Saturday, April 21, 2012

Avocado Benefits :Protein

 Avocado Benefits :Protein
Cultivars vary somewhat but the dominant 'Hass' is about 2.4% protein on a fresh weight basis (Slater et al., 1975). This is unusually high for a fruit. Hall et al. (1980) compared the essential amino acid content of 15 fruits: the avocado was second only to the rare Tucuma from Brazil which had about three times as much as mango, orange, peach and persimmon, and about six times as much as the two other common fruits listed, apricot and apple. Polansky and Murphy (1966) compared the protein content of 26 more common fruits and vegetables (41 entries counting separate cultivars and years). The avocado was in first place with about two to ten times the protein content of the others. The avocado is a "complete food" in terms of protein, containing all 9 essential amino acids, although not in the ideal proportions.

The fact that the avocado is an excellent source of essential protein is of little interest to most residents of the United States and other industrialized countries who are already consuming more protein than they need. It could be of increasing importance as health concerns move people away from meats and toward more vegetarian dishes, especially for those who do not care to consume many legumes. It could already be of significant benefit in tropical areas where protein consumption is insufficient (Hall et al., 1980).

Friday, April 20, 2012

Avocado Benefits : Stroke prevention

Avocado Benefits : Stroke prevention
Heart disease, cancer and stroke are the three leading causes of death in the United States. Additionally, stroke can cause many years of partial or total incapacitation and tragic crippling. The Associated Press, 15 October, 1987, reported an interview with Dr. Louis Tobian of the University of Minnesota on protection from strokes by fruit and vegetable consumption, in particular, by high potassium intake. Dr. Tobian is quoted as suggesting that bachelors may die earlier than married men because they have less balanced diets, specifically insufficient in potassium. As the best sources of potassium, he included strawberry, banana, citrus juice, potatoes, and milk (avocado is not mentioned).

Smith et a/. (1983) measured potassium in 100 g portions of 10 tropical fruits (including avocado), seven common fruits, nine common vegetables, and eight tropical vegetables. The seven common fruits, including strawberry, banana and orange, ranged from 1/5 to less than half the potassium content of avocado. Similarly, the nine common vegetables ranged from less than 1/4 (summer squash) to less than 2/3 (carrots) the avocado level. The other, lesser used, tropical fruits ranged from 1/2 to just over half the potassium supplied by avocado. Tropical vegetables, which are rare in the United States, ranged upward from 1/5 to about the same potassium richness of avocado.

Prevention magazine for August, 1987, reported the results of a 1 2-year study of stroke entitled "Potassium was the key.", conducted jointly by the Schools of Medicine of the University of California San Diego and Cambridge University in England. A 40% reduction in stroke risk was associated with an average daily increase in potassium consumption of about 400 mg, the amount supplied by less than half an avocado! Moreover, blood pressure, a stroke factor, was linked in the same article to potassium-sodium imbalance, namely to a sodium excess. The avocado has about 52 times as much potassium as sodium. For the touted potassium-rich carrot, the potassium to sodium ratio is less than 7 to 1 according to the brochure by Dr. William Sears cited earlier. Moreover, vegetables high in potassium which include the common potato and winter squash, are commonly eaten cooked. Boiling can remove up to 30% of potassium originally present, according to a researcher cited in the above Prevention article, giving the avocado an additional advantage.

Finally, avocado and olive oils are the two chief foods that are very high in monounsaturated fats, while being comparatively low in both polyunsaturated and saturated fats. An Italian epidemiological survey of 4,903 people (reported in a press release in February, 1990, based on an article in the Journal of the American Medical Association), found that while both monounsaturated and polyunsaturated fat were associated with lower blood cholesterol as compared with saturated, only monunsaturated fat was also associated with lower blood pressure. The next part of this paper will look at factors contributing to a healthy heart and related to avocado consumption. There is evidence to indicate that eating avocado may reduce the incidence of all three of the major causes of death in the United States.

Avocado Benefits :Antioxidants and free radicals: cancer, cataracts and ageing

Avocado Benefits :Antioxidants and free radicals: cancer, cataracts and ageing
The University of California at Berkeley Wellness Letter for October, 1991, discusses the basic role of oxygen for human cellular energy and for life, but notes that an inevitable by-product of this activity is the formation of highly reactive "free radicals." These unstable troublemakers can affect various cell constituents: perhaps artery walls or LDL cholesterol advancing coronary heart disease; eye lens tissue causing cataracts; a critical gene leading to cancer; perhaps arthritis; or DNA (the genetic material) causing gradual deterioration and aging.

