Possible contraindications and adverse reactions associated with the use of ocular nutritional supplements

The role of oxidation in the development of age-related eye disease has prompted interest in the use of nutritional supplementation for prevention of onset and progression. Our aim is to highlight possible contraindications and adverse reactions of isolated or high dose ocular nutritional supplements. Web of Science and PubMed database searches were carried out, followed by a manual search of the bibliographies of retrieved articles. Vitamin A should be avoided in women who may become pregnant, in those with liver disease, and in people who drink heavily. Relationships have been found between vitamin A and reduced bone mineral density, and beta-carotene and increased risk of lung cancer in smoking males. Vitamin E and Ginkgo biloba have anticoagulant and anti-platelet effects respectively, and high doses are contraindicated in those being treated for vascular disorders. Those patients with contraindications or who are considered at risk of adverse reactions should be advised to seek specialist dietary advice via their medical practitioner. © 2005 The College of Optometrists.

Exploring attitudes towards dietary modification and nutritional supplementation in people with and without age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause for visual impairment and blindness registration in the developed world. Due to the large amounts of conflicting AMD research on the role of nutrition and antioxidant intake, it is difficult for patients and practitioners to determine which measures can be taken to slow down the disease progression. The aim of this research was to determine the beliefs and knowledge that patients with AMD have about nutrition, to identify whether their condition is preventing them from eating a healthy diet, and to discover what their diet consists of. For the initial study, 158 participants with AMD (mean age 79 ± 7.8 years) and 50 participants without AMD (mean age 67 ± 8 years) were recruited from the Macular Society helpline, or from optometric practice. Participants had a 25 minute telephone interview where a 36-question survey was completed. The survey elicited demographic information, and questions covered the knowledge that participants had on nutrition and their current diet. The results from this survey uncovered three major findings: 1) 100% of AMD participants felt that they do not have enough information and support from eye-care practitioners regarding nutrition, 2) AMD patients are confused over, and display a lack of knowledge of, which foods are beneficial for eye health and when and what nutritional supplements to take, evidenced by 65% of participants not taking the correct dosage 3) AMD patients are not eating enough nutrients that would be beneficial for their condition - consuming an average of 1.4mg of lutein and zeaxanthin rather than the recommended 10mg. A clinical decision-making aid was created as an intervention based upon these findings. The aim of the aid was to help eye-care practitioners give the correct nutritional advice to their patients. Founded on the AREDS 2 inclusion and exclusion criteria, practitioners are able to identify which patients could benefit from a nutritional supplement, and which patients could benefit from dietary modification. An evaluation of the aid with 72 qualified eye-care practitioners exhibited a statistically significant increase in confidence after using the aid for two weeks. An evaluation using 51 student optometrists showed a statistically significant increase in confidence and a statistically significant increase in appropriate management of patients after using the aid. This project has elicited findings that are significant for AMD patient education. It is hoped that through these studies, patients will receive consistent advice about the risk factors for AMD, the link between AMD and nutrition, and the importance of maintaining a healthy, well-balanced diet.

Innovative biomarkers for predicting type 2 diabetes mellitus:relevance to dietary management of frailty in older adults

Type 2 diabetes mellitus (T2DM) increases in prevalence in the elderly. There is evidence for significant muscle loss and accelerated cognitive impairment in older adults with T2DM; these comorbidities are critical features of frailty. In the early stages of T2DM, insulin sensitivity can be improved by a “healthy” diet. Management of insulin resistance by diet in people over 65 years of age should be carefully re-evaluated because of the risk for falling due to hypoglycaemia. To date, an optimal dietary programme for older adults with insulin resistance and T2DM has not been described. The use of biomarkers to identify those at risk for T2DM will enable clinicians to offer early dietary advice that will delay onset of disease and of frailty. Here we have used an in silico literature search for putative novel biomarkers of T2DM risk and frailty. We suggest that plasma bilirubin, plasma, urinary DPP4-positive microparticles and plasma pigment epithelium-derived factor merit further investigation as predictive biomarkers for T2DM and frailty risk in older adults. Bilirubin is screened routinely in clinical practice. Measurement of specific microparticle frequency in urine is less invasive than a blood sample so is a good choice for biomonitoring. Future studies should investigate whether early dietary changes, such as increased intake of whey protein and micronutrients that improve muscle function and insulin sensitivity, affect biomarkers and can reduce the longer term complication of frailty in people at risk for T2DM.