Diets

Diets

Diet is the core treatment for many diseases, including obesity, hypertension, hyperglycemia, and dyslipidemia. Many interventions are beneficial, including replacing harmful fats with health-promoting fats; increasing fiber; increasing phytonutrient content such as flavonoids, polyphenols, and antioxidants from plant-based foods; reducing salt; and restricting calories. The Mediterranean diet is one of the most studied diets and recommends high consumption of extra virgin olive oil, fruits, vegetables, nuts, seeds, legumes, cereals, moderate fish, poultry, dairy, and red wine and lower consumption of eggs, red meat, processed meat, and processed foods. The Mediterranean diet improves blood pressure, lipid profiles, insulin sensitivity, CRP, oxidative stress, atherosclerotic disease, and cognitive function. To reemphasize, a one-size-fits-all diet or macronutrient recommendation is not plausible. The percentage of calories from carbohydrate, fat, and protein needs to be determined on an individual basis. Specific conditions such as chronic kidney disease will benefit from a controlled protein intake, and epilepsy can benefit from a very low-carbohydrate, high-fat ketogenic diet. For years, the field of nutrition has been bombarded with claims of various adjustments in macronutrient ratios having benefit. Nutritionists need to take into account individual disease states and give the patient the most sustainable, realistic plan to improve health. While the ketogenic diet (low-carbohydrate, high-fat) is showing promise for various conditions including epilepsy, cancer, weight loss, type 2 diabetes, metabolic syndrome, dementia, and neurological diseases, the ketogenic diet can be difficult for the average person to sustain. Intermittent fasting (IF) and time-restricted feeding (TRF) may prove to have as important cardiometabolic and neurological benefits as the ketogenic diet and may be appropriate for those who cannot sustain a ketogenic diet. Time-restricted feeding (TRF) may be a feasible alternative to calorie restriction, ketogenic diet, and intermittent fasting when compliance with more restrictive eating regimes is not likely or not recommended. TRF is an eating pattern based around circadian rhythms that occurs within a limited time span (usually 8–12 hours), with a span of 4 hours in between meals with no attention paid to calorie intake.

Integrative and Functional Medical Nutrition Therapy by: Diane Noland, Jeanne A. Drisko, Leigh Wagner

Fatty Acids

Fatty Acids

A balanced ratio of omega-6 to omega-3 fatty acids is important for overall health related to its impact on inflammation, immune balance, obesity, depression, and cardiovascular disease. Alpha-Linolenic acid (omega-3) and linoleic acid (omega-6) are the two essential fatty acids that must be obtained through the diet; The ratio of omega-6–omega-3, historically, was 1:1–4:1, and today it is reported to be around 20:1. This change in consumption correlates with the rising epidemic of obesity and inflammatory disorders. Omega-3 fatty acid-enriched diets improve inflammatory status of metabolic dysfunction and reduction in adipose tissue if kept in balance with other essential fats. Supplementation with omega-3 fatty acids and certain doses of omega −6 fatty acids was shown to help with decreasing body fat mass and hip circumference loss. Dietary interventions optimizing the ratio of omega-6 to omega-3 have shown significant reduction in low-density cholesterol as well. Short-chain fatty acids (SCFA) are the major metabolic products formed by anaerobic bacterial fermentation of soluble fiber in the gastrointestinal tract and may be the link between microbiota and host tissues. SCFA include acetate (C2), propionate (C3), and butyrate (C4). Acetate is utilized for lipogenesis in the liver and as a fuel source once it enters circulation; propionate is also used in the liver as a substrate for hepatic gluconeogenesis; butyrate is primarily used as a fuel source for the colonocytes. Besides serving as a fuel source for the intestinal epithelial cells, SCFA also modulates electrolyte and water absorption in the GI tract and regulates the inflammatory process in the GI tract. The concentration of SCFA in the GI tract and blood may predispose to or prevent illnesses such as inflammatory bowel disease (IBD), cancer, and diabetes. SCFA modulates different processes such as cell proliferation and differentiation, hormone secretion of leptin and peptide YY, and immune and inflammatory responses and serves as an energy source for colonocytes, the liver, and muscle. Recommend lowering omega-6 by changing vegetable oils from corn, sunflower, safflower, cottonseed, and soybean oils to oils that are high in omega-3, such as flax, perilla, chia, rapeseed, and oils that are high in monounsaturated fats such as olive oil, macadamia nut oil, hazelnut oil, and increasing fish intake to two to three times per week while decreasing meat intake. Processed foods are notoriously high in omega-6; therefore, consuming a whole-food, unprocessed diet is also an important factor in balancing the ratio of omega-6–omega-3 fatty acids. Hydrogenated oils are harmful fats also known as trans-fatty acids. Hopefully, trans-fatty acids will be less of a concern in the United States due to the phasing out of these fats in the food manufacturing industry. Trans-fatty acids are harmful because, although listed as unsaturated fats, they behave like saturated fats and lead to higher cholesterol levels, and they mimic unsaturated fats by binding to desaturase enzymes and interfering with the normal production of necessary substances. Trans-fatty acids have been shown to contribute to the risk of heart disease and cancer. Trans-fatty acids are found in margarine, hydrogenated peanut butter, baked goods, desserts, snack foods, and crackers.

