Friday, November 17, 2006

Ginkgo May Protect Against Alzheimer’s Protein

Ginkgo biloba may protect neurons from the toxic effects of Я-amyloid protein, a major constituent of the senile plaques found in the brains of Alzheimer’s disease patients. Researchers at McGill University in Canada showed that a standardized extract of ginkgo biloba could protect cells taken from the hippocampus, a region of the brain involved in memory formation, from the cytotoxic, or “cell-killing,” effects of Я-amyloid.

The researchers grew hippocampal cells in a dish, then exposed these cultured cells to Я-amyloid. Without any protection, the cells died, but when the researchers added a standardized extract of ginkgo biloba developed in 1964 by a German pharmaceutical company, the hippocampal cells were able to withstand the exposure to Я-amyloid.

The ginkgo extract used in the study is known as EGb 761 and has been standardized to contain specific percentages of its chemical components: 24% flavonoids, 6% terpenoids, 5-10% organic acids, and >0.5% proanthocyanidins. This extract and its components have been used in hundreds of research studies. In this study, both EGb 761 and its flavonoid component were shown to be neuroprotective, with the flavonoid component being somewhat less protective than the whole extract. However, the terpenoid components tested in the study did not protect against Я-amyloid toxicity.

Although the neurotoxic mechanisms of Я-amyloid are not fully understood or agreed upon, a popular theory is that beta-amyloid triggers the production of free radicals known as reactive oxygen species (ROS).

Since the flavonoid component has been shown to have antioxidant and free radical scavenging activities, these results indicate that the neuroprotective effects of the ginkgo biloba extract may be due, at least in part, to its antioxidant properties. Since the terpenoid components tested did not protect against beta-amyloid toxicity, the neuroprotective effects of EGb 761 are probably not attributable to the anti-inflammatory properties that have been previously demonstrated for the terpenoids.

Oxidative stress has been implicated in many disease processes, including neurodegeneration in Alzheimer’s disease and after stroke and trauma. It occurs when free radicals are produced at a higher rate than they can be eliminated by the cell’s antioxidant defenses. Massive release of the excitatory neurotransmitter glutamate into the extracellular fluid occurs, and its reuptake is slowed.

There are two types of cell death that can be triggered by oxidative stress. Necrotic cell death occurs within 24 hours of injury and involves increased permeability (leakiness) of the cell membrane, resulting in the cell swelling then bursting, an event called cell lysis. Apoptosis, or programmed cell death, is also known as delayed cell death and involves the activation of a series of cell events that result in mitochondrial injury, DNA fragmentation and cell shrinkage and death.

Cell survival was increased at all concentrations of EGb 761 used, with the amount of protection increasing (dose-dependently) as the concentration of EGb 761 increased from 10 micrograms per milliliter to 100 micrograms per milliliter. The highest concentration provided complete protection. Using this concentration, the researchers in the McGill University study investigated whether EGb 761 was protective against apoptotic cell death induced by beta-amyloid. They found that co-treatment with EGb 761 inhibited apoptosis of hippocampal neurons for 24 hours in a medium containing Я-amyloid fragments. This occurred even when the EGb 761 was not added to the cells until 8 hours after exposure to Я-amyloid began.

Previous clinical trials of ginkgo biloba extract with Alzheimer’s patients have shown some improvements in memory and cognition and positive changes in EEG profiles. Ginkgo has also been shown to produce an improvement in mood in some studies. