Fresh vs Processed
Because the availability of fresh blueberries is limited seasonally, people have many questions regarding the sustainability of the antioxidant health benefit in blueberries after they've been processed. Good question - and here's some good answers!
Does cooking blueberries effect their antioxidants?
Apparently not. The substances are fairly heat-stable. In a 2009 study, for instance, blueberries that were microwaved, simmered, pan-fried or baked showed no significant loss in antioxidants. In fact, pan-frying for a short time actually increased antioxidant activity, possibly because it breaks down cell walls, releasing the antioxidants.
What about freezing or drying them?
A study from Australia in 2004 found that blueberries frozen for up to eight months still had high levels of antioxidants. Dried blueberries also showed as much antioxidant activity as fresh ones.
What are the health benefits of blueberries?
They have blood sugar-lowering, anti-inflammatory, neuroprotective, anti-cancer and other beneficial effects—at least in lab studies. Many of the benefits of blueberries are attributed to their anthocyanins, which are also found in lower levels in blackberries, black currants, red wine, grape juice and other red/blue/purple foods.
In one, published in the Journal of Nutrition last year, obese people with cardiovascular risk factors who drank a blueberry beverage every day for eight weeks showed a significant drop in blood pressure and a decrease in markers of oxidative stress. The study used the equivalent of two cups of blueberries a day. And in a small study published in the Journal of Agricultural and Food Chemistry, older people with early memory decline who drank a lot of blueberry juice (15 to 21 ounces a day) for 12 weeks showed improvements on memory tests.
The bottom line
Blueberries are super in terms of their antioxidants and potential health benefits. And they cost less than fruits such as goji and açaí, which are hyped as superfruits. Frozen, juiced, dried or canned blueberries are great options to turn to when berries are not in season, or just for convenience.