Integrative and Functional Medical Nutrition Therapy by: Diane Noland, Jeanne A. Drisko, Leigh Wagner

Fat Soluble Vitamins and Minerals

Fat Soluble Vitamins and Minerals

Integrative and Functional Medical Nutrition Therapy by: Diane Noland, Jeanne A. Drisko, Leigh Wagner

Fat-soluble vitamins are at risk of deficiency with certain states of malabsorption and malnutrition. In postmenopausal women, 5 mg of vitamin K1 protected postmenopausal women from bone fractures. In nature, vitamins A and D are found together in balance such as in cod liver oil, egg yolk, and organ meats. Vitamins A and D function in many systems throughout the body beyond the eyes and bones. Furthermore, vitamins A and D are important as immune and hormone modulators as well as affecting structural forms such as bones, cell membranes, tissues, etc. Vitamin E is a family of fat-soluble antioxidants that mainly refers to alpha tocopherol, but naturally includes several tocopherols and tocotrienols. Vegetable oils contain higher amounts of tocopherols, while tocotrienols are found in palm oil. Both tocopherols and tocotrienols have four homologues consisting of alpha, beta, gamma, and delta. Gamma-tocopherol is known mainly for its beneficial function in maintaining cardiovascular health, whereas the tocotrienols have shown more diverse application and protection against cancer, cardiovascular disease, neurodegeneration, oxidative stress, fertility, and immune regulation. Magnesium is often left undiscussed in treating bone health and cardiovascular disease. Low magnesium status may lead to a greater risk of metabolic syndrome, type 2 diabetes, cardiovascular disease, skeletal disorders, chronic obstructive pulmonary disease, depression, decreased cognition, and vitamin D deficiency. Magnesium plays a critical synergistic role in the synthesis and metabolism of parathyroid hormone (PTH), vitamin D-binding protein (VDBP), and three major enzymes that determine 25-OH vitamin D concentrations. Inconsistencies have been found in observational studies around the world showing a relationship between high sodium intake and hypertension. Potassium is an electrolyte needed for normal cellular function and is easily excreted by healthy functioning kidneys rather than stored in the body. Therefore, humans need a constant supply of potassium through the diet. Adequate intake of fruits and vegetables is a major source of potassium. Zinc is used clinically in supplement form to facilitate wound healing; decrease skin inflammation; support immune function, tissue growth, and maintenance of thyroid function; promote GI tract healing; protect against such ocular diseases as macular degeneration; and promote testosterone balance. Symptoms of severe zinc deficiency include hypogonadism, dwarfism, growth-retarded infants and children, dermatitis, diarrhea, alopecia, and loss of appetite. More moderate zinc deficiency can result in decreased immune function, increased mortality due to infections, and brain damage in a fetus when the pregnant mother is zinc deficient.