Author Archive

Calcium in Selected Plant Foods

Monday, November 12th, 2012

I noticed that the new USDA nutrient database seemed to have changed the amounts of calcium in some of the greens they had listed. I have updated Table 5 in Bones, Vitamin D, and Calcium at VeganHealth.org.

The USDA database lists a number of different versions for foods – for each type of greens, for example, there are a half dozen to a dozen entries. In the past, I’ve tried to take the most usual or average them out. This time, in updating Table 5, I used the exact entry and I included a number of entries for some of the foods.

Unfortunately, the amount of calcium in broccoli was lowered from 50 to 31 mg per serving. Other greens seemed to stay about the same.

Dr. Greger: Volume 11

Wednesday, November 7th, 2012

Dr. Michael Greger’s Latest in Clinical Nutrition Volume 11 is now available.

I found Volume 11 to be especially interesting. Some of the highlights:

  • The spice saffron can improve PMS symptoms and even reduced depression on par with Prozac.
  • Some cases of fibromyalgia appear to be caused by the artificial sweetener aspartame.
  • Mushrooms are the best source of the amino acid ergothioneine which may be an important antioxidant for the mitochondria. Mushrooms can also reduce the risk of breast cancer.
  • Dr. Greger has previously talked about bacteria endotoxins from meat causing a state of inflammation in the body. This time, he spends a few videos on a unique molecule found in meat, Neu5Gc, as a cause of inflammation.
  • Potassium can reduce the risk of stroke and rheumatoid arthritis symptoms and 98% of Americans are not meeting the DRI of 4,700 mg per day. The best sources are tomato sauce, orange juice, greens, beans, and dates.
  • Fructose can increase uric acid which can in turn increase gout, diabetes, heart disease, and stroke.

Supporting JackNorrisRD.com and Vegan Outreach

Friday, November 2nd, 2012

Dear Readers,

It has been a very long time since I reminded everyone how you can support this blog.

If you click on any of the links in the sidebar to buy something at Amazon or Pangea, JackNorrisRD.com gets a percentage! This is a meaningful amount of money, too! And I really appreciate that so many people follow through and buy through these links. Thank you!

Vegan Outreach has started our end of year matching fundraiser where anything you donate will be doubled by another supporter. Our leafleters have been on a tear! They have been to 700 schools and handed out booklets to just short of 700,000 students this Fall, and have persuaded multitudes of students to change to a more compassionate diet. They do this in all sorts of weather and remote parts of the U.S. and Canada that are never reached otherwise. Please help support this terribly important work in our efforts to make veganism mainstream!

Click here to donate.

Thank you again!

Seitan – A High Lysine Food

Friday, November 2nd, 2012

Awhile back, a reader sent me a copy of a 2009 paper that analyzed the amino acid amounts in wheat gluten protein (1).

The USDA nutrient database does not give amino acid amounts for wheat gluten and it doesn’t include seitan at all. I have long suspected that seitan would be a good source of the amino acid lysine (which is generally the limiting amino acid in vegan diets), but I had no way to verify this until getting the 2009 paper.

Upon doing some calculations I estimate that White Wave seitan has approximately 656 mg of lysine per serving, making it one of the highest sources of lysine among plant foods. I have added this information to Table 3 of Protein at VeganHealth.org. You can see more details about how I came up with this amount in the footnotes of the table, if interested.

There is one disconcerting thing about the 2009 paper – it has no amounts for tryptophan and no explanation as to why. And if you add up the amounts of the other amino acids in mg/g of protein, it comes to almost exactly 1 g, leaving no room for tryptophan. I have written the authors to find out why this might be.

The paper is rather technical and not being a laboratory scientist, I didn’t even understand most of it. If any readers would like to take a look at it, let me know through the contact form.

In any case, I feel confident now that seitan is a good source of lysine and I have added it to my protein recommendations as an option for getting your daily amount of lysine.

