Toxic effects of water-soluble vitamins

Vitamin C mitigates heat damage by reducing oxidative stress, inducing HSP expression in TM4 Sertoli cells

Heat stress is a major stressor that can lead to male reproductive dysfunction. Sertoli cells play a crucial role in spermatogenesis by providing germ cells with structural and nutritional support, and contributing to blood-testis barrier formation. Vitamin C (Vc) is an antioxidant capable of neutralizing reactive oxygen species and preventing lipid peroxidation widely used because it is inexpensive and highly accessible. In the present study, we investigated the protective effect of Vc on TM4 cells following heat stress. Pretreatment with Vc could effectively inhibit apoptosis (p < 0.01), lipid peroxidation, and lactate dehydrogenase (LDH) activity. However, a significant increase in the malondialdehyde (MDA) level and LDH activity (p < 0.01) was observed in TM4 cells without Vc-pretreatment, in conjunction with vacuole degeneration and karyopyknosis. In addition, both the messenger RNA and protein levels of CryAB, Hsp27, Hsp70, and Hsp110 substantially increased in the 3 and 12 hr recovery groups (p < 0.01). Vc also prevented microtubule aggregation following heat stress. These results suggest that pretreatment with Vc-protected TM4 cells against heat stress by reducing the level of oxidative stress and inducing heat shock protein expression.

Viewing Disease as the Synergistic Interaction of Host, Agent, and Environment

The agent of disease, whether it is an infectious organism, the deficiency or excess of a nutrient, a toxin, or the expression of a gene, is not sufficient to explain its cause. The impact of the agent depends on host factors and the influence of physical, biological, and social factors in the environment. For nutritional disorders those of the social environment, including the complex of educational, economic, religious, political, and other factors, are likely to be the most important and also the most difficult to understand and modify. If nutritional and other diseases are viewed as problems in human ecology, the primary health-care approach to their prevention follows naturally.

6: Final Report on the Safety Assessment of Panthenol and Pantothenic Acid

Panthenol is the alcohol analogue of Pantothenic Acid (vitamin B3). The LD50for D-Panthenol administered orally to mice was 15 g/kg. No toxicological effects were associated with the subchronic and/or chronic oral administration of Panthenol to rats. Minimal cutaneous hyperkeratosis was noted in rats in a subchronic dermal study of creams containing 0.2% Panthenol. In ocular irritation studies involving rabbits, concentrations up to 2% produced, at most, slight conjunctival redness and chemosis. Panthenol (100%) and products containing Panthenol (0.5% and 2%) administered to rabbits during skin irritation studies caused reactions ranging from no skin irritation to moderate-to-severe erythema and well-defined edema. Neither teratogenic nor fetotoxic effects were noted in the offspring when rats were fed calcium pantothenate prior to mating and throughout gestation. Skin irritation and sensitization studies of cosmetic products at concentrations up to 0.5% indicated that they were, at most, mild irritants but did not induce allergic sensitization. No test substance-related observations of eye irritation were reported for 23 subjects receiving instillations of products containing 0.1% Panthenol. Mutagenicity and carcinogenicity data were not available for the safety assessment of Panthenol. It is noted that the level of this ingredient required by humans exceeds the amount that could be absorbed from the low concentrations used in cosmetic products. The human metabolic requirement would preclude the likelihood of genotoxicity. It is concluded that Panthenol and Pantothenic Acid are safe as presently used in cosmetics.

Reducing Cancer Risk with Vitamins C, E, and Selenium

Current research has provided evidence that nearly 90 percent of all cancers may be related to diet, environment, and lifestyle. Of this number, 30 to 40 percent of cancers in men and up to 60 percent of cancers in women may be related to diet and nutrition. The two-stage process in the formation of many cancers, defined as initiation and promotion, is influenced by many dietary components. Vitamins C, E, and the mineral selenium are nutrients that function as antioxidants, reducing potential cancer-causing chemicals in the body. These natural anticarcinogens are thought to alter the cancer process and are currently under study for their cancer prevention properties. The functions, Recommended Dietary Allowances, food sources, research evidence for cancer prevention, and recommendations for supplementation are presented for these three nutrients. Research suggests that the proper and prudent use of nutrients, along with a healthy diet and lifestyle, may offer protection against this devastating disease.

