There’s a general view out there, I think, that vegetarian and vegan diets are, on balance, healthier than those that include flesh foods including meat. I personally don’t agree with this view. My beliefs on this are partly based on the evidence that non-vegetarians don’t appear to have their lives curtailed by their consumption of flesh foods [1]. Also, there is at least some evidence that vegetarian and vegan diets can come up short on certain nutrients such as iron and vitamin B12.
Because vegans do not eat dairy products, there can be a tendency for their diet to be relatively low in calcium. I think the role of calcium and dairy products in bone health has been somewhat overstated, but I was nonetheless interested to read about a study published last year which assessed bone fracture risk in non-vegetarians, vegetarians and vegans [2]. The study followed a total of more than 35,000 individuals aged 20-89 for a period of just over 5 years.
The researchers discovered that meat-eaters, fish-eaters and vegetarians had very similar risk of fracture. However, compared to them, risk of fracture in vegans was 30 per cent greater.
The obvious potential reason for this is the generally lower calcium content of the vegan diet. So the authors of the study went on to factor this into the equation. And when they did, they discovered that if a vegan diet contains at least 500 mg (525 mg to be precise) of calcium each day, then there was no increased fracture risk.
Now this sort of ‘epidemiological’ study cannot prove that low calcium intake caused the enhanced fracture risk, but the results sure are consistent with this finding.
So, it seems like a generally good idea for vegans who want to optimise their bone health to make sure they have a decent calcium intake. Good vegans sources of calcium include sesame seeds (including tahini), nuts (especially almonds), and beans.
References:
1. Key TJ, et al. Mortality in British vegetarians review and preliminary results from EPIC-Oxford. Am J Clin Nutr 2003;78(suppl):533S-8S
2. Appleby P, et al. Comparative fracture risk in vegetarians and nonvegetarians in EPIC-Oxford. Eur J Clin Nutr, 2007;61(12):1400-6.
