I LOVE YAM!
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| YAM RICE |
YAM
Yam provides around 110 calories per 100 grams of product. Yam is high in vitamins C and B6, potassium, manganese and dietary fiber while being low in saturated fat and sodium. A product that is high in potassium and low in sodium is likely to produce a good potassium-sodium balance in the human body, and so protects against osteoporosis and heart disease.
Yam products generally have a lower glycemic index than potato products, which means that they will provide a more sustained form of energy, and give better protection against obesity and diabetes.
It is also known to replenish fast-twitch fibers and West Indians use it as a way of recovering after sprinting.
Africa
Yams of African species must be cooked to be safely eaten, because various natural substances in raw yams can cause illness if consumed. (Excessive skin contact with uncooked yam fluids can cause the skin to itch. If this occurs, a quick cold bath or application of red palm oil to the affected part of the body will stop the itching.) Yams are consumed in various ways, but are usually boiled and eaten. This involves cutting the yam into pieces, then peeling the skin, and boiling the starchy "meat". This is usually consumed with palm oil (traditional way), or with other sauces. The boiled yam can also be pounded with a traditional mortar and pestle to create a thick starchy paste known as Pounded Yam Iyan, as well as Fufu. This is also eaten with traditional stews and sauces. Another method of consumption is to sun dry the raw yam pieces. When dry, the pieces turn a dark brown color. This is then milled to create a powder known as "elubo" in Nigeria. The brown powder can be prepared with boiling water to create a thick brown starchy paste known as "amala". This is also consumed with the local stews and sauces. The most common cooking method in Western and Central Africa is cooked "boiled" yam. The Philippines
In the Philippines, the purple ube species of yam (Dioscorea alata), is eaten as a sweetened dessert called "ube halaya", and is also used as an ingredient in another Filipino dessert, halo-halo. Vietnam
In Vietnam, the same purple yam is used for preparing a special type of soup canh khoai mỡ or fatty yam soup. This involves mashing the yam and cooking it until very well done.
Indonesia
In Indonesia, the same purple yam is used for preparing desserts. This involves mashing the yam and mixing it with coconut milk and sugar.
Japan
An exception to the cooking rule is the Japanese mountain yam (Dioscorea opposita), known as nagaimo or yamaimo (山芋?) depending on the root shape. It is eaten raw and grated, after only a relatively minimal preparation: the whole tubers are briefly soaked in a vinegar-water solution to neutralize irritant oxalate crystals found in their skin. The raw vegetable is starchy and bland, mucilaginous when grated, and may be eaten plain as a side dish, or added to noodles. In Japan, the purple yam is popular as lightly deep fried tempura as well as being grilled or boiled. Additionally, the purple yam is a common ingredient of yam ice cream with the signature purple color.
India
In central parts of India, the yam (or Garadu) is prepared by being finely sliced, seasoned with spices and deep fried. In southern parts of India, the vegetable is a popular accompaniment to fish curry. In Assam, it is known as Kosu (কচু) and is normally boiled, mashed and lightly seasoned with salt. Also eaten in India, Dioscorea alata, a purple-pigmented species, is known as ratalu or violet yam. The West
'Yam powder' is available in the West from grocers specializing in African products, and may be used in a similar manner to instant mashed potato powder, although preparation is a little more difficult because of the tendency to form lumps. The 'yam powder' is sprinkled onto a pan containing a small amount of boiling water, and stirred vigorously. The resulting mixture is served with a heated sauce, such as tomato and chili, poured onto it. To avoid lumps forming, the powder and the water are mixed before putting on the heat, then stirred continuously as the mixture is heating.
Vitamin C Deficiency
Scurvy is an avitaminosis resulting from lack of vitamin C, since without this vitamin, the synthesised collagen is too unstable to perform its function. Scurvy leads to the formation of brown spots on the skin, spongy gums, and bleeding from all mucous membranes. The spots are most abundant on the thighs and legs, and a person with the ailment looks pale, feels depressed, and is partially immobilized. In advanced scurvy there are open, suppurating wounds and loss of teeth and, eventually, death. The human body can store only a certain amount of vitamin C and so the body stores are depleted if fresh supplies are not consumed. The time frame for onset of symptoms of scurvy in unstressed adults switched to a completely vitamin C free diet, however, may range from one month to more than six months, depending on previous loading of vitamin C. It has been shown that smokers who have diets poor in vitamin C are at a higher risk of lung-borne diseases than those smokers who have higher concentrations of vitamin C in the blood.
Nobel prize winner Linus Pauling and G. C. Willis have asserted that chronic long term low blood levels of vitamin C ("chronic scurvy") is a cause of atherosclerosis. Western societies generally consume far more than sufficient Vitamin C to prevent scurvy. In 2004, a Canadian Community health survey reported that Canadians of 19 years and above have intakes of vitamin C from food of 133 mg/d for males and 120 mg/d for females these are higher than the RDA recommendations.
Notable human dietary studies of experimentally-induced scurvy have been conducted on conscientious objectors during WW II in Britain, and on Iowa state prisoner "volunteers" in the late 1960s. These studies both found that all obvious symptoms of scurvy previously induced by an experimental scorbutic diet with extremely low vitamin C content could be completely reversed by additional vitamin C supplementation of only 10 mg a day. In these experiments, there was no clinical difference noted between men given 70 mg vitamin C per day (which produced blood level of vitamin C of about 0.55 mg/dl, about 1/3 of tissue saturation levels), and those given 10 mg per day. Men in the prison study developed the first signs of scurvy about 4 weeks after starting the vitamin C free diet, whereas in the British study, six to eight months were required, possibly due to the pre-loading of this group with a 70 mg/day supplement for six weeks before the scorbutic diet was fed.
