Category Archives: Supplements

Still Taking Fish Oil Supplements? Think Again

Salmon is one the the cold-water fatty fish loaded with omega-3 fatty acids

Salmon is one the the cold-water fatty fish loaded with omega-3 fatty acids

I’ve been sitting on this research report a few years, waiting until I had time to dig into it. That time never came. The full report is free online (thanks, British Medical Journal!). I scanned the full paper to learn that nearly all the studies in this meta-analysis used fish oil supplements, not the cold-water fatty fish the I recommend my patients eat twice a week. If you’re taking fish oil supplements on your doctor’s advice, don’t stop without consulting her.

Here’s the abstract:

Objective: To review systematically the evidence for an effect of long chain and shorter chain omega 3 fatty acids on total mortality, cardiovascular events, and cancer.

Data sources: Electronic databases searched to February 2002; authors contacted and bibliographies of randomised controlled trials (RCTs) checked to locate studies.

Review methods Review of RCTs of omega 3 intake for 3 6 months in adults (with or without risk factors for cardiovascular disease) with data on a relevant outcome. Cohort studies that estimated omega 3 intake and related this to clinical outcome during at least 6 months were also included. Application of inclusion criteria, data extraction, and quality assessments were performed independently in duplicate.

Results: Of 15 159 titles and abstracts assessed, 48 RCTs (36 913 participants) and 41 cohort studies were analysed. The trial results were inconsistent. The pooled estimate showed no strong evidence of reduced risk of total mortality (relative risk 0.87, 95% confidence interval 0.73 to 1.03) or combined cardiovascular events (0.95, 0.82 to 1.12) in participants taking additional omega 3 fats. The few studies at low risk of bias were more consistent, but they showed no effect of omega 3 on total mortality (0.98, 0.70 to 1.36) or cardiovascular events (1.09, 0.87 to 1.37). When data from the subgroup of studies of long chain omega 3 fats were analysed separately, total mortality (0.86, 0.70 to 1.04; 138 events) and cardiovascular events (0.93, 0.79 to 1.11) were not clearly reduced. Neither RCTs nor cohort studies suggested increased risk of cancer with a higher intake of omega 3 (trials: 1.07, 0.88 to 1.30; cohort studies: 1.02, 0.87 to 1.19), but clinically important harm could not be excluded.

Conclusion: Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer.

Steve Parker, M.D.

Reference: Hooper, Lee et al. Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review. BMJ  2006;332:752-760 (1 April), doi:10.1136/bmj.38755.366331.2F (published 24 March 2006).

Magnesium Supplementation May Enhance Effects of Exercise in Elderly Women

…according to this study published at American Journal of Clinical Nutrition.

Average age of study subjects was 71

Average age of study subjects was 71

Weekly mild exercise sessions were supplemented with 300 mg/day of magnesium. Those taking the supplement showed improved physical performance compared with control subjects. Whether effects are long-lasting is unknown; the study lasted only 12 weeks.

Steve Parker, M.D.

Dr. Oz Discovers the Cure for Overweight….Again

Dr. Harriet Hall writes about it:

Dr. Oz has promoted a series of weight loss supplements on his show.  Raspberry ketones were presented as a fat-busting miracle, thengreen coffee bean extract was touted as “magic,” “staggering,” and “unprecedented.”  And now both of those miracles have apparently been superseded by an even greater miracle: Garcinia cambogia extract.

Dr. Oz calls it “The newest, fastest fat buster.” A way to lose weight without “spending every waking moment exercising and dieting.” “Triples your weight loss.”  “The most exciting breakthrough in natural weight loss to date.”  “The Holy Grail.” Oz claims that “Revolutionary new research says it could be the magic ingredient that lets you lose weight without diet or exercise.”

But does it work? Click for details at Science-Based Medicine.

Omega-3 Fatty Acid Supplements Fail to Stall Age-Related Brain Decline

I like fish, but cold whole dead fish leave me cold

Supplementation with omega-3 fatty acids does not help prevent age-related cognitive decline or dementia, according to an article at MedPage Today.

The respected Cochrane organization did a meta-analysis of three pertinent studies done in several countries (Holland, UK, and ?).

The investigators leave open the possibility that longer-term studies—over three years—may show some benefit.

I leave you with a quote from the MedPage Today article:

And while cognitive benefits were not demonstrated in this review, Sydenham and colleagues emphasized that consumption of two servings of fish each week, with one being an oily fish such as salmon or sardines, is widely recommended for overall health benefits.

Steve Parker, M.D.

