April 26, 2013

Verdict on Supplements Especially Popular with Older Americans

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Yesterday we wondered if we're wasting money buying the four most popular supplements: multivitamins, calcium, fish oil, and vitamin D. The consensus for all four? Most consumers would save money and be better off health-wise to ditch the pills and focus instead on getting the nutrients they need from food.

Those top four on the pill "hit parade" are also popular with older consumers as well, with some variations. For example, a survey conducted by ConsumerLab.com found that while only 31 percent of respondents under 35 use vitamin D, intake of that vitamin increases to over 50 percent for people 45-54, and up to 58 percent for those 65-74. Calcium is also very popular with older consumers. Younger adults are slightly more likely than seniors to have recently used fish oil or multivitamins.

The ConsumerLab.com survey mentioned other supplements especially popular with older adults. Today, we'll consider the research on some of them.

Many claims are made for coenzyme Q10 (CoQ10), a vitamin-like substance reputed to help treat heart disease, certain cancers, hypertension, Parkinson's, migraines, allergies, and more. Nothing can really do all that, but since CoQ10's discovery 50 years ago, research continues to uncover a range of potential benefits.

CoQ10 is essential for energy production in cells, and it's a powerful antioxidant. Meat and fish contain small amounts of CoQ10.

Like many substances in the body, CoQ10 levels decline with age and are lower in people with certain medical conditions, like Parkinson's disease and certain cardiac disorders. That reality doesn't mean CoQ10 "deficiency" causes disease, or that the supplement will treat disease or reverse the effects of aging.

According to the Natural Standard, which evaluates complementary and alternative therapies, there is "unclear scientific evidence" for most uses of CoQ10. Much of the encouraging work has been in the lab, while human studies have tended to yield inconsistent results. For example:

CoQ10 and Parkinson's:  A study in 2002 found that very large doses of CoQ10 appeared to slow the progression of early Parkinson's and improve daily life. As a result of this study, I began taking the recommended 1,200mg of CoQ10 every day, even though the official recommendation suggested waiting for the results of a larger, more definitive study that was underway . . . and even though that high dosage was expensive.

The study broke participants into three groups: 1) those taking 1200mg of CoQ10 a day, 2) those taking 2400mg, and 3) those taking a placebo. Halfway through the test, NIH ended the study because the results were identical for each group.

As some consolation for those taking CoQ10, NIH reported that even the 2400mg dose was safe. The study's authors also said it was still possible that CoQ10 might prove effective if a new formulation were developed that was better able to enter the brain. Such a study using a water-soluble form of CoQ10 is now underway in Canada.

I stopped taking the 1200 mg of CoQ10.

CoQ10 and heart conditions: The National Standard couldn't recommend for or against taking CoQ10 for coronary heart disease. Still, CoQ10 is prescribed for certain heart conditions in Japan and several European countries. 

CoQ10 and hypertension:  The Natural Standard gave CoQ10 a "B" for hypertension, citing "good" evidence for this use, but recommends further study.

B Vitamins
Based on solid research, there was reason to hope a few years ago that folate (also known as folic acid) -- taken alone or with B-6 and B-12 -- might reduce risk of heart disease and stroke. But in the past few years, a series of randomized clinical trials have dashed those hopes. Except for people who have inherited a metabolic glitch, B vitamin supplements do not protect the heart or brain, according to the latest studies.

But two of these B vitamins warrant additional consideration:
  • Vitamin B-12 is found only in animal-based foods, so strict vegetarians may need supplements. In addition, many older people don't make enough of the stomach acid needed to liberate B-12 from the animal products for proper absorption. But a single bowl of fortified breakfast cereal can provide the RDA (Recommended Daily Allowance) of B-12. It's also easy to get that RDA from dairy products, fish, and red meats.
  • A folic acid supplement of at least 400mg a day is recommended for women of child-bearing age. On the other hand, high amounts of folic acid may fuel the growth of rapidly dividing cancer cells. Some recent studies suggest that for men and postmenopausal women, even modest doses of supplementary folic acid when added to the folic acid in fortified food may increase the risk of colon, prostate, and breast cancers. That finding provides a cautionary note about multivitamins which include supplemental folic acid.  

Vitamin C
From orange-flavored chewables to Emergen-C packets, megadoses of vitamin C are staples in many American medicine cabinets, largely a result of Nobel laureate Linus Pauling's claim that vitamin C could prevent and treat colds, and treat cancer.

But there's no good evidence that vitamin C pills can prevent a cold altogether. There is only a weak scientific link between regular use of vitamin C supplements and shorter or less severe colds.

Vitamin C supplements are not necessary or recommended. Despite thousands of studies, all that can be said with certainty is that vitamin C plays many roles in human health, and that it prevents scurvy. All you need is 75-90mg daily, easily obtained from eating fruits and vegetables rich in vitamin C. These foods also supply many other nutrients that help keep you healthy and may reduce the risk of cancer and heart disease.

Once again, maintaining a good, balanced diet beats popping a pill.

Vitamin E
Supplement skeptics (I'm now one) often point to the story of vitamin E, once considered promising for preventing prostate cancer. The National Cancer Institute was so hopeful that it funded a study in 2001 to test the theory.

Instead, findings revealed that men who took vitamin E were 17 percent more likely -- not less -- to develop the disease.

There were similar hopes that vitamin E could reduce the risk of heart disease. But large clinical studies using high-dose supplements found no benefit. Later research showed that vitamin E doses of about 400 IU a day (17 times greater than recommended doses) actually increased mortality.

Vitamin E is a key player in immune function and cell communication. But it's best obtained from food --  nuts, seeds, vegetable oils, whole grains, and leafy greens -- and worse when taken in supplements with high doses.

Resveratrol is a substance found in red grapes and red wines. Studies with rats show its promise to protect against hearing and cognitive decline. Animal data from other studies suggest it could prevent various cancers, heart disease, and diabetes.

But there have been no human studies yet. Too often, initial promising results based on animal studies don't hold up in clinical trials with humans.

A 2011 systematic review paper concluded that evidence isn't strong enough to recommend taking resveratrol supplements.

Many more studies are underway. Until we know more, here's the recommendation: get resveratrol from your diet. Grape juice, grapes, blueberries, peanuts, and wine are good sources.

See the pattern here?

Vitamin K 
We need this vitamin so bones can synthesize proteins. Many studies have shown that people who consume the most vitamin K from food have higher bone mineral density and reduced risk of osteoporosis.

Research on supplemental vitamin K is less consistent. Still, a 2009 review found that high doses of vitamin K (at least 200 micrograms) reduce fracture risk in older women.

While it's too early to recommend these supplements, it's a good idea to get more vitamin K from food. Good sources include broccoli, spinach, kale, and other leafy green vegetables.

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  • The Wellness Reports: Dietary Supplements, University of California, Berkeley, School of Public Health
  • Book of Alternative Medicine, Mayo Clinic
  • The Truth About Vitamins and Minerals, A Harvard Medical School Special Report.

1 comment:

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