Exercise Training

Few studies have followed the impact of long-term training on the immune systems of elderly people. Given that a number of age-related changes occur in many systems (e.g., neuroendocrine) known to alter immune function both at rest and during exercise, it would be of value to learn the extent to which both acute and chronic exercise influence immune function in the elderly. In older humans, aerobic exercise training lowers the heart rate at rest, reduces levels of the heart rate and plasma...

Introduction Fatty Acids And Neuronal Excitability

The critical role of fatty acids in nervous system development have been emphasized by multiple authors in this volume and in numerous previous studies (for reviews, see Innis, 1991 Neuringer et al., 1994 Uauy et al., 1996 Kurlak & Stephenson, 1999 Gibson, 1999). Essential fatty acids, especially long-chain polyunsaturated fatty acids (PUFAs), are necessary for development of normal retinal and neuronal membranes (Neuringer, et al., 1988) and subsequent normal behavior and cognition (Enslen,...

PET Imaging of Labeled Fatty Acid Incorporation into the Human Brain

Positron emission tomography (PET) has been used to quantify local glucose metabolism and blood flow in the human brain and to image brain receptor densities (Rapoport, 1995). However, to date, PET has not been employed successfully in humans to image signal transduction beyond the receptor, the downstream process by which neurotransmitters and drugs are closely linked to cognition and behavior (Cooper et al., 1996). In view of our results on dopaminergic and cholinergic signaling in normal and...

Schizophrenia And Its Treatment

Schizophrenia is the most devastating of the major mental illnesses. Its prevalence is stable across cultural and national boundaries, affecting between 0.5 and 1.5 of all populations. In the United Kingdom the economic cost of schizophrenia has been put at some 850 million per year, ranking it third behind strokes and learning disabilities as the most costly illness to the health service (Knapp, 1997). In human terms, the damage caused by schizophrenia is incalculable. It is known, for...

Negative Results In Crossnational Studies Of Schizophrenia

In cross-national analyses, no specific relationship between seafood or fish consumption and schizophrenia prevalence nor outcome has been reported. Among eight countries, Christensen and Christensen (1988), reported that better outcome measures for patients with schizophrenia were correlated with a low percentage of fats from animals (r 0.91-0.95, p < 0.01) but not correlated to a higher percentage of dietary fat from vegetable and seafood sources (r 0.23-0.50, p < 0.10). These results are...

The Etiology Of Schizophrenia

There are currently two dominant theories as to the etiology of schizophrenia. The most popular postulates abnormal neurotransmitter receptor function within the brain and, to a large extent, concentrates on studying dopamine and serotonin. Although this theory still provides psychiatry with its best tools for dealing with psychosis, namely medications, it has proved sterile ground for developing radical new treatment approaches. The second most dominant theory is known as the...

Diet And Schizophrenia

Although there have been studies that have shown the importance of dietary essential fatty acids (EFAs) for healthy neurodevelopment (Crawford, 1993), until recently there had been no studies of infant feeding practices in relation to subsequent schizophrenia. It has been shown that the children of women pregnant during the Dutch famine (19441945) were significantly more likely to develop schizophrenia in later life (Susser & Lin, 1992). Although these women suffered multiple dietary...

Dietary n3 Deficiency in the

Visual Acuity and n-3 Deficiency Perhaps the most consistent effect of n-3 deficiency is found on vision. For instance, when Wistar rats that had been fed sunflower-oil-based chow for three generations were compared to a similar soybean-oil-fed group, there were striking and highly significant differences in their electroretinograms (Bourre, et al., 1989). In 4-wk-old rats, the amplitudes of the a- and b-waves in the LNA-rich group were 39 and 80 higher, respectively, compared to the...

Blindness To Dim Light Is Not The Cause Of Inferior Learning Performance In Aladeficient Rats

As retinal response was also impaired in ALA deficient rats (Fig. 4), one can argue that the decrease in learning ability observed in the brightness-discrimination learning test is the result of retinal dysfunction but not of cognitive dysfunction. However, we interpreted that rats that were n-3 fatty acid deficient could recognize even dim light because its intensity was sufficient to evoke electroretinographic responses (Yamamoto, 1988). Moreover, the R- responses were significantly more than...

Biochemical Bases For Aladeficiencyinduced Alterations Of Behavior And Retinal Function

Earlier, some membrane enzymes in the brain (e.g., 5'-nucleotidase, cyclic nucleotide phosphodiesterase, acetylcholine esterase and Ca2+-ATPase) were reported to be specifically associated with dietary n-3 fatty acid levels. However, we have been unable to find significant differences in the activities of these enzymes of the safflower-oil group and the perilla-oil group of rats. A possible difference in the activities of Na+,K+-ATPase isozymes has not been excluded (Gerbi, 1993 Tutsumi, 1995),...

