Tuesday, October 18, 2011

Throw away your multivitamins and antioxidants?

Matt Hart shared two articles/posts on dietary supplement use that are interesting reads.  Follow Matt at CoachingEndurance.com and on Twitter at @TheMattHart.

The first, is an NPR story from yesterday, October 17, 2011 titled "Americans Urged to Rethink Dietary Supplement Use."




The second is titled, "Throw away your multivitamins and dantioxidants!" It was posted on April 30, 2010 by Chris Kresser and is pasted below. 

Throw away your multivitamins and antioxidants!

If you’ve been reading this blog for a while, you’ll know I’m not a big fan of supplements. I’ve always believed that it’s preferable to get the nutrients we need from whole foods, as they’re found in nature, rather than from isolated, synthetic sources (i.e. supplements).

Unfortunately, modern medicine is obsessed with isolated, synthetic nutrients and has convinced itself that they have the same beneficial properties as nutrients found in whole foods.
A gigantic dietary supplement industry has arisen from this misguided belief. A 2006 National Institute of Health (NIH) conference (PDF) revealed that 20-30% of Americans use a multivitamin daily, forking over $23 billion a year to supplement manufacturers for the privilege. Many more Americans effectively take a multivitamin by eating fortified grain products, like Shredded Wheat cereal and Wonder Bread.

Most supplements don’t work

With these statistics in mind, you might be surprised (or even shocked) to learn that clinical trials have shown that most of these supplements not only don’t work as intended, they actually make things worse. The NIH conference examined the efficacy of 13 vitamins and 15 essential minerals as reported in long-term, randomized clinical trials.
First the positive results:
  • A combo of calcium and vitamin D was shown to increase bone mineral density and reduce fracture risk in postmenopausal women.
  • There was some evidence that selenium reduces risk of certain cancers.
  • Vitamin E may decrease cardiovascular deaths in women and prostate cancer deaths in male smokers.
  • Vitamin D showed some cardiovascular benefit.
Um, not too impressive considering the near universal faith considering how many people are popping these pills on a daily basis.
Now for the negative results:
  • Trials of niacin (B3), folate, riboflavin (B2), and vitamins B6 and B12 showed no positive effect on chronic disease occurrence in the general population
  • There was no evidence to recommend beta-carotene and some evidence that it may cause harm in smokers.
  • High-dose vitamin E supplementation increased the risk of death from all causes.
Then there’s the now infamous JAMA meta-analysis on antioxidants. They looked at 68 trials with over 230,000 participants. Here’s what they found:
Treatment with beta carotene, vitamin A, and vitamin E may increase mortality. The potential roles of vitamin C and selenium on mortality need further study.
Oops!

(Re)-introducing the concept of food synergy

It’s crazy to me that so many health care practitioners – both conventional and alternative – tell their patients to take multivitamins and antioxidants when their is little support for that position in the medical literature.

That’s why I was so happy to come across a study in the American Journal of Clinical Nutrition addressing this issue. It’s called “Food synergy: an operational concept for understanding nutrition” and it’s one of the most encouraging pieces of research I’ve seen in a while. I’m relieved to learn that their are researchers working in the nutrition field that don’t buy into the synthetic nutrient hype, and understand the importance of whole food.

