A study was just released out of the UK that measured the response of various markers of cyanocobalamin supplements in adults 65 years and older (1).

The study was a double-blinded, placebo-controlled study on 100 people with evidence of poor vitamin B-12 status. It used daily supplements in the amount of 10, 100, and 500 µg/day of cyanocobalamin for 8 weeks. The main marker of interest was urinary methylmalonic acid (uMMA) levels.

They found that 500 µg/day made a significant improvement in uMMA levels and most of that improvement was made in the first 2 weeks.

This result is in contrast to what the authors of the recent homocysteine meta-analysis said about cyanocobalamin taking 4 to 9 weeks to be converted to methylcobalamin. But, it should be noted, that the adenosylcobalamin co-enzyme form of vitamin B12 is required to reduce uMMA levels, not methylcobalamin. Methylcobalamin is required to reduce homocysteine levels and the 100 and 500 µg/day regimen also lowered homocysteine levels over the course of 8 weeks, though they did not say how long it took for the change to take place.

In a number of measurements, the ex-smokers improved more than the never-smokers. This is surprising because it would seem reasonable that, if there were any difference, ex-smokers would have more of a problem metabolizing cyanocobalamin than non-smokers.

Only 75-85% of the participants fully corrected their metabolic deficiency with 500 µg per day. It’s possible these people’s metabolic deficiency stemmed from a problem not related to vitamin B12.

The takeaway messages:

1. Even in people 65 years and older, cyanocobalamin worked in only two weeks time.

2. It might be a good idea to increase B12 recommendations for people 65 and older to 500 µg per day, rather than the 25 to 100 µg per day that I recommend for all adults.

3. Cyanocobalamin was effective even for ex-smokers. There were not enough current smokers in the study to determine the effectiveness for them.

Reference

1. Hill MH, Flatley JE, Barker ME, Garner CM, Manning NJ, Olpin SE, Moat SJ, Russell J, Powers HJ. A Vitamin B-12 Supplement of 500 μg/d for Eight Weeks Does Not Normalize Urinary Methylmalonic Acid or Other Biomarkers of Vitamin B-12 Status in Elderly People with Moderately Poor Vitamin B-12 Status. J Nutr. 2013 Feb;143(2):142-7. doi: 10.3945/jn.112.169193. Epub 2012 Dec 12. | link

[Erratum from yesterday’s post on Vitamin A: The amount of vitamin A in the chart at VeganHealh.org in mangoes was listed as 181 for 1 cup. I copied the amount from the wrong column – it is actually 89 for 1 cup.]

Commenting on a report by the International Osteoporosis Foundation (IOF), Ginny Messina, MPH, RD has an interesting post on retaining muscle and bone mass in older age, Staying Strong on a Vegan Diet: Protein and Muscles.

Ginny also has added the Food Guide 4 Vegans from our book, Vegan For Life, to her website, which provides a convenient way, especially for new vegans, to see how to eat in order to meet all the nutrition requirements.

Vitamin A is found only in animal products, but the body can create it out of carotenoids, like beta-carotene.

When I first got involved in vegan nutrition, vitamin A was considered a non-issue because we assumed most vegans would easily get enough beta-carotene with any sort of varied diet to cover our needs.

But in 2001, the Food and Nutrition Board (FNB) doubled the amount of beta-carotene they said was enough to meet vitamin A needs. According to the FNB, this change was based on “data demonstrating that the vitamin A activity of dietary β-carotene is one-sixth, rather than one-third, the vitamin activity of purified β-carotene in oil (1).”

They go on to say:

“This change in bioconversion means that a larger amount of provitamin A carotenoids, and therefore darkly colored, carotene-rich fruits and vegetables, is needed to meet the vitamin A requirement. It also means that in the past, vitamin A intake has been overestimated.”

This change mostly flew under the radar, but it made a significant difference in how easy it would be to get enough beta-carotene.

I recently became more concerned about vitamin A, quite literally, by accident. Early last Fall, I twice got up in the middle of the night and walked straight into my bedroom door that was halfway open, face-first!

Over the previous year or so, I had slacked off on vitamin A, relying only on a bit of shredded carrots on salad and mangoes on most days. In mid-November, I decided I needed to make a real effort to add more yellow vegetables to my diet and started eating sweet potatoes every day. A few weeks later, I realized that I had been having no trouble seeing the bedroom door at night. I wondered if there was a connection to what seemed to be my improved night vision.