Dietary and pharmacological intervention to mitigate the cardiopulmonary effects of air pollution toxicity

BACKGROUND

Exposure to air pollution contributes importantly to excess morbidity and mortality. And while regulatory actions under the "Clean Air Act" have saved millions of lives by improving air quality, there are still millions of people in the U.S. who live in areas where particulate air pollution (PM) levels exceed the U.S. Environmental Protection Agency's National Ambient Air Quality Standards. Therefore, apart from such localities working to attain such standards the protection of the health of public and in particular those at high risk might benefit from interventional strategies that would ameliorate air pollution's adverse health effects. Because inflammation and oxidative stress appear to mediate the health effects of air pollution, one interventional approach to consider is the use of dietary supplementation or medication with anti-inflammatory or antioxidant properties to block the biological responses that initiate the pathophysiological process that culminates in adverse health effects.

SCOPE OF REVIEW

This article reviews the capability of dietary supplementation, such as antioxidant vitamins, polyunsaturated fatty acids, and medications as a strategy to mitigate air pollution-induced subclinical cardiopulmonary effects.

MAJOR CONCLUSIONS

Antioxidant vitamins C and E protect the lungs against short-term ozone and PM exposure. Polyunsaturated fatty acids, such as fish oil and olive oil appear to offer protection against short-term air pollution-induced adverse cardiovascular responses.

GENERAL SIGNIFICANCE

Taking dietary supplements or medications with antioxidant or anti-inflammatory properties has the potential to provide at least partial protection against air pollution-induced adverse health effects in those individuals who are known to be most susceptible, namely those with pre-existing respiratory and cardiovascular diseases. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu.

Treatable childhood neuronopathy caused by mutations in riboflavin transporter RFVT2

Childhood onset motor neuron diseases or neuronopathies are a clinically heterogeneous group of disorders. A particularly severe subgroup first described in 1894, and subsequently called Brown-Vialetto-Van Laere syndrome, is characterized by progressive pontobulbar palsy, sensorineural hearing loss and respiratory insufficiency. There has been no treatment for this progressive neurodegenerative disorder, which leads to respiratory failure and usually death during childhood. We recently reported the identification of SLC52A2, encoding riboflavin transporter RFVT2, as a new causative gene for Brown-Vialetto-Van Laere syndrome. We used both exome and Sanger sequencing to identify SLC52A2 mutations in patients presenting with cranial neuropathies and sensorimotor neuropathy with or without respiratory insufficiency. We undertook clinical, neurophysiological and biochemical characterization of patients with mutations in SLC52A2, functionally analysed the most prevalent mutations and initiated a regimen of high-dose oral riboflavin. We identified 18 patients from 13 families with compound heterozygous or homozygous mutations in SLC52A2. Affected individuals share a core phenotype of rapidly progressive axonal sensorimotor neuropathy (manifesting with sensory ataxia, severe weakness of the upper limbs and axial muscles with distinctly preserved strength of the lower limbs), hearing loss, optic atrophy and respiratory insufficiency. We demonstrate that SLC52A2 mutations cause reduced riboflavin uptake and reduced riboflavin transporter protein expression, and we report the response to high-dose oral riboflavin therapy in patients with SLC52A2 mutations, including significant and sustained clinical and biochemical improvements in two patients and preliminary clinical response data in 13 patients with associated biochemical improvements in 10 patients. The clinical and biochemical responses of this SLC52A2-specific cohort suggest that riboflavin supplementation can ameliorate the progression of this neurodegenerative condition, particularly when initiated soon after the onset of symptoms.

Reversible effects of vitamins C and E combination on oxidative stress-induced apoptosis in melamine-treated PC12 cells

Due to its high nitrogen content, melamine was deliberately added to raw milk for increasing the apparent protein content. Previous studies showed that melamine-induced apoptosis and oxidative damage on PC12 cells and rats' hippocampus. Several evidences suggested that vitamin antioxidant reduced oxidative stress and improved organic function. Whether treatments with antioxidant vitamins C or E, otherwise combination of them can attenuate oxidative stress after melamine administration remains to be elucidated. In this study, the reversible effects of vitamin antioxidants was investigated on melamine-induced neurotoxicity in cultured PC12 cells, an in vitro model of neuronal cells. When comparing vitamin C and E, the combination of both statistically increased PC12 cells viability. The results further showed that vitamin complex has effectively reduced the formation of reaction oxygen species, decreased the level of malondialdehyde, and elevated the activities of antioxidative enzymes. Hoechst 33342 staining and flow cytometric analysis of apoptosis showed that vitamin combination treatment effectively prevented PC12 cells from this melamine-induced apoptosis. It revealed the apoptotic nuclear features of the melamine-induced cell death. Additionally, a combination treatment of vitamins effectively inhibited apoptosis via blocking the increased activation of caspase-3. In summary, the vitamin E and C combination treatment could rescue PC12 cells from the injury induced by melamine through the downregulation of oxidative stress and prevention of melamine-induced apoptosis.

