Wednesday, October 20, 2010

Keeping the Pipes Clean: it's a dirty job but someone's gotta do it!

Fiber (aka ruffage, or as my mom calls it, "cardboard") is a component of food that, although not actually a nutrient, bears equal weight as vitamins and minerals in the promotion of health...especially for preventing colon cancer and heart disease. Americans under-consume fiber so much that just 13g more per day across the nation would reduce the colorectal cancer rate by 31%.

Our bodies actually do not derive energy from fiber; it is any material in plants for which we lack the enzymes to digest (but other animals such as cows successfully get energy from fiber such as grass). The not-so-pretty reality is that fiber is an essential fuel for the bacteria residing in our colons. It's a natural and necessary partnership that we have with these little guys, and they do a lot of work that they don't get enough credit for (and get wiped out when people "cleanse" their colons). Resident bacteria are able to use fiber for food, promoting their proliferation. Here's why we want them to succeed:

1) the good bacteria scavenge our intestines for toxins and carry the toxins out when they exit our better end, 2) their colonization prevents pathogenic microbes from taking hold and causing illness, such as E. coli or salmonella, 3) certain bacteria inhibit growth of tumor cells, 4) their eating habits (fermentation) produces an acidic environment that prevents our good bile from being converted to cancer-causing secondary bile acids, 5) Lactobacillus acidophilus bacteria prevents the conversion of pro-carcinogens to actual carcinogens 6) they produce fatty acids which serve as fuel for new colon cells, denying toxins or carcinogens the chance to take root. Basically, they do a lot of good work in there, which is why we should feed them.

You'll see fiber in two forms- soluble and insoluble -under the category "dietary fiber" on your food labels. Both are functional and necessary, and a good balance of the two keeps things moving. Together they provide many benefits:
       -Fibers increase our feeling of fullness so can help in controlling hunger and weightloss. 
       -They slow down digestion of a meal, which leads to a more controlled release of nutrients for more
         stable blood sugar levels.
       -Fiber acts like a sponge, sopping up fats and cholesterol in its path and reducing their presence in the
         bloodstream (read: heart and artery health, and lower LDL levels). This property is also why it is
         essential, though, to drink enough water to keep high-fiber foods from clogging the pipes.

As you can see, consuming higher amounts of fiber benefits not only our downstairs tenants, but many other aspects of bodily health. The current daily recommendation is 25g for women and 38g for men. But I don't advocate an increase in fiber supplements, which are usually nutrient deficient. Instead you can find fiber in the following DELICIOUS foods, and many others:

Raw:                                                                        Cooked:
Blueberries - 3.5 g per cup                                       Beans - 11-19 g per cup
Pears - 5.1 g each                                                  Oranges - 3.4 g each   
Almonds - 3.3g per ounce                                        Broccoli - 5.1g per cup
Raisin bran - 5.0 g per cup                                       Brown rice - 3.5 g per cup
                                                                             Oats - 5.7 g per cup
                                                                              
So do your part for colon and heart health - and appreciate all the dirty work that gets done while you go about your day - by incorporating more fiber into YOUR diet!

Monday, October 11, 2010

Oh so sweet

The amount of fat consumed by Americans has decreased by about 10% over the past 50 years... from 42% of total calories in the 1960s to 33% of total calories today. The rate of obesity in the US has tripled - increased by 300% - in that same time period....

It appears that other factors are the major contributors to our nation's struggle with overweight. And it is really a global epidemic...as I have posted before there are now more overweight people in the world than starving people, and the rapid rise in obesity is no longer reserved just for wealthy nations. India, China, Russia, the Phillipines, and Mexico are now seeing an increase in obesity and overweight. My current read "The World is Fat" is a fascinating examination of these global trends by researcher/professor Barry Popkin. While describing how agricultural efficiencies + sedentary lives + manufactured foods + human genes for preventing starvation = a recipe for disaster, Popkin makes a bold claim. He argues that caloric beverages are the largest contributor to obesity worldwide. Drinking our calories is a relatively recent phenomenon - for the first 200,000 years of our species' existance the only liquids we consumed were water and breast milk. About two thousand years B.C. we find records of milk, wine, beer, and juice being consumed. And then in the past one-thousand years is where we see an explosion of caloric beverages: coffee and tea (with milk and sugar), liquor, juice concentrates, soda pop, and "energy" drinks. Popkin theorizes that our human genetics have not yet adapted to these new consumption habits: they were designed for the hunter-gatherer's survival when food was more scarce, and are no match for our appetites in this world of plenty.

Several recent research studies have demonstrated that intake of beverages does not off-set food intake. If we drink a 200-calorie soft drink at a meal, we do not eat 200 calories LESS of food. Drinks are additional calories on top of the calories we eat based on our hunger cues, and our appetites do not compensate for them. The liquids may give us a short-lived feeling of fullness from the expanding of our stomachs, but it then empties much quicker than for solid foods and so we feel hungry very shortly. Other times sweetened beverages actually increase our appetite for food: think of how the sweetness of coke drives us to eat more salty french fries (which the food industry takes full advantage of).

Pensive if this phenomenon, I converted the grams of sugar to teaspoons in the 6 common beverages pictured below for a presentation in school. The amount per serving of 8 ounces was listed on the label of each bottle, but every single one of these contained atleast 2 servings. In our over-sized American minds we feel good about "getting more" for our money and then consume the entire portion available to us, rather than rationing it out to make it last twice as long. The following are the amounts of sugar in the entire bottle of each product:


Sunkist orange soda: 18 tsp sugar
Coca Cola: 14 tsp sugar
Red Bull: 11 tsp sugar
Snapple: 10 tsp sugar                   
Starbucks Frappuccino: 9.5 tsp sugar        
Vitamin Water: 5 tsp sugar

For each beverage, the first ingredient listed is water, and the second ingredient is some form of sugar (cane sugar, crystalline fructose, high fructose corn syrup, sucrose, glucose, maltodextrin): they are literally sugar-water. I ask you all: would you find it appetizing to pour one of those cups of solid sugar into your mouth? Probably not. When dissolved in water, the caloric part -the sugar- is hidden, and our brain is partially tricked, although it does register that pleasant sweet taste which we instinctively enjoy. With beverages we also do not benefit from the mouth-feel of the amount of calories consumed as we would with a muffin or a candy bar (both full of sugar), which is a significant way that our body gauges the energy we have taken in.

Caloric beverages can be very useful for periods of prolonged physical activity in which energy stores need to be replenished more frequently to sustain that exertion. In these cases solid food is less efficient than liquid calories: the sugar is the simplest form of energy that our body can use immediately for energy without needing to do much digestion, and it is rapidly absorbed into the bloodstream. Protein, fat, and more complex carbs spend more time in our digestive tract while enyzmes break them down and then need to be converted by our liver into glucose (the only molecule that our body can use to get energy!). So pure glucose is fantastic for athletes and mountain-climbers, but not so appropriate for those of us who barely manage to get to the gym a couple times a week.

Even so, it has become increasingly common world-wide for a person to have a latte with breakfast, a lemonade at lunch, a coke or red bull mid-afternoon for a pick-me-up, and a beer or glass of wine with dinner. These add up to a lot of extra calories that the world consumes every day, in a time when extra calories are more and more unnecessary. I think Popkin has drawn some very insightful conclusions from his breadth of research, and I would highly recommend the read. I know that this knowledge has changed the way I look at a soda or latte or glass of juice...just picture all those heaping teaspoons of pure, sweet sugar.