To soy or not to soy...

Today I was craving my old standby for days spent writing a thesis -- the soy latte. I started drinking these upon the advice of a personal trainer. She was concerned that if I started burning calories with workouts, my body would utilize my own muscle mass as an energy source if I didn't incorporate more protein into my diet. She suggested substituting dairy milk with soymilk in my coffee for starters. That was waaaay back in the early 2000's when I lived in Arizona, worked out at 24 Hour Fitness, and was a size 16 at 175 pounds.

My diet right now is all messed up. I am super stressed and craving carbs galore. I am spending days and days in front of the computer and not spending time outdoors taking exercise. I am

anxious that I will look down at my belly one day and not be able to see my feet on the scale which reads 180 pounds again. When I felt healthier, I craved milk so why am I all of a sudden reaching for soy?

Clif bars have become a staple of my diet, which contain soy protein and a ton of ready-for-action carbs. I like them because they are easily digestible and allow me about 2 more hours of productivity from the time I eat them to when I start to feel hungry again. Easy to eat on the run. The company uses soy protein because it provides amino acids in a vegetarian-friendly form. The other pillar in my diet right now is Premier Nutrition shakes (chocolate and vanilla) which are fortified with milk isolate protein & whey concentrate. So I am getting a non-soy source of protein too! These are also individually packaged as well for on-the-go days.

I have heard repeatedly that Clif bars are essentially junk food. Just because these items are marketed as "healthy" they may in fact be harmful to me. So I decided to investigate for myself whether soy is harmful or helpful. It seems the literature is full of contradictions. Some claim to have shown that soy is harmful and the studies that tout its benefits can only demonstrate a marginal difference from a placebo.

Isoflavones are part of a class of molecules called FLAVONOIDS. Isoflavones are molecules made by plants which are thought to (1) have harmful estrogenic effects in the animals that eat them and (2) have helpful health-promoting effects on the animals that eat them such as preventing cancer and cardiovascular disease and (3) are used by the plant for recruitment of rhizobacteria and pollinator animals. These studies were of particular interest in light of the molecules I have been studying in my research.

I have been looking at flavonols in the model plant Arabidopsis, while another colleague in my lab has been looking at anthocyanins in pomegranate. The structural similarity between isoflavones (phytoestrogens) and the estrogen made by animals (17-b-estradiol) is pretty low to my eyes. This entire class of molecules has low toxicity in animals, which is why we enjoy so many foods that contain these molecules.

Levels of isoflavones in soy are high, which I found in the USDA 2008 report on the isoflavone content of 557 food items (I have pulled out only a few of these for the purposes of this blog). Clif bars contain even more isoflavones per 100 grams than soybeans. For some reason blogger isn't letting me use more than 3 images per post, so this topic will be continued shortly...