The interplay between diet and emerging allergy: what can we learn from Indigenous Australians?

The pathophysiology of atopic diseases, including asthma and allergy, is the result of complex gene-environment interactions. Since European colonization the Indigenous population of Australia has undergone significant changes with respect to their lifestyle as hunter-gatherers. These changes have had a detrimental effect on Aboriginal health, in part due to immunological modification. This review provides a comparative look at both the traditional Aboriginal/Indigenous diet and modern Western diets, examines some common allergies increasingly reported in contemporary Indigenous populations, and reviews concepts such the effect of vitamin deficiencies and changes in gut microbiota on immune function.

Effects of hypervitaminosis of vitamin B3 on silkworm biology

A high-dose of vitamin B(3) in silkworm diet interrupts larval feeding and normal growth. High mortality of larvae occurs during molting and they cannot complete this process normally. Also the larvae exhibit nicotinamide hypervitaminosis symptoms such as immobility, dyspepsia, darkening of the skin, inability to excrete normally, exerting brownish fluid from anus and swelling of rectal muscles. Maximum larval weights in 1, 2 and 3 g/l treatments were 2.9, 1.6 and 1.2 g respectively, while maximum larval weight in the control was 5.6 g. Larval stage compared to control had increased 18, 26 and 31 days respectively. The concentration increase of uric acid in haemolymph demonstrates the hyperuricemia, while other measured biochemical compounds show significant decrease; sodium and potassium did not change significantly.

Pyridoxine (vitamin B6) toxicity: enhancement by uremia in rats

Pyridoxine is not completely innocuous. Large doses can cause a peripheral neuropathy despite renal excretion of this water-soluble vitamin. Renal failure patients are treated with pyridoxine to prevent a deficiency. The safety of pyridoxine treatment in the presence of renal dysfunction has not been studied. Our experiments on anephric rats show that the uremic state, in a mere 3 or 4 days, causes a 5- to 10-fold increase in susceptibility to pyridoxine-induced neuronopathy. These results suggest a need for caution in prescribing pyridoxine to uremic patients who will probably take the vitamin daily for many years.

Avaliação das Propriedades do Ácido Nicotínico no Desempenho e no Balanço Térmico de Frangos de Corte Durante Estresse por Calor

Foram oferecidas 4 doses de ácido nicotínico (AN) na água de beber de frangos de corte, a fim de estudar seu efeito no desempenho e na produção de calor em condições de estresse por calor (6 h de 35º C). As doses foram 15, 100, 330 e 1000 mg/L. Não houve efeito do AN nas doses usadas para ganho de peso, consumo de alimento, eficiência alimentar, consumo de água e temperatura retal. Foram observadas algumas alterações devido ao AN e estresse por calor nos parâmetros sangüíneos das aves. A produção de calor (kcal/h/peso metabólico) diminuiu com o uso de 100 e 1000 mg/L comparados com 15 mg/L. Nas dosagens usadas não foi observado efeito benéfico do AN no controle do estresse por calor.

Drug Poisoning and Overdose for the Health Professional: Review of Select Over-the-Counter (OTC) and Prescription Medications

Exposure to over-the-counter and prescription medications can pose significant therapeutic and health hazards to patients, and present health care professionals with scenarios that require proper assessment and treatment. Knowing when an exposure to or overdose of a drug requires emergency medical attention is equally as important as to knowing when such assistance is not necessary—that simple treatment measures performed at home will suffice. This current discussion is intended to highlight select principles and clinical information pertaining to common drug exposures and overdoses, but not replace the full spectrum of information that would be available to health care professionals (and the lay public) by contacting their nearest poison control center. Many of the basic principles and concerns that are encountered with exposures to chemicals (i.e., route of exposure, patient medical history, quantity of the substance involved, elapsed time since the initial exposure, etc.) apply equally well to drug exposures. Likewise, evaluating each of these variables will determine which type of treatment approaches are, and are not, considered in situations of drug (or chemical) exposure and overdose.

