Holistic Health Articles and Research Related to Herbal Medicines, Foods and Phytochemicals : #Healthy Foods

Tuesday, 5 November 2013

#Healthy Foods - Yams (Dioscorea)

Yam
Yam is the genus Dioscorea belongs to the family Dioscoreaceae. It has a long and cylindrical shape with rough and scaly exterior skin. It can be stored up to six months in open air, which makes them a valuable resource when foods are scarce.

Nutritional Supplements
1. Carbohydrate
2. Protein
3. Fiber
4. Vitamin B1
5. Vitamin B3
6. Vitamin B6
7. Folate
8. Vitamin C
9. Vitamin E
10. Vitamin K
11. Potassium
12. Manganese
13. Calcium
14. Magnesium
15. Phosphorus
16. Selenium
17. Zinc
18. Copper
19. Iron
20. Etc.

Health benefits
A. Health benefits according to studies
1. Hyperlipidemia and oxidative stress
In the investigation of Dioscoreae Nipponicae Rhizoma and its effect against cardiovascular diseases found that this was the first time to reveal the anti-hyperlipidemic and anti-oxidative effects of trillin. These results would be important in developing food supplements for health improvements and therapeutic drugs against hyperlipidemia and cardiovascular diseases in future, according to "Trillin, a steroidal saponin isolated from the rhizomes of Dioscorea nipponica, exerts protective effects against hyperlipidemia and oxidative stress" by Wang T, Choi RC, Li J, Bi CW, Ran W, Chen X, Dong TT, Bi K, Tsim KW.(a)

2. Oral cancer
In the evaluation of ethanol extract of red mold dioscorea (RMDE) and its anticancer effects found that RMDE treatment inhibited the growth of SCC-25 cells by arresting cell cycle at the G2/M phase and induced apoptosis in a time- and dose-dependent manner. Therefore RMDE may be a good candidate for development as a dietary supplement against oral cancer, according to "Red mold dioscorea-induced G2/M arrest and apoptosis in human oral cancer cells" by Hsu WH, Lee BH, Pan TM.(b)

3. Anti-inflammatory activity
In the assessment of 6-Hydroxy-2,7-dimethoxy-1,4-phenanthraquinone (PAQ) isolated from the tuberous roots of Yam (Dioscorea batatas) and its anti-inflammatory activity found that the compound also inhibited the degranulation reaction in a dose-dependent manner with an IC(50) of 2.7 μM. Thus, these results suggest that PAQ may be useful in regulating mast cell-mediated inflammatory diseases, according to "Anti-inflammatory activity of 6-hydroxy-2,7-dimethoxy-1,4-henanthraquinone from tuberous roots of yam (Dioscorea batatas) through inhibition of prostaglandin D₂ and leukotriene C₄ production in mouse bone marrow-derived mast cells" by Jin M, Lu Y, Yang JH, Jo TH, Park YI, Lee CK, Park SJ, Son KH, Chang HW.(c)

4. Antidiabetic activity
In observation of ethanolic extract of Dioscorea alata and its antidiabetic effect found that the blood glucose level was reduced significantly by 47.48% and 52.09% after 21 days treatment at dose levels 100 and 200 mg/kg, respectively. Serum lipid levels, total protein, albumin, and creatinine were reversed toward near normal in treated rats as compared to diabetic control, according to "Antidiabetic activity of ethanolic extract of tubers of Dioscorea alata in alloxan induced diabetic rats" by Maithili V, Dhanabal SP, Mahendran S, Vadivelan R.(d)

5. Osteoporosis
In the examination of the effect of the oral administration of different dosages of dioscorea, red mold dioscorea (RMD), and soy isoflavones on bone mineral density (BMD) in postmenopausal osteoporosis found that reconstructed 3D imaging indicated increases in cancellous bone mineral content, cancellous bone mineral density, and cortical bone mineral content of the proximal tibia in OVX rats, according to "Osteoprotective effect of Monascus-fermented dioscorea in ovariectomized rat model of postmenopausal osteoporosis" by Chiang SS, Chang SP, Pan TM.(e)

6. Etc.

B. Health benefits according to concentration
1. Vitamin C
In the evaluation of pulmonary dysfunction. and it effects on pulmonary dysfunction found that At present, evidence from randomised-controlled trials is insufficient to recommend a specific role for vitamin C in the treatment of asthma. Further methodologically strong and large-scale randomised controlled trials are needed in order to address the question of the effectiveness of vitamin C in children with asthma but some outcome data showed effectiveness on lung function, symptom scores, IgE levels and inhaled steroid use. One small study showed a significant difference in % drop in FEV1 post-exercise, according to the study of "Vitamin C supplementation for asthma" by Kaur B, Rowe BH, Arnold E.(1)

2. Potassium
Potassium beside is important in maintaining the regular contraction and relaxation of the muscle, that helps to reducing the risk of hypokalemia, it also helps the lymphatic system in regulating the levels of fluid in the body, thus lessening the risk of lymphedema, swelling caused by the accumulation of lymph fluid. In a study of "Narrative review: evolving concepts in potassium homeostasis and hypokalemia" by Greenlee M, Wingo CS, McDonough AA, Youn JH, Kone BC., posted in PubMed (http://www.ncbi.nlm.nih.gov/pubmed/19414841), researchers found that recent experimental insights into the participation of feedback and feedforward control mechanisms in potassium homeostasis. New data make clear that feedforward homeostatic responses activate when decreased potassium intake is sensed, even when plasma potassium concentration is still within the normal range and before frank hypokalemia ensues, in addition to the classic feedback activation of renal potassium conservation when plasma potassium concentration decreases.