In checking out whether it was likely that my apparent change in night vision was possibly caused by eating more beta-carotene, I was reminded that vitamin A metabolism is involved with immune function. When vegans get sick easily, I tell them to think about more zinc or protein, neglecting any concern about vitamin A. (Interestingly, vitamin A metabolism appears to rely on zinc.)

Vitamin A deficiency symptoms begin with night blindness, and if it progresses, can lead to the more severe eye problems of corneal ulcers, scarring, and blindness (2). Vitamin A is also important for growth and development in infants and children, and for red blood cell formation (2).

Because I suspect that many vegans might not be giving vitamin A any thought, I decided to make this post and add some information to Vitamin A at VeganHealth.org. That link has a chart showing which foods are high in carotenoids. I would encourage everyone to check the chart to make sure they are getting enough. And you might save yourself a few bumps on the noggin!

References

1. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: The National Academies Press, 2001. | link

2. Vitamin A. Linus Pauling Institute. Accessed 1/25/2013. | link

Isn’t it great to be living in a time where there have been so many studies on homocysteine levels of vegans that someone can do a meta-analysis? We have officially arrived.

This past week, such a study was released by a team from the University of West London, School of Psychology, Social Work and Human Sciences. I have tracked most of this research, so their findings that vegans have higher homocysteine levels due to low B12 status came as no surprise. They included results from six cohort and eleven cross-sectional studies.

Ideally, you want your homocysteine levels below 10 µmol/l, with above 15 µmol/l being strongly associated with increased chronic disease (cardiovascular disease and early death).

The average homocysteine levels in the studies were (µmol/l):

omnivore – 11.0
lacto-ovo vegetarian – 13.9
vegan – 16.4

Average vitamin B12 levels were (pmol/l):

omnivore – 303
lacto-ovo vegetarian – 209
vegan – 172

This was no surprise as most of the vegans in these studies were not taking vitamin B12 supplements or eating fortified foods, B12 being an important part of keeping homocysteine levels in check (see Mild B12 Deficiency – Cardiovascular Disease & Homocysteine for more information).

However, there were a couple things that the authors concluded that did raise my eyebrows.

They expressed skepticism that fortified foods can prevent elevated homocysteine levels in vegans, due to the fact that fortified foods contain cyanocobalamin, rather than methylcobalamin. The authors said that it takes four to nine weeks for cyanocobalamin to be converted into methylcobalamin, the form needed to lower homocysteine.

Readers of my blog probably know that only in rare circumstances do I think it’s necessary to supplement with methylcobalamin rather than cyanocobalamin. I will address these author’s concerns in an upcoming post.

In discussing the one study that showed vegans to have healthy homocysteine levels, the authors say:

“The study by Haddad et al. concluded that, statistically, vegans had similar plasma tHcy to omnivores (i.e. 8·0 against 7·9 mmol/l, respectively) and serum vitamin B12 levels (i.e. 313 against 312 pmol/l, respectively). In this case, it was noted that 36 % of the participating vegans were users of vitamin B12 supplements, although the type, dosage and frequency of usage were not reported.”

However, Haddad et al. did give the average amount of vitamin B12 intake for the vegans and it was 6.0 µg for the vegan women and 5.0 µg for the vegan men (2). And the possibility that any of it wasn’t cyanocobalamin is low.

Stay tuned for more on the cyano wars…

References

1. Obersby D, Chappell DC, Dunnett A, Tsiami AA. Plasma total homocysteine status of vegetarians compared with omnivores: a systematic review and meta-analysis. Br J Nutr. 2013 Jan 8:1-10. [Epub ahead of print] | link

2. Haddad EH, Berk LS, Kettering JD, Hubbard RW, Peters WR. Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. Am J Clin Nutr. 1999;70(suppl):586S-93S. | link

Thank you for reading JackNorrisRD.com! As you might have noticed, I have been upping my nutrition output lately. I’m hoping that most readers have found it interesting.

I’ve been trying to focus on answering the questions that so many vegans have. Almost any vegan is by default an advocate because you are going to get so many questions. My aim is to answer them as accurately as possible and without spin. I never set off to research a topic with the intention of finding studies to support my position, but rather to find out what evidence there is for various points of view. My opinion on many of the questions I answer changes as I research the subject for a post. And after posting, my readers often point out angles that I hadn’t considered — thank you!

There are not many places you can go for this sort of frankness. And the more you support this site, the more I can address additional topics. I currently have a nutrition inbox of almost 200 messages – many are questions or new information from readers that I am hoping to get to in the near future.

