Antioxidant supplements to prevent heart disease. Real hope or empty hype?

Aspects of oxidative stress in children with type 1 diabetes mellitus

Diabetes mellitus is considered to be one of a rank of free radical diseases. The existence of hyperglycemia produces increased oxidative stress (OS) via non-enzymatic glycation, glucose autoxidation, and alterations in polyol pathway activity with subsequent influences on the whole organism. In childhood, Type 1 diabetes prevails and is characterized by its autoimmune character with progressive destruction of beta cells and lack of insulin in genetically predisposed patients. Our study focused on diabetic children and their 1st degree relatives and confirmed increased oxidative stress in diabetic children as well as a similar tendency in their siblings. Following this, we carried out a one-year study comprising diabetic children supplemented with vitamins E and C. The vitamin treatment improved diabetes control and reduced markers of oxidative stress substantially when compared with non-supplemented diabetic children. As oxidative stress impairs not only lipids and proteins, but also DNA, we attempted to examine the level of DNA strand breaks as well as DNA repair processes using comet assay modifications. Though children with Type 1 diabetes demonstrated increased oxidative stress (lower SOD and GSH when compared with healthy children), their oxidative DNA damage (measured as DNA strand breaks) were not substantially altered compared with normals. On the other hand, their DNA repair capacity was significantly increased. This demonstrates a stimulated DNA repair process that is most certainly a response to the permanently elevated state of oxidative stress. Owing to the presented results, it is appropriate to ponder the increased influence of oxidative stress on children with Type 1 diabetes and to take into account this fact when considering their treatment.

Dietary diversity: case study of fruit and vegetable consumption by chiropractic patients

BACKGROUND

A distinct health advantage has been linked with eating a wide variety of fresh fruit and vegetables.

OBJECTIVE

This study explores the diversity of fruits and vegetables consumed by chiropractic patients and inquires into their preferred purchasing patterns.

METHOD

A case study that included patients attending 24 chiropractic practices in 5 states and the Australian Capital Territory was undertaken. Seven hundred eighty-two patients were asked to complete a questionnaire providing general information about their life-style and particular information about the number of servings of fruits and vegetables that they usually consumed.

RESULTS

Although overall chiropractic patients reported adhering to a number of healthy life-style behaviors, participants in this study would benefit from eating a greater diversity of fruits and vegetables.

CONCLUSION

In view of the substantial health benefits associated with eating a wide variety of fruits and vegetables, it is suggested that chiropractic patients be encouraged to follow a color code system for purchasing their fresh produce.

Dietary supplement use and medical conditions: the VITAL study

BACKGROUND

Over half of U.S. adults use vitamin or mineral supplements, and some are likely using supplements to treat chronic diseases or risk factors for disease. Information on the relationship between supplement use and medical conditions is useful to health professionals to understand the self-medication behavior of their patients, and important for researchers because medical conditions may be potential confounding factors in observational studies of supplement use and disease risk.

METHODS

The cross-sectional data in this report are from 45,748 participants, aged 50 to 75 years, who completed a self-administered, mailed questionnaire on current dietary supplement use (multivitamins plus 16 individual vitamins or minerals), medical history (cancer, cardiovascular-related diseases, and other self-reported medical conditions), and demographic characteristics.

RESULTS

Supplement use (mean number used at least once a week) was higher among respondents who were older, female, highly educated, Caucasian, and of normal body mass index (all p<0.001). After controlling for these covariates, supplement use was higher among those with the condition for 13 of the 21 conditions examined (p<0.01); only having diabetes or high stress was associated with using fewer supplements. For specific supplements, the strongest associations were for cardiovascular disease and its risk factors with vitamin E, niacin, and folate, and for calcium with indigestion and acid reflux disease. For several conditions, the relative odds of using specific supplements were consistently higher for men than for women.

CONCLUSIONS

Supplement use was associated with many medical conditions in this cohort. However, these cross-sectional data do not permit inferences about the temporal sequence. Some associations appeared to be based on evidence for efficacy (e.g., folate with coronary artery disease), and others could be based on misinformation (e.g., selenium with benign prostatic hyperplasia).

Neurovascular disease, antioxidants and glycation in diabetes

People with diabetes are ten to fifteen times more likely to have a lower limb amputation (LLA) than non-diabetic individuals. Fifteen percent of people with diabetes will develop a foot ulcer during their lifetime, the rate of major amputation amongst diabetic individuals continues to rise, foot problems remain the commonest reason for diabetes-related hospitalisation and recurrence rates in patients with previous foot ulcers are 50% or more. Hyperglycaemia-induced oxidative stress has been shown to result in decreased nerve conduction velocity, and decreased endoneural blood flow-both precursors for neuropathy. Vitamin antioxidants have been shown to be effective therapy in experimental models in reducing free radical species and inhibiting the oxidative process in diabetes subjects. Little work has been published, however, regarding the dietary use of antioxidants from foods, and their specific effects on neurovascular disease and glycation within the diabetes population. Aetiological and prevention studies with dietary antioxidants from foods aimed at the complex nature of foot problems in diabetes are needed.