Visio-Max

[Nutritional Advisers Product Information]

Rationale

Visio-MAX is an antioxidant formula specially designed to support eye health, containing the trace mineral selenium with beta-carotene, vitamins C, E, B1, B2, B6 and bilberry extract.

Every day the human eye is exposed to ultra-violet light and other damaging influences. As a result free radicals may form in the lens of the eye. The oxidation of lens proteins is believed to play an important part in the development of eye disease.

The health of the eye is largely dependent on a rich supply of nutrients and oxygen. Relatively speaking the amount of blood flow through the eye is the greatest in the body, which explains the importance of nutrition and the circulatory system for optimal eye health and function. Overview of the Main Ingredients

Bilberry Extract

The anthocyanosides found in bilberry have been shown to:

• Cross link collagen fibre and so strengthen connective tissue (1,2)
• Prevent free radical damage with their antioxidant action (2,3,4)
• Prevent the release of compounds that promote inflammation, normalise capillary fragility, (5) a possible beneficial factor for the prevention of glaucoma, where fluid balance is affected.
• Increase intra cellular vitamin C (6)

It appears that purple anthocyanosides have an affinity for the pigmented epithelium of the visual purple area of the retina. This area is responsible for vision and controls the adaptation from light to dark and vice versa. (7)

In one human study, bilberry extract plus vitamin E stopped progression of cataracts formation in 97% of fifty patients with senile cortical cataracts. (8)

Beta-Carotene

Carotenoids are the most ancient protectors against light, which were first developed by photosynthetic bacteria when life first began on earth. Like selenium, carotenoids have been shown to protect the skin from redness and damage following exposure to UV radiation.

Carotenoids are naturally occurring colourful compounds that are abundant in pigment in plants. Between 500-600 specific carotenoids have been identified, but only a small number have been shown to play a part in human health as a precursor to vitamin A and as antioxidants.

The beta-carotene preparation in Visio-MAX is Betatene®, which provides beta-carotene in combination with other carotenoids.

• A study in the US showed that high plasma levels of at least two of three antioxidant vitamins (carotenoids, vitamin C and E) were associated with a significant decreased risk of cataract development. (9)
• A Multicentre Eye Disease Case-Control study in the United States showed that individuals in the highest quintile of carotenoid intake had a 43% lower risk for Age Related Macular Degeneration compared to those in the lower quintile. Zeaxanthin and lutein were the carotenoids most strongly associated with a decreased risk. (10)

Beta-carotene can also be converted to vitamin A. The best known function of this vitamin is its role for eye health, where it is needed for the production of rhodopsin, a pigment essential for good vision, especially in relation to night blindness. (12)

Selenium

Selenium is required as a co-factor for the enzymes glutathione peroxidase and thioredoxin reductase. These enzymes form part of the body's antioxidant enzyme systems that deal with the neutralisation of hydrogen peroxide and lipid peroxides.

Research indicates that the various antioxidant enzymes enhance the body's ability to deal with free radicals, which are destructive molecules or atoms created by pollutants such as cigarette smoke, smog or exposure to ultraviolet light for example. It appears that oxidative damage is a common denominator in the ageing process as well as certain major diseases such as heart disease, cancer, diabetes, cataract and macular degeneration. (11)

Vitamin C

This vitamin is classed as a water phase antioxidant, which also regenerates vitamin E. Research studies indicate that vitamin C has an immune boosting effect in those who have low intakes of this vitamin. In addition it is important for the synthesis of procollagen of connective tissue cells, expecially during periods of growth. Glycosaminoglycan (GAG's) formation may require ascorbic acid as sulfate carrier. GAG's are part of the 'gel matrix' of the ground substance between all cells in organs. Strong connective tissues play a part in making the body more resistant to unwanted micro organisms and increase the resilience of certain body tissues to wear and tear. An example is the pressure exerted on arteries by blood pressure. The adrenal medulla is one of the tissues with the highest vitamin C concentration, where this vitamin is involved in the production of hormones closely linked with stress control. (12)

