Historically, blueberries have been used to treat diarrhea, scurvy, and other ailments. Today, blueberries are used as a traditional remedy for diarrhea, eye problems, varicose veins, poor circulation, and even cancer prevention.
The leaves of the blueberry plant are used for other conditions, including diabetes. The leaves can be turned into extracts or used to make blueberry tea.
What makes these berries so phenomenal is their content of substances called anthocyanins. Anthocyanins are plant pigments that have strong antioxidant properties. A study showed that blueberries had positive effects on vision in low-light conditions. These antioxidants cleanse the body of free radicals, with the intention of helping to prevent or reverse damaged cells.
In other studies, blueberries showed many other health benefits, such as reducing the risk of heart disease, stroke, cancer, and macular degeneration. They also contain vitamin C, which is another powerful immune system booster.
Most importantly, the blueberry, known scientifically as Vaccinium myrtillus L., is one of the richest natural sources of anthocyanins. Anthocyanins are polyphenolic components that give blueberries their blue/black color and a very high antioxidant content.
These powerful anthocyanins are considered key bioactive compounds responsible for numerous health benefits. They are most famous for their ability to improve vision, but it has been reported that they lower blood sugar, have anti-inflammatory effects, promote antioxidant defense, and reduce oxidative stress.
This makes the fruit highly sought after in the prevention and treatment of diabetes, inflammation, dyslipidemia, hyperglycemia, or increased oxidative stress, cardiovascular diseases, cancer, and dementia, among other age-related diseases.
Blueberries contain numerous phenolic compounds, including flavonols, quercetin, catechins, tannins, ellagitannins, and phenolic acids; however, the anthocyanins found in the fruit are by far the largest contributor to its phytonutrient density. These phenolic compounds are antioxidants, as well as iron chelators, which can help eliminate heavy metals from the body and are used in chelation therapy.
Although most focus on the antioxidant properties of this fruit, studies have shown that the effects can extend to involve cellular signaling pathways, gene expression, DNA repair, and cell adhesion, as well as antitumor and antimicrobial effects.
Health Benefits
1. Improved Vision
Due to anthocyanins, blueberries are widely used to improve night vision or visual impairments in low-light conditions, reducing vascular permeability and capillary fragility. It has been reported that during World War II, British fighter pilots improved their night vision after eating blueberry jam.
Blueberries have been suggested as a treatment for retinopathy, which is damage to the retina. They have also shown protective effects against macular degeneration, glaucoma, and cataracts, especially when used with lutein.
2. Helps Eliminate Circulation Problems
Health professionals use blueberry extracts to treat circulation problems, known as chronic venous insufficiency. Research suggests that this condition, which occurs when the valves in the veins of the legs that transport blood to the heart are damaged, can be improved by taking blueberry extract.
Other studies suggest that daily intake of anthocyanins from blueberries for up to six months could reduce swelling, pain, cramps, and burning sensations associated with chronic venous insufficiency.
3. Reduces Bad Cholesterol
The anthocyanins found in blueberries can strengthen blood vessels and prevent the oxidation of LDL cholesterol (bad cholesterol), a major risk factor for atherosclerosis, the plaque that blocks blood vessels, leading to heart attacks and strokes.
One study reported that blueberry intake, compared to blackcurrants, reduced total and LDL cholesterol levels. In fact, the total anthocyanin content was four times higher in blueberries than in blackcurrants, making them a better choice for lowering LDL cholesterol levels.
4. May Improve Blood Sugar Levels in Diabetics
Traditionally, blueberry leaves have been used to control blood sugar levels in people with diabetes. Research shows that most berries help reduce the body’s glucose response after consuming a high-sugar meal, and studies suggest they can be effective for managing blood sugar levels, especially when combined with oatmeal, although more research is needed.
5. Helps Prevent Cancer
In vitro studies and animal tumor models have demonstrated that the anthocyanins in these fruits have cancer-preventive properties due to their antioxidants; additionally, berries have anti-inflammatory effects. It has been shown that anthocyanin-rich blueberry extract inhibits the growth of colon cancer cells.
In a DNA study, an anti-inflammatory profile was observed in macrophages treated with blueberry extract, and since inflammation is a significant risk factor for cancer, it may be very useful in its prevention.
6. Effective for Treating Diarrhea
Blueberries have been used in European medicine to treat diarrhea for many years. The fruit contains tannins, substances that act both as an anti-inflammatory and as an astringent that helps constrict and tighten tissues. By reducing intestinal inflammation, it is believed to help alleviate diarrhea symptoms.
7. Reduces the Risks of Alzheimer’s Disease
Evidence suggests that fruit and vegetable juices containing various phenolic compounds can reduce the risk of developing Alzheimer’s disease. In some cases, symptoms of Alzheimer’s disease have significantly decreased following treatment with myricetin, quercetin, or anthocyanin-rich extracts found in blueberries, and behavioral anomalies have been shown to be alleviated.
