Dr. Grossman’s Blog

A recent study published in the journal “Archives of Ophthalmology” showed an inverse link between vitamin C and cataracts. This Indian study was a population-based cross-sectional analytic study measuring the plasma vitamin C levels in 5638 people 60 years of age or older. These people were checked for cataracts and type of cataracts.

Low levels of lutein, zeaxanthin, retinol and vitamin C all showed to be correlated to cataracts. However, low vitamin C levels had by far the strongest association and were also consistent by type of cataract.

Ref: Ophthalmology. 2011;118(10):1958-1965

Editor’s Note: For more related information, go to Cataracts and Nutrition, Diet, Lifestyle

image via www.ars.usda.gov

Antioxidants have been shown to help the body in yet another way: treating male infertility.

A new study published in the journal Human Fertility discusses how oxidative stress can be a major factor in male infertility.  Oxidation is the natural byproduct of metabolism; antioxidants help to clear away this cellular debris.

The research highlights the effectiveness of antioxidants found in carnitines, and vitamins C and E as well as glutathione, selenium and coenzyme Q10 when it comes to measurable positive outcomes – that is, pregnancy rates in the subjects’ partners.  http://www.lef.org/news/LefDailyNews.htm?NewsID=10573&Section=Vitamins

Men who start loading up on their antioxidants may find that their eye health improves as well.  For example, studies have shown that glutathione can help reduce the likelihood of developing age related eye diseases like macular degeneration.

Learn more about how to prevent and treat macular degeneration naturally.

Scientists at the Laboratory for Nutrition and Vision Research have found that the regular consumption of specific “protective nutrients” in conjunction with  a low-glycemic-index, or “slow carb,” diet protected study participants from age-related macular degeneration. A food’s glycemic index is an indicator of how fast the carbohydrate it contains will spike blood sugar levels.

Vitamins C and E, zinc, lutein, zeaxanthin, and the omega-3 fatty acids DHA and EPA taken as part of a diet rich in low-glycemic-index foods reduced the risk of developing AMD.

Source: http://www.ars.usda.gov/is/pr/2010/100701.htm

For more ways to eat your way to healthier vision, please click here.

Researchers from Tufts University have found that a diet rich in omega-3 fatty acids and low in starchy carbohydrates can significantly reduce the risk of age-related macular degeneration (AMD).

The study, published in the journal Ophthalmology, is the first to calculate the combined effect of specific dietary nutrients and eating habits on a person’s risk for age-related macular degeneration.

During the study of 4003 participants in the ongoing Age-Related Eye Disease Study (AREDS), each dietary factor was assigned a percentile score; these scores were accumulated to find each participant’s compound score. The compound score was then evaluated for its association with the risk of AMD.

Researchers showed that vitamins C and E, zinc, lutein, zeaxanthin and the omega-3 fatty acids known as D.H.A. and E.P.A. were linked to lower risk for AMD.

The lowest risk of AMD was found in participants who regularly consumed a combination of these nutrients as part of a low-glycemic index diet.

The glycemic index (GI) is a measure of the effects of carbohydrates on blood glucose levels. Carbohydrates that break down rapidly during digestion, such as white bread and pastries, have a higher GI, as they release glucose into the bloodstream rapidly. Foods that break down more slowly, such as vegetables and proteins, have a lower GI value.

Read more about AMD on the Natural Eye Care website

Learn more about food sources for nutrients important for good eye health, including omega-3 fatty acids

SOURCE: “Dietary Compound Score and Risk of Age-Related Macular Degeneration in the Age-Related Eye Disease Study”, Chiu, et al, Ophthalmology, Volume 116, Issue 5, Pages 939-946.

Consumption of lutein has been linked to a reduced risk of developing age-related macular degeneration (AMD).  (read studies showing the benefits of lutein for eye health ).

In order to consume the levels of lutein recommended for good eye health many people take lutein supplements.  Results from a study published in the Journal of the American Dietetic Association suggest that it may be beneficial to take supplements of lutein along with vitamin C.

Researchers from the University of Wisconsin gave young healthy men and women supplements of lutein alone, or supplements of lutein combined with vitamins C or E.  It was noted that absorption of lutein varied greatly among individuals, regardless of whether they had taken lutein alone or with vitamins C or E.  However, it was determined that lutein was absorbed significantly faster when given simultaneously with vitamin C.

