Jack Norris & Ginny Messina interview

In Vegan Views No.123, Paul Appleby reviewed the book Vegan for Life by American dietitians Jack Norris and Virginia (Ginny) Messina (Da Capo Press 2011; ISBN 978-0-7382-1493-1, e-book ISBN 978-0-7382-1497-9). Here Paul interviews the authors.

Could you begin by telling us a little about yourselves and your paths to veganism?

Jack Norris: My path to veganism started on a fishing trip I took while in college. It had always bothered me how people treated animals with no regard to their feelings, and witnessing the fish struggle to breathe made me seriously question our treatment of animals.

Eventually I got some information from PETA that persuaded me to give up eggs from battery cage hens. Soon after, I stopped eating mammals and birds, then fish, and finally became vegan. I got involved in animal advocacy and in 1993 co-founded Vegan Outreach.

Vegan Outreach produces booklets exposing the conditions on modern day animal farms and in slaughterhouses. We personally hand them to millions of pedestrians each year, mainly at colleges in the U.S. and Canada.

I became a Registered Dietitian in 2001 after coming across numerous people who said they had been vegan or vegetarian and had not been healthy. I wanted to address this, along with other nutrition issues surrounding a vegan diet. Now I maintain the websites www.VeganHealth.org and www.JackNorrisRD.com

When I'm not doing my various jobs, I like to play ultimate frisbee and lift weights.

Ginny Messina: It’s interesting that Jack and I both ended up as vegan dietitians who bring fairly similar perspectives to our work, since we followed very different paths to get here. Vegetarian or vegan diets weren’t really on my radar when I started out in dietetics. I came to vegetarianism through the kitchen - newly married and experimenting with different cooking styles.

As someone who has always cared deeply about animals, but just wasn’t making the connection with the food on my plate, I was ready for a vegetarian message. I found that message in the 1970s cookbook Laurel’s Kitchen, which was dedicated to a “glossy black calf on his way to the slaughterhouse many years ago”. I don’t know why those words hit me so profoundly and changed the way I was to eat (and live) forever, but reading them started me on a path towards a very different kind of life and career.

It was several years later when I went to work for the Physicians Committee for Responsible Medicine (PCRM) that I had my first exposure to a vegan message and an animal rights ethic. That’s an ethic that really touches on all parts of my life now because it underscores my work and all of my lifestyle choices. When I’m not working on vegan nutrition projects, I’m involved in local animal issues related to spay/neuter programs and the animal shelter.

When I can grab a little bit of leisure time, it’s usually spent reading, practising piano, learning to knit, and working in the garden.

What prompted you to write Vegan for Life?

Ginny Messina: I had been working on and off on a book for several years before Jack approached me about writing Vegan for Life. I had this idea that vegans needed a book that they could read in just a few hours - something that offered just enough information to give vegans confidence that they are making good food choices. My concern has long been that many vegans are not getting reliable nutrition information, and so I wanted to write something that was very accessible and balanced.

Jack Norris: We also felt that there needed to be an updated, comprehensive yet concise guide to eating vegan. Becoming Vegan by Brenda Davis and Vesanto Melina had been that guide, but it had not been updated in many years, during which time much pertinent research had been conducted. For example, about ten studies were published showing vegans who did not supplement their diets with vitamin B12 had elevated homocysteine (greatly elevated in many cases) which can lead to stroke, dementia, and other long term illnesses.

Studies on vegans and calcium needs had been indicating vegans were not getting enough calcium, and I had come across many vegans who had become vitamin D deficient and suffered from severe fatigue. These issues needed to be addressed.

In the introduction to Vegan for Life you list the “top ten myths about vegan diets”. Which do you consider to be the most persistent of these myths and how can we best dispel it?

Jack Norris: In the book we phrase one myth as "vegans need less calcium than omnivores", but my biggest concern is for vegans who think they don't need to pay attention to calcium. If a vegan isn't aware of how they are specifically getting enough calcium, then there is a very good chance they aren't. Only a few leafy greens are high in absorbable calcium - collard greens, turnip greens, mustard greens, and kale. If you are not eating at least three servings of those foods a day (one serving is ½ cup cooked), then you need to be having calcium fortified non-dairy milk (or another calcium-fortified food), calcium-set tofu, or taking a calcium supplement to ensure you are getting enough calcium.

Ginny Messina: It’s hard to choose just one! I think the most important myths are those pertaining to vitamin B12 and calcium. I still encounter vegans on a very regular basis who don’t want to believe that they need vitamin B12 supplements.