Here is what you can do:

1. Share it! Tweet it! Pass the posts onto friends who might be interested in vegan nutrition!

I currently have just under 1,500 subscribers, making this the least-subscribed-to blog in the vegan movement! (Actually, I’m not sure about that, but I wouldn’t be surprised.) I would love to see that rise to 2,000 by the end of February – it would make a huge difference.

2. I greatly appreciate direct donations – you can enter any amount:

If button doesn’t work, please click through to website. Thank you!

3. Buying stuff through the links below is this site’s largest source of support.

If you buy anything from Pangea through this link, you not only support me, but also the good people at Pangea who painstakingly research their products to minimize any impact on animals, the earth, and workers.

You can buy gift cards, compact discs, digital music downloads and most anything else through any of the links to Amazon.com below.

I am not someone who tends to be very product-oriented, but there is one I recently discovered that is simply amazing: Hurraw lip balm. Not only does it make your lips feel fantastic, but it lasts forever. I bought a stick last August and am still using it. I have the green tea flavor which I love, but even better is their coffee flavored stick that, in a rare act of shameless altruism, I gave to my beloved wife.

Hurraw! Lip Balm

Vegan for Life: Everything You Need to Know to Be Healthy and Fit on a Plant-Based Diet from Amazon.com

 

Amazon.com Gift Cards – E-mail Delivery

Thank you very much for supporting this site – it makes a big difference!

Lysine is the limiting amino acid in most vegan diets. It is typically not hard for vegans to get enough lysine, but you have to eat three to four servings of high lysine foods each day. High lysine foods are legumes, seitan, quinoa, and pistachios.

The USDA lists pumpkin seeds in the same entry as other squash seeds and the entry for such seeds has listed high amounts of lysine. But I have not included them among the high lysine foods because it was not clear which seeds they are specifically talking about.

A reader decided to write the USDA Nutrient Data Laboratory and ask them about their entries. It turns out that three of the “pumpkin and squash seed” entries are for pumpkin seeds only.

According to the pumpkin seeds-only entry for roasted kernels (USDA nutrient #12016), a one-quarter cup of pumpkin seeds has 360 mg of lysine, which qualifies it as a high lysine food.

I have updated the Protein article at VeganHealth.org to reflect the addition of pumpkin seeds to the list of high lysine foods.

In reference to my post on soaking legumes and reducing oligosaccharides, a reader asked me if there has been any research on the efficacy of Solgar’s Vegetarian Digestive Aid.

In my research on soaking beans and reducing oligosaccharides, I didn’t come across any study using a battery of digestive enzymes such as what is contained in Solgar’s preparation. Solgar’s Vegetarian Digestive Aid does not contain the digestive enzyme considered most effective at reducing flatulence from beans, alpha-galactosidase. Bean-zyme, a vegan version of Beano, contains alpha-galactosidase, as does Deva’s Vegan Digestive Support.

In their article, Effective Management of Flatulence, American Family Physician provides a chart comparing the effectiveness of various methods. They rank a couple of probiotic preparations as being highly effective, and slightly more effective than a large dose of alpha-galactosidase (they cite reference 1 below). The large dose, 1200 GaIU, would be the equivalent of 8 Bean-zyme tablets. A smaller dose of 300 GaIU, the equivalent of 2 Bean-zyme tablets, was also somewhat effective.

I found one other study (2) measuring the effectiveness of alpha-galactosidase, in which it did not seem quite as effective, but they were using drops rather than tablets and I’d be concerned about the drops themselves being digested before they could take effect.

As an aside, in preparing legumes, they can be treated with enzymes that will remove all of the oligosaccharides, but I’m not aware of a practical way for people to do that at home.

You can support JackNorrisRd.com by purchasing anything through these links

Vegan for Life: Everything You Need to Know to Be Healthy and Fit on a Plant-Based Diet from Amazon.com

Amazon.com Gift Cards – E-mail Delivery

Pangea: The On-Line Vegan Store

References

1. Di Stefano M, Miceli E, Gotti S, Missanelli A, Mazzocchi S, Corazza GR. The effect of oral alpha-galactosidase on intestinal gas production and gas-related symptoms. Dig Dis Sci. 2007 Jan;52(1):78-83. | link

2. Ganiats TG, Norcross WA, Halverson AL, Burford PA, Palinkas LA. Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance. J Fam Pract. 1994 Nov;39(5):441-5. | link

I think there might have to be a Part 3 (and, who knows, maybe a Part 4, 5, and 6) to deal with all the questions regarding soaking foods. I might not do them in consecutive posts.

