Sitting in a Caribou Coffee shop in Chicago, a sign tells me that "The Caribou Coffee location's last day of business will be June 22. Thank you for 13 fantastic years. Your patronage has brought many smiles, much laughter and memories that we will cherish forever."

Such are the passages of life, a long run that eventually ends. The same passage will mean a new beginning; this Caribou location will become a new fangled tea shop, the barista told me.

So the beat of the industry goes on, and today is the start of the United Fresh Produce Association expo, another convention in a long line that promises to stretch far into the future. There will be new products, technology and innovations that could be game-changers, the type of punctuation marks in the industry timeline that we will only recognize later.

It is impressive that Peruvian avocados nabbed the "superfood nutrition" language from the U.S. Department of Agriculture regulators. Once applied to one fruit item, I'm sure that other commodities will also angle for similar distinction.

In that context, a new study that identifies "powerhouse" fruits and veggies is making news in recent days. Of course, any naming of specific fruits and vegetables to a "powerhouse" or "superfood" lists is bound to be a little controversial. The most shocking part of this recent list is that blueberries are not among the powerhouse produce items. I kid you not. The chief reason for this is that researchers did not include phytonutrients in their equation for powerhouse fruits and vegetables.

The abstract of the study, called "Defining Powerhouse Fruits and Vegetables: A Nutrient Density Approach," says this about the approach:

National nutrition guidelines emphasize consumption of powerhouse fruits and vegetables (PFV), foods most strongly associated with reduced chronic disease risk; yet efforts to define PFV are lacking. This study developed and validated a classification scheme defining PFV as foods providing, on average, 10% or more daily value per 100 kcal of 17 qualifying nutrients. Of 47 foods studied, 41 satisfied the powerhouse criterion and were more nutrient-dense than were non-PFV, providing preliminary evidence of the validity of the classification scheme. The proposed classification scheme is offered as a tool for nutrition education and dietary guidance.

Of 47 foods studied, all but 6 (raspberry, tangerine, cranberry, garlic, onion, and blueberry) satisfied the powerhouse criterion (Table 2). Nutrient density scores ranged from 10.47 to 122.68 (median score = 32.23) and were moderately correlated with powerhouse group (ρ = 0.49, P = .001). The classification scheme was robust with respect to nutrients protective against chronic disease (97% of foods classified as PFV were separately classified as such on the basis of 8 nutrients protective against cancer and heart disease). For ease of interpretation, scores above 100 were capped at 100 (indicating that the food provides, on average, 100% DV of the qualifying nutrients per 100 kcal). Items in cruciferous (watercress, Chinese cabbage, collard green, kale, arugula) and green leafy (chard, beet green, spinach, chicory, leaf lettuce) groups were concentrated in the top half of the distribution of scores (Table 2) whereas items belonging to yellow/orange (carrot, tomato, winter squash, sweet potato), allium (scallion, leek), citrus (lemon, orange, lime, grapefruit), and berry (strawberry, blackberry) groups were concentrated in the bottom half (4–7).

The proposed classification scheme is offered in response to the call to better define PFV and may aid in strengthening the powerhouse message to the public. The focus on individual foods in terms of the nutrients they provide may facilitate better understanding of PFV than green leafy, yellow/orange, citrus, and cruciferous food groups that are emphasized. Messages might specify PFV to help consumers know what they are and choose them as part of their overall fruit and vegetable intake. As numeric descriptors of the amount of beneficial nutrients PFV contain relative to the energy they provide, the scores can serve as a platform for educating people on the concept of nutrient density. Expressing the nutrient desirability of foods in terms of the energy they provide may help focus consumers on their daily energy needs and getting the most nutrients from their foods. The rankings provide clarity on the nutrient quality of the different foods and may aid in the selection of more nutrient-dense items within the powerhouse group.

Foods within particular groups were studied; thus, other nutrient-dense items may have been overlooked. Because it was not possible to include phytochemical data in the calculation of nutrient density scores, the scores do not reflect all of the constituents that may confer health benefits. Warranting study is the utility of approaches defining PFV based on the presence (regardless of amount) of nutrients and phytochemicals. Although nutrient density differences by powerhouse group were examined, a true validation of the classification scheme is needed. Future studies might identify healthful diets and examine correlations with PFV or look for correlations between intake of PFV and health outcomes (3).

This study is an important step toward defining PFV and quantifying nutrient density differences among them. On the basis of the qualifying nutrients, 41 PFV were identified. The included foods may aid in improving consumer understanding of PFV and the beneficial nutrients they provide.


TK: There is no fruit and vegetable that is not a PFV compared with a Butterfinger. So, for those few commodities that didn't make the cut, growers can at least take comfort in that. And, in an outcome we didn't see coming(like the vanishing Caribou coffee house), watercress can lord it over blueberries. At least for now.

 Also read:

 Washington Post Watercress;who knew?