Nutrition in the exercising elderly

When making nutrition recommendations to the exercising elderly population, four important areas should be taken into consideration: (1) the changing needs that occur with age; (2) the changing needs that occur with exercise; (3) the presence of any chronic illnesses or diseases; and (4) whether one is exercising for fitness, recreation, or competition. For the most part, these four areas have been researched separately, and recommendations for elderly athletes need to be synthesized from this information. The nutrients for which food consumption is often inadequate and has the largest impact on the exercising elderly population include vitamin B6, vitamin B12, calcium, and vitamin D. The exercising elderly population needs to be aware of their bodies changing needs with exercise and should focus on maintaining energy balance while selecting a wide variety of foods high in complex carbohydrates. When adequate dietary intakes cannot be obtained, supplementation with a multivitamin of no more than 100% of the RDA is recommended.

Vitamins, Minerals, and Nutritional Supplements

Vitamins, minerals, and nutritional supplements constitute materials which have been confused in the minds of consumers. They are promoted and sold by health care providers, including pharmacists, as well as by a wide variety of retail merchants. The relative safety and effectiveness of these substances in treatment of deficiency states has been extended to the notion that since the small recommended daily allowance ensures health or at least a non-deficient state, larger amounts will provide wellness or at least improve health. The proper use of diet, including vitamin and mineral supplements, has been supplanted by a form of unrestricted and unprofessional pharmacy practice. In large amounts, vitamins and minerals can have pharmacological effects including drug interaction and toxicity. The 1994 Dietary Supplements Health & Education Act has opened up the legal use by the general public of some pharmaceutically active ingredients unless they are demonstrated to be dangerous.

Megavitamin treatment of mental retardation in children: a review of effects on behavior and cognition

ABSTRACT Many forms of vitamin supplementation have been proposed for the treatment of behavioral and cognitive disorders in children with mental retardation. Except for nutrient deficiencies and selected inborn errors of metabolism, the efficacy of these treatments has not been established. Therapeutic supplementation with vitamin B(6) in Down syndrome and folie acid in fragile X syndrome was attempted following the identification of apparent biochemical aberrations involving the nutrients. Double-blind controlled trials have revealed no evidence that B(6) treatment was effective in Down syndrome. Very limited evidence, only among prepubertal subjects, suggested that behaviors improved with folie acid treatment in fragile X syndrome. There is less clarity of the scientific rationales for various combinations of vitamins (or vitamins and minerals) that have been promoted according to the concept of orthomolecular medicine. Well-designed controlled studies, with data presented in conformity with generally accepted scientific standards, have not supported the efficacy of megadose supplementation with 1) multivitamins in cognitive disabilities or attention deficit disorders, or 2) multivitamins and minerals in Down syndrome or other forms of mental retardation. Insufficient data are available to support claims made for vitamin B(6) and magnesium supplementation in autism. Research in the larger field of nutrient-behavior research has reinforced the need for studies to be more rigorously designed and to draw on the expertise of multiple disciplines. Evidence of toxic effects of nutrients continues to accrue, reinforcing the fact that megadoses should not be used indiscriminately or without physician monitoring. For children with mental retardation generally, assuring that established nutritional needs are met warrants primary consideration.

Vitamin supplementation and physical exercise performance

Vitamins, just as minerals and trace elements, meet with great interest in the world of sports because of their supposed role in enhancing physical performance. Of the 13 compounds now considered as vitamins, most water-soluble vitamins and vitamin E are involved in mitochondrial energy metabolism. The influence of vitamin supplementation on mitochondrial metabolism is largely unknown. The principal argument for vitamin supplementation is the assumed increased vitamin requirement of athletes. Theoretically, an increased requirement can be caused by decreased absorption by the gastrointestinal tract, increased excretion in sweat, urine and faeces, increased turnover, as well as biochemical adaptation to training. Of course, a marginal low vitamin status can simply be the consequence of a long-term inadequate intake. However, considering the RDAs there are no indications that long-term vitamin intake among athletes is insufficient. Neither are there indications that vitamin excretion or turnover is increased in athletes. However, it is very likely that the (apparently) increased requirement is the consequence of biochemical adaptation to training and does not indicate a decreased intake. Although a marginal vitamin status, induced by inadequate vitamin intake, may have a negative effect on performance, there is no evidence to support the view that this occurs in trained athletes. Moreover, vitamin supplementation in athletes with an adequate vitamin status has no effect on physical working capacity. Possibly, exceptions have to be made for the use of vitamin E at high altitudes and for the use of vitamin C and multiple B-vitamin supplements in hot climates.

