blood), among other important micronutrients, boost the immune system and help to prevent infections.
In addition to its rich nutritional qualities, blueberries have the ability to neutralize so-called “free radicals,” which are unstable molecules that can cause many diseases and accelerate the aging process. This is mainly due to the concentrated presence of anthocyanin, the pigment that gives these berries their dark bluish color.
Some believers in the multiple powers of this “superfruit” think of blueberries also as an effective anti-depressant, although, to my knowledge, no conclusive research has yet been done in this regard. But it wouldn’t surprise me at all. I personally eat a bowl of blueberries every morning as part of my breakfast – and I haven’t had a bad day in a very long time. Maybe it’s the berries.
Timi Gustafson R.D. is a clinical dietitian and author of the book “The Healthy Diner – How to Eat Right and Still Have Fun”®, which is available on her blog, “Food and Health with Timi Gustafson R.D.” ( http://www.timigustafson.com), and at amazon.com. You can follow Timi on Twitter at http://twitter.com/TimiGustafsonRD