These myths about B12 and calcium get repeated over and over again in the vegan community, sometimes even by those who are in positions of considerable authority in that community.

This was a big reason for writing Vegan for Life. We wanted to provide solid evidence to counter those beliefs and help vegans make optimal food choices.

Many vegans place great faith in the China Study, and the book of the same name by Professor T Colin Campbell. However, you do not cite results from the study in Vegan for Life, saying that it “doesn’t provide information … on the health of vegans”. Would you care to explain to readers why the findings of the China Study are largely irrelevant to vegans?

Jack Norris: The China Study is an ecological study, which means that it pools information from different populations, in this case different regions of China, and compares the averages among the groups, rather than from individual subjects.

There is certainly nothing wrong with doing this - it gives researchers an idea of what about those regions might be useful for further research, looking at individuals rather than regions. We now have a great deal of data on many of the disease markers of actual vegans, and some data on their disease rates, through the Oxford Vegetarian study, EPIC-Oxford, studies of Seventh-day Adventists, and a few other studies. That data, which is highly relevant to vegans at large, is what we focused on in the book.

Ginny Messina: I would add that the findings from the China Study aren’t exactly irrelevant to vegans. Any well-designed study like the China Study that looks at health impacts of animal versus plant foods has relevance to vegans. However, because it didn’t include vegan subjects, the China Study doesn’t speak specifically to the health of vegans. We can’t look at that data and conclude that vegans are healthier than lacto-ovo- vegetarians or pesco-vegetarians, for example.

Something that is also a little bit unique to our book is that we wanted to help readers understand that some types of studies carry more weight than others - or that they have different purposes. As Jack pointed out, ecological studies, which include the China Study, generate findings that stimulate further research. But they aren’t the type of studies that allow us to make statements about causal relationships between diet and health.

In fact, there are instances where ecological studies have led us completely astray. For example, the belief that vegans have lower calcium needs than omnivores comes, in part, from an ecological study that compared rates of hip fracture to protein intake around the world. It showed that hip fracture rates were highest in countries with the highest per capita protein intake. The obvious conclusion is that eating protein causes weak bones. But it’s turning out that this conclusion may in fact be wrong. There are other explanations for the differences in hip fracture rates in these countries, all of which are missed in ecological studies.

Jack Norris: On average, vegans have lower LDL (low-density lipoprotein) and total cholesterol levels. In studies done on healthy populations, vegans have had an average cholesterol level of 160 mg/dl (4 mmol/l) compared to 202 mg/dl (5 mmol/l) for regular meat eaters.

Vegans also have lower levels of triglycerides, which is interesting because many clinical trials have shown that high carbohydrate diets raise triglyceride levels; apparently this isn't the case for vegans. Vegans are less likely to have high blood pressure, and more likely to have lower body weight.

Best of all, after adjusting for all the factors that might affect diabetes, vegans have been shown to have a 62% lower risk of diabetes than regular meat-eaters. Not bad!

Ginny Messina: I agree that the findings regarding health benefits for vegans are encouraging. I’m not quite convinced that a person needs to be 100% vegan to reap them, since it’s a theory that hasn’t been tested. But, definitely, a person who is eating a typical American or British diet is extremely likely to see some improvements in their health by switching to a vegan diet; a drop in cholesterol level at the very least.

But, what we tried to do in our book was to recognize those advantages without over-promising any particular health benefit. Not all vegans are slender and not all vegans are protected from heart disease and cancer. I always think of those health benefits as a nice little perk anyway. The real advantage to me is the positive impact we make with a vegan diet.

What are the main disadvantages of a vegan diet and how can they be overcome?

Ginny Messina: Aside from vitamin B12 and vitamin D, we know that all nutrient needs can be met through consumption of plant foods. The real disadvantage is that western cultures rely on animal foods for many of their nutrients and so vegans don’t have cultural or family habits to fall back on. I grew up getting calcium from milk and if you had taken that milk away, my mother would not have had any idea what to feed me to ensure adequate calcium intake.

The fact is that a vegan diet is a foreign way of eating for most people and so we have to actually learn how to meet nutrient needs. It’s not hard; it’s just different. We do need to learn where to get calcium and iodine, and we have to work a little bit harder to ensure adequate intake of zinc and adequate absorption of both zinc and iron. We also need to ensure adequate vitamin D, although that’s an issue for everyone, vegan or not.

