Blueberries
Blueberries are often labeled a superfood. They are low in calories and incredibly good for you. The blueberry bush (Vaccinium sect. Cyanococcus) is a flowering shrub that produces berries with a bluish, purple hue.
They are green in color when they first appear, then deepen to purple and blue as they ripen.
The two most common types are:
- Highbush blueberries: The most common cultivated variety in the US.
- Lowbush or “wild” blueberries: Typically smaller and richer in some antioxidants.
Blueberries are among the most nutrient-dense berries. A 1-cup serving of blueberries contains:
- Fiber: 4 grams
- Vitamin C: 24% of the RDI
- Vitamin K: 36% of the RDI
- Manganese: 25% of the RDI
- Small amounts of various other nutrients
They are also about 85% water, and an entire cup contains only 84 calories, with 15 grams of carbohydrates.
Antioxidants protect your body from free radicals, which are unstable molecules that can damage your cells and contribute to aging and diseases. Blueberries have one of the highest antioxidant levels of all common fruits and vegetables.
The main antioxidant compounds in blueberries belong to a family of polyphenols antioxidants called flavonoids. One group of flavonoids in particular called anthocyanins is thought to be responsible for much of these berries’ beneficial health effects. Blueberries directly increase antioxidant levels in your body.
Oxidative DNA damage is an unavoidable part of everyday life. It is said to occur tens of thousands of times per day in every cell in your body. DNA damage is part of the reason we grow older. It also plays an important role in the development of diseases like cancer. Because blueberries are high in antioxidants, they can neutralize some of the free radicals that damage your DNA.
In one study, 168 people drank 34 ounces of a mixed blueberry and apple juice daily. After four weeks, oxidative DNA damage due to free radicals was reduced by 20%.
Oxidative damage is not limited to your cells and DNA. It is also a problem when your LDL cholesterol is oxidized. In fact, oxidation of LDL cholesterol is a crucial step in the heart disease process. The antioxidants in blueberries are strongly linked to reduced levels of oxidized LDL, making blueberries very good for your heart.
A daily 2-ounce serving of blueberries lowered LDL oxidation by 27% over eight weeks in obese people. Another study determined that eating 2.5 ounces of blueberries with a main meal significantly reduced the oxidation of LDL cholesterol.
A study in 93,600 nurses found that those with the highest intake of anthocyanins, the main antioxidants in blueberries, were at a 32% lower risk of heart attacks compared to those with the lowest intake.
Oxidative stress can accelerate your brain’s aging process, negatively affecting brain function. According to animal studies, the antioxidants in blueberries may affect areas of your brain that are essential for intelligence. They appear to benefit aging neurons, leading to improvements in cell signaling.
Human studies have also yielded promising results. In one of these studies, nine older adults with mild cognitive impairment consumed blueberry juice every day. After 12 weeks, they experienced improvements in several markers of brain function.
A six-year study in over 16,000 older individuals found that blueberries and strawberries were linked to delays in mental aging by up to 2.5 years.
Blueberries provide moderate amounts of sugar compared to other fruits. One cup holds 15 grams of sugar, which is equivalent to a small apple or large orange. The bioactive compounds in blueberries appear to outweigh any negative impact of the sugar when it comes to blood sugar control.
Research suggests that anthocyanins in blueberries have beneficial effects on insulin sensitivity and glucose metabolism. These anti-diabetes effects occur with both blueberry juice and extract. In a study in 32 obese people with insulin resistance, two blueberry smoothies daily caused major improvements in insulin sensitivity. Improved insulin sensitivity should lower the risk of metabolic syndrome and type 2 diabetes.
Blueberries are closely related to cranberries. They also have substances called anti-adhesives that help prevent bacteria like E. coli from binding to the wall of your bladder.
Blueberry supplements may lessen the damage that occurs at a molecular level after exercise, minimizing soreness and reduced muscle performance. In a small study in 10 female athletes, blueberries accelerated muscle recovery after strenuous leg exercises.
People who are taking blood-thinners, such as warfarin, must not suddenly change their intake of blueberries or other sources of vitamin K. Vitamin K plays a key role in blood clotting, and it could affect the blood-thinning action of the drug.
How to Buy
Blueberries are available fresh, frozen, freeze dried, and in jellies, syrups, and jams. Be sure to check the label of frozen and dried blueberries for added sugars. When selecting jellies or jams, choose all-fruit spreads without added sweeteners, juices, or fillers.
When you buy fresh blueberries, look for berries that are firm, dry, plump and smooth-skinned, with a silvery surface bloom and no leaves or stems. Size isn’t an indicator of maturity but color is. Berries should be deep purple-blue to blue-black.
Reddish blueberries aren’t ripe, and won’t ripen once they are picked but you can use them in cooking. Avoid blueberries that look soft or shriveled or have any signs of mold. If you see juice stains in a container of blueberries, the fruit might be bruised.
You can find pre-washed, unsweetened frozen blueberries packed in poly bags or boxes in most co-op frozen food sections.
A bag of frozen blueberries should feel loose and not clumped together. They’ve been individually quick frozen so you can remove a few at a time or use them in larger portions.
How to Store
Refrigerate fresh blueberries when you get them home, either in their original pack or in a covered container. Wash your blueberries just before you start snacking, and eat them within 10 days of purchase.
Avoid keeping blueberries in the coldest part of the fridge, or they will get damaged from the cold. The best place to store the berries is on the middle or bottom shelf. Try not to keep them in the crisper.
Store frozen blueberries in the freezer.
How to Cook
- Use blueberries as fresh toppings on oatmeal, waffles, pancakes, yogurt, or cereal for an extra burst of flavor and nutrition in your breakfast.
- Whip up a quick and easy smoothie using frozen berries, plant-based milk or yogurt.
- Mix fresh or dried blueberries into a spinach salad with walnuts.
- Fold blueberries into muffins and breads.
- Blend them in a food processor with a little water, as part of a fresh syrup to top desserts or breakfast foods.
Lemon and mint are common flavor pairings for blueberries, but there are plenty of others that often go overlooked. For example, rosemary, coconut, balsamic and banana all pair well with blueberries.