The flatulence caused by eating beans is normally attributed to the oligosaccharide content of the beans. Oligosaccharides are chains of sugar molecules, usually two to ten in length, and comprising of at least some sugars other than glucose. (Long chains of glucose-only molecules are considered starches and are typically easy to digest.)

The flatulence is caused by the fact that humans do not have digestive enzymes to break down the oligosaccharides and, instead, they are broken down by bacteria in the lower intestines which produce gas in the process.

Soaking reduces the amount of oligosaccharides in beans. But how does it compare to simply cooking? Unfortunately, in the time I had to search, I did not find a study that compared soaking and cooking to only cooking. But I did find a study that compared the oligosaccharide reduction in pinto beans among different preparation methods (1):

– Soaking for 18 hours: 10% reduction
– Soaking for 18 hours, then boiling for 90 minutes: 50% reduction
– Soaking for 18 hours, then autoclaving for 30 minutes: 57% reduction

Autoclaving is approximately the same as pressure-cooking.

It’s not clear from this study that you first need to soak the pinto beans to produce the 50% reduction in oligosaccharides.

In her article on reducing flatulence in veg diets, Dina Aronson, MS, RD suggests, “If you make beans from scratch, soak them overnight first, rinse them well, and rinse them several times during the cooking process, as this will help get rid of more of the gas-causing oligosaccharides. Also, the longer you cook beans (with rinsing), the better.”

It should also be noted that in their comments, the authors of the study above say, “Soaking of Great Northern, kidney, and pinto beans and their subsequent boiling for 90 min decreased the amount of [the oligosaccharides] raffinose and stachyose by 70-80%. In marked contrast, sucrose, raffinose, stachyose, and verbascose contents increased [emphasis added] following the cooking of red, Bengal, black, and green grams (1).”

Sigh. Luckily, I don’t think too many of us eat “grams,” so we probably don’t need to worry about that. I looked up the study and they did not soak the beans before cooking, so perhaps that was the problem (2).

You can support JackNorrisRd.com by purchasing anything through these links

Vegan for Life: Everything You Need to Know to Be Healthy and Fit on a Plant-Based Diet from Amazon.com

Amazon.com Gift Cards – E-mail Delivery

Pangea: The On-Line Vegan Store

References

1. Song D, Chang SK. Enzymatic degradation of oligosaccharides in pinto bean flour. J Agric Food Chem. 2006 Feb 22;54(4):1296-301. | link

2. Rao PU, Belavady B. Oligosaccharides in pulses: varietal differences and effects of cooking and germination. J. Agric. Food Chem. 1978 26:316-319 | link

This is Part 1 of a two-part series. In Part 2, I will discuss research on whether soaking beans reduces their propensity to produce intestinal gas.

Question:

I’m a mom of three vegan kids (13, 8, and 5) so I’m always tweaking our diet to ensure we are eating well. The kids eat a variety of nuts (usually on a daily basis) and I was wondering if we should be soaking them first to aid in digestion and absorption of nutrients. I know raw foodists suggest soaking, but I’ve never seen anything about this from a reputable source.

Answer:

It’s not easy to find much information on soaking nuts, but here is what I came up with…

Phytic acid is a molecule found in many seeds of plants. Legumes and grains tend to have large amounts of phytic acid, which often attach to calcium, magnesium, iron, or zinc and prevents their absorption.

I see many articles claiming that nuts are also high in phytic acid, but I could not confirm this to my satisfaction and so it should come as no surprise that I couldn’t find any research on whether soaking nuts could reduce their phytic acid content.

I did find two papers discussing the research on soaking legumes and grains:

The first review said that ten hours of incubating California small white beans at 140°F (60°C) resulted in an almost complete loss of phytic acid, with 75% being hydrolyzed (broken into phosphorus and inositol) and 25% being diffused into the water. Germination reduced phytic acid by over 60% in garbanzo beans and over 40% in soybeans. Boiling reduced phytic acid in soybeans by 40%. Soaking for 12 hours in room temperature water reduced phytic acid by 7.7%, 8.1%, 13.2%, and 19.1%, respectively, for black-eyed beans, red kidney beans, mung beans, and pink beans. Soaking for 18 hours reduced phytic acid by 52.7%, 69.6%, and 51.7% in pinto, Great Northern, and red kidney beans. So, as far as legumes go, soaking for 18 hours appears to be fairly effective at reducing phytic acid levels (1).

