More Anti-Oxidants Provide No Benefit for Aging Eyes

Eye Glasses, Older WomanTwo papers presented at the Association for Research in Vision (ARVO) conference in Seattle emphasized that in a population of patients with adequate nutrition the addition of more antioxidants, vitamins and supplements do not help your vision or prevent progression or development of eye disease. In fact, not only did they not help but there was a significant concern that the addition of lutein and beta carotene to the diet of smokers and former smokers actually increased the risk of those individuals developing carcinoma of the lung. The studies were published in JAMA Ophthalmology and the Journal of the American Medical Association.

The study, known as Age-Related Eye Disease Study 2 (AREDS2), concluded that adding lutein, zeaxanthin, and fish oil to daily multivitamin supplements does not boost prevention of age related macular degeneration or cataracts in high risk individuals.

The original AREDS study showed that adding high doses of Vitamin C and Vitamin E, beta carotene and zinc slowed and lowered progression of early and intermediate age related macular degeneration and associated vision loss. That original study suggested that the addition of more antioxidants might help. This was the basis for the follow-up study AREDS2.  The follow up study randomized patients to receive lutein plus zeaxanthin, or omega 3 fatty acids, plus DHA and EPA, both, or a placebo. No benefit of adding these antioxidants was noted except in patients with extreme nutritional deprivation situations.

Vitamin C is a water soluble vitamin.  You keep what you need and the rest is eliminated harmlessly through the kidneys. Vitamin E is a fat soluble vitamin and excess intake is stored in the cells of your body.  Toxicity can occur from ingesting too much of Vitamin E or Vitamin A.  Beta Carotene has been postulated to have an effect on lung cancer in other studies.   The bottom line, too much of anything is not good for you. 

Patients should be asking their ophthalmologists about the constituents of the supplements being recommended to them for eye health.  If they are a cigarette smoker or former smoker they should question the need for beta carotene and lutein because of the association with lung cancer. They should review their total Vitamin A, E, D and K intake from their ophthalmologic vitamins and supplements and their other vitamins and supplements to insure that their total daily intake does not exceed recommended levels.

Do Tomatoes Prevent Strokes?

The University of Pennsylvania Department Of Medicine online magazine Medpage Today published a synopsis of an article that appeared in the October 9th issue of the Journal of Neurology. Written by Jouni Karppi, PhD, of the University of Eastern Finland, and colleagues, it discusses how tomatoes and tomato based products may lower the risk of strokes in men. The key ingredient seems to be lycopene. Lycopene is a carotenoid that acts as an antioxidant.

The study looked at 1,031 Finnish men between the ages of 42 and 61 who were followed for 12 plus years. The researchers used statistical techniques to eliminate the influence of variables such as hypertension, tobacco usage, lipid levels and other risk factors of strokes. The research showed that the individuals with the highest levels of lycopene in their serum had the lowest risk of stroke compared to individuals with lower levels. Tomatoes do contain several types of carotenoids such as alpha-carotene, beta-carotene, alpha–tocopherol and retinol, but it is the lycopene that is the difference maker.

Nancy Copperman, MS, RD from the North Shore- Long Island Jewish Health System was quoted as saying, “This study supports the recommendation of eating more servings of fruit and vegetables a day. Foods such as tomatoes, guava, watermelon and grapefruit are good sources of lycopene. When a tomato is cooked, the heat processing actually increases the levels of cis-lycopene – which is easily absorbed by the body.”

This explains why tomato sauce is felt to be such an excellent source of anti-oxidants. Lycopene is believed to have numerous additional health benefits including “reducing inflammation, blocking cholesterol synthesis, boosting immune function, and inhibiting platelet aggregation and thrombosis.”

“Buyer Beware”- Supplements Are Not What They Are Advertised to Be

According to an article authored by Maria Elena Martinez’s (Ph.D., University of California, San Diego) in the Journal of the National Cancer Institute, “Consumers need more information and guidance about the risks as well as the benefits, of using dietary supplements for cancer prevention.” Dr. Martinez states that dietary supplements have little supporting evidence for health benefits in disease prevention – particularly cancer.

“Despite this evidence, marketing claims by the supplement industry continue to imply anti-cancer benefits“ Martinez wrote.  “Insufficient government regulation of the marketing of dietary supplement products may continue to result in unsound advice to consumers. Both the scientific community and government regulators need to provide clear guidance to the public about the use of dietary supplements to lower cancer risk.”

Half of US adults use one or more daily dietary supplements. “Use of supplements has been fueled primarily by marketing oriented claims of wide ranging benefits,” Martinez and her co-authors wrote. “As a result, sales of dietary supplements have grown into a $30 billion a year industry.”

To assess the current status of evidence supporting use of supplements, Martinez and her associates reviewed literature for supplements that have been tested in adequately powered clinical trials or in large, well-designed observational studies.  The review looked at data for the use of antioxidants, folic acid, Vitamin D and calcium to prevent cancer.

Preclinical studies suggested that dietary antioxidants including beta carotene, alpha tocopherol, and Vitamin C encouraged growth of normal cells and tissue and inhibit growth of abnormal tissue. Clinical studies failed to support those ideas:

>  Beta carotene did not prevent recurrence of non melanoma skin cancer

>  Beta carotene, alpha tocopherol and Vitamin C failed to prevent recurrence of colonic adenomas

>  Beta carotene, Vitamin A and alpha tocopherol did not prevent lung cancer

>  Vitamins C and E did not protect against cancer

>  Alpha tocopherol, Vitamin C and beta carotene had no effect on cancer incidence or mortality

>  Vitamins A, C and E with beta carotene alone or in combination did not prevent gastrointestinal cancers

>  Alpha tocopherol and selenium failed to prevent prostate cancer in average risk men

In some instances studies actually showed an increased risk of cancer in those taking supplements.

Two different randomized trials showed an increased risk of cancer (prostate) and pre cancerous lesions (colonic adenomas) in individuals taking long term folic acid supplementation.

The paper was equally negative about Vitamin D use. They cited three short term studies that failed to demonstrate an effect of Vitamin D on cancer incidence or mortality. The authors went on to support the Institute of Medicine position that “there is not enough evidence to state that there is a causal association between low Vitamin D intake and increased cancer risk.”

The material was published in the Journal of the National Cancer Institute and summarized recently in the on line news service MedPage.

In my practice I will continue to emphasize that a balanced diet prepared in a manner to preserve the nutrients is the best way to meet your nutritional needs. I will screen for those malabsorptive states and surgical situations that require supplementation with vitamins and supplements. These are sufficiently rare. In some cases, administration of medications such as anti-cancer agents causes depletion or malabsorption of vitamins and trace elements. In those cases I will supplement.  Women requiring calcium to prevent osteopenia and osteoporosis should be supplemented. In most other instances, I will suggest a balanced diet and correct preparation of food which should provide all the vitamins, minerals and antioxidants needed to stay healthy