Many foods commonly consumed in the U.S. are valuable sources of antioxidants. But researchers have recently ranked the 50 best antioxidant sources among commonly eaten foods and found strawberries to be quite exceptional. When total antioxidant capacity was measured against a uniform amount of food (100 grams, or about 3.5 ounces), strawberries ranked 27th best among U.S. foods. In addition,
when only fruits were considered, strawberries came out 4th among all fruits (behind blackberries, cranberries, and raspberries). However, since many foods (for example, spices and seasonings) are seldom consumed in amounts as large as 3.5 ounces, researchers also looked at common serving sizes for all foods and their total antioxidant capacity. In this evaluation based on common serving sizes, strawberries came out 3rd among all U.S. foods including spices, seasonings, fruits, and vegetables! (In this analysis
based on serving size, only blackberries and walnuts scored higher in total antioxidant capacity.) When we hear the word "strawberry," we might think about a very commonplace fruit. But the antioxidant capacity of strawberry is anything but common!
Recent research has shown strawberries to be a surprisingly fragile, perishable, and delicate fruit. Food scientists recently took a close look at storage time, storage temperature, storage humidity, and degree of strawberry ripeness and found significant differences between different types of strawberry storage. On average, studies show 2 days as the maximal time for strawberry storage without
major loss of vitamin C and polyphenol antioxidants. It's not that strawberries become dangerous to eat or invaluable after 2 days. It's just that more storage time brings along with it substantially more nutrient loss. In terms of humidity, 90-95% has been shown optimal. Most refrigerators will average a much lower humidity (between 80-90%). Because air circulation inside the fridge can lower humidity, you may want to give your strawberries more storage humidity by putting them in your refrigerator's cold storage
bins (if available). Those cold storage bins will help boost humidity by reducing air circulation. If your fridge does not have storage bins, you can use a sealed container for refrigerator storage of your strawberries. Optimal temperature for strawberry storage over a 2-day period has been found to be relatively cold—36F (2C). All public health organizations recommend refrigerator temperatures of 40F (4.4C) as the maximum safe level for food storage. However, if you are storing sizable amounts of fruits and
vegetables—including strawberries—in your refrigerator, you may want to consider setting your refrigerator to a lower-than-maximum temperature setting in the range of 36-38F (2-3C). In terms of ripeness, recent studies have found that both underripeness and overripeness can have an unexpectedly large impact on the phytonutrient content of strawberries, especially their antioxidant polyphenols. Fortunately, optimal strawberry ripeness can be judged by color. You'll want to consume your strawberries when their
amazing pinkish-red color is most vibrant and rich in luster.
Improved blood sugar regulation has been a long-standing area of interest in research on strawberries and health. However, scientists have recently discovered a fascinating relationship between intake of strawberries, table sugar, and blood sugar levels. As you might expect, excess intake of table sugar (in a serving size of 5-6 teaspoons) can result in an unwanted blood sugar spike. But you
might not expect this blood sugar spike to be reduced by simultaneous consumption of strawberries! Yet that's exactly what researchers have discovered. With the equivalent of approximately one cup of fresh strawberries (approximately 150 grams), blood sugar elevations from simple sugar intake can be reduced. These health science researchers have further speculated that polyphenols in strawberries played a major role in helping regulate blood sugar response. This finding is great news for healthy persons wanting
to maintain healthy blood sugar levels, and also for persons with type 2 diabetes who enjoy fresh strawberries and want to enjoy them on a regular basis.
Given their amazing combination of phytonutrients—including anthocyanins, ellagitannins, flavonols, terpenoids, and phenolic acids—it's not surprising to find increasing research interest in the anti-inflammatory properties of strawberries. But it's still exciting to see this remarkable fruit lowering levels of inflammatory markers like C-reactive protein (CRP) when consumed several days per
week in everyday amounts of approximately one cup. Recent research has shown that several blood markers for chronic, unwanted inflammation can be improved by regular intake of strawberries. Interestingly, in one large-scale study, consumption of strawberries did not show anti-inflammatory benefits until strawberries were consumed at least 3 times per week. This research is one of the reasons we recommend inclusion of berries at least 3-4 times per week in your overall fruit intake.
In our Healthiest Way of Eating Plan, we encourage the consumption of 5-10 servings of fruits-plus-vegetables (combined) each day. We believe that the balance between fruits and vegetables can vary from day to day, depending upon personal health factors, personal taste preferences, and optimal combining of foods in recipes as well as meals. We recognize that our recommendation calls for a more
generous amount of fruits and vegetables than the amount recommended by the Centers for Disease Control (CDC) at the U.S. Department of Health and Human Services (DHHS). The CDC recommends between 1.5-2.5 cups of fruit and 2.5-4.0 cups of vegetables per day, as well as a target goal of at least 5 fruit-plus-vegetable servings (combined) per day.
With respect to berries, the CDC approach provides the example of strawberries and explains that 8 large strawberries count as 1 cup. If all fruit for the day were to be obtained from strawberries, the CDC recommendation would translate into 12-20 strawberries for the day as a way of meeting a requirement for 1.5-2.5 cups of fruit.
We recommend that you set your fruit goals higher than these CDC amounts. Based on the scientific research, we believe it's going to take closer to 3 fruit servings per day to provide you with optimum health benefits. With respect to berries in particular, we recommend that you include berries at least 3-4 times per week within your fruit servings.
In several of our sample meal plans, we include berries on a daily basis! It would definitely not be a mistake for you to include a serving of berries in your daily meal plan! At the same time, we recognize that the fruit group contains many outstanding fruit options, and personal preferences (as well as local and seasonal availability) can vary greatly. Also, remember that large strawberries--at
about 18 grams per berry and 8 berries per cup--stand at one end of the berry range in terms of size and recommended amount. Most berries are considerably smaller in size and weight, and a one-cup serving allows you to eat a lot more berries! With blueberries, for example, the average weight per berry is closer to 1-2 grams, and a cup's worth of blueberries means about 100-150 berries. For cranberries and raspberries, the amount would be similar.
The fragrantly sweet juiciness and deep red color of strawberries can brighten up both the taste and aesthetics of any meal. Not only do they taste great they are among the fruits and vegetables ranked highest in health-promoting antioxidants. Antioxidants help combat the damaging effects of free radical activity to cellular structures and DNA. Like the other World's Healthiest Fruits, we recommend
enjoying strawberries raw (not in baked/cooked desserts) because they provide you with the best flavor and the greatest benefits from their vast array of nutrients and digestion-aiding enzymes. Peoples around the world have long been eating fruit for dessert, not only as a delicious ending to a meal but as a great digestive aid as well.