I am happy to report that we have updated and added a feature to the protein page at VeganHealth.org. If you scroll down to Table 3, you can now type in your ideal body weight, click Submit, and the table will show you how many servings of the listed foods it would take to meet the RDA for protein and the essential amino acids.

Of course, you shouldn’t get all your protein from just one food, but it can give people an idea of what might be required from various food combinations. It’s also not important for everyone to meet the RDA for protein; some people need less.

I’d like to thank Vegan Outreach’s volunteer, Jean B., for all the work she has done to make VeganHealth.org look nicer! She has been redoing the pages one at a time and I really appreciate all her help!

WNYC’s Radiolab is an NPR program that tries to explain the science behind peculiar and unusual phenomena. While a very interesting program, the two hosts, Jad Abumrad and Robert Krulwich, have antiquated attitudes towards animals, in my humble opinion, and are annoyingly fixated on the question of “What makes us human?”

Today I was listening to their Emergence episode in which they discuss ant behavior. The conversation later turned to people trying to trick Google into giving their websites a higher rating and Jad pointed out in a serious voice, “See this is what separates us from the ants right here…”

Really? We are so insecure that we need to point out what makes humans different from ants?

Back in 1988, I read an article in Psychology Today that ran down the list of the different traits that people have traditionally thought separates humans from other animals, and one by one showed that some animals also possess each of those traits. They concluded, tongue in cheek, that what separates us from other animals is that we are the only species that tries to find things that separates us from the other animals.

It’s not much, but hopefully will provide some comfort for those who are searching.

Ginny Messina made an interesting blog post on Reliable Nutrition Information for Vegans. Click here to read. And I’m not just posting it because she gives my work a plug, though I do appreciate it!

Dr. Michael Greger brought my attention to a paper published last year on the B12 activity of Aphanizomenon flos-aquae (also known as blue-green algae).

My write-up on the study is too long to post here, but it appears that Aphanizomenon flos-aquae might provide some vitamin B12 activity in humans. On the other hand, it did not succeed in lowering homocysteine to an ideal level whereas vitamin B12 supplements do succeed at doing so. At this time, it would be prudent not to rely on it for optimal health.

Click here for the entire update.

On April 7, I linked to an NPR report about a European Prospective Investigation into Cancer (EPIC) paper that found that eating more fruits and vegetables cuts the risk of cancer by only 4%. After reading his comments elsewhere, I invited Paul Appleby, Senior Statistician at the Cancer Epidemiology Unit at the University of Oxford, to share his thoughts on the paper.

Paul writes…

Do fruits and vegetables prevent cancer? No. Does eating more fruits and vegetables reduce the risk of some cancers? Probably yes. To quote from the WCRF/AICR expert report on “Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective” (2007), “The strongest evidence, here corresponding to judgments of ‘probable’, shows that non-starchy vegetables and also fruits probably protect against cancers of the mouth, larynx, pharynx, oesophagus, and stomach, and that fruits also probably protect against lung cancer; and that allium vegetables, and garlic specifically, probably protect against stomach cancer.”

As I see it, there were two disappointing aspects to the EPIC paper in question (1). First, the authors examined the composite end point of all malignant cancers. Thus, the beneficial effects of fruit and vegetables at some cancer sites (see the WCRF/AICR list above) would be diluted by the inclusion of common cancer sites for which there appears to be no association with fruit and/or vegetable intake. As a result, the authors found only a small (but statistically significant) 3% reduction in overall cancer risk per 200 g/d increased intake of total fruits and vegetables. Although this would equate to the prevention of thousands of cancers every year, much of the media chose to put a rather negative spin on the story, overlooking the evidence for a beneficial effect of fruits and vegetables on other diseases such as cardiovascular disease (see, for example, ref 2 below). Interestingly, the latter study found that the “risk of coronary heart disease was decreased by 4% [RR (95% CI): 0.96 (0.93-0.99), P = 0.0027] for each additional portion per day of fruit and vegetable intake”, a benefit similar in magnitude to that found for cancer in the EPIC study. It is unrealistic to expect to see risk reductions of 10% or higher per extra portion of fruits and vegetables for such broad end points as all cancers or coronary heart disease.

The second disappointing aspect of the EPIC paper was the fact that the authors only considered total fruits and total vegetables (and the sum of the two) as their exposure variables, and did not look at sub-types of fruit and vegetables. As readers will be aware, different fruits and vegetables can have quite different nutritional characteristics (compare the vitamin C content of apples and oranges, for example) and it was a pity that the authors did not examine the associations between, say, citrus fruits or cruciferous vegetables and cancer risk. Such an analysis might have revealed stronger protective effects for certain types of fruit and vegetables that could have pointed the way to more nuanced public health advice to supplement the rather crude ‘5-a-day of any sort of fruits and vegetables’ message.

References

1. Boffetta P, et al. Fruit and vegetable intake and overall cancer risk in the European Prospective investigation Into Cancer and Nutrition (EPIC). J Natl Cancer Inst. 2010;102:1-9 Advanced access published April 6, 2010.