Addendum of November 7, 2012:

I have communicated with one of the paper’s authors, Dr. Ine Rombouts who told me that the protein in wheat is 80% gluten and that gluten is very low in tryptophan – that it only has negligible amounts. The other 20% of wheat protein is made up of albumins and globulins which have more tryptophan. This is why wheat has tryphtophan but wheat gluten does not.

Reference

1. Rombouts I, Lamberts L, Celus I, Lagrain B, Brijs K, Delcour JA. Wheat gluten amino acid composition analysis by high-performance anion-exchange chromatography with integrated pulsed amperometric detection. J Chromatogr A. 2009 Jul 17;1216(29):5557-62. Epub 2009 Jun 3. | link

Cooking B12

Thursday, November 1st, 2012

Have had two questions in the last two days from people asking whether they can get vitamin B12 from cooked fortified foods. To answer them, I updated Vitamin B12: Are You Getting It – Vegan Sources:

Tucker et al. (2000, USA, 13) found that vitamin B12 from fortified breakfast cereals and dairy products was associated with better vitamin B12 status than was B12 intake from red meat, poultry, and fish, leading the researchers to suspect that the B12 from meat might be damaged by cooking. The B12 in animal foods tends not to be cyanocobalamin, the form used in fortified foods and that is more stable during cooking. For example, in an acid medium (pH 4-7), cyanocobalamin can withstand boiling at 120° C (1).

Even so, for people wondering whether they are destroying the B12 in their fortified foods by cooking, we do not have enough evidence to know for certain, so it is safest to make sure you rely on uncooked sources of vitamin B12.

1. Personal communication, March 6-7, 2002 with Dr. Fumio Watanabe, Kochi Women’s University, Department of Health Science, 5-15 Eikokuji-cho Kochi 780-8515 Japan.

13. Tucker KL, Rich S, Rosenberg I, Jacques P, Dallal G, Wilson PW, Selhub J.
Plasma vitamin B-12 concentrations relate to intake source in the Framingham
Offspring study. Am J Clin Nutr. 2000 Feb;71(2):514-22. | link

Arsenic in Kelp Supplements

Friday, October 26th, 2012

Just updated the Iodine page of VeganHealth.org regarding arsenic in kelp supplements:

“Most iodine supplements are simply tablets made from kelp. Being a seaweed, kelp likely contains at least small amounts of arsenic. There are some very rare cases in which people taking kelp supplements have developed symptoms of arsenic toxicity (8). A survey of kelp supplements in the U.S. found that eight out of nine batches contained some level of arsenic (8). Another survey in the UK of imported seaweed found very little arsenic in kelp, and no detectible amounts of inorganic arsenic, which is the harmful type (9).

“It is very unlikely that, taken at recommended amounts of 150 µg every other day, arsenic toxicity is likely to occur from kelp supplements. However, if you are concerned, at least one company makes iodine tablets that appear not to come from kelp: Nature’s Plus Potassium Iodide.”

Some additional notes:

The highest level of arsenic found in U.S. supplements was 65.5 mg/kg (8). My iodine supplement contains 225 µg of iodine in 45 mg of kelp. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has set a tolerable intake of 15 µg/kg of body weight per week (9). For a 140 pound person, that would be 953 µg per week. Supplementing three times per week with these tablets, at the highest toxicity level found, arsenic exposure would be 8.8 µg per week, well below the 925 µg level.

Wakame, kombu, and arame are all types of kelp.

References

8. Amster E, Tiwary A, Schenker MB. Case report: potential arsenic toxicosis secondary to herbal kelp supplement. Environ Health Perspect. 2007 Apr;115(4):606-8. Epub 2007 Jan 18.   |   Link | Follow-up letters to the editor.

9. Rose M, Lewis J, Langford N, Baxter M, Origgi S, Barber M, MacBain H, Thomas K. Arsenic in seaweed–forms, concentration and dietary exposure. Food Chem Toxicol. 2007 Jul;45(7):1263-7.   |   Link

2002 Study of MPV in Vegans

Monday, October 22nd, 2012

A reader asked me about a 2002 study that showed vegans to have a higher mean platelet volume (MPV) than high and moderate meat-eaters and lacto-ovo vegetarians (1). I had not previously reviewed this study and decided to do so here.

