Nutrition Noteworthy

Breastfeeding, a natural next step of the pregnancy, comes with many obvious advantages to the infant. Benefits of breastfeeding known to most include its ability to provide unique quality of nutrients along with immunity, certain enzymes and vitamins to the baby. Over the past few decades, particular attention has been paid to the long chain polyunsaturated fatty acid (LC PUFA) composition of breast milk, especially arachidonic acid (AA) and docosahexaenoic acid (DHA). These LC PUFAs, found abundantly in the brain, the retina, and other nervous tissue, are not found in any of the current baby formulas on the market. Being essential part of the infant nutrition, this poses a problem for those infants who are formula-fed and are thus deprived of these essential fatty acids. The benefits of these fatty acids have been found to be numerous including but not limited to possible visual acuity in infancy, higher scores on mental development tests at infancy, higher IQ scores, increased growth and increased insulin sensitivity. The benefits are striking, yet the process of supplementation of current formulas with these essential fatty acids is simple. In fact, further research is currently being done to investigate certain side effects of supplementation before the FDA can make a final decision.

The plant commonly known as echinacea, used widely as an alternative medical technique in Europe, is becoming increasingly popular in the United States. It is native to the central United States and, historically, is one of the most important plants used medicinally by North American Indians. Today, echinacea is primarily used for its immune–stimulating and anti–inflammatory effects. Recent studies have indicated that several of its active components–high molecular weight polysaccharides, alkamides, and echinacoside–are very effective in mediating these effects. The polysaccharides have been shown to induce acute phase reactions in humans, activate phagocytes in humans and mice, and protect mice against lethal infection doses with Listeria monocytogenes and Candida albicans (3, 5). Inflammatory responses have been proven to be alleviated by alkamide inhibition of the enzymes 5–lipoxygenase and cyclooxygenase, both responsible for arachidonic acid metabolism to leukotrienes and prostaglandins respectively (2). Echinacoside was shown to strongly protect collagen from free radical attack, suggesting the use of echinacea extracts for the prevention of skin photodamage (1). Increasing concentrations of echinacea extracts given to normal individuals and patients with either chronic fatigue syndrome or AIDS caused increased antibody–dependent cellular cytotoxicity and natural killer cell function (4). The long history of successful echinacea use both in the United States and in Europe combined with the research which is now coming to light prove that it is deserving of continued attention by scientists and especially by clinicians seeking alternative ways to help their patients.

"Phantom fat" or trans fatty acids are created by the partial hydrogenation of vegetable oils to produce margarine and shortening products. When introduced to the body, these fatty acids increase serum levels of low-density-lipoprotein cholesterol and decrease serum high-density-lipoprotein cholesterol.(7, 19)Companies place these fats in foods with the goal of increasing profits by decreasing the amount of saturated fat reported on "nutrition facts" labels. Consumers buying these products are generally trying to decrease their intake of saturated fats to lower their risk for coronary heart disease. Conversely, the intake of trans fatty acids has been shown to be directly related to the risk for coronary heart disease in women (P<0.001).(5) The seriousness of this issue can be emphasized by the ability of trans fatty acids to have more adverse effects on serum lipoproteins than equal amounts of saturated fat (P<0.001).(9) Because amounts of trans fat are not listed on product labels, consumers may unknowingly be increasing their risks for coronary heart disease by eating trans fatty acids.

The study of migrant populations has been employed in epidemiological studies to better characterize the causality of multifactorial disease, where both genetic and environmental factors contribute to the onset of pathological states. By examining migrant populations, groups of individuals sharing a fairly common genetic background—thus exhibiting fairly uniform predispositions toward certain disease processes—can be compared to populations from their countries of origin in order to better understand the environmental factors that precipitate disease. Studies of acculturation of people of Japanese descent have yielded important information on environmental factors that contribute to ailments such as coronary heart disease and non-insulin-dependent diabetes mellitus. However, migration studies may be plagued by confounding factors which detract from the validity of the analysis of data gathered from migrant and native populations. This paper will discuss the complications that arise in migration studies with respect to the work that has been done in acculturation studies comparing Japanese-Americans and natives of Japan.

Coronary heart disease (CHD) is the major cause of death in most developed countries and the roles of lifestyle and diet in its genesis are undeniable. The soybean has been under intense investigation as having protective effects on cardiovascular health. This legume, a staple of most Asian diets, has received attention from both health care providers and researchers because of its excellent nutritional profile and unique non-nutritive component. Animal and human studies have shown that consumption of soy food products is cholesterol-lowering, and there is also evidence of protective effects directed at later events in the atherosclerotic process. The protein, lipid and carbohydrate components are likely responsible for soy’s hypocholesterolemic effects. Modulation of later events in atherogenesis, e.g., lipoprotein peroxidation and cell signalling pathways, may be mediated by the isoflavones, non-nutritive phytochemicals unique to the soybean. These diphenolic compounds are also of interest because of their structural similarity to the hormone estrogen, an important player in many chronic diseases of multifactorial etiology (CHD, cancer, osteoporosis, etc.) that affect women. While the need for further investigation is warranted, particularly that directed at elucidating mechanisms of action, the evidence at this point for the hypocholesterolemic and anti-atherogenic effects of the soybean and soy food products is convincing and attempts should be made to better incorporate this food into the American diet.