Cancer Cachexia Influence of n3 PUFAs

In patients with cancer, weight loss indicates a poor prognosis and a shorter survival time. Cancer cachexia involves a massive loss of body weight, with extensive breakdown of both body fat and skeletal muscle, often, but not always, accompanied by anorexia (DeWys, 1985). Metabolic studies have shown that increased free fatty acid mobilization Fig. 5. The increase in plasma triacylglycerol concentrations after ingestion of a 50-g test meal. Individuals were maintained on saturated fat,...

Oxidative Stress Antioxidants And Lipid Peroxidation

A weakening of antioxidant defenses has been convincingly demonstrated in both human diabetic patients and experimentally diabetic rodents, although there appear to be tissue-dependent differences (cf. van Dam 1995 Low et al. 1999 for references). In several non-neural tissues, GSH concentrations as well as Cu-Zn superoxide dismutase and catalase activities are decreased in diabetes. In the case of the peripheral nerve, information is relatively scant, but as compared to the brain and liver,...

Effect of Dietary Fat on Very Long Chain Fatty Acids and Rhodopsin Content

Very Long Chain Fatty Acids

Retina membrane phospholipids, particularly phosphatidylethanolamine, contain a high level of 22 6n-3 (Birch et al., 1992 Suh et al., 1994). In the rod outer segment of the retina, significant amounts of 22 6n-3 in phosphatidylserine and phosphatidylcholine also occur (Suh et al., 1994). Increased dietary intake of n-3 fatty acids increases the n-3 20 4n-6 ( w w) 22 6n-3 ( w w) 20 4n-6 ( w w) 22 6n-3 ( w w) Fig. 2. Developmental profiles and effect of dietary 20 4n-6 and 22 6n-3 on 20 4n-6 or...

Possible Implications Of Observations In Rat In Human Behavior

Rudin (1981) described a causal relationship between ALA deficiency and neurotic disorders in humans. Psychoses and neuroses of some pellagra cases unresponsive to multivitamin therapy have been treated effectively with linseed oil enriched with ALA. In 1982, Holman described numbness, paraesthesia, weakness, inability to walk, pain in the legs, and blurring of vision in a 6-yr-old girl under total parenteral nutrition taking safflower oil as the source of essential fatty acid. When the regimen...

Applicability To Humans

What are the implications of these studies of n-3 fatty acid deficiency and subsequent repletion in rhesus monkeys to human beings First, these data strongly suggest that any n-3 fatty acid-deficient state will be corrected by fish oil containing EPA and DHA or in other studies, a diet containing n-3 fatty acids from soy oil (18 3n-3 linolenic acid). The brain phospholipids will readily assemble the correct amounts of DHA in the sn-2 position of the phospholipid molecular species. Furthermore,...

Influence of n3 PUFAs on Fat Metabolism Oxidation and Thermogenesis

Jones and Schoeller (1988) showed that when added to a saturated-fat diet, n-3 PUFA increased basal metabolic rate and total energy expenditure. Within minutes of ingestion, n-3 PUFAs upregulate genes involved in lipid oxidation and downregulate genes involved in lipogenesis. Hepatic oxidation of fatty acids increases within 3 d when the diet contains 12-15 fish oil, but does not increase for several weeks when the diet contains n-6 PUFAs. Evidence suggests that unlike intake of a high-fat...

Nerve Fatty Acid Metabolism In Diabetes

The impact of diabetes mellitus causes an inability of tissues to metabolize glucose properly and this, in turn, leads to accelerated triacylglycerol breakdown and enhanced P-oxidation of fatty acids. The resulting increase in fat catabolism, together with a depletion of Krebs cycle intermediates, produces a marked increase in ketone body formation. Glucose is the major metabolic fuel for the normal nerve axon and Schwann cells, although in its absence, the peripheral nerve is able to utilize...

Attentiondeficit Hyperactivity Disorder

Initial reports of deficiencies of essential fatty acids among children with attention-deficit hyperactivity disorder and dyslexia raised the promise of potential nondrug treatments. Convincing treatment data from interventional trials has not yet been reported. (Stevens et al. (1995) found that 53 subjects with attention-deficit hyperactivity disorder had significantly lower concentrations of AA, EPA, and DHA in plasma polar phospholipids when compared to 43 control subjects. (Stordy 1995) has...