Reference:
Sydenham E, et al “Omega 3 fatty acid for the prevention of cognitive decline and dementia” Cochrane Database of Systematic Reviews 2012; DOI: 10.1002/14651858.CD005379.pub3.

Calcium Supplementation Linked to Heart Attacks

A new European study suggests that calcium supplements almost double the risk of having a heart attack, at least in Germans.  You can read the full report in the current issue of Heart.

The medical literature on this issue is a confusing mess.  In other words, lots of conflicting results.

Huge numbers of women in the U.S. are taking calcium supplements either to treat or prevent osteoporosis and the associated broken bones (e.g., hips, wrists, spine).

What I’d like to know, and what nobody knows, is what is the effect of calcium supplementation on average longevity and quality of life.  Maybe I’d accept a higher risk of heart attack if calcium supplementation prolonged lifespan by two years.

In the interest of brevity, I’ll just say that the best way to get your calcium is probably through food rather than supplements.

Shereen Jegtvig has an article at About.com listing foods rich in calcium.

Exercise can also help keep your bones strong and break-resistant.

Steve Parker, M.D.

PS: If your doctor has you on a calcium supplement, you’d best get his blessing before you stop it.

Do We Need Supplements Because Our Soils Are Now So Depleted?

In my recent review of The Blood Sugar Solution, I noted the numerous supplements recommended by Dr. Mark Hyman: between 11 and 16 supplements.  And one of those supplements is a multivitamin/multimineral supplement that has 20 or so different components.

One reason we need the supplements, according to Dr. Hyman, is because the soils in which we grow food over the years has been depleted of minerals and other basic plant building blocks.

I know one doctor who told his patients the same thing while selling them over-priced supplements straight from his office.

So is there any truth to the “soil depletion” argument for supplements?

 Not much, if any, according to Monica Reinagel.  She reviewed the topic in 2010 at her Nutrition Diva blog: http://nutritiondiva.quickanddirtytips.com/are-fruits-and-vegetables-getting-less-nutritious.aspx.  I trust Monica.  In the same article, you’ll find links to her opinion on whether organic vegetables are healthier and worth the cost.

I’ve not done a comprehensive review of the soil depletion issue myself.   It’s quite a difficult area to research; try it and you’ll see.  The Soil Science Society of America, founded in 1936, sounds like a great place to find the answer.  No such luck.

The U.S. is a huge country with lots of different soil types and usage histories.   Soils in one field may be depleted in certain components whereas the field across the road may be quite rich.  Soils are not static.  Farmers are always making amendments to the soil, either with fertilizers or other additives, or by rotating crops.

Wouldn’t you think farmers, whether small family units or huge corporate enterprises, would do what’s necessary to keep their soils productive? 

Another way to look at soil depletion would be to look at the nutrient content of the plants and animals that depend on soil for life.  The U.S. Department of Agriculture did that in its 2004 publication, “Nutrient Content of the U.S. Food Suppy, 1909-2000.”  This paper includes 10 vitamins and nine minerals.  For the boring details, see   http://www.cnpp.usda.gov/publications/foodsupply/foodsupply1909-2000.pdf.   Some excerpts:

Levels for most vitamins and minerals were higher in 2000 than in 1909.

Levels for vitamin B12 and potassium were lower in 2000 than in 1909, but over the series, met or exceeded current recommendations for a healthy diet….

The authors attibute lower potassium availability to lower consumption of plant foods, especially fresh potatoes.  I’m increasingly interested in the possibilty that low potassium consumption may contribute to heart disease and premature death.  But that’s a topic for another day.

I’m skeptical about claims of widespread soil depletion in the U.S. as a cause of food supply degradation.  Supplement sellers are sure to disagree.  To be sure you’re getting the nutrients you need, eat a wide variety of foods. 

Steve Parker, M.D.

PS: The American Council on Science and Health has a brief article on whether everybody needs a multivitamin/multimineral supplement. 

New research is questioning the benefits of taking supplemental vitamins and minerals, suggesting that, for the general population, such supplements may actually pose more risks than benefits.

Click for the full article: http://www.acsh.org/factsfears/newsid.3067/news_detail.asp

PPS:  Oregon State University’s Linus Pauling Institute published a long article on the multivitamin/multimineral supplement issue.  It seems fairly balanced to me.  The Institute notes the 2006 National Institutes of Health assessment that we have insufficient evidence to recommend either for  or against such supplementation (Annals of Internal Medicine, 145(5), 2006: 364-371).  Nevertheless, the Linus Pauling Institute recommends supplementation as “insurance.”  You know, just in case.