In relation to eye health one of the presumed functions of vitamin C is the protection of of lens and retina from the damaging effects of ultraviolet radiation. In addition it seems to be required for the removal of hydrogen peroxide. Non-enzymatic reactions are particularly important in the aqueous humour, where enzymes are largely absent but vitamin C concentration high. (13)

In a laboratory experiment, vitamin C in the retina fell under continous light exposure indicating that this vitamin was used up to protect the retina from light damage. (14)

Vitamin E

Vitamin E is a lipid phase antioxidant, playing an especially important role in all cell membranes where it protects unsaturated fatty acids and cholesterol. This vitamin has also been linked to healthy muscle function and fertility in both males and females. (12)

Vitamins B1, B2 and B6

Vitamin B1 functions as part of the enzyme, thiamine pyrophosphate, essential for energy production, carbohydrate metabolism and nerve cell function. Vitamin B2 is crucial in the energy production process and is involved in the regeneration of glutathione, an important protector against free radical damage. Vitamin B6 is required by the human body for the proper functioning of more than 60 different enzymes. This vitamin plays a vital role in the multiplication of cells and therefore is important in the proper function of the immune system, mucous membranes, skin and red blood cells, as these cells and tissues are rapidly replicating. Vitamin B6 plays a critical role in brain chemistry, as it is involved in the manufacture of certain amino acid neurotransmitters. (15)

Vitamin B2 deficiency can lead to cataract BUT people prone to cataract should not take more than 10 mg of this vitamin daily, because the combination of light oxygen and riboflavin increases the risk of cataract development.

References:

1. Detre A. et al, Studies on vascular permeability in hypertension, Action of anthocyanosides. Clin. Physiol Biochem, 4, 143-49, 1986

2. Gabor M., Pharmocologic effect of flavonoids on blood vessels, Angiologica, 9, 355-74, 1972

3. Monboisse J. C. , Braquet P and Borel J.P, Oxygen-free radicals as mediators of collagen breakage, Agents Action, 1984, Vo1.5, pp49-50

4. Laplaud P. M., Antioxidant action of Vaccinium myrtillus extract on human low density lipoproteins in vitro; initial observations, Fundam Clin Pharmacol, 1997; 11, (1): pp35-40

5. Mian E. et al. , Anthocyanosides and the walls of microvessels: Further aspects of the mechanism of action of their protective effect in syndromes due to abnormal capillary fragility, Minerva Med, 68, 3565-3581, 1977

6. Khunau J., The flavonoids, a class of semi-essential food components: Their role in human nutrition, World Rev Nutr Diet, 24, 117-191, 1976

7. Wegman R. Maeda K., Tronche P. and Bastide P., Effects of anthocyanosides on photoreceptors, Cytoenzymatic aspects, Ann Histochim, 14, 237-256, 1969

8. Bravetti G., Preventive medical treatment of senile cataract with vitamin E and anthocyanosides: Clinical evaluation, Ann Ottalmol Clin Ocul, 1989, 115,

9. Jacques P. F., et al., Antioxidant Status in Persons With and Without Senile Cataracts, Arch. Opthalmol, 1988, 106, pp 337-340

10. Seddon J. M. et al., Dietary carotenoids, Vitamins A, C and E and Age-Related Macular Degeneration, JAMA, 1994, 272, pp1413-20

11. Cherskin E., Antioxidants in Health and Disease, The Big Picture, Journal of Orthomolecular Medicine, 1995, Vol. 10, No. 2

12. Linder M. C., (Editor), Nutritional Biochemistry and Metabolism with Clincial Applications, Prentice-Hall International Inc., 1991

13. Riley M. V., Physiologic neutralisation mechanisms and the response to corneal endothelium to hydrogen peroxide, CLAO J, 1990, Vol. 16, (Suppl 1.) pp S 16-21; discussion S21-2

14. Phelps-Brown N., Nutrition Supplements and the Eye, Optometry Today, September 1994

15. Murray M. T., Encyclopedia of Nutritional Supplements, Prima Publishing, 1996