Absorción de suplementos y medicamentos
La absorcion de suplementos y medicamentos se puede ver seriamente afectada por algunos alimentos muy comunes.
Incrementan o decrementan la absorcion: (Segun cada casi pueden actuar de una forma o la otra)
– Pimienta negra
– Pomelo
– Naranja
– Manzana
Sobre el Pomelo:
"Recently, we discovered that grapefruit and these other fruit juices substantially decrease the oral absorption of certain drugs undergoing intestinal uptake transport," says study leader David G. Bailey, Ph.D., a professor of clinical pharmacology with the University of Western Ontario in London, Ontario. "The concern is loss of benefit of medications essential for the treatment of serious medical conditions."
Bailey and colleagues announced almost 20 years ago the unexpected finding that grapefruit juice can dramatically boost the body’s levels of the high-blood-pressure drug felodipine, causing potentially dangerous effects from excessive drug concentrations in the blood. Since then, other researchers have identified nearly 50 medications that carry the risk of grapefruit-induced drug-overdose interactions. As a result of the so-called "Grapefruit Juice Effect," some prescription drugs now carry warning labels against taking grapefruit juice or fresh grapefruit during drug consumption.
In the most recent research, Bailey’s group had healthy volunteers take fexofenadine, an antihistamine used to fight allergies. The volunteers consumed the drug with either a single glass of grapefruit juice, water containing only naringin (substance in grapefruit juice that gives the juice its bitter taste), or water. When fexofenadine was taken with grapefruit juice, only half of the drug was absorbed compared to taking the drug with water alone, Bailey says. Loosing half of the amount of drugs taken into the body can be critical for the performance certain drugs, he points out.
They also showed that the active ingredient of grapefruit juice, naringin, appears to block a key drug uptake transporter, called OATP1A2, involved in shuttling drugs from the small intestine to the bloodstream. Blocking this transporter reduces drug absorption and neutralizes their potential benefits, the researchers say. By contrast, drugs whose levels are boosted in the presence of grapefruit juice appear to block an important drug metabolizing enzyme, called CYP3A4, that normally breaks down drugs.
"This is just the tip of the iceberg," Bailey says. "I’m sure we’ll find more and more drugs that are affected this way."
To date, grapefruit, orange and apple juices have been shown to lower the absorption of etoposide, an anticancer agent; certain beta blockers (atenolol, celiprolol, talinolol) used to treat high blood pressure and prevent heart attacks; cyclosporine, a drug taken to prevent rejection of transplanted organs; and certain antibiotics (ciprofloxacin, levofloxacin, itraconazole). But additional drugs are likely to be added to the list as physicians become more aware of this drug-lowering interaction, Bailey says.
Orange and apple juices also appear to contain naringin-like substances that inhibit OATP1A2, Bailey says. The chemical in oranges appears to be hesperidin, but the chemical in apples has not yet been identified, the researchers notes.
Sobre la pimienta:
Piperine is able to increase bio-availability of many substances through a number of mechanisms. It inhibits several enzymes responsible for metabolizing nutritional substances, stimulates amino-acid transporters in the intestinal lining, inhibits removal of substances from cells so they continue to be available for use, and decreases the intestinal activity allowing more of the substances to enter the body in active form. The results of these actions are that substances reach, enter and remain within their target cells for longer periods of time than would normally be the case.
Piperine can turn a marginally effective therapeutic substance into a highly effective one by increasing its bio-availability and intracellular residency time. As an example, piperine can increase the bio-availability of the cancer, inflammation and infection fighter, curcumin (alimentos-saludables-f112/turmeric-curcumin-t1489-10.html), by twenty-fold.
Piperine favorably simulates the digestive enzymes of the pancreas, enhances digestive capacity and significantly reduces gastrointestinal food transit time. Black pepper or piperine treatment has also been evidenced to lower lipid per-oxidation in vivo and beneficially influence the cellular status of organic sulfur compounds, antioxidant molecules, and antioxidant enzymes in a number of experimental situations of oxidative stress.
In addition to its effects on bio-availability, piperine has many other actions in the body that include increasing beta-endorphins in the brain, acting as an anti-depressant, increasing serotonin production, boosting brain functioning, stimulating adrenal production, relieving pain and asthma symptoms, stimulating melanin production, decreasing ulcerations of the stomach, reducing stomach acid production, and coordinating digestive tract contractions. It is highly effective against colon cancer.
Estudio Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers.: http://www.ncbi.nlm.nih.gov/pubmed/9619120
Concomitant administration of piperine 20 mg produced much higher concentrations from 0.25 to 1 h post drug (P < 0.01 at 0.25 and 0.5 h; P < 0.001 at 1 h), the increase in bioavailability was 2000%. The study shows that in the dosages used, piperine enhances the serum concentration, extent of absorption and bioavailability of curcumin in both rats and humans with no adverse effects.
Hay que tener cuidado con las semillas y los frutos secos ya que contienen muchos fitatos que se unen a minerales como el Zinc y el Magnesio y previenen su absorcion, por lo tanto no es muy recomendable comer grandes cantidades de estos, sobre todo junto a otras comidas que lleven estos nutrientes, quiza solos como snack de vez en cuando y en cantidades moderadas:
Phytic acid is the storage form of phosphorus found in many plants, especially in the bran or hull of grains and in nuts and seeds. Although herbivores like cows and sheep can digest phytic acid, humans can’t. This is bad news because phytic acid binds to minerals (especially iron and zinc) in food and prevents us from absorbing them. 3 Studies suggest that we absorb approximately 20 percent more zinc and 60 percent more magnesium from our food when phytic acid is absent4. It’s important to note that phytic acid does not leach minerals that are already stored in the body; it only inhibits the absorption of minerals from food in which phytic acid is present.
Phytic acid interferes with enzymes we need to digest our food, including pepsin, which is needed for the breakdown of proteins in the stomach, and amylase, which is required for the breakdown of starch. Phytic acid also inhibits the enzyme trypsin, which is needed for protein digestion in the small intestine.
Humans can tolerate a small to moderate amount of phytic acid – in the range of 100 mg to 400 mg per day. According to Ramiel Nagel in his article “Living With Phytic Acid”
Para evitar fitatos es mejor consumir los frutos secos sin piel y tostados en vez de crudos.
100 gramos de frutos secos contienen de media unos 1000 mg de fitatos, por lo que mas de unos pocos al dia ya es mucho, el coco y el arroz no refinado tambien contienen muchos fitatos.
El chocolate tambien es muy muy alto en fitatos:
In milligrams per 100 grams of dry weight
Brazil nuts 1719
Cocoa powder 1684-1796
Oat flakes 1174
Almond 1138 – 1400
Walnut 982
Peanut roasted 952
Brown rice 840-990
Peanut ungerminated 821
Lentils 779
Peanut germinated 610
Hazelnuts 648 – 1000
Wild rice flour 634 – 752.5
Yam meal 637
Refried beans 622
Corn tortillas 448
Coconut 357
Corn 367
Entire coconut meat 270
White flour 258
White flour tortillas 123
Polished rice 11.5 – 66
Strawberries 12