TOP NUTRITION NEWSLETTER                          VOLUME 2, NO 12:DECEMBER 1999  

Editorial  

This is the last issue of TOP NUTRITION NEWSLETTER in 1999. In this issue  the following topics are updated for your interest. 
 
Asthma, oxidant stress, and diet

By how much does fruit and vegetable consumption reduce the risk of ischaemic heart disease: response to commentary.

A prospective, randomized clinical trial on perioperative feeding with an arginine-, omega-3 fatty acid-, and RNA-enriched enteral diet: effect on host response and nutritional status.

Successful intradialytic parenteral nutrition after abdominal "Catastrophes" in chronically hemodialysed patients

Any comments or suggestions to include the interesting topics are welcomed for future issues. 
 

Dr Shwe Win  

Editor  

Asthma, oxidant stress, and diet

Reference: Nutrition 1999 Nov-Dec;15(11-12):899-907

It has been suggested that the increased prevalence of atopy and asthma observed in many developed countries over the past 30 y is in part the result of a decrease in the incidence and severity of early childhood infections. The immunologic consequence of this phenomenon has been the expansion of T-lymphocyte populations away from the T-helper 1 (Th1) subset and in the direction of the Th2 subset. This leads to the creation of a cytokine-mediated propensity for the development of an intense inflammatory response in the airways, resulting in oxidative stress, airway tissue injury, and the development of atopy and asthmatic symptomatology. Over this same period, there has been a decreased intake of dietary substances that contribute to antioxidant defense, and this appears to have contributed to the rise of atopy and asthma. Studies evaluating the efficacy of these antioxidant substances in the prevention of asthma and as adjuvants in the treatment of asthma are reviewed, and suggestions are made for the direction of future studies.

By how much does fruit and vegetable consumption reduce the risk of ischaemic heart disease: response to commentary.

Reference: Eur J Clin Nutr 1999 Nov;53(11):903-4 

In our review (Law & Morris, 1998), we presented analyses of data from 10 cohort studies yielding the summary estimate that the risk of ischaemic heart disease was 15% lower at the 90th than at the 10th centile of fruit and vegetable consumption. This 10th-90th centile difference in consumption is a realistic increase for an individual (Zino et al, 1997). The estimate of a 15% difference in heart disease mortality was similar to the expected difference in risk from the increase in potassium consumption (given the corresponding decrease in blood pressure) and the increase in folate consumption (given the corresponding decrease in plasma homocysteine) that would result from this specified increase in fruit and vegetable consumption. Ness and colleagues' own approach to such a review was to tabulate the studies with their methodological details and list the result of each study as showing 'no association' or 'protective effect' (Ness & Powles, 1997), when the evidence did not justify the implicit dichotomy. Associations were reproduced as published, in different formats for different studies, and confidence intervals commonly not reported. This left the reader with little impression of the average size of the association nor the degree of consistency between studies. Ness and colleagues express disapproval of our quantitative approach but provide no sound basis for rejecting it. We believe that our results are valid, and that the quantification of the effect is useful in establishing for the first time the moderate but important reduction in heart disease risk that results from a realistic increase in fruit and vegetable consumption. The main argument of Ness and colleagues is that estimates of effect derived from cohort studies are unreliable. We respond to this first, and then to four methodological issues that they raise.

 A prospective, randomized clinical trial on perioperative feeding with an arginine-, omega-3 fatty acid-, and RNA-enriched enteral diet: effect on host response and nutritional status.

Reference: JPEN 1999;23(6):314-20.

BACKGROUND: The use of immune-enhancing enteral diets in the postoperative period has given contrasting results. The purpose of this prospective, randomized, double-blinded clinical study was to evaluate the effect of immunonutrition given perioperatively on cytokine release and nutritional parameters. 

METHODS: Patients with cancer of the stomach or colo-rectum were eligible. Subjects consumed 1 L/d of either a control enteral formula (n = 25; control group) or a formula supplemented with arginine, omega-3 fatty acids, and RNA (n = 25; verum group) for 1 week before surgery. Both formulas were given by mouth. Six hours after the operation, jejunal infusion with the same diets was started and maintained for 7 days. Blood was drawn at different time points to assess albumin, prealbumin (PA), transferrin, cholinesterase activity, retinol binding protein (RBP), interleukin-2 receptors alpha (IL-2Ralpha), IL-6, and IL-1 soluble receptors (IL-1RII). The composite score of delayed hypersensitivity response (DHR) to skin test also was determined (the higher the score, the lower the immune response). 

RESULTS: During the 7 days of presurgical feeding, none of the above parameters changed in either group. Eight days after operation, in the control group, the concentration of PA and RBP was lower than in the verum group (0.18 vs 0.26 g/L for PA and 30.5 vs 38.7 mg/L for RBP; p < .05). IL-2Ralpha concentration was 507 pg/mL in the verum group vs 238 pg/mL in the control group (p < .001), whereas IL-6 and IL-1RII were higher in the control group than in the verum group (104 vs 49 and 328 vs 183 pg/mL, respectively; p < .01). The DHR score was 0.68 in the control group vs 0.42 in the verum group (p < .05). 

CONCLUSIONS: Perioperative feeding with a supplemented enteral diet modulates cytokine production and enhances cell-mediated immunity and the synthesis of short half-life proteins. 

Successful intradialytic parenteral nutrition after abdominal "Catastrophes" in chronically hemodialysed patients.

Reference: J Ren Nutr 1999;9(4):206-13.

OBJECTIVE: To assess the therapeutic contribution of intradialytic parenteral nutrition (IDPN) in four acutely ill, hypercatabolic, hemodialysed patients. All underwent major surgery, complicated by infection and malnutrition. 

DESIGN: A retrospective clinical study.

SETTING: An in-center hemodialysis unit, at a tertiary referral hospital. PATIENTS: Patient 1: a young woman, with a good renal transplant. Developed gastric lymphoma, which required gastrectomy. After cessation of immunosuppression, "lost" her kidney and returned to hemodialysis. Received IDPN for 4 months and recovered well from severe malnourishment. Patient 2: an elderly, malnourished man, on continuous ambulatory peritoneal dialysis (CAPD). Developed biliary peritonitis and bacteremia. In a 3-month period, the patient had four operations. Maintained on IDPN for 4 months. Patient 3: a young and obese man, who suffered from life-threatening staphylococcal aureus peritonitis, resulting in widespread bowel adhesions. Underwent repeated aspirations of purulent ascites, laparoscopy, and explorative laparotomy. IDPN was administered for 4 months and stopped on the patient's request. Patient 4: a young man, who after cadaveric renal transplantation remained hospitalized for 6 months because of acute rejection and peritoneal and retroperitoneal abscesses. Had major surgery performed seven times. Received IDPN for 6 months, and is now well. 

RESULTS: All four patients benefited from 4 to 6 months of IDPN, as an integral part of intensive supportive and nutritional treatment. Weight loss was halted, as patient appetite returned and oral nutrition became adequate. Estimated daily protein intake reached 1.2 g/kg, while caloric intake rose to nearly 30 kcal/kg/d. Mean serum albumin levels increased from 25.5 g/L +/- 0.9 g/L to 38.0 g/L +/- 1.5 g/L. No adverse side effects were seen from IDPN.

CONCLUSION: IDPN is a worthwhile part of treatments used in the catabolic, postoperative hemodialysed patient. It is safe and efficient when used over a 6-month period in trying to attenuate existing, or worsening malnutrition in these patients. It should be commenced at an early stage in these patients, after attempts at oral nutritional support have been deemed inadequate.