People who abandon plant-based diets often say that they suffered from depression as vegans. One common belief is that vegans can’t get adequate tryptophan, an essential amino acid. Tryptophan is needed to make the neurotransmitter serotonin and low levels of serotonin are linked to depression. In the book The Vegetarian Myth (which I plan to review here in the next few weeks), author Lierre Keith notes that she suffered from severe depression as a vegan partly because “there are no good plant sources of tryptophan.”
While it’s true that meat is higher in tryptophan than plants, a well-balanced vegan diet is […]
Quite a few popular vegan websites and books make the claim that vegans don’t need as much calcium as omnivores. The theory dates to some interesting research from the early 1990s which found that hip fracture rates among different countries increased as per capita protein intake went up.
The observations were backed by decades of clinical studies, too. As far back as the 1920s, nutritionists were showing that feeding meat to subjects caused them to excrete more calcium in their urine. Theoretically, this is because protein has an acidifying effect on the blood. Calcium is leached from […]
I’ve talked with three different reporters this past month, all with questions about vegetarian diets. All three asked, of course, which nutrients require special attention in vegetarian diets. And each expressed surprise that I didn’t mention protein. They also asked about soy—and whether it was true that it’s the only plant food that is a “complete protein”—ie, the only one that contains all 9 of the essential amino acids.
The answer is no. All plant foods that contain protein—which would be all grains, beans, nuts, seeds and vegetables—provide all 9 of the essential amino acids. So they are all […]