Stressinduced Analgesia

Stress-induced analgesia (SIA) is the phenomenon that certain stressors can induce changes in the pain threshold following the stress situation. The biological basis of SIA is not clear. Some studies showed that SIA is mediated by the opiate system ( Altier and Stewart, 1996 Starec, et al., 1006 Vaccarino, et al., 1999 Yamada, et al., 1995), by P-endorphin (Hawanko, et al., 1994 Herz, 1995, Nakagawassi et al., 1999), substance P (Altier and Stewart, 1998), corticosterone (Filaretou, et al.,...

Functional Deficits in n3 Deficiency

The earliest studies investigating the effects of n-3 dietary fatty acid manipulation on vision date back to the early 1970s. Benolken and others (1973) fed rats a fat-free diet, which resulted in a 60 reduction in the retinal DHA content. This was associated with reductions in the amplitudes of the ERG a-wave (and b-wave), reflecting anomalous photoreceptor function. In a later study, the same authors (Wheeler et al., 1975) studied the effects of feeding rats diets free of fat or supplemented...

Dietary Modulation of Retinal Fatty Acid Composition and Function

The effect of maternal diet on the modulation of n-3 fatty acid in the retina of offspring has been studied in newly hatched chicks (Anderson et al., 1989), juvenile felines (Pawlosky et al., 1997) and piglets (Arbuckle & Innis, 1993). Docosahexaenoic acid appears to be the preferred fatty acid for raising the level of 22 6n-3 in the retina and brain among different sources of n-3 fatty acids (Anderson et al., 1990). Feeding corn oil supplemented with 22 6n-3 is able to restore the 22 6n-3...

High Fat Diets and Obesity Possible Influence of n3 PUFAs

Obesity is one of the major health risks for a number of diseases, particularly heart disease and diabetes. It is well known that ingestion of a diet high in saturated fats is one of the major causes of obesity. There are two explanations for this observation. First, diets high in saturated fats do not seem to be as satiating as either high-carbohydrate or highprotein diets (Doucet et al., 1998), even when the high-fat diet is less palatable (Warwick, 1996). Second, whereas increased intake of...

References

Induced hypercholesterolemia and decreased susceptibility to seizures in experimental animals. Exp Neurol 1971 32 134-140. Al-Mudallal AS, LaManna JC, Lust WD, Harik SI. Diet-induced ketosis does not cause cerebral acidosis. Epilepsia 1996 37 258-261. Al-Mudallal AS, Levin BE, Lust WD, Harik SI. Effects of unbalanced diets on cerebral glucose metabolism in the adult rat. Neurology 1995 45 2261-2265. Appleton DB, DeVivo DC. An animal model for the ketogenic diet....

Ketones And The Ketogenic Diet

The KD was formulated as an epilepsy treatment around 1921 (Wilder, 1921). The diet was designed to simulate the biochemical changes of fasting, which was long recognized as an efficacious, short-term way to reduce seizures in persons with epilepsy (Geyelin, 1921). The diet consists of a high percentage of fat, adequate protein for growth, and minimal carbohydrate, constituted in a ratio of 3-4 g of fat for every gram of combined protein and carbohydrate (hence the notations 3 1 or 4 1 for the...

Genetic And Dietary Factors Which Influence N3 Fatty Acid Metabolism

Because of the inability to synthesize n-3 fatty acids de novo, all animals require these fatty acids in their diet to meet their demand for maintaining a high concentration of DHA in the brain. Although little direct evidence exists in any species concerning the quantitative conversion of n-3 fatty acid precursors to DHA, it has been estimated based on rodent studies that an n-3 fatty acid intake of 0.5 of energy as a-linolenic acid (LNA) is needed in order to maintain an adequate level of DHA...

Therapeutic Approaches

A variety of compounds intended to combat oxidative stress have been used to treat experimental diabetic neuropathy and considerable success has been attained in correcting neural and vascular abnormalities (cf. Cameron and Cotter 1999). These substances include hydrophilic and lipophilic free-radical scavengers, as well as chelators of transition metals. A complete discussion of these approaches is beyond the scope of this chapter. However, it is pertinent to comment on several in the context...

Nutrition Intervention

Undernutrition is a common factor underlying many pathological conditions in the elderly and a common symptom in over 50 of hospitalized elderly patients. Macronu-trient and micronutrient deficits are though to be partially responsible for the depressed immune system in the elderly, even in the apparently healthy independent-living elderly (Lesourd, 1999). Protein-energy malnutrition is associated with decreased lymphocyte proliferation, reduced cytokine release, and decreased antibody...