Learn about lutein and vitamin C supplements, as well as food sources for nutrients essential to good eye health

SOURCE:  “Lutein absorption is facilitated with co-supplementation of ascorbic acid in young adults”, Tanumihardjo, et al, J Am Dietetic Assoc 105:114-18, 2005.

Fresh-cut fruits is one of the fastest growing food categories in U.S. supermarkets, but what effect does processing and storage have on the nutritional value of the fruit?

Surprisingly, an international team of scientists has found that cutting and packaging fruit had almost no affect on the main antioxidants.

Their report, published in the Journal of Agricultural & Food Chemistry, shows that fresh-cut fruit retains vitamin C and other healthful antioxidants after days on the shelf.

The researchers obtained pineapples, mangoes, cantaloupes, watermelons, strawberries and kiwifruits from wholesale commercial sources in California.  The fruit was taken to a laboratory at the University of California in Davis. Half of each lot was processed as fresh-cut and half left whole.

Both lots were refrigerated under identical conditions for nine days and then tested for nutrient content. Tests showed only small losses of antioxidant compounds in the cut fruit compared to fruit left whole. Levels of some antioxidants in fresh-cut mango and watermelon actually increased due to exposure to light.

In general, researchers found that fresh-cut fruits visually spoil before any significant nutrient loss occurs. 

Learn more about antioxidants

Read other articles about the benefits of antioxidants for good eye health

SOURCE:  Quality Changes and Nutrient Retention in Fresh-Cut versus Whole Fruits during Storage, Gil et al, J. Agric. Food Chem., 2006, 54 (12), pp 4284–4296.

Age-related macular degeneration (AMD) is the most prevalent cause of irreversible blindness in developed countries. Researchers have shown that high dietary intake of beta carotene, vitamins C and E, and zinc may substantially reduce the risk of AMD.

Scientists at the Erasmus Medical Centre in the Netherlands investigated whether regular dietary intake of antioxidants is associated with a lower risk of incident AMD.

Participants in the study included 7983 inhabitants aged 55 years or older in a middle-class suburb of Rotterdam, the Netherlands. A baseline home interview and a series of examinations at the study center were conducted from 1990 until 2004. Food intake was assessed with a food questionnaire, and participants were evaluated for incident AMD (defined as soft distinct drusen with pigment alterations, indistinct or reticular drusen, geographic atrophy, or choroidal neovascularization). Incident AMD occurred in 560 participants after follow-up exams (conducted 8 years later, on average).

Study results showed that participants who consumed vitamin E and zinc were less likely to have AMD.

An above-median consumption of all 4 nutrients studied (beta carotene, vitamin C, vitamin E, and zinc) was associated with a 35% reduced risk of AMD.

Learn more about macular degeneration (AMD)

Find excellent food sources for beta carotene, vitamin C, vitamin E and zinc

SOURCE: Dietary intake of antioxidants and risk of age-related macular degeneration, Leeuwen et al, JAMA, 2005 Dec 28;294 (24):3101-7.

Cataracts are the leading cause of blindness around the world.  Studies suggest that oxidation is responsible for much of the damage to the lens and that antioxidants might protect the lens against formation of cataract.

Scientists at the University of Sydney and the University of Melbourne in Australia have released their investigation of the relationship between antioxidant nutrient intakes and the incidence of age-related cataract.

During 1992–1994, 3654 people aged 49 years or older attended baseline examinations as part of the Blue Mountains Eye Study.  Of these, 2464 (67.4%) of the participants were evaluated again at either 5 years or 10 years.  At each examination, lens photography was performed and food-frequency questionnaires were administered.  Antioxidants, including beta-carotene, zinc, and vitamins A, C, and E, were assessed. Cataract was assessed at each examination from lens photographs with the use of the Wisconsin Cataract Grading System.

Participants whose total intake of vitamin C (diet as well as supplements) was in the top 20% of the group had a reduced risk of nuclear cataract.  An above-median intake of combined antioxidants (vitamins C and E, beta-carotene, and zinc) was also associated with a reduced risk of incident nuclear cataract. 

Study authors concluded that higher intakes of vitamin C or the combined intake of antioxidants had long-term protective associations against development of nuclear cataract in this older population.