Another review (2) showed that soaking maize for 24 hours reduced phytic acid by about 50%, with most of the reduction occurring in the first hour. It said that soaking also removes other anti-nutrient factors such as saponins, trypsin inhibitors, and polyphenols.

Given the above, I would say that if nuts are high in phytic acid, soaking is likely to reduce it. And because vegans’ zinc intakes tend to be marginal, increasing the zinc absorption from nuts would be beneficial. Personally, I prefer to take a supplement with zinc rather than worrying if I’m absorbing enough from the food I eat.

One final note about soaking nuts:

In the comments section of the article, Go nuts for better health, in The Sydney Morning Herald (July 13, 2012), Lisa Yates, Program Manager and Dietitian of the organization Nuts for Life (established by the Australian nut industry), points out that the many studies showing nuts to reduce the risk of heart disease and type-2 diabetes use unsoaked nuts, so, there is no reason to think that you must soak them to receive the benefits.

You can support JackNorrisRd.com by purchasing anything through these links

Vegan for Life: Everything You Need to Know to Be Healthy and Fit on a Plant-Based Diet from Amazon.com

Amazon.com Gift Cards – E-mail Delivery

1. Urbano G, López-Jurado M, Aranda P, Vidal-Valverde C, Tenorio E, Porres J. The role of phytic acid in legumes: antinutrient or beneficial function? J Physiol Biochem. 2000 Sep;56(3):283-94. | link

2. Mensah P, Tomkins A. Household-level technologies to improve the availability and preparation of adequate and safe complementary foods. Food Nutr Bull. 2003 Mar;24(1):104-25. | link

A reader sent me a link to this study, DHA inhibits differentiation of prostate fibroblasts into myofibroblasts and tumorigenesis, and asked me if it changed my recommendations that vegans (under age 60) don’t need to supplement with DHA every day.

The study is in vitro and animal research, and indicates that DHA can prevent prostate cancer growth. I told him that it did not change my recommendations and he asked me to make a blog post to explain why.

Creating nutrition recommendations is not something that should be taken lightly. The United States government calls upon the National Academy of Sciences to make nutrition recommendations for the nation. This is done through the Institute of Medicine’s Food and Nutrition Board and the recommendations are referred to as the Dietary Reference Intakes (DRI).

All known essential nutrients are given a DRI. In most cases, these are based on a large body of research and arrived at by a panel of experts in the area. The research they have reviewed for most nutrients has been based on acute symptoms of deficiency and toxicity; they are rarely based on long-term, chronic disease prevention. This may be changing as more research becomes available and acute deficiencies are no longer the problem they once were.

So, with that background, a very good reason would be needed for me to overrule the Institute of Medicine and set my own “DRI.” But because the DRI are not set with vegans in mind, we have to fill in the gaps and most of my recommendations are to get vegans in compliance with the spirit of the DRI.

The study on DHA and prostate cancer, mentioned above, is only a test-tube and animal study. The results may or may not translate for humans, and even if they do, there is no way to know how much humans need to take to achieve such results or if there are negative side effects from taking whatever level of DHA we might determine is appropriate. The Food and Nutrition Board would not make recommendations based on one in vitro or animal study. There are many studies looking at DHA intake and levels in humans and associated diseases and these studies are fraught with confounding variables with no clear answer as to how much DHA humans should be taking on a regular basis to prevent overall chronic disease.

Some vegan RDs do not think it’s necessary to recommend DHA for vegans; I choose to do so, but err on the conservative side. The Food and Nutrition Board has not created a DRI for DHA, but given that studies have shown that vegans have much lower levels of DHA in the blood than your average person, I recommend DHA to make sure that we are not at a disadvantage compared to non-vegans. If you want to see the reasoning behind my DHA recommendations, you can read it in Omega-3 Fatty Acid Recommendations for Vegetarian.

For more information on the types of studies that provide more evidence for nutrition recommendations than others, please see my article Basics of Nutrition Research.

In conclusion, I try not to supersede the Food and Nutrition Board in formulating nutrition recommendations and I do not change recommendations based on in vitro or animal studies.

You can support JackNorrisRd.com by purchasing anything through these links

Vegan for Life: Everything You Need to Know to Be Healthy and Fit on a Plant-Based Diet from Amazon.com

Amazon.com Gift Cards – E-mail Delivery

Pangea: The On-Line Vegan Store