A-Z vision health Articles

What Is Bilberry?

Bilberry extract became valued as a medicinal agent during World War II when British pilots claimed that eating bilberries improved their visual acuity, night vision and ability to adapt to glare. Scientific studies have backed up these testimonials by uncovering bilberry’s antioxidant properties. Free radicals are unstable molecules that in their bid to become more stable must bump into healthy cells and cause damage.

Bilberry Extract Health Benefits: An Antioxidant Powerhouse

Eye Health

Bilberry’s antioxidant properties neutralize free radicals and therefore reduce damage to vessels all over the body, including those in the eye. Cataracts are caused by free radical damage in the lens of the eye and therefore bilberry may help protect against and heal cataracts. Other eye problems that Bilberry supports, include:

• Macular Degeneration
• Diabetic Retinopathy
• Night Blindness 
• Myopia

Anti-Aging

Bilberry has anti-aging properties because as an antioxidant, it protects the body against environmental pollutants, free radicals and other substances that lead to aging. Bilberry makes an excellent anti-aging skin supplement when taken internally and since it boosts collagen, can also have a positive effect on hair and nail health. 

Collagen Support

Bilberry also stabilizes the connective tissue called collagen. Thus it is beneficial for conditions of collagen instability in the vascular system such as varicose veins, phlebitis, joints and heart disease. 

Promotes Healthy Circulation 

Bilberry inhibits blood clotting and can be useful to increase circulation in cases of atherosclerosis and diabetes. Therefore, if you have circulatory issues, you may want to consider a bilberry supplement. 

Bilberry Extract Supplement Varieties

The berries of the bilberry plant contain the greatest concentration of the medicinally active ingredients, anthocyanidins. Supplements often contain the whole plant in encapsulated form. By purchasing supplements standardized to anthocyanadins one can be sure that there are some dried berries in the formula. Bilberry can be found in formulas for enhancing eye health and are often combined with other antioxidants, berries and herbs, such as eyebright.

Safety Information Of Bilberry Extract

Bilberry should be used with caution if you are nursing or pregnant. Bilberry can interfere with iron absorption and should not be taken at the same time as iron supplements. Bilberry may alter blood sugar levels and should be used cautiously in diabetics and hypoglycemics.

What Are Carotenoids?

Carotenoids are a class of compounds that are produced in the chloroplasts of some plants, bacteria, algae and fungae. Since these molecules absorb light in the blue spectrum, foods containing them often appear yellow, orange, or red. Interestingly, this blue light easily excites other molecules to form free radicals, so by absorbing it, carotenoids act as antioxidants.

Science has not yet discovered all of the carotenoids, although over 600 have been identified so far. Two major classifications are carotenes, an oxygenated form of carotenoid, and xanthophylls, which do not contain oxygen. Common xanthophylls are astaxanthin, lutein and zeaxanthin. The most well-known carotenes are lycopene and beta-carotene. Beta-carotene is the only carotenoid mentioned in this article that can be converted to vitamin A in humans.

What Do Carotenoids Do?

The function of each carotenoid is different, although each can be considered as an antioxidant that helps to protect the body against the damage caused by free radicals. The more common ones are involved in eye and vision health, as well as the prevention of cancer and the visible signs of aging.

Types of Carotenoids

Beta Carotene

Beta-carotene is converted to vitamin A in the liver and is often used instead of vitamin A supplementation to avoid potential toxicity. The remaining beta-carotene that is not converted to vitamin A by the liver is a free radical scavenger (antioxidant).

Lycopene

Lycopene is the carotene pigment molecule that gives ripe tomatoes their bright red colour. It is a potent antioxidant with affinity for the prostate gland that may help lower the risk of unhealthy cell growth.

Lutein and Zeaxanthin

Lutein and zeaxanthin work in the eye as antioxidants. Studies show that lutein and zeaxanthin protect the eye from damage and can reduce the incidence of eye diseases such as macular degeneration and cataracts.

Astaxanthin

This red pigment molecule is responsible for making shrimp and lobster change colour when they are cooked. It is a strong antioxidant and plays a role in protecting the eye, heart, and liver as well as preventing diabetes, metabolic syndrome, and neurodegenerative diseases such as Parkinson's and Alzheimer's.

Taking Carotenoids As A Supplement

The carotenoids are most effective when taken together in a complex, likely because this is how they exist in food. It is recommended to use a natural beta-carotene or carotenoid complex for the best results. Some companies extract natural carotenoid complex from sea algae, to create a product called "Betatene".

Important Information

Absorption of carotenoids is inhibited by some medications including colchicine, mineral oil and some cholesterol-lowering medications. Most carotenoids have not been tested for supplementation use during pregnancy or lactation, because of this it is recommended that these women limit their intake to dietary sources.