Since it’s such a great article, I’m going to quote from it and riff off of a few passages.
A person or animal eating a diet consisting solely of purified nutrients in their Dietary Reference Intake amounts, without benefit of the coordination inherent in food, may not thrive and probably would not have optimal health. This review argues for the primacy of food over supplements in meeting nutritional requirements of the population.
This is the crux of the authors’ argument, which I’m 100% behind. They congratulate science on the discovery of fundamental nutrients such as vitamin C, and clarifying their role in health and disease. The realization that scurvy is caused by vitamin C deficiency has saved a lot of lives. But, the approach to nutrition that is fundamentally guided by nutrients has a dark side:
The aspect of science that reduces to fundamental principles, however, can lead to oversimplification and ultimately stifle understanding and progress.
Translation: reductionistic thinking can get us in trouble if we’re not careful.
The concept of food synergy is based on the proposition that the interrelations between constituents in foods are significant. This significance is dependent on the balance between constituents within the food, how well the constituents survive digestion, and the extent to which they appear biologically active at the cellular level.
Yes! It makes me so happy to see this in a major, peer-reviewed journal. The authors go on to define several aspects of food synergy:
  • A buffer effect, i.e. the effect of a large intake of a particular nutrient may vary depending on if it is taken in concentrated form or as part of a whole food.
  • Nutrients can affect each other’s absorption, such as copper-inc and magnanese-iron. These interdependent nutrients tend to appear together in foods, but not necessarily in isolated supplements.
  • It matters whether the nutrients have been produced by technologic or biological processes. Trans fat produced in ruminant animals (such as conjugated linoleic acids in dairy products) are beneficial to health, whereas trans fats produced in the processing of industrial seed oils are highly toxic.
Then they provide evidence that whole foods are more effective than supplements in meeting nutrient needs:
  • Tomato consumption has a greater effect on human prostrate tissue than an equivalent amount of lycopene.
  • Whole pomegranates and broccoli had greater antiproliferative and in vitro chemical effects than did some of their individual constituents.
  • Free radicals were reduced by consumption of brassica vegetables, independent of micronutrient mix.
Note: In the supplement world, the idea is that “a nutrient is a nutrient, a molecule is a molecule” regardless of what source it comes from. These folks claim that it doesn’t matter whether a nutrient comes from a whole food complex or a laboratory. Did you know that most vitamin B1 supplements are made from derivatives of coal tar? That ascorbic acid (vitamin C) is made by reacting high-fructose corn syrup with sulfuric acid? That many iron supplements are made from rusty nails? I don’t know about you, but I’d rather eat some meat and vegetables to get those nutrients.
Should we all take a daily multivitamin as “insurance” against a nutrient deficiency? Here’s how the authors respond to that question:
In our view, the better “insurance” would be to eat food with a broad coverage of nutrients and take no supplements at all, unless they are deemed necessary to fix a specific medical problem.
Hallelujah! I’d like to buy these researchers a beer.

Okay, not all supplements are bad

Now that I’ve made my point (or at least I hope I have), I need to add a qualifier or two.
There are a few supplements that I do recommend – in certain situations.

Vitamin D may be necessary for those who live in northern latitudes, especially during the winter months. Low vitamin D is associated with so many diseases that it’s probably a good idea to keep levels up. The first choice would be to do this by eating seafood, but that’s not always practical or desirable for a number of reasons. Cod liver oil is my second choice for maintaining D levels. But note that this is more of a whole food than it is a supplement. In some cases when people are very deficient, i.e. under 25 ng/ml, I may suggest adding a D3 supplement in addition to the cod liver oil.

Fish oil has been shown to provide great benefit for cardiovascular disease and other inflammatory conditions. My preference here is that people reduce their intake of omega-6 fats and simply eat cold-water, oily fish a couple times a week to meet their omega-3 needs. Unfortunately, people have been scared away (unnecessarily, which is a topic for a future post) from eating fish, or perhaps it’s difficult for them to find or afford wild fish on a regular basis. In this situation I may recommend a fish oil. My favorites are whole-food based oils such as Green Pasture’s Fermented Cod Liver Oil and Vital Choice Wild Salmon Oil.

Magnesium is one of the most crucial nutrients in our diet, and many people are deficient. It protects against nearly every modern disease, and can be therapeutic for difficult to treat inflammatory conditions such as fibromyalgia, irritable bowel syndrome, arthritis, etc. Seaweed and various nuts and seeds are high in magnesium, but occasionally supplementation may be useful. I suggest using a highly-absorbable form such as magnesium glycinate.

Vitamin K2 has recently been revealed as an important nutrient in protecting against heart disease. It does this by telling the body to put calcium in the bones and teeth where it belongs, and not in the arteries and soft tissue. K2 is found in the fat of grass-fed animals and certain fermented foods like natto and hard cheese. I recognize that not everyone eats these foods for various reasons, so if someone has heart disease or is at risk for it I may recommend either Fermented Cod Liver / Butter Oil from Green Pastures, and/or an MK-4 supplement. For more on vitamin K, see my post Vitamin K2: The Missing Nutrient.

But even in these cases, I only suggest that people take these if they need them, and if they can’t (or won’t) get the nutrients from foods.

 

1 comment:

  1. Thanks for putting the time in on this one. You got my attention! I do take a multivitamin everyday, but also eat healthy (most days).

    ReplyDelete