The human body has two main defenses against these free radicals: enzymes and other blood compounds that depend on trace minerals and good general nutrition and three potent antioxidants vitamins C, E, and beta carotene (vitamin A precursor). An article in the June, 1991, issue of the American Journal of Clinical Nutrition indicates that only about 57% of nonsmokers may be getting enough vitamin C daily (for smokers the deficit is much greater). Men's Health (June, 1991) concluded that most of us are not getting enough vitamin E. A number of nutritionists have called for greater consumption of beta carotene.

As we have discussed, the avocado provides about twice as high a proportion of our daily needs for the above three antioxidant vitamins as its calorie proportion. Recall also that the avocado is rich in copper and iron, two mineral constituents of antioxidant enzymes. Nutritionists usually recommend that we get our needs met from basic food rather than from supplements. And while the risk of colon cancer, for example, has been associated with fat consumption, the Harvard Health Letter for March, 1991, reported that while meat indeed increased that risk sharply, there was no association with plant fat. Thus, eating avocados could be an enjoyable way to help protect ourselves against cancer, heart disease, arthritis, and eye cataracts; it may even delay the processes of aging.

Avocado Benefits : High nutritional density

Avocado Benefits : High nutritional density
The fourth reason given above for the avocado's role in weight control is its "rich supply of minerals and vitamins." More important than a food's calorie content is its total nutritional contribution to human needs. A good measure is nutrients per calorie. Different avocado analyses have given somewhat variable results. The most detailed publication is that of Slater et al. (1973). Their data indicate that one half of a 'Hass' avocado, about 80 g edible fruit, provides a substantial percentage of the daily nutritional needs of a child aged 7 to 10 (adult percentages are generally a little lower, especially iron for females) (Table 1).

The avocado contains little vitamin B 12 and calcium, limited zinc and modest phosphorus. Its half-a-fruit quota of riboflavin and thiamine for children is about 9.5 and 8%, respectively, hence about equal to its relative calorie contribution. But the striking thing is that no less than eight essential nutrients are apparently present in about a 2: 1 calorie ratio. Nor is that all; three additional nutrients, potassium, copper and pantothenic acid, (for which I could not find precise Recommended Dietary Allowances) are also estimated to be present in avocado at about twice the calorie content. Per calorie, the avocado is indeed remarkably nutritious.

There is not space here to discuss either the human body's uses or the status in typical diets of these various nutrients. Judgments vary; several surveys have concluded that one or another of them is deficient in a considerable portion of American diets. Next we will look briefly at one of the least discussed vitamins in the group of nutrients provided by the avocado.

Vitamin B6 (pyridoxine) is important for the nervous system, red blood cells, teeth and gums. The Harvard Health Letter for March, 1991, reported 1990 data indicating that most Americans consume too little of vitamin B6. Among good sources they list watermelon and banana (overlooking avocado). Polansky and Murphy (1966) compared the 86 content per unit weight of 26 vegetables and fruits. For total chromatographed 86' banana and avocado had the highest amounts, the remaining 24 vegetables had from 1/5 to 1/25 of the amount of the avocado, with watermelon 1/6. A more recent report by William Sears, M.D., privately printed Nature's Guide to First Foods"(1988) reports that avocado has three times as much B6 per gram as banana.

Avocado benefit: Weight control

Avocado benefit: Weight control
Contrary to popular assumptions, the avocado can be a helpful part of a successful weight-management program. It brings several advantages.

      Its monounsaturated fat speeds up the basal metabolic rate, as compared with saturated fat. #
      Its high fat content gives a quicker feeling of satiation ("fullness"), thus helping to reduce overeating.
      Its high fat content makes an overall sound diet more palatable, reducing the temptation to binge on foods high in sugars or saturated fats.
      Its rich supply of vitamins and minerals also makes the diet more wholesome and satisfying and thus more conducive to overall health and to moderation in consumption.

The high fat content of most avocados (up to 90% of its calories) will make some people dubious about its positive effects on weight control. Not only does fat have over twice as many calories per unit weight as does carbohydrate or protein, but also if excess calories are consumed, the body apparently burns about three times as many calories when storing calories from carbohydrate or protein as it burns when calories from fat are stored. Recent evidence, however, suggests that calories are not the whole story for body weight, with timing of both consumption and exercise as factors and with calories from fat also a possible added handicap.