Learn more about antioxidants and their importance for good eye health

Read more about cataracts

SOURCE:  Tan, et al, Antioxidant nutrient intake and the long-term incidence of age-related cataract: the Blue Mountains Eye Study,  American Journal of Clinical Nutrition, Vol. 87, No. 6, 1899-1905, June 2008.

Long-term use of vitamin E supplements, as well as increased intake of riboflavin (vitamin B2) and/or thiamin (vitamin B1), may help reduce the progression of age-related lens opacification.

Lens opacification (or clouding) is caused by the disruption of the transmission of light through the eye lens due to damage to the lens cells.  When the opacification creates a reduction in visual acuity, it is referred to as a cataract.   Studies suggest that oxidation is responsible for much of the damage to the lens and that antioxidants, such as vitamins C and E, might protect the lens against formation of cataract.

Researchers conducted a five-year study of 408 women from the Nurses’ Health Study, aged 52 to 74 years at baseline. The women’s nutrient intake was calculated from five food frequency questionnaires collected over a 13- to 15-year period.  During this time the duration of vitamin supplement use was assessed using seven questionnaires.  At the end of this period the degree of nuclear density was determined.

Women who never supplemented with vitamin E had a 42% higher risk of getting cataracts than women who had supplemented vitamin E for 10 years.

Researchers concluded that long-term use of vitamin E supplements and higher riboflavin and/or thiamin intake may reduce the progression of age-related lens opacification.

Where can you find good sources of these vitamins?

• Vitamin E can be found in almonds, asparagus, avocado, nuts, olives, red palm oil, seeds, spinach and other leafy vegetables, wheat germ, and milk
• Riboflavin is found naturally in asparagus, bananas, okra, chard, cottage cheese, milk, yogurt, meat, eggs and fish.
• Foods rich in thiamin include yeast, oatmeal, brown rice, whole grain flour (rye or wheat), asparagus, kale, cauliflower, potatoes, oranges, liver (beef or pork), and eggs.

Learn more about cataracts, including recommended vitamins and supplements

Source:  Jacques, et al, Long-term Nutrient Intake and 5-Year Change in Nuclear Lens Opacities, Arch Ophthalmol. 2005;123:517-526.

A new European study suggests that the combination of low levels of antioxidants and blue light exposure from the sun is associated with certain forms of age-related macular degeneration (AMD).

The EUREYE study, led by Astrid Fletcher, Professor of Epidemiology of Ageing at the London School of Hygiene & Tropical Medicine, is the first to report an adverse association between sunlight exposure and AMD in people with low levels of antioxidants.

It is known that the eye is vulnerable to the damaging effects of sunlight. Ultraviolet radiation is absorbed by the lens, but visible or “blue” light penetrates to the retina, enabling us to see. Protection against the harmful effects of blue light is provided by antioxidant enzymes—including vitamins C and E, the carotenoids (lutein and zeaxanthin) and zinc.

Researchers measured levels of these nutrients in the blood of 4,753 older adults (average age 73.2) who were part of the European Eye Study. Participants were interviewed about their lifetime sunlight exposure and had photographs taken of their retinas to detect AMD.

Participants with the lowest concentrations of antioxidants in the blood were found to be most at risk of AMD due to blue light exposure. In fact, participants with the combination of blue light exposure and low levels of zeaxanthin, alpha tocopherol and Vitamin C were nearly four times more likely to develop AMD. Researchers also noted that blue light exposure in middle age might be more damaging than at younger ages.

Professor Fletcher comments: ‘In the absence of cost-effective screening methods to identify people in the population with early AMD, we suggest that recommendations on protecting the eyes, ensuring that diets contain the right nutrients and antioxidants, are targeted at the general population, and especially middle-aged people’.

Study authors don’t advise people to stay out of the sun altogether — sunlight is important for its role in vitamin D synthesis. However, they do recommend avoiding exposing eyes to too much sunlight by wearing a wide-brimmed hat and sunglasses when outdoors.

In addition, study authors advise consumption of key antioxidants, which can be accomplished by consuming recommended dietary intake levels of vitamin C and zinc and increasing consumption of carotenoid-rich fruits and vegetables.

Learn more about macular degeneration

Read more about antioxidants and nutrient food sources for good eye health

SOURCE: Fletcher AE et al. Sunlight exposure, antioxidants, and age-related macular degeneration. Archives Ophthalmology 2008; 126:1396-1403.