Author Archive

Reader Comments Requested

Saturday, March 24th, 2012

I have some questions to ask the readers of JackNorrisRD.com. I’m particularly interested from hearing from you if you support this site in some way (like buying through the links, donating, or sharing on social media sites).

I see a lot of media stories about nutrition, and sometimes stories not related to nutrition, that are fairly interesting but not necessarily related to vegetarianism, and for which I do not have time to track down the journal articles and read and analyze. I rarely post about them but I’m wondering if that’s a mistake. I have no intention of just posting every nutrition story that comes out – I get a daily list of nutrition stories from the Academy of Nutrition and Dietetics and it’s unbelievably long – just reading the article titles can take a good chunk of time. So, I would not want to overwhelm people but wonder if I should err on the side of passing these stories on rather than not passing them on as I do now. I’m guessing it would be up to two posts per day.

I also get a lot of nutrition questions (in fact, I’m fairly backlogged right now – sorry if you’re waiting on an answer from me!). I sometimes think I should be answering most of these questions publicly with a blog post, rather than just responding to one individual as many people might have the same question. I rarely post publicly though – for one thing I have a tendency not to want to post something unless I’ve done a lot of research on it and there’s no time to do a lit review for every question I get. But maybe readers would like to hear these answers anyway? And sometimes this can be very beneficial as a reader will know about some pertinent research I haven’t seen. (Of course, I always keep the questioner’s identity anonymous.) The number would vary quite a bit – probably up to 2 per day.

So, what do you think? Do you want to see more posts from me, or do you prefer I stick with blogging about research directly relevant to vegetarian diets?

You can answer in the comments sections below. If you would like to remain anonymous, just put in a bogus name and email address (the email will have to be formatted as a typical email address: xxxx@xxx.xxx). Thank you!

Greger on Beets, Nitrates, and Athletic Performance

Friday, March 23rd, 2012

Never one to shy away from talking about the benefits of greens, Dr. Michael Greger has a very interesting blog post, Using Greens to Improve Athletic Performance, that highlights his series of videos on nitrates, nitrites, and nitric oxide which are now available on NutritionFacts.org.

To sum it up, beets and many dark leafy greens contain nitrates which can improve athletic performance, by making oxygen usage more efficient, via the body turning the nitrates into nitrites and then into nitric oxide.

But if nitrites from plant foods can be beneficial, what about the nitrites added to cured meat which are supposed to be so harmful? It turns out that in the presence of vitamin C, nitrites from plants are converted to nitric oxide, while the nitrites in meat tend to be turned into nitrosamines which are, in turn, thought to be the culprit in cured meats.

Tea lowers iron status in women with low levels

Thursday, March 22nd, 2012

A reader pointed out a paper that will be published in the May issue of Food Research International on tea and iron absorption.

The study tested black tea and green tea (1 liter per day with meals), independently for four weeks each, on both vegetarian and omnivore women. It found:

  • Black tea lowered serum ferritin levels in omnivore women, but not vegetarian women.
  • Both teas lowered serum ferritin levels in both omnivore and vegetarian women who began the study with serum ferritin levels below 20 µg/l.
  • Male vegetarian and omnivore ferritin levels were not affected, but none started with serum ferritin levels below 20 µg/l.

This study supports my suggestion from earlier this month:

“If your iron status is always fine when tested, then I don’t see a need to change your tea drinking habits; but if you have a tendency towards iron deficiency, it’s probably a good idea to avoid drinking tea with meals.”

Reference

Schlesier K, Kühn B, Kiehntopf M, Winnefeld K, Roskos M, Bitsch R, Böhm V. Comparative evaluation of green and black tea consumption on the iron status of omnivorous and vegetarian people. Food Research International. 2012 May;46(2):522-27. | link

Obese children and low-carb diets

Monday, March 19th, 2012

I thought this story was interesting enough to share, Obese kids have hard time sticking to low-carb diet:

“For the new study, researchers randomly assigned 100 obese 7- to 12-year-olds to one of three eating plans: one that followed the conventional wisdom of portion control; a low-carb diet; or a reduced glycemic load plan that cut down on certain carbs that typically cause surges in blood sugar…

“Over one year, all three plans worked equally well in controlling kids’ weight gain. The difference, researchers found, was that the low-carb plan was tough to stick with.