2. Dauchet L, Amouyel P, Hercberg S, Dallongeville J. Fruit and vegetable consumption and risk of coronary heart disease: a meta-analysis of cohort studies. J Nutr. 2006 Oct;136(10):2588-93.

I just updated VeganHealth.org/articles/bones with the following tidbits:

Dr. Jacqueline Chan sums up the studies on vitamin D2 vs. D3, “Treatment for most of the studies finding D2 to be less effective than D3 were extremely large boluses given only once, whereas in studies finding them equally effective, the treatment was daily amounts between 400 and 2,000 IU.” (38)

Test Kit

The Vitamin D Council has partnered with ZRT Labs to make a discounted take-home vitamin D test kit available (for $65 as of April 2010).

Sun Tips

According to Dr. Jacqueline Chan, in order to make vitamin D, “The sun must shine directly on skin without being blocked by sunscreen, glass and most plastics. Glass and most plastics block UVB, the part of the spectrum that converts pro-vitamin D3 but allow passage of UVA which contributes to skin cancer.” (38)

Also according to Dr. Chan, increasing the surface of the skin exposed to the sun proportionately decreases the amount of time needed in the sun to produce the same amount of vitamin D. The duration of the sun exposure should be no more than about half the amount of time it takes for the skin to turn pink. (38)

I have also been getting the impression, based on hearing from people who have been supplementing and getting tested regularly, that it could take large amounts of vitamin D2 (1,000 – 2,000 IU per day) over the course of months to see a significant increase in 25(OH)D levels.

References

38. Vitamin D Update for Nutrition Professionals. Chan J. Vegetarian Nutrition. Volume XVIII, Number 1 and 2, 2009:1.

Here are some studies addressing the question of whether tanning beds are a safe and reliable source of vitamin D.

A 2004 study found that tanners had much higher levels of vitamin D (and lower rates of vitamin D deficiency) than non-tanning bed users. They noted that to produce vitamin D, the tanning bed must emit ultraviolet B rays of 290–315 nm. This study did not indicate that they screened subjects based on the UV ray type of the tanning bed they used. A link to entire study is below (1). This study was confounded by the fact that the tanners stayed out in the sun significantly longer than non-tanners (2).

In their 2010 paper, Woo and Eide state that most tanning “devices” emit ultraviolet A rays, which do not produce much vitamin D (2). They say:

“Given the relative inefficiency of UVA-emitting tanning devices in increasing serum vitamin D levels, especially in those most at risk of vitamin D deficiency, indoor tanning is not recommendable as a way to achieve optimal vitamin D levels in the general public.”

The authors also argue that for tanning to occur, DNA damage must also occur. In fact, the American Academy of Dermatology (AAD) says, “There is no scientifically validated, safe threshold level of UV exposure from the sun or indoor tanning devices that allows for maximal vitamin D synthesis without increasing skin cancer risk (3).” The AAD recommends against using even sunlight to raise vitamin D levels.

In summary, it appears that you can get vitamin D from tanning beds if you make sure the bed uses UV B rays of 290–315 nm, but doing so can raise the risk of skin cancer.

References

1. Tangpricha V, Turner A, Spina C, Decastro S, Chen TC, Holick MF. Tanning is associated with optimal vitamin D status (serum 25-hydroxyvitamin D concentration) and higher bone mineral density. Am J Clin Nutr. 2004 Dec;80(6):1645-9.

2. Woo DK, Eide MJ. Tanning beds, skin cancer, and vitamin D: An examination of the scientific evidence and public health implications. Dermatol Ther. 2010 Jan;23(1):61-71.

3. The American Academy of Dermatology. Position Statement on Vitamin D. Amended by the Board of Directors December 22, 2010. Link

Also Reviewed:

Schulman JM, Fisher DE. Indoor ultraviolet tanning and skin cancer: health risks and opportunities. Curr Opin Oncol. 2009 Mar;21(2):144-9.

Article from Men’s Fitness. Link.

Thanks, Matt!

This abstract shows that exposing one serving (84 g) of post-harvest, white button mushrooms to UVB rays for 5 minutes resulted in their having 86.9 µg (3,476 IU) vitamin D2, which is well above the recommended daily intake.

So if you see mushrooms in the store labeled as having 100% of the Daily Value or RDA for vitamin D, it’s probably true.

NPR ran an article today, Fruits and Veggies Prevent Cancer? Not So Much, It Turns Out…

Excerpts:

“A huge nine-year study of diet and cancer, involving nearly a half-million Europeans in 10 countries, finds only a very weak association between intake of fruits and vegetables and cancer incidence. The study is in the current issue of the Journal of the National Cancer Institute. Those who get an extra two servings of fruits and veggies a day lower their cancer risk by only four percent.”

Not the best news, but at least it cuts the risk by 4%. I’m inclined to think this study is correct, that fruits and vegetables help prevent cancer, but not by a lot. Good news is later in the article:

“But meanwhile, there’s a pretty strong reason for everybody to continue eating lots of fruits and vegetables. It’s called cardiovascular disease. A 2004 study in the JNCI found that eating five servings of fruits and vegetables a day is associated with a 28 percent lower risk of heart disease and stroke, compared to people who eat fewer than 1.5 servings a day.”