Archive for the ‘Testing for Nutrient Deficiencies’ Category

Paleo Diets

Thursday, October 11th, 2012

In July, Scientific American ran an article, Human Ancestors Were Nearly All Vegetarians, by Rob Dunn of the Department of Biology at North Carolina State University.

I found it to be a well-balanced article on the subject of how our pre-historic ancestors ate. Here are some particularly interesting excerpts:

“…And so if you are serious about eating a really old school paleo diet, if you mean to eat what our bodies evolved to eat in the “old” days, you really need to be eating more insects.

“But, we know our human digestive systems DID evolve to deal with agriculture and the processing (fermenting and cooking) of food.…some human populations evolved extra copies of amylase genes, arguably so as to better be able to deal with starchy foods…several human populations independently evolved gene variants that coded for the persistence of lactase (which breaks down lactose) so as to be able to deal with milk, not just as babies but also as adults.

“So, what should we eat? The past does not reveal a simple answer, ever. …The recent adaptations of our bodies differ from one person to the next, whether because of unique versions of genes or unique microbes, but our bodies are all fully-equipped to deal with meat (which is relatively easy) and natural sugars (also easy, if not always beneficial), and harder to digest plant material, what often gets called fiber.”

Even though I appreciate this article, and think it is useful for people to send to their paleo-eating friends, I don’t agree with the assumption that if we knew exactly what our ancestors ate (and it was consistent throughout time) it could override today’s nutrition science. Not everything our ancestors ate was necessarily optimal and we can only know what was and what wasn’t by examining different eating patterns using modern methods.

That said, I would be elated if paleo-eaters gave up their chicken legs and spare ribs for insects in an attempt to eat more naturally. More power to them!

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What Should I Be Tested For?

Tuesday, November 30th, 2010

I am regularly asked by vegans what they should be tested for. Here is a run down:

Vitamin B12

As I say in Should I Get My B12 Status Tested?

Vegans do not need to get their homocysteine or B12 levels checked merely because they are vegan. Rather, being vegan means that you should get a regular, reliable source of vitamin B12 from fortified foods and/or supplements. (Though if you’ve gone a month or so without a reliable source of B12, you should replenish your stores as described in Step 1 of the Recommendations.)

About 2% of people do not absorb B12 well. While this has nothing to do with being vegan, it is nice to know if you are such a person. You will not be able to tell unless you first have a reliable source of B12 for at least a few weeks before your B12 level is checked. Additionally, there are specific tests that directly measure B12 absorption.

If you get your B12 level checked, please note that eating seaweeds can falsely inflate B12 levels. Methods for determining B12 levels do not distinguish between B12 and some inactive B12 analogues. Many seaweeds contain a variety of inactive B12 analogues. Someone who is eating large amounts of seaweed may have serum B12 levels well above normal, but much of it could be inactive B12 analogues.

Vitamin D

This is probably the one nutrient that vegans really can benefit from getting tested even if they do not have any symptoms of poor health.

Calcium

The body keeps blood calcium levels relatively constant regardless of your diet, so getting calcium levels tested doesn’t tell you much of anything (other than that you are not seriously ill). Getting your bone mineral density tested is the best way to find out what shape your bones are in. I don’t necessarily recommend this, unless you have reason to believe you might have osteoporosis. I’ve said it many times before, but I’ll say it again – most vegans should drink calcium-fortified non-dairy milks (or other foods) or take a calcium supplement.

Omega-3s

If you are taking a DHA supplement, then you are probably fine. If you are not and want to see what your DHA levels are, here are some testing places.

There is a more common test that could shed some light on your EPA status – blood clotting time. Most doctors test for this routinely. If your blood is clotting too fast, you might be lacking EPA. But, I rarely hear from a vegan whose blood is clotting too fast. If blood clotting time is normal, it doesn’t necessarily mean you have enough DHA.

Iron

If a doctor is going to draw blood, getting an iron panel to see if you have enough (or too much) iron is a good idea, especially for menstruating women.

Iodine

There is no direct test for iodine. Like B12, it’s best to just make sure you’re getting enough (but not too much). Iodine deficiency (and excess) can lead to thyroid problems, so getting your thyroid tested would be an indirect indicator. Click here for more on iodine.

And that covers it for any routine nutrients to test for regarding the vegan diet.