So, what is known from experiments with the avocado? The next part of this article will discuss in detail results from the three studies of known changes in cholesterol resulting from the addition of avocado to the diet. In each of the three studies, there was an average small weight loss associated with avocado consumption. In the most pertinent experiment (Grant, 1960), a mean of just over one California avocado a day for a mean of 33 days increased average daily calories by a calculated 24% and fat by 54% but resulted in a weight loss averaging approximately 1 kg (2.2 lbs). This remarkable result (under exceptional and tightly controlled hospital conditions) should not be taken as a universal guarantee; individual results will vary depending upon complex individual metabolic histories and interactions. What can be said is that eating avocado has been shown to be fully compatible with good weight control.

Very few people will have rapid weight loss as a result of increasing their consumption of avocado; however, the more slowly one loses weight, the less likely one is to regain it. It has become clear that an effective solution to the widespread overweight problem will not come from simply eating less. Indeed, such 'dieting' can actually make things worse by causing muscle loss so that the usual 'yo-yo' weight rebound leaves one fatter than ever and subsequent weight loss more difficult to achieve than ever. Goodrick and Foreyt reported in the October, 1991, issue of the American Dietetic Journal that even a combination of behavioral self-management training plus sharply reduced calories gave a discouraging 90% eventual relapse level. Part of the reason is genetic: we tend to inherit our body fat amount and distribution. Part of the solution is more exercise which, of course, is good for us for other reasons.

The emerging picture is quite complex. In the February, 1990, issue of the American Journal of Clinical Nutrition, Bouchard reported from Canada that women who were small eaters (mean of 1488 calories/day) as compared with similarly exercising 2393 calories/day eaters, actually weighed 10 lbs (22 kg) more on the average, plus having 22% more body fat. The explanation is probably a combination of average differences in both genes and food consumption: i.e., reducing calorie intake can lower an individual's metabolic rate and thus defeat its purpose. We need to eat enough healthful food to keep our metabolism high, and to provide the sated feeling that eliminates binge eating.

Calorie-counting, dieting, advertised gimmicks and quick weight loss are recipes for failure; whereas exercise plus healthy food habits as a permanent way of life can bring success. The situation is analogous to that of personal philosophy: Focus on happiness and it will probably elude you; focus on wholesome living and happiness is a likely by-product. Similarly, focus on weight loss and it will probably elude you; focus on wholesome eating and weight control is a likely by-product.

This insight was expressed years ago by Wood (1983) in a book hailed by one health magazine as the finest method for weight reduction known to them. Wood emphasized 'playful' exercise, but his introduction begins: "The solution to our national overweight problem is to encourage people to eat more." He counseled eating fresh plant food "heartily." And his recommended list of "ingredients for a healthy diet" included the avocado.

10 Health Benefits of Avocado Fruit

10 Health Benefits of Avocado Fruits

Here are ten reasons to do just like I do and eat an avocado a day:

Prostate Cancer Prevention
Avocados have been shown to inhibit the growth of prostate cancer.

Oral Cancer Defense
Research has shown that certain compounds in avocados are able to seek out pre-cancerous and cancerous oral cancer cells and destroy them without harming healthy cells.

Breast Cancer Protection
Avocado, like olive oil, is high in oleic acid, which has been shown to prevent breast cancer in numerous studies.

Eye Health
Avocados have more of the carotenoid lutein than any other commonly consumed fruit. Lutein protects against macular degeneration and cataracts, two disabling age-related eye diseases.

Lower Cholesterol
Avocados are high in beta-sitosterol, a compound that has been shown to lower cholesterol levels. In one study, 45 volunteers experienced an average drop in cholesterol of 17% after eating avocados for only one week.

Heart Health
One cup of avocado has 23% of the recommended daily value of folate. Studies show that people who eat diets rich in folate have a much lower incidence of heart disease than those who don't. The vitamin E, monounsaturated fats, and glutathione in avocado are also great for your heart.

Stroke Prevention
The high levels of folate in avocado are also protective against strokes. People who eat diets rich in folate have a much lower risk of stroke than those who don't.
Better Nutrient Absorption Research has found that certain nutrients are absorbed better when eaten with avocado. In one study, when participants ate a salad containing avocados, they absorbed five times the amount of carotenoids (a group of nutrients that includes lycopene and beta carotene) than those who didn't include avocados.

Glutathione Source
Avocados are an excellent source of glutathione, an important antioxidant that researchers say is important in preventing aging, cancer, and heart disease.

Vitamin E Powerhouse
Avocados are the best fruit source of vitamin E, an essential vitamin that protects against many diseases and helps maintains overall health