Low fat and high monounsaturated fat diets decrease human low density lipoprotein oxidative susceptibility in vitro.

Oxidative modification of low density lipoprotein (LDL) is thought to play an important role in the development of atherosclerosis. Some studies have found that LDL enriched in monounsaturated fatty acids (MUFA) are less susceptible to oxidation than LDL enriched in polyunsaturated fatty acids (PUFA). A high MUFA diet is an alternative to a lower-fat blood cholesterol-lowering diet. Less is known about the effects of high MUFA versus lower-fat blood cholesterol-lowering diets on LDL oxidative susceptibility. The present study was designed to evaluate the effects of men and women consuming diets high in MUFA (peanuts plus peanut butter, peanut oil and olive oil) on LDL oxidative susceptibility, and to compare these effects with those of a Step II blood cholesterol-lowering diet. A randomized, double-blind, five-period crossover design (n = 20) was used to study the effects of the following diets on LDL-oxidation: average American [35% fat, 15% saturated fatty acids (SFA)], Step II (25% fat, 7% SFA), olive oil (35% fat, 7% SFA), peanut oil (35% fat, 7% SFA) and peanuts plus peanut butter (35% fat, 8% SFA). The average American diet resulted in the shortest lag time (57 +/- 6 min) for LDL oxidized ex vivo, whereas the Step II, olive oil and peanuts plus peanut butter diets resulted in a lag time of 66 +/- 6 min (P < or = 0.1). The slower rate of oxidation [nmol dienes/(min x mg LDL protein)] observed when subjects consumed the olive oil diet (24 +/- 2) versus the average American (28 +/- 2), peanut oil (28 +/- 2) and peanuts plus peanut butter diets (29 +/- 2; P < or = 0.05) was associated with a lower LDL PUFA content. The results of this study suggest that lower-fat and higher-fat blood cholesterol-lowering diets high in MUFA have similar effects on LDL oxidative resistance. In addition, our results suggest that different high MUFA sources varying in the ratio of MUFA to PUFA can be incorporated into a high MUFA diet without increasing the susceptibility of LDL to oxidation.

Polyunsaturated fatty acids in the food chain in the United States.

In the United States, intake of n-3 fatty acids is approximately 1.6 g/d ( approximately 0.7% of energy), of which 1.4 g is alpha-linolenic acid (ALA; 18:3) and 0.1-0.2 g is eicosapentaenoic acid (EPA; 20:5) and docosahexaenoic acid (DHA; 22:6). The primary sources of ALA are vegetable oils, principally soybean and canola. The predominant sources of EPA and DHA are fish and fish oils. Intake data indicate that the ratio of n-6 to n-3 fatty acids is approximately 9.8:1. Food disappearance data between 1985 and 1994 indicate that the ratio of n-6 to n-3 fatty acids has decreased from 12.4:1 to 10.6:1. This reflects a change in the profile of vegetable oils consumed and, in particular, an approximate 5.5-fold increase in canola oil use. The ratio of n-6 to n-3 fatty acids is still much higher than that recommended (ie, 2.3:1). Lower ratios increase endogenous conversion of ALA to EPA and DHA. Attaining the proposed recommended combined EPA and DHA intake of 0.65 g/d will require an approximately 4-fold increase in fish consumption in the United States. Alternative strategies, such as food enrichment and the use of biotechnology to manipulate the EPA and DHA as well as ALA contents of the food supply, will become increasingly important in increasing n-3 fatty acid intake in the US population.

High-monounsaturated fatty acid diets lower both plasma cholesterol and triacylglycerol concentrations.