What is Vitamin A?

Vitamin A is a nutrient in the body that can be found in many forms. When it is being stored for later use, vitamin A is found in a form called retinol. The active form of this vitamin is called retinal, and is used in the retina (the back of our eye) for both low light and colour vision. These two forms are easily converted back and forth between them as the body requires. 

Oxidized vitamin A is called retinoic acid and cannot be converted back to the other forms in the body. Interestingly, although humans cannot synthesize this vitamin directly, the liver can convert certain types of carotenoids, such as beta-carotene, into retinol as required.

Carotenes and Vitamin A

Vitamin A is absorbed through the digestion of animal products. The liver can also synthesize vitamin A from some carotenes that are found in vegetables. The only carotenes that can undergo this conversion in humans are: alpha-carotene, beta-carotene, gamma-carotene (xanthophyll) and beta-cryptoxanthin. This conversion is also dependent on an enzyme that may have reduced function in some individuals, resulting in an increased need for direct ingestion of vitamin A.

Key Health Benefits of Vitamin A

Vision Health

In the retina of the eye, retinal binds to two different protein types called rods (rhodopsin), and cones (iodopsin). These proteins line the back of the eye in vast numbers, like the pixels of your computer screen. When these pigment molecules are exposed to light, enzymatic reactions occur that trigger the optic nerve to send a signal to the visual centre of the brain. The brain then processes the pattern of these reactions to produce the image we see in our minds. Interestingly, iodopsin is required to see colour, and rhodopsin is needed to see black and white, and for night vision. Vitamin A deficiency often initially presents with poor night vision or night blindness as one of the first symptoms. As deficiency progresses, colour vision may suffer as well.

Retinoic Acid and Skin

Another form of this nutrient in the body is called retinoic acid, which is created by irreversible oxidation. This form of vitamin A plays a role in gene transcription, either signalling or inhibiting gene expression. Retinoic acid also plays a role in skin health and can be synthesized in the body from retinyl palmitate. Thus, retinyl palmitate is often found in commercial acne treatments and skin creams. Tretinoin, a similar chemical, can be applied topically to reduce fine lines in the skin and fade age spots. In fact, one form of retinoic acid is used in high doses orally, and is a prescription medication for acne treatment, you probably know as "Accutane" (isotretinoin).

Immune Effects

This nutrient is also required for red blood cell production and overall immune function. It serves to enhance the immune response in epithelial tissues, like skin and mucous membranes, making them more resistant to infection. Some current research has been exploring the use of extremely high doses of vitamin A for the treatment of immunocompromised conditions, but severe toxic side effects have prevented further human trials.

Signs of Vitamin A Deficiency

In most of the world, deficiency in this nutrient is uncommon, but it is extremely common in developing countries, particularly Southeast Asia and Africa. When these deficiencies occur, they primarily affect the eye, causing dryness, night blindness or total blindness. Vitamin A deficiency can also result in growth issues and has been found to be associated with a variety of female reproductive system concerns. It is believed that this is due to its function in the development of mucous membranes. Individuals with amenorrhea, menorrhagia, cervical dysplasia, fibrocystic breasts, interstitial cystitis, and vaginitis will all benefit from either oral supplementation or topical applications of this nutrient.

Increasing Vitamin A Intake

Food sources of vitamin A include: 

• Liver (beef liver, cod liver oil)
• Carrot
• Sweet potato
• Spinach & Kale
• Pumpkin
• Butter, Cheddar cheese, Egg, and Milk

Recommended dosing of Vitamin A in supplement form varies, but is from 2000-3000IU/day (600-900 μg/day). During lactation and pregnancy, the RDAs are slightly increased, but caution should be used as this nutrient can cause birth defects when taken in high doses.

Important Information

Osteoporosis is more likely to develop in individuals ingesting higher than recommended amounts of Vitamin A (5000IU/day or more). 

High amounts of this nutrient are particularly hard on a developing fetus and can cause birth defects, particularly during the first trimester. Pregnant women should be careful to take the appropriate dosage. It may be preferable to supplement beta-carotene instead of directly supplementing this during these times to allow the body to only synthesize as much vitamin A as it requires.

Vitamin A Toxicity

Vitamin A is fat-soluble, so excesses are not easily excreted from the body (unlike most water-soluble vitamins), and large amounts can cause toxicity. Toxic signs and symptoms include: nausea, vomiting, jaundice, elevated liver enzymes, lack of appetite, blurry vision, headaches, hair loss, drowsiness, and altered mental state. A water-soluble form of vitamin A was synthesized in a lab, but was found to be significantly more toxic than its natural counterpart.