The exact measurements were not given for the four diet groups, but the chart indicates that vegans had an average MPV of about 9 fl while the other groups had an MPV of about 8 fl. A normal MPV is between 7.2 and 11.7 fl (2).

MPV is a measure of the size of platelets and a high level can indicate a state of platelet activation or increased propensity for blood-clotting.

In the 2002 study, MPV was inversely correlated with the percentage of docosapentaenoic acid (DPA) and dihomo gamma linolenic acid (DGLA). DPA is an intermediary fatty acid that can be produced from EPA and that can be turned into EPA or DHA. DPA has not been studied like EPA and DHA because it is not as prevalent in fish oil and isolated supplements have not been readily available – it is not known if it has any unique functions.

The higher MPV of the vegans is likely due to a lower intake of omega-3 fatty acids and/or a higher intake of omega-6 fatty acids. The lower omega-3 fatty acid status of vegans who do not ensure a regular source of omega-3s is not news, and the vegans’ MPV levels were well within the normal range (a fact not pointed out in Li’s paper which was supported by Meat and Livestock Australia).

In other words, there is nothing really new or surprising here.

1. Li D, Turner A, Sinclair AJ. Relationship between platelet phospholipid FA and mean platelet volume in healthy men. Lipids. 2002 Sep;37(9):901-6. | link

2. Demirin H, Ozhan H, Ucgun T, Celer A, Bulur S, Cil H, Gunes C, Yildirim HA. Normal range of mean platelet volume in healthy subjects: Insight from a large epidemiologic study. Thromb Res. 2011 Oct;128(4):358-60. Epub 2011 May 28. | link

Roasting Nuts and Rancidity

Friday, October 19th, 2012

I recently got into a discussion with someone on an email list about whether roasting nuts causes them to be rancid and if makes them unhealthy. This is a case where I did not go through the research and do a lit review, but here are my comments:

“I agree that it seems like nuts should go rancid if they are roasted, but they also contain antioxidants and other molecules which might protect them. Even the ALA in flaxseeds is protected when baked, and the Canola Council says that the ALA even in canola oil is not damaged by cooking. There is probably some rancidity in cooking nuts, but I tend to think it’s very little. My sense with the clinical trials on nuts is that they would be roasted since raw nuts are not as easy to digest for many people, and my bet would be that researchers have taken that into account. But I could very well be wrong. In epidemiological studies, which have also shown favorable results for nuts, I think it’s a safe bet that most of them are roasted.”

I’m guessing some of my readers have followed this in the scientific literature and can quickly point out any studies that have indicated whether the nuts were cooked or raw…

The person I was corresponding with pointed out this article by Andrew Weil which I thought was worth passing on:

http://www.drweil.com/drw/u/QAA400930/Are-Roasted-Nuts-Unhealthy.html

Vegan Tube Feeding

Wednesday, October 17th, 2012

Update Feb 8, 2014: There is now a vegan tube feeding product on the market, Liquid Hope by Functional Formularies.

I received the following question:

“My husband is going to require a feeding tube for the next couple months and I cannot find any commercial products that are vegan. Any idea if I could meet his nutritional needs using say a VitaMix and pureeing his vegan food? Any ideas would be most helpful.”

In further correspondence, I found out his tube is abdominal which is good because they are larger than the nasal tubes.

A fellow RD sent me this link which was very helpful (thanks, Debbie!):

http://csn.cancer.org/node/205380

And I told the person who wrote me that I would make a blog post to see if anyone else has experience with vegan tube feeding and to create a page that people can refer to in the future. So, please comment if you have some good info.

Thanks!

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!

P.S. If you are looking for a great gift for kids, please check out this ad below that helps support JackNorrisRD.com. Thanks!

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