February 09, 2012

Calcium in a vegan diet + Marinated baked tofu and wheat berry salad

Considering that us Scandinavians are known to consume the highest amount of dairy products in the world, it probably doesn't come as a surprise that I thought I could never live without dairy. Before cutting dairy out of my diet a few months ago, my standard excuse to keep consuming it had always been "it's a good source of calcium". This is, of course, true and we are taught to believe that we should drink milk and eat cheese "to build strong bones". When I was growing up, there were hardly any other sources of calcium mentioned in any food pyramids or dietary guidelines. There was no mention of any plant-based ingredients that can certainly provide a good source of calcium in both vegan and non-vegan diets.

What is the role of calcium?

Calcium, one of the most important and abundant minerals in the human body, is essential to life. Calcium works together with magnesium to support the proper functioning of nerves and muscles, and it also helps to maintain the strength and density of bones. The body's need for calcium is especially important during the growth years, but it is also necessary throughout life to keep the bones healthy. 

There are many factors that can affect the absorption of and need for calcium and it is thus difficult to determine the correct amount of calcium for everyone. Some of the factors increasing calcium absorption include: body needs (growth, pregnancy), exercise and vitamin D. In turn, high phosphorus intake (phosphorus is high in meat foods), high protein intake, lack of exercise and stress can all decrease the absorption of calcium. 

What are good plant-based sources calcium?

Many green, leafy vegetables, such as broccoli, collard greens and turnip greens are good sources of calcium. However, some vegetables, including spinach, rhubarb and chard contain oxalic acid which makes the calcium in them harder to absorb. Some beans, especially pinto, adzuki and soybeans are excellent sources of calcium. Many nuts and seeds, particularly almonds, Brazil nuts, sesame and sunflower seeds, also contain good amounts of calcium.

It is still a good idea to take a calcium supplement, especially if you think you have a higher need for it. Seeing that calcium is artificially added to all dairy products, you might as well skip the middle-man (aka. the cow or the goat) and go straight to the source yourself.

I like to include a variety of greens, beans, nuts, seeds and some tofu or other soybean products in my daily diet. This salad with marinated, baked tofu, wheat berries, carrots and snow peas is one of my favourites. I love the crunchy tofu and the crisp veggies, and can happily devour a bowl any time.

Marinated baked tofu and wheat berry salad
(serves 2)

350g block extra-firm tofu
4 tablespoons extra-virgin olive oil
1 tablespoon apple cider vinegar
1 tablespoon tamari or Bragg's all-purpose seasoning
1 pinch of chilli flakes

200g wheat berries, soaked in water for a few hours
3-4 tablespoons sesame seeds, toasted
2 small carrots, thinly chopped
1 big handful of snow peas, thinly chopped
2 green shallots, thinly sliced

1. Whisk olive oil, apple cider vinegar and tamari in a bowl. Slice the tofu into 1-2 cm thick slices and place the slices in a shallow (rimmed) dish. Pour the marinade over the slices and turn the slices to coat both sides. Leave to marinate for 1-2 hours.

2. Preheat the oven to 200C and line a baking tray with baking paper. Arrange the tofu slices on the tray (gently shaking off any extra marinade). Bake for 20-25 minutes on each side or until golden and crispy. 

3. In the meantime, drain the soaked wheat berries, place in a saucepan and cover with fresh water. Bring to boil, then let simmer for about 30 minutes or until the grains are tender. Drain and leave to cool. 

4. Combine the cooled down grains, sesame seeds, left-over marinade and chopped vegetables in a bowl. Toss to combine and arrange in serving bowls. Cut the tofu into bite-sized pieces and place on top of the grains. Serve immediately.

Source: Haas, E. M. Staying Healthy with Nutrition - The Complete Guide to Diet and Nutritional Medicine (2006).