A conceptual approach to optimal nutrition of brood mares

Cumulative nutritional demands on good brood mares are unrivalled among domestic livestock, but little attention has been given to the influence of nutrition on their reproductive performance and efficiency. We suggest that part of the decline in racing performance of progeny of mares over 10 years of age may be caused by suboptimal nutrition. This article contrasts the concepts of minimal and optimal nutrient requirements, revives Hammond's concept of nutrient partitioning to the conceptus and mammary gland, and discusses energy and nutrient requirements during gestation and lactation. Further consideration is given to the aged brood mare.

Enteric function in cats after subtotal colectomy for treatment of megacolon

The enteric function of four cats that had undergone subtotal colectomy for megacolon was compared with that of four normal cats. All cats were fed the same diet before and during the study. History, physical condition, body weight, blood chemistry panel, fasting and postprandial serum bile acids, serum cobalamin concentration, serum folate concentration, fecal weight, fecal water content, fecal fat content, fecal osmolality and electrolyte concentration, quantitative anaerobic fecal bacterial culture, partial thromboplastin time, prothrombin time, breath hydrogen concentration, urinary calcium, phosphorus and electrolyte concentrations, and abdominal radiographic examination with air contrast studies (pneumocolon) were examined. The four cats treated surgically were healthy and thriving and, in general, enteric function was similar to the controls. Bowel movements occurred only slightly more frequently with no significant differences in fecal volume or water content. Serum cobalamin concentrations were significantly higher in cats treated surgically. Fecal sodium concentrations were high and fecal potassium concentrations were low. Results of this study did not show any significant subclinical evidence of abnormal bowel function in cats after subtotal colectomy.

Dietary supplement use in a randomly selected group of elderly Australians. Results from a large nutrition and health survey

The prevalence of dietary supplementation and its relationship to health and dietary habits was investigated in a random mail survey of 2,195 people aged 65 years and over in Adelaide, South Australia. Subjects were selected from the electoral rolls in an urban area, and 77% returned completed survey instruments. Thirty-five percent of men and 46% of women reported taking some form of supplement at least once a week regularly throughout the year (these are defined as "regular" supplementers). The most popular supplements (in descending order of popularity for the total group) were: unprocessed bran, wheatgerm, vitamin C, and multivitamins or minerals. Thirteen percent of men and 15% of women reported the use of supplements on an occasional basis (once every few months or "now and then")--these are defined as "irregular" or "occasional" supplementers. Supplement users did not differ from non-supplementers in their use of medical facilities or in the number of bouts of minor illness they had experienced in the preceding year. Regular supplement users had more favorable dietary habits and higher intakes of several vitamins, minerals, trace elements and fiber than either non-supplementers or occasional supplementers.

Blood levels of water-soluble vitamins in pediatric patients on total parenteral nutrition using a multiple vitamin preparation

Although guidelines for the parenteral use of vitamin preparations in pediatric patients have been published, there are very limited data on the efficiency of these preparations and on the exact needs of infants and children on total parenteral nutrition (TPN). We report here an open, prospective, study of the blood levels of water-soluble vitamins in infants and children on TPN before and during supplementation with a new water-soluble multivitamin formula containing per vial unit: B1, 3 mg; B2, 3.6 mg; B6, 4 mg; niacin, 40 mg; pantothenate, 15 mg; ascorbate, 100 mg; biotin, 60 micrograms; folic acid, 400 micrograms; B12, 5 micrograms. Thirteen children, 9 months to 15 yr old, on home TPN for 1.5 months to 7 yr, and 17 hospitalized infants and children, 1 week to 15 yr old, receiving TPN were studied for 2 weeks to 4 months. Daily doses were given according to age: 1/2 vial if less than 18 months; 1 vial if greater than 18 months and less than 10 years; 1.5 vials if greater than 10 years. Assays for B1, B2, biotin, niacin, plasma and red blood cell (RBC) folates were performed by microbiologic methods, B12 was measured by radioimmunoassay. During the study, B1 levels were consistently above the upper limit of the normal range, B2 and B12 remained in the normal range although there was a slight decrease in B12 values. Almost half of the patients had initially low levels of biotin, niacin, and folates. Biotin, after a significant sharp rise during the first month of supplementation returned to normal range. Niacin levels were initially low in infants and rose toward normal values during treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary pyridoxine interaction with tryptophan or histidine on brain serotonin and histamine metabolism

