Wednesday, January 18, 2012

Go to Health: Teenagers’ diets, Your feet, B12 update

What Teenagers are Eating:
Nationwide, teens are eating very few fruits and vegetables; this isn’t news to many parents who are struggling financially and competing with chips and soda in their kid’s diets. Data from a national survey of high school students show that typical daily intake of fruits and vegetables combined was slightly more than one serving a day. More than 25% of students ate fruit less than once a day, and 33% ate vegetables less than once a day. My partner, Alan, has a grandson, now 21, who refused to eat a single vegetable until recently, when his savvy girlfriend persuaded him to try some greens. I asked my 12 year old neighbor, Ibarra, for her advice to parents and teens. Her answer was immediate – kids love the smoothie shop in downtown Bolinas – make smoothies at home and put fruit in them. Make pasta for dinner and put vegetables in the sauce, disguised by blending them if necessary. Make fruit salad. Thanks, Ibarra for your thoughtful advice.

Your Feet:
Anthropologists studying the evolution of the foot say that as we became bipedal, the foot was under selection pressure to deal with both balance and propulsion in a highly efficient way. Think about balance and propulsion when you select your shoes. Your toes should not be compressed, because from the big toe to the fifth toe, they assist your balance as they spread out, and then they push you forward into the next step. There is a new interest in barefoot walking, and in shoes that enable you to walk in a way that resembles being barefoot, but gives protection to your soles on hard or rocky surfaces. Take shorter strides to allow you to land more softly on your heel with your knees slightly bent. Roll forward until the ball lands, and spreads slightly as your toes spread and bend to push you forward. Shoes that enable this kind of walking are light and flexible. Several shoe companies have ‘barefoot’ models. Be sure to get one with a wide toe box. Beginners’ advice – walk the beach barefoot, and take off your shoes at home. Women - rethink high heels if you want to keep your toes happy and your calf muscles from shortening. Stretch your calves whenever you take off high heels. Foot binding in China kept women in thrall, and Thorstein Veblen, writing in 1899, thought high heels were indicative of conspicuous consumption and the subjugation of women. Times have changed, and heels have become symbols of sexiness and power. But our feet haven’t caught up. Should we change our views on glamour? It won’t be easy, but thinking women are already making huge changes in the world.

Vitamin B12 Update:
A new study from Rush University looked at levels of vitamin B12 in people over 65, and found that B12 deficiency was associated with smaller total brain volume and lower scores on tests of memory and cognition. These finding are supported by earlier (2008) study at Oxford University in England which found that over five years, people with higher vitamin B12 levels were 6 times less likely to experience brain shrinkage compared to those with lower levels. Vitamin B12 is found only in animal food, and is especially high in clams and other shellfish. Fortified breakfast cereals are an important source of vitamin B12 for vegans, who should also take a B12 supplement. Older people may have difficulty absorbing B12 from food, because of a lack of a substance called ‘intrinsic factor’ in the stomach that enables B12 absorption. Therefore, B12 supplements are recommended for seniors; getting the sub-lingual (under the tongue) kind that is absorbed directly into the bloodstream is the best. Low B12 levels are also related to depression, bone loss and macular degeneration in the eye. It’s worth paying attention to this issue.
Sadja Greenwood, MD, MPH back issues on this blog