Body Energy Homeostasis

Many factors are involved in the control of food intake. Some of the most important factors controlling the amount of food that we eat include environmental factors such as food availability, the characteristics of the food itself (e.g., smell, taste, our eating habits, learned preferences and aversions) as well as other psychological and social factors, including our lifestyle. Although these psychosocial factors are extremely important to the food intake patterns of humans, this section will...

Dietary Lna And Dha As Substrates For Brain And Retina Dha Compositional Studies

Dha Found Retina

In nontracer experiments, relative contribution of dietary LNA and DHA to CNS DHA accretion have been examined in various species, including chicks, rat pups, newborn piglets, and guinea pigs. Anderson and colleagues studied the relative efficacy of LNA and DHA in restoring neural DHA levels in newly hatched chicks, as presented in Fig. 1 (Anderson, Connor, & Corliss, 1990). Laying hens were fed a n-3-deficient diet for 2 mo, and their hatched chicks were then fed a control diet or...

Exercise and Immune Function

Aging leads to a diminution of resting immune function, increasing the risk of infection, tumor development, and autoimmune diseases (Shephard and Shek, 1995). The production of IL-2 is decreased, sometimes with a decrease of total T-cell count, and often with changes in T-cell subsets and proliferative responses to mitogens. However, NK cell activity remains unchanged. In theory, moderate exercise training should help to reverse the adverse effects of aging upon the immune system. However,...

Dietary n3 Deficiency in the Mouse 721 Mouse Visual Acuity and n3 Deficiency

As seen in rats, there is no evidence of a strong correlation between visual acuity and learning in the mouse. The second generation of mice (F1) fed a diet poor in LNA was compared to a group fed laboratory chow. In adult mice, there was a significant difference in the retinal concentration of DHA, but the difference in b-wave electroretinograms ceased to be significant at the seventh week (Carrie, et al., 1999). The ability to learn was examined using the passive-avoidance test and the...

Impact Of Dietary Essential Fatty Acids On Neuronal Cell Composition And Function

Brain membranes were generally viewed as resistant to structural change by both endogenous and exogenous factors. Data have shown that brain membranes are much more sensitive to changes in composition induced by dietary fat than previously thought (Bourre et al., 1989a Foot et al., 1982 Jope & Jenden, 1979 Lee, 1985 Wurtman et al., 1981). Moreover, the extent of the changes in brain membrane composition by dietary fat varies among brain regions, cell types, and organelles (reviewed by...

Effects Of La And Gla Treatment On Diabetic Nerve

The reduced activity of the n-6 fatty acid biosynthetic pathway in the diabetic nerve could decrease the availability of AA for prostanoid formation and this could have deleterious consequences on the nerve vasculature, with resultant adverse effects on nerve function. The depletion of AA could be exacerbated by a heightened level of reactive oxygen species (ROS), which react readily with the double bonds of polyunsaturated fatty acids. A number of investigators have examined the effect of...

Chronic Effects of the Ketogenic Diet

In addition to acute effects of ketones on neuronal excitability and seizure threshold, the KD may exert longer-term seizure-suppressive actions. Using the kainic acid KA model of chronic epilepsy, we have investigated whether the KD alters the process by which the brain becomes epileptogenic i.e., epileptogenesis Muller-Schwarze et al., 1999 . KA is a glutamate analog that causes an epilepsy syndrome characterized by status epilepticus Ben-Ari, 1985 . After recovery from status epilepticus,...

Pufa A Feasible Epilepsy Treatment

The preceding discussion has established the following 1 PUFAs are an important modulator of neuronal excitability 2 dietary PUFA can alter several aspects of brain function 3 the ketogenic diet is an effective therapeutic modality for some persons with epilepsy 4 the mechanism of the ketogenic diet's seizure protective effect is unknown but may involve lipid components 5 the ketogenic diet is composed of a high volume of fats that contain a variable proportion of PUFA. From these observations,...

Anticonvulsant Mechanisms Of The Ketogenic Diet 41 Mechanistic Criteria

Understanding how the KD protects against seizures would allow the design of a more effective diet or improve and simplify the current regimen. Animal models offer many advantages in exploring possible mechanisms Diet components can be controlled precisely, including the ketogenic ratio, constituents, caloric intake, and fluid balance biochemical and neurologic abnormalities can be quantitated seizure type can be controlled the effects of the experimental diet on seizure susceptibility,...