We studied the metabolic effects of high dietary intakes of pyridoxine and of the substrate-cofactor interaction between dietary histidine or tryptophan and pyridoxine in rat brain. In the substrate-cofactor interaction study, histamine and serotonin levels were determined in rats fed elevated or requirement levels of substrate (histidine: 0.3% and 0.8%, tryptophan: 0.15% and 0.6%) and excess or requirement levels of pyridoxine HCl (7 mg vs. 3,000 mg/kg). Excess pyridoxine intake caused a differential effect on brain histamine concentration--inhibitory with the requirement level of histidine (-29%), and stimulatory (+21%) with the elevated level of histidine. When dietary tryptophan was fed at the requirement level, excess pyridoxine caused essentially no changes in hypothalamic serotonin and 5HIAA (-2%, -2%). With elevated tryptophan intake, excess pyridoxine significantly increased serotonin and 5HIAA (+32%, +20%) in the hypothalamus. These results indicate a clear interaction between substrate and coenzyme precursor which influences brain metabolism of histamine and serotonin.

Adverse effects of hypolipidaemic drugs

Cholestyramine, colestipol, clofibrate, gemfibrozil, nicotinic acid (niacin), probucol, neomycin, and dextrothyroxine are the most commonly used drugs in the treatment of hyperlipoproteinaemic disorders. While adverse reaction data are available for all of them, definitive data regarding the frequency and severity of potential adverse effects from well-controlled trials using large numbers of patients (greater than 1000) are available only for cholestyramine, clofibrate, nicotinic acid and dextrothyroxine. In adult patients treated with cholestyramine, gastrointestinal complaints, especially constipation, abdominal pain and unpalatability are most frequently observed. Continued administration along with dietary manipulation (e.g. addition of dietary fibre) and/or stool softeners results in diminished complaints during long term therapy. Large doses of cholestyramine (greater than 32 g/day) may be associated with malabsorption of fat-soluble vitamins. Most significantly, osteomalacia and, on rare occasions, haemorrhagic diathesis are reported with cholestyramine impairment of vitamin D and vitamin K absorption, respectively. Paediatric patients have been reported to experience hyperchloraemic metabolic acidosis or gastrointestinal obstruction. Concurrent administration of acidic drugs may result in their reduced bioavailability. Serious adverse reactions to clofibrate will probably limit its role in the future. Of particular concern are ventricular arrhythmias, induction of cholelithiasis and cholecystitis, and the potential for promoting gastrointestinal malignancy which far outweigh the reported benefits in preventing new or recurrent myocardial infarction, cardiovascular death and overall death. Patients with renal disease are particularly prone to myositis, secondary to alterations in protein binding and impaired renal excretion of clofibrate. Drug interactions with coumarin anticoagulants and sulphonylurea compounds may produce bleeding episodes and hypoglycaemia, respectively. Nicotinic acid produces frequent adverse effects, but they are usually not serious, tend to decrease with time, and can be managed easily. Dermal and gastrointestinal reactions are most common. Truncal and facial flushing are reported in 90 to 100% of treated patients in large clinical trials. Significant elevations of liver enzymes, serum glucose, and serum uric acid are occasionally seen with nicotinic acid therapy. Liver enzyme elevations are more common in patients given large dosage increases over short periods of time, and in patients treated with sustained release formulations.(ABSTRACT TRUNCATED AT 400 WORDS)

Unconventional eating practices and their health implications

The authors discuss a number of unconventional or faddist foods and eating practices and their health implications. Among the topics included are vegetarianism, Zen macrobiotic diets, fast foods, junk foods, megavitamins and their toxicity, health foods, fad diets in infancy, and elimination diets.

Nutritional requirements

GOOD NUTRITIONAL health calls for an ade quate intake of all the nutrients and can only be achieved by consuming a wide variety of foods. Some of our modern 'diseases of affluence' are blamed on excessive intakes of fat and sugar and salt with inadequate dietary fibre, consequently current nut ritional advice is that everyone should change his diet accordingly. Since meat is a major contributor of satu rated fat to the British diet it is being recommended that leaner carcasses should be produced, that less meat should be eaten and replaced by poultry and fish, and that the fat content of meat products should be reduced.