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Micronutrients: Calcium. major component of bones, teeth Required for many physiological processes Roles of parathyroid hormone, calcitonin bone loss begins to increase during young adulthood (>35 years) Estrogen and menopause designer estrogen called Evista
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Micronutrients: Calcium • major component of bones, teeth • Required for many physiological processes • Roles of parathyroid hormone, calcitonin • bone loss begins to increase during young adulthood (>35 years) • Estrogen and menopause • designer estrogen called Evista • lack of calcium > porous bones (osteoporosis)
Calcium, cont’d. • daily requirements: • adolescence = 1200 mg/day • non-pregnant, non-lactating women = 800 mg/day • after menopause = 1500 mg/day • typical intake of post-men. women = 500 mg/day • food sources of calcium: dairy products, green leafy vegetables • http://www.lowfatweekly.com/calcium_content_in_foods.htm • absorption requires vitamin D
Osteoporosis • 80% of osteoporotic individuals are female • 8 million women, 2 million men in U.S. currently suffer from osteoporosis • 1 out of 2 women will be affected after age 50 years • $38 million / day spent on treatment • Risk factors: • gender, age, smoking, family history, calcium intake, sedentary lifestyle, drinking
Osteoporosis • Bones most often affected: vertebrae, hips, wrists
Iron • part of hemoglobin • deficiency: fewer red blood cells, decreased oxygen availability • low levels result in “iron deficiency anemia” • women susceptible due to monthly blood loss • daily requirements: • premenopause: 50-70 mg/day • postmenopause: 30 mg/day • foods rich in iron: red meat, liver, rice, beans, eggs, dried fruit • http://www.dialadietitian.org/resources/handouts/fe-food.html
Folic acid • form of vitamin B (folate) • foods rich in folic acid: • green leafy veggies, lentils, asparagus, broccoli, orange juice, fortified cereals, liver • important during childbearing years • may also protect against heart disease, cancer, psychiatric disorders • important for regulating blood homocysteine levels
Homocysteine • metabolite of the amino acid methionine • can be “recycled” to form methionine or can be degraded into cysteine and excereted • B vitamins (Vit B12, folate, Vit B6) are required for these processes • Vit B12 and folate participate in “recycling” of homocysteine into methionine • Vit B6 required for degradation into cysteine • High levels of homocysteine can adversely affect many tissues
Dangers of high homocysteine levels • Correlation between high hcy levels and cardiovascular disease: • Increased activation of clotting factors • Increased atherosclerosis • Correlation between low folate, high hcy and neural tube defects during pregnancy • Correlation between high hcy levels and schizophrenia • Genetic defects in metabolic enzymes can also contribute
Phytoestrogens • Plant compounds that are structurally similar to estrogen • Are “weak” estrogens or antiestrogens • Isoflavones, lignans, coumestans • Present in soy foods, oilseeds (e.g., flaxseed), and whole grain cereals • Cultures in which soy is a regular part of daily diet (~200 mg/day) have: • Decreased rates of breast, ovarian cancer • Decreased menopausal symptoms (<25% vs. 80%) • Decreased cardiovascular disease
Isoflavone content of various foods • Roasted soybeans: 162.5 mg • Textured vegetable protein: 138.2 mg • Green soybean: 135.4 mg • Tofu: 33.7 mg • Soy hot dog: 15 mg