Powerhouse Produce: What tops the list?

 Which fruit or vegetable is the most nutrient dense? You may be surprised to find out what tops the list.

Which fruit or vegetable is the most nutrient dense? You may be surprised to find out what tops the list.

Are all fruits and vegetables created equal? Ever wondered which fruits and vegetables provide us with the most disease fighting nutrients?  New research comparing the nutrient density of fruits and vegetables tells us that indeed there are significant differences between the nutrient quality of fruits and vegetables. And you may be surprised to find out which fruits and veggies topped the list.

In an attempt to better define powerhouse fruits and vegetables or those most associated with chronic disease reduction, a study was devised to classify and rank produce based on 17 different nutrients known for their role in preventing chronic disease. The nutrients tested were protein, fiber, potassium, calcium, zinc, iron, thiamine, riboflavin, folate, niacin, and vitamins A, B6, B12, C, D, E and K.   The study found that 41 of the 47 fruits and vegetables tested qualified under their definition of powerhouse fruits and vegetables, that is, they contained at least 10% of the recommended daily allowance (RDA) of the nutrients tested per 100 grams serving.

Of those 41 powerhouse fruits and vegetable, only the cruciferous vegetables and leafy greens cracked the top ten. The top ten powerhouse vegetables were watercress, Chinese cabbage, chard, beet greens, spinach, chicory, leaf lettuce, parsley, romaine lettuce, and collard greens. It seems the age old adage to ‘eat your greens’ really is solid advice.

 The colour green dominates the top 10 list of powerhouse fruits and vegetables. These 10 veggies packed in the greatest concentration of the 17 nutrients tested in the study.

The colour green dominates the top 10 list of powerhouse fruits and vegetables. These 10 veggies packed in the greatest concentration of the 17 nutrients tested in the study.

A surprising result of this study is the ranking of lettuce, a vegetable often thought to not provide much in the way of nutrition. The researchers ranked leaf lettuce in 7th, romaine lettuce in 9th and iceberg lettuce in 29th place. What's more surprising is that both leaf and romaine lettuce out ranked the much celebrated kale, which placed 15th.

Another notable observation is of the fruit tested, the top ranked fruit was red pepper at #17. Other fruits on the list were pumpkin (#20), tomato (#27), lemon (#28), strawberry (#30), winter squash (#32), orange (#33), and lime (#34). This may be an indication that we should focus a little more of our attention on vegetable consumption, if we want to pack in those disease fighting nutrients. In other words, of the 7-10 servings of fruits and vegetables recommended each day, perhaps only 2-3 of those should be limited to fruits.  

  Powerhouse Fruits and Vegetable list from Di Noia J. Defining Powerhouse Fruits and Vegetables: A Nutrient Density Approach. Prev Chronic Dis 2014;11:130390. DOI:    http://dx.doi.org/10.5888/pcd11.130390

Powerhouse Fruits and Vegetable list from Di Noia J. Defining Powerhouse Fruits and Vegetables: A Nutrient Density Approach. Prev Chronic Dis 2014;11:130390. DOI: http://dx.doi.org/10.5888/pcd11.130390

The six fruits and vegetables that did not qualify to carry the powerhouse title were raspberries, blueberries, cranberries, tangerines, onions and garlic. This may come as a surprise as a number of those disqualified from the study have been touted in the scientific community and media for their healthfulness. Does the exclusion of these fruit and vegetables, along with others not included in the study, mean that they aren’t nutritious or that they don’t benefit us? Certainly not!

As noted, this study only tested for the presence of 17 nutrients in a relatively small number of fruits and vegetables. Although those 17 nutrients examined are important for maintaining health, there are other nutrients including phytochemicals that were not tested for in this study. For example, phytochemicals such as the organosulfur compounds in garlic and the anthocyanidins in blueberries are believed to play a role in disease prevention, yet both garlic and blueberries failed to meet the powerhouse criteria.

The take home message from this study is that there are some fruits and vegetables that will get you more bang for your buck, nutritionally speaking. Take a look at the list of powerhouse fruits and vegetables and try to include the top ranking ones as part of your recommended 7-10 daily servings of fruits and vegetables. It’s always best to mix it up and include a variety of fruits and vegetables each day, whether they are on the list or not. Variety is the spice of life, not only keeping your palate entertained but also ensuring you get a wide array of vitamins, minerals and phytonutrients.

Interested in giving the number one ranked powerhouse vegetable, watercress, a try? This refreshing watercress salad is a wonderful way to introduce this nutrient packed vegetable to your family!