Men in both studies on a diet devoid, or nearly devoid, of vitamin C had blood levels of vitamin C too low to be accurately measured when they developed signs of scurvy, and in the Iowa study, at this time were estimated (by labeled vitamin C dilution) to have a body pool of less than 300 mg, with daily turnover of only 2.5 mg/day, implying a instantaneous half-life of 83 days by this time (elimination constant of 4 months).
Moderately higher blood levels of vitamin C measured in healthy persons have been found to be prospectively correlated with decreased risk of cardiovascular disease and ischaemic heart disease, and an increase life expectancy. The same study found an inverse relationship between blood vitamin C levels and cancer risk in men, but not in women. An increase in blood level of 20 micromol/L of vitamin C (about 0.35 mg/dL, and representing a theoretical additional 50 grams of fruit and vegetables per day) was found epidemiologically to reduce the all-cause risk of mortality, four years after measuring it, by about 20%. However, because this was not an intervention study, causation could not be proven, and vitamin C blood levels acting as a proxy marker for other differences between the groups could not be ruled out. However, the four-year long and prospective nature of the study did rule out proxy effect from any vitamin C lowering effects of immediately terminal illness, or near-end-of-life poor health. Studies with much higher doses of vitamin C, usually between 200 and 6000 mg/day, for the treatment of infections and wounds have shown inconsistent results. Combinations of antioxidants seem to improve wound healing.
Vitamin B6
Vitamin B6 has long been publicized as a cure for premenstrual syndrome (PMS). Study results conflict as to which symptoms are eased, but most of the studies confirm that women who take B6 supplements have reductions in bloating, breast pain, and premenstrual acne flare, a condition in which pimples break out about a week before a woman's period begins. There is strong evidence that pyridoxine supplementation, starting ten days before the menstrual period, prevents most pimples from forming. This effect is due to the vitamin's role in hormone and prostaglandin regulation. Skin blemishes are typically caused by a hormone imbalance, which vitamin B6 helps to regulate.
Mental depression is another condition which may result from low vitamin B6 intake. Because of pyridoxine's role in serotonin and other neurotransmitter production, supplementation often helps depressed people feel better, and their mood improves significantly. It may also help improve memory in older adults. However, the effectiveness as treatment for PMS, PMDD, and clinical depression is debatable. There is anecdotal evidence suggesting supplemental Vitamin B6 may be associated with lucid dreaming.
It is also suggested that ingestion of vitamin B6 can alleviate some of the many symptoms of an alcoholic hangover and morning sickness from pregnancy. This might be due to B6's mild diuretic effect. Though the mechanism is not known, results show that pyridoxamine has therapeutic effects in clinical trials for diabetic nephropathy.
Larsson et al. have shown that vitamin B6 intake and pyridoxal phosphate (PLP) levels are inversely related to the risk of colon cancer. While in their study the correlation with B6 intake was moderate, it was quite dramatic with PLP levels where the risk of colon cancer was nearly decreased in half.
Vitamin B6 is also known to increase the metabolism of Parkinson's medication such as levodopa, and should be used cautiously.
Potassium
In diet
Adequate intake
A potassium intake sufficient to support life can generally be guaranteed by eating a variety of foods. Clear cases of potassium deficiency (as defined by symptoms, signs and a below-normal blood level of the element) are rare in healthy individuals. Foods rich in potassium include parsley, dried apricots, dried milk, chocolate, various nuts (especially almonds and pistachios), potatoes, bamboo shoots, bananas, avocados, soybeans, and bran, although it is also present in sufficient quantities in most fruits, vegetables, meat and fish.
Optimal intake
Epidemiological studies and studies in animals subject to hypertension indicate that diets high in potassium can reduce the risk of hypertension and possibly stroke (by a mechanism independent of blood pressure), and a potassium deficiency combined with an inadequate thiamine intake has produced heart disease in rats. There is some debate regarding the optimal amount of dietary potassium. For example, the 2004 guidelines of the Institute of Medicine specify a DRI of 4,000 mg of potassium (100 mEq), though most Americans consume only half that amount per day, which would make them formally deficient as regards this particular recommendation. Similarly, in the European Union, particularly in Germany and Italy, insufficient potassium intake is somewhat common. Italian researchers reported in a 2011 meta-analysis that a 1.64 g higher daily intake of potassium was associated with a 21% lower risk of stroke.
Medical supplementation and disease
Supplements of potassium in medicine are most widely used in conjunction with loop diuretics and thiazides, classes of diuretics which rid the body of sodium and water, but have the side effect of also causing potassium loss in urine. A variety of medical and non-medical supplements are available. Potassium salts such as potassium chloride may be dissolved in water, but the salty/bitter taste of high concentrations of potassium ion make palatable high concentration liquid supplements difficult to formulate. Typical medical supplemental doses range from 10 milliequivalents (400 mg, about equal to a cup of milk or 6 US fl oz (180 ml). of orange juice) to 20 milliequivalents (800 mg) per dose. Potassium salts are also available in tablets or capsules, which for therapeutic purposes are formulated to allow potassium to leach slowly out of a matrix, as very high concentrations of potassium ion (which might occur next to a solid tablet of potassium chloride) can kill tissue, and cause injury to the gastric or intestinal mucosa. For this reason, non-prescription supplement potassium pills are limited by law in the US to only 99 mg of potassium.
Individuals suffering from kidney diseases may suffer adverse health effects from consuming large quantities of dietary potassium. End stage renal failure patients undergoing therapy by renal dialysis must observe strict dietary limits on potassium intake, as the kidneys control potassium excretion, and buildup of blood concentrations of potassium (hyperkalemia) may trigger fatal cardiac arrhythmia.
Manganese
Dietary fiber
Saturated Fat
Sodium