3. Manganese

It is one of important trace in preventing osteoporosis, according to the study of "[Study of estrogen deficiency impact on manganese levels in teeth and mandible of rats after ovariectomy]. [Article in Polish]" by Rahnama M, Błoniarz J, Zareba S, Swiatkowski W.(1)and regulating blood sugar level, according to the study of "[An inadequate intake of manganese may favour insulin resistance in girls]. [Article in Spanish]" by Rodríguez-Rodríguez E, Bermejo LM, López-Sobaler AM, Ortega RM.(2)

4. Dietary Fibers

Daily intake of right amount of fibers can prvent and treata. Diabetes, as Increased consumption of vegetables, whole grains, and soluble and insoluble fiber is associated with improved glucose metabolism in both diabetic and nondiabetic individuals. Improvements in insulin sensitivity and glucose homeostasis were more evident in participants following a plant-based diet compared with other commonly used diets, according to the study of "Efficacy of high-fiber diets in the management of type 2 diabetes mellitus" by Wolfram T, Ismail-Beigi F.(3)

5. Etc.

C. Other health benefits
1. Cardiovascular disease
Vitamin B6 in yam helps to break down homocysteine, an amino acid produced by byproduct of consuming meat in the body, that can damage the blood vessel wall as a result of cholesterol cause of plague building up, according to the study of "Homocysteine, Folate, Vitamin B6, and Cardiovascular Disease" by Kilmer S. McCully, MD, posted in The Journal of the American medical Association (http://jama.ama-assn.org/content/279/5/392.extract)

2. Premenstrual syndrome
Yam, which has an active phytoestrogen ingredient called "diosgenin", triggers the production of natural progesterone that helps to balance the estrogen, thus reducingthe risk of premenstrual cramps and pain in the abdomen, 2 weeks before menstruation. In a study of "Estrogenic and progestagenic effects of extracts of Justicia pectoralis Jacq., an herbal medicine from Costa Rica used for the treatment of menopause and PMS" by Locklear TD, Huang Y, Frasor J, Doyle BJ, Perez A, Gomez-Laurito J, Mahady GB., posted in PubMed (http://www.ncbi.nlm.nih.gov/pubmed/20452152), researchers found that extracts of J. pectoralis have estrogenic, progestagenic and anti-inflammatory effects, and thus have a plausible mechanism of action, explaining its traditional use for menopause and PMS.

3. Immune system
Selenium is one of powerful antioxidant minerals, that not only helps to enhances the immune system in fighting against forming of the free radicals due to hydroperoxides (according tothe study of "Protective role of intraperitoneally administrated vitamin E and selenium on the levels of total lipid, total cholesterol, and fatty acid composition of muscle and liver tissues in rats" by Yilmaz O, Celik S, Cay M, Naziroğlu M., posted in PubMed), but also promotes liver function in expelling acrylamide toxicity. In the study of "Protective effects of selenium on acrylamide toxicity in the liver of the rat. Effects on the oxidative stress? by Teodor V, Cuciureanu M, Filip C, Zamosteanu N, Cuciureanu R., posted in PubMed (http://www.ncbi.nlm.nih.gov/pubmed/21870766), researchers found that This study investigates the effect of selenium (as sodium selenite and as a selenium dietary supplements--Celnium) on the oxidative stress in Wistar rats which received high doses of acrylamide.

4. Manganese
Manganese beside ensures a healthy bone structure by enhancing some essential enzymes for building bones (according to the study of "Bone formation within alumina tubes: effect of calcium, manganese, and chromium dopants" by Pabbruwe MB, Standard OC, Sorrell CC, Howlett CR., posted in PubMed, (http://www.ncbi.nlm.nih.gov/pubmed/15109850))it is also a super oxide dismutase enzyme that helps to neutralize the damaging particles and prevents any potential danger of sperm cryopreservation, according to the study of "Manganese provides antioxidant protection for sperm cryopreservation that may offer new consideration for clinical fertility" by Cheema RS, Bansal AK, Bilaspuri GS., posted in PubMed (http://www.ncbi.nlm.nih.gov/pubmed/20592770),.

5. Etc.

Side effects

1. Oxalates or purines may be a concern for some people.
2. Etc.