BACKGROUND: Low-fat diets increase plasma triacylglycerol and decrease HDL-cholesterol concentrations, thereby potentially adversely affecting cardiovascular disease (CVD) risk. High-monounsaturated fatty acid (MUFA), cholesterol-lowering diets do not raise triacylglycerol or lower HDL cholesterol, but little is known about how peanut products, a rich source of MUFAs, affect CVD risk. OBJECTIVE: The present study compared the CVD risk profile of an Average American diet (AAD) with those of 4 cholesterol-lowering diets: an American Heart Association/National Cholesterol Education Program Step II diet and 3 high-MUFA diets [olive oil (OO), peanut oil (PO), and peanuts and peanut butter (PPB)]. DESIGN: A randomized, double-blind, 5-period crossover study design (n = 22) was used to examine the effects of the diets on serum lipids and lipoproteins: AAD [34% fat; 16% saturated fatty acids (SFAs), 11% MUFAs], Step II (25% fat; 7% SFAs, 12% MUFAs), OO (34% fat; 7% SFAs, 21% MUFAs), PO (34% fat; 7% SFAs, 17% MUFAs), and PPB (36% fat; 8% SFAs, 18% MUFAs). RESULTS: The high-MUFA diets lowered total cholesterol by 10% and LDL cholesterol by 14%. This response was comparable with that observed for the Step II diet. Triacylglycerol concentrations were 13% lower in subjects consuming the high-MUFA diets and were 11% higher with the Step II diet than with the AAD. The high-MUFA diets did not lower HDL cholesterol whereas the Step II diet lowered it by 4% compared with the AAD. The OO, PO, and PPB diets decreased CVD risk by an estimated 25%, 16%, and 21%, respectively, whereas the Step II diet lowered CVD risk by 12%. CONCLUSION: A high-MUFA, cholesterol-lowering diet may be preferable to a low-fat diet because of more favorable effects on the CVD risk profile.

Neurological complications associated with pregnancy.

Prospective multidisciplinary audit from both hospital and community has identified neurological complications persisting for more than 6 weeks in association with pregnancy and delivery. They occurred at a frequency of 1 in 2530 deliveries in the North West Thames Region. Extradural analgesia was considered contributory to a neurological disorder in one of 13,007 patients. The woman had prolonged paraesthesiae along a nerve root. The types of sensory, motor and sympathetic neurological problems presented ranged from transient problems to more serious disorders resulting in death in one case. Seven of 19 patients had a continuing neurological disability for more than 1 yr. Although obstetrics may be associated with lumbar and sacral neurological disorders, problems occurred with the same frequency in the upper as in the lower half of the body. Significant morbidity is not being recognized in hospitals where women are being delivered and it is within the community that these disorders are recognized. This has implications for training, audit and risk assessment.

Primary panendoscopy.

Primary panendoscopy is defined as a limited-consultative, diagnostic, UGI endoscopic examination that provides, in non-critically ill patients with dyspeptic symptoms, an accurate and cost-effective alternative to the standard UGI x-ray examination. The procedure was instituted at St. Mary's Medical Center's hospital in February 1985. During the first 12 months, a total of 321 patients were examined: 212 inpatients and 109 outpatients. In those patients with complete information, primary panendoscopy changed the diagnosis in 67% and the treatment in 52%. As expected, the number of esophagogastroduodenoscopies decreased during this time, but the combined numbers of primary panendoscopies and esophagogastroduodenoscopies exceeded the projected increase of esophagogastroduodenoscopies. Similarly, the number of UGI x-ray examinations fell sharply. With a physician fee of $150.00 and a facility fee of $50.00, theoretical savings of some $117,000.00 to the patients were estimated. The authors conclude that primary panendoscopy provides a cost-effective and beneficial patient service that warrants broad consideration by gastroenterologists as they face the cost constraints being imposed within the health care system of the 1980s.

Orientation of PMN in a pH gradient: acid-induced release of a chemotactic factor.

Human and rabbit PMN, placed in a gradient of pH 5 to pH 8 over 1 mm, orient their locomotion toward pH 5. This orientation is due to the release or production of a chemotactic factor by the cells in the acid pH. This activity can be recovered in the supernatant and is maximal when the cell incubation is at pH 5.5. Its appearance is rapid, occurring within 1 min, and is temperature dependent. Cells survive treatment at pH 5.5 and are capable of subsequently responding to chemotactic peptides.

Colonoscopic polypectomy: silent perforation.

The management of colon polyps has been completely revolutionized since the introduction of colonoscopic polypectomy. The reductions in patient time, cost, morbidity, and mortality are major advantages. Reported complications include primarily hemorrhage (1.7%) and frank clinical perforation (0.32%). This report describes a silent perforation after the removal of a broad based polyp through the colonscope.