Strawberries rank fourth among fruits, behind only blackberries, raspberries, and cranberries in antioxidant content. In addition to their rich phytonutrient content, strawberries contain the highest levels of Vitamin C of any other of 66 fruits tested in a study in Iran. They also contain substantial amounts of manganese, which contributes to the enzyme superoxide dismutase, a key source of antioxidant activity in our bodies.
Cancer
Strawberries are high in phytonutrients. They contain anthocyanins, flavonols, and ellagic and gallic acids. All of which have been shown to fight cancer. They also contain ellagitannins, which is considered a strong cancer fighter. Researchers believe these substances boost the activity of antioxidant enzymes such as superoxide dismustase, and to reduce inflammation by interacting with the enzymes that trigger the body’s inflammation response.
An in vitro study published in the Journal of Agricultural and Food Chemistry reported that strawberry extract decreased proliferation of both colon and breast cancer cells. The researchers tested both conventional and organic strawberries. Just as we have seen in other berry studies, the organic berries had more nutrients and showed better cancer-fighting results (1). Studies have also documented the strawberry’s cancer fighting power for cervical, esophageal and lung cancers.
In fact, an actual study using human participants in China was conducted by the Ohio State Comprehensive Cancer Center. After eating freeze-dried strawberry powder equivalent to two ounces of strawberries per day for six months, the pre-cancerous esophageal lesions of twenty-nine out of thirty-six participants were downgraded one degree. That is, those with lesions rated as having a severe chance of becoming cancer regressed to being only moderately likely to become cancerous, moderate lesions regressed to mild, and mild lesions regressed to not likely to become cancerous. (2)
Dementia
The newest strawberry research is in the area of age-related diseases and the impact of strawberries anti-inflammatory properties. While studies on humans are not completed, research has shown improved cognitive and motor function in aged animals. Researchers attribute these improvements to the strawberry’s anti-inflammatory properties of their phytonutrients, and suggest that strawberries may play a role in the prevention of or delay of age-related cognitive illnesses such as dementia. (3)
Diabetes
Strawberries also have a strong impact on blood sugar. Because strawberries have a glycemic index score of only 40, they are a recommended fruit for persons with type 2 Diabetes. However, recent research has shown that strawberries even reduce the blood sugar spike when eaten with table sugar. Researchers believe this is because the polyphenols in strawberries inhibit alpha-amylase, the enzyme responsible for breaking amylose starches into simple sugars. They reason that inhibiting this enzyme means fewer starches are reduced to simple sugars in the blood. (4)
Most strawberry research suggests, however, that dosage is important. Studies administering only one serving of strawberries per week didn’t share the positive results that studies where participants ate three or more servings per week.
Additional Health Benefits of Strawberries
The anti-inflammatory benefits of strawberries extends to the digestive system as well. Studies have suggested that the salicylic acid in strawberries helps to improve the symtoms of inflammatory problems in the colon, such as Crohn’s disease and ulcerative colitis.
Several cardiovascular benefits of eating strawberries have been documented by researchers. Eating one to two cups of strawberries per day reduces LDL cholesterol, helps control free radicals to reduce oxidation of cholesterol, and promotes healthy blood pressure.