For The Love Of Food

For The Love of Food
Welcome to Friday’s For The Love of Food, Summer Tomato’s weekly link roundup.
This week the emphasis seems to be on the value of whole foods over single nutrients or supplements. Check out my article on the danger of vitamin E supplements over at KQED, the cool new study about why whole broccoli is better than its single nutrients as well as a cool trick for preventing avocados from browning.
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Links of the week
- Vitamin E Supplements Increase Prostate Cancer Risk <<Scary stuff. But read all the way to the bottom, dosage is important. (KQED Quest)
- Health Benefits of Broccoli Require the Whole Food, Not Supplements <<A small clue as to why vegetables are still more healthy than supplements. I imagine there are many more. (ScienceDaily)
- Is “Natural” A Food Marketing Scheme? <<Big thanks to Food Republic for calling BS of the week for me on the food industry’s gratuitous use of the word “natural.”
- Radical thinking on antioxidants <<I love a nice, healthy dose of reality. Antioxidants aren’t a magic bullet, not by a long shot. (Chicago Tribune)
- Cheating Father Time: 50-Year-Old Can Be Every Bit as Fit as Someone 30 Years Younger, but Exercise Is Key <<Though I still think diet is the most important factor in body weight, don’t forget that exercise is just as important in health. It also makes you look better at any size. (ScienceDaily)
- Eating Green Veggies Improves Immune Defenses <<The difference was much larger than researchers expected. (ScienceDaily)
- Proper Protein Intake Crucial for Moderating Energy Intake, Keeping Obesity at Bay <<Interestingly, raising protein intake from 10% to 15% made a significant difference in reducing overall energy intake, but raising from 15% to 25% did not. (ScienceDaily)
- First Physical Evidence Bilingualism Delays Onset of Alzheimer’s Symptoms <<I think this is really cool. Use that brain, travel, it’s good for you. (ScienceDaily)
- ‘Gardener’ Gives ‘Heirloom Life’ To Forgotten Flora <<Looks like a great resource for gardeners looking to expand their crop. (NPR)
- How To Stop An Avocado From Browning <<Really cool trick from Chow (via Treehugger) on preventing avocado browning with an onion. Also sounds like the start of a great guacamole.
http://www.cbs.com/e/7gcqHsHaWrENebawgpv5c5B_kWM4_xVm/chow/1/
What inspired you this week?
Regarding the protein study: is that a large enough sample size or long enough duration (22 people, 12 days) to draw any meaningful conclusions? What about psychological variables: did the subjects go from one four day diet right into the next? Were they more relaxed or stressed at various times, affecting their appetite? Color me skeptical about this one…
Sure the design has its limitations, but it also has its strengths. The reason they can achieve statistical significance with such a small sample size is that they have internal controls–the same people did all conditions and serve as their own control. I didn’t read the experiment myself, but it is standard for the researchers to shuffle the design so that different people start on different diets first and the progression is randomized. This would control for any problems with one diet progressing to another.
It’s good to be skeptical, but peer-review generally assures that total idiocy is averted. PLoS One is particularly stringent on methods.
Good to know!
Regarding the vit E supplementation, do you know what kind of vit E was given in this trial: synthetic, natural, type of tocopherol ? That could make a huge difference. Not all vit E are created equal.
It was alpha-tocopherol: http://www.cancer.gov/newscenter/pressreleases/2001/select
YAY YAY yippee for green avocados!
I saw that it’s possible to read the entire protein study, so I went ahead and did just that. I’m not a math guy, so some of the statistical stuff is over my head. That being said, from Table 1 ( http://www.plosone.org/article/slideshow.action?uri=info:doi/10.1371/journal.pone.0025929&imageURI=info:doi/10.1371/journal.pone.0025929.t001 ) it appears that individuals in the study ate an average of 2475 kcal (converted from the original MJ) per day on the 10% protein diet, as opposed to 2216 kcal per day on the 15% protein diet, a difference of 259 kcal. Interestingly, the increase in carb intake from a 15% day to a 10% day amounted to 260 kcal. Fat intake was also slightly increased.
As I understand it, the operating theory here is that there is a set point of protein intake (“protein leverage”) that the human body is programmed to seek out. When that protein target is not reached, we compensate by simply eating more of all types of food in the hopes of getting the required protein.
I see where they hope to go with this: is preventing obesity as simple as having people eat slightly more protein every day? On a 2000 kcal per day diet, an extra 5% protein would translate to about 25 grams, or the equivalent of a small chicken breast. That’s not much at all.
I don’t have a competing study to back me up, but I think this is an oversimplification of how people deal with food in their day-to-day lives. Yes, it would be nice if eating that extra helping of chicken magically flipped a switch in our brains. But there are so many other variables in the mix: mood, activity level, stress or absence thereof, social considerations, etc. I know that this study purposefully chose a limited area of inquiry to focus on, and the results certainly are interesting. I just don’t see how this information helps on a practical level. I’ve gone through plenty of periods of eating massive amounts of protein (40% of daily calories and sometimes more), but I can’t say I ever lost the desire to start snacking on cookies at any point. The only thing that stopped me was the self-discipline that came from wanting to stay on track. If my body had won out I would have happily eaten 200 grams of protein PLUS ice cream and pizza.
Sorry for the super long post, but I do find this stuff fascinating.
Yes, I tend to agree. I encourage people to eat protein for breakfast, since that has shown to reduce appetite throughout the day, but I don’t think it’s a cure for obesity. Studies like this are valuable, but are never enough to dictate a living human’s entire diet. This stuff is complicated!
Thank you Darya for all these interesting articles! I look forward to your for the love of food series every Friday.
Hi, Darya! The broccoli article advises to “go easy on cooking” broccoli and other cruciferous vegetables. I love your roasted cauliflower dish and I also love roasting broccoli for 15 minutes, but I’d like to pursue other ways of cooking/eating cruciferous vegetables without reducing their health benefits. Any thoughts or yummy suggestions?
Hi AJ,
Some nutrients do better with less cooking, some do better with more. So I wouldn’t go nuts worrying about a single nutrient. The value of this study is showing that some nutrients are dependent on the presence of other nutrients and cannot be taken out of context. The best approach is to eat a wide variety of both raw and cooked veggies, fruits, and other natural foods.