Cancer is a tremendous health concern in the United States; incidence is high, treatment techniques are often dangerous, ineffective, and, as must be considered in this age, expensive. Increasingly, interest is turning to means of cancer prevention. Epidemiological studies have suggested that one of the most important controllable determinants of cancer risk for an individual is his or her diet; it is an important etiology in 30-60% of varieties of cancers. Of the many foods that appear to have positive and negative influences on carcinogenesis, one of the most striking is the plant genus Brassica, the cruciferous vegetables. Vegetables such as Brussles sprouts, cabbage, and broccoli seem to have greater health benefits than other vegetables. Why is this? Certain chemical compounds unique to cruciferous vegetables have been identified that appear to decrease an individual's chance of developing cancer. Several mechanisms of action have been suggested and considerations of dosage and side-effects also deserve consideration.

Vitamin A is necessary for fetal development, cell growth and development, and reproduction. It is a fat soluble vitamin found in many different foods, but is also available in a synthetic form. Taking Vitamin A in doses larger than the Recommended Daily Allowance (RDA) can cause deleterious effects on the developing fetus during the critical period of embryogenesis namely Neural Tube Defects (NTDs). While taking Vitamin A in such large amounts can lead to many different congenital malformations, it has been shown that other environmental and inherited genetic factors also cause similar effects. Due to the recent advances in molecular biology techniques, many of genetic defects have been identified, including those involving the Retinoic Acid Receptor (RAR) and various Hox genes.

Finding a method of contraception that is both convenient and effective has been a challenge faced by women of reproductive age for many years. The hormonal contraceptive Depo-Provera® (depot medroxyprogesterone acetate, DMPA) has addressed this problem in recent years. However there are side effects that must be considered with any drug therapy, and one of the major concerns for women in the United States has been with the assumed or experienced weight gain associated with DMPA use. Early studies and product information report a gain anywhere from 4-6 pounds in the first year of use. This correlated to dissatisfaction with the product and discontinuation of DMPA as a birth control method. However, more recent evidence contradicts this research and shows only non-significant gains in weight. A possible explanation is proposed by looking at demographic data, specifically age differences between the women in the older studies and women in the more recent research.

Stroke is the third leading cause of death in the U.S. Many of these strokes can be prevented using a bit of dietary management with dietary, non-supplementary, antioxidants. Vitamins C, B-complex, E, and beta-carotene due their part in stroke prevention by preventing oxidation of LDL and free-radical oxidation in aqueous phase, a mechanism in part responsible for atherosclerotic plaques. Vitamin B12, another antioxidant vitamin, does its part in the equation by preventing hyperhomocysteinemia, a condition with improper sulfur amino acid metabolism, leading to thiolactone initiated oxidation of LDLs. Flavonoids and other phytocompounds are important for oxygen free-radical "soaking up" and also are involved in other forms of stroke prevention.

The significant economic, social, and emotional costs of depression would bestow much value on a cost-effective nutritional therapy such as supplementation. Recently, a relationship between folate and depression has been observed in clinical studies and inferred from increased understanding of the role of folate in neural mechanisms involved in mood regulation. Current studies suggest that a subpopulation of depressed patients may benefit from treatment with folate supplementation. However, further studies are needed to replicate and extend these findings and to clarify the circumstances under which folate supplementation may effect a role in antidepressant therapy; only then can any routine screening criteria or treatment protocols be established.

Premenstrual syndrome (PMS) is a recurring cyclical disorder that encompasses a variety of emotional and physical symptoms that appear in the luteal phase of the menstrual cycle. Overall, approximately 75% of the women with regular cycles complain of some premenstrual symptoms. Emotional symptoms include emotional hypersensitivity, depression, irritability, mood swings, anxiety, tension, fear of loss of control, and confusion. Somatic complaints include feelings of bloating, body aches, breast tenderness, headaches, food cravings, and poor coordination. The etiology of PMS is still largely unknown, but current research suggests that serotonin may be important in its pathogenesis. Although the underlying cause remains unclear, significant progress has been made in treatment of symptoms. If presenting symptoms are mild, infrequent, or of short duration, use of nonpharmacologic approaches such as dietary modification, exercise, support, and stress reduction are suggested. This paper examines the dietary modifications that have recently been studied, some of which may offer relief from certain premenstrual symptoms. The current literature indicates that increased carbohydrate, calcium, manganese, and magnesium intake can decrease certain symptoms of PMS. However, recent studies do not indicate a clear role for sodium, caffeine, or vitamin B6 in alleviating symptoms.

Olestra, brand name olean® , is a non-absorbable, non-digestible, fat substitute that contributes zero calories to the diet. In 1996, the Food and Drug Administration approved olestra as a macro-ingredient food additive in savory snacks. Olestra can replace up to 100% of the fats and oils used in the preparation of these foods. Consumer advocacy groups and members of the scientific community find olestra's presence in the consumer market appalling. There are numerous claims and studies that show that moderate consumption of olestra may result in gastrointestinal discomfort, such as abdominal cramps, diarrhea, nausea, and "anal leakage". Olestra also decreases the absorption of fat-soluble nutrients (carotenoids, vitamins A, D, E, and K) by the body. Despite the negative effects on the gastrointestinal system and lipophilic nutrient absorption, olestra has some potential benefits. The non-digestible, non-absorbable property of olestra accounts for its zero calorie contribution to the diet. Olestra can be used as an aid in weight reduction; can limit and or reduce dietary fat consumption without compromising caloric intake; reduce caloric intake; and help at risk populations to more closely follow recommended dietary guidelines. This paper assesses olestra's effect on vitamin absorption, gastrointestinal system, and daily energy intake and fat reduction.