Jack Norris: You should make sure you have a reliable source of vitamin B12, calcium, iodine, vitamin A, and omega-3 fatty acids. For some people, vitamin D, zinc, and iron could also be issues. Rarely will protein be a problem unless someone doesn't eat legume products.

Which aspects of the health of vegans require further research?

Jack Norris: Docosahexaenoic acid (DHA) is a long-chain omega-3 fatty acid and the main dietary sources for omnivores are fish and eggs. DHA is much lower in the blood of vegans who do not take DHA supplements than in the blood of omnivores, but it is not clear if these lower DHA levels matter. My main concern is with the possibility of low DHA levels reducing cognition. It could be that vegans have all the DHA they need in their tissues (where it matters) while having low levels in the blood. It would be great to know more about this.

Ginny Messina: I agree that we need more research on the significance of those lower blood levels of DHA in vegans, and also on the effects and potential benefits of DHA/EPA (eicosapentaenoic acid, another long-chain omega-3 fatty acid) supplements for vegans.

Zinc is another area where I’d like to see some more data. Vegans often have lower intakes, and zinc is absorbed less well from plant foods. Does this matter? Since it’s hard to measure zinc status, and indeed the effects of the lower intakes among vegans, it’s something we don’t fully understand.

We also need much better information about the health and nutrient needs of older vegans. As a post-menopausal vegan, I’m especially interested in the relationship of protein intake to health in older women. It’s so important for preserving muscle mass and for bone health. There is ongoing discussion among the experts in protein nutrition about whether recommended intakes for older people are high enough. I’d like to know more about how that impacts those of us who are vegan and trying to hold on to every milligram of bone and muscle we can!

Jack Norris: I’d also add that we don’t know much about the cancer rates of vegans. I see that a report from the Adventist Health Study-2 is in the process of being published indicating that vegans have a 16% reduced risk of cancer compared with meat eaters. That's actually a disappointingly low risk reduction, in my opinion. I was hoping for more like the approximately 50% reduced risk of diabetes for vegans.

What do you consider to be the chief ‘take home’ message of Vegan for Life?

Jack Norris: For years, the mantra in the vegan community was that plants contain all the necessary nutrients for good health with the implication being that all you had to do was eat a variety of plant foods and you'd be just dandy.

The message of Vegan for Life is: "Not so fast - there's more to it than that."

Ginny Messina: Yes, I think this sums up the message pretty well. There is a little bit of a learning curve when it comes to healthy eating. That’s true for any kind of diet, of course.

You are both Registered Dietitians: does veganism have a generally positive or negative image among dietitians in North America?

Jack Norris: My assessment is that it's a mixed bag, with many RDs thinking it's a great diet and even one to strive for, but others consider it lacking in too many nutrients. The Academy of Nutrition and Dietetics (AND) has a position paper that supports the use of "appropriately planned" vegan diets at all stages of the life cycle. Many of our colleagues balk at the phrase "appropriately planned" because they believe all diets should be appropriately planned. While that is a good point, it's also true that it's easier to suffer acute nutritional deficiencies on a vegan diet. Although I appreciate the fact that the AND qualify their statement, it is annoying to know that, in comparison to the vegan diet, inappropriately-planned, or unplanned, long-term omnivore diets can increase the risk for type 2 diabetes and heart disease, among other problems.

Ginny Messina: I’d say that “mixed bag” describes it pretty well. Many dietitians are still nervous about vegan diets, believing that it’s difficult to meet nutrient needs. In the U.S. the dairy industry has done an incredible job of convincing even health professionals that dairy foods are absolutely essential in the diet. But other RDs embrace veganism for health benefits. I don’t see many dietitians speaking out on the ethical imperative of veganism, though. That’s an area where we have a long way to go.

What are your plans for the future?

Ginny Messina: My goal as always is to help make a vegan diet a safe and realistic option for as many people as possible. To that end, I plan to keep writing about vegan nutrition on my blog www.TheVeganRD.com and elsewhere on the internet. I also volunteer for the vegetarian practice group of the AND, contributing and reviewing written materials on vegetarian nutrition for dietitians. I have a book on vegan nutrition for women being published this summer and am working on another book for next year.

Jack Norris: I will continue to maintain www.VeganHealth.org and www.JackNorrisRD.com to make sure vegans have the latest pertinent information regarding their diet. And Vegan Outreach will continue to promote a vegan diet. We are happy to report that, in the United States, the demand for meat has decreased in recent years, saving millions of animals from a lifetime of misery - we plan to continue until our efforts are no longer needed.

Thank you for your time and for giving readers the benefit of your knowledge and experience.