“…kids in all three diet groups ended up with healthier cholesterol levels.”

Thanks, Chris!

Vegetarianism and Disordered Eating

Friday, March 16th, 2012

In November of 2011, I blogged about a study out of The College of William & Mary that showed that semi-vegetarians scored higher on restrictive eating behavior tests, but that vegetarians did not show signs of disordered eating.

In February, another paper was published finding semi-vegetarians to have higher scores for disordered eating than other diet groups. The paper out of the University of Pennsylvania and Towson University contained two studies.

The first study was a survey of vegans, lacto-ovo vegetarians, semi-vegetarians, and omnivores. The semi-vegetarians were the only group that had especially high disordered scores.

The second study compared only semi-vegetarians to omnivores. Again, they found the semi-vegetarians to have higher disordered eating scores, but the researchers believed some of these findings to be due to the questions not being appropriate for semi-vegetarians; in other words, people who choose to avoid meat are naturally going to score high on questions about avoiding groups of food.

In the discussion, the researchers stated that the vegans had the most healthy scores, healthier even than omnivores, and even wondered if becoming vegan “could actually serve as a protective factor against developing disordered eating.”

As the researchers noted, a flaw in this study could be that, “only those vegetarians or vegans who have healthy attitudes towards food opted to participate.” And, as always with cross-sectional studies, you cannot know for sure if the diet leads to a particular characteristic, or if that characteristic leads to a particular diet.

Reference

Alix Timko C, Hormes JM, Chubski J. Will the real vegetarian please stand up? An investigation of dietary restraint and eating disorder symptoms in vegetarians versus non-vegetarians. Appetite. 2012 Feb 14. | link

LimeTreeLife audio interview with Jack Norris, RD

Friday, March 16th, 2012

Maria of LimeTreeLife has posted a 20-minute audio interview of me talking about how it came about that I became a dietitian and a recap of vegan nutrition.

Ginny on Red Meat

Wednesday, March 14th, 2012

A new study has been making the rounds showing that increased red meat intake is associated with an increased risk of early death. Ginny updated her article Bad news for red meat is bad news for chickens to reflect this new study (she addresses it in the final paragraph).

Win a free copy of Vegan For Life!

Wednesday, March 14th, 2012

This coming weekend, March 17-18, Heather Nauta of Healthy Eating Starts Here is putting together an online video event, The Better Health Summit which will include
videos of many well-known vegan cooks and nutritionists.

On Sunday at 3 pm Eastern Daylight Time, The Better Health Summit will feature a short video with me and give away a free copy of Vegan For Life to the winner of an online scavenger hunt.

You will be able to see the video any time after it first appears.

Check it out!

Comparison of current and former animal product limiters

Monday, March 12th, 2012

The results of a survey from Western Washington University on current and former “animal product limiters” has been released in the journal Appetite.

With a cross-sectional survey that is not randomly selected, it is pretty hard to draw any strong conclusions, but I thought there were some interesting findings:

  • Current animal product limiters were more likely to have made changes to their diet gradually than all at once.
  • Current animal product limiters were (much) more likely to be part of a vegetarian group.
  • The biggest reasons former limiters gave for not continuing with their diets were: difficulty preparing food (35.2%), boredom with food options (41.2%), and cravings for meat (54.9%).
  • More details can be seen in the abstract.

    Reference

    Haverstock K, Forgays DK. To Eat or Not to Eat: A Comparison of Current and Former Animal Product Limiters. Appetite. 2012 Mar 1. Epub ahead of print. | link

    Good News: Marcus on Bittman on Brown’s Vegan Chicken

    Friday, March 9th, 2012

    Erik Marcus on Ethan Brown’s Vegan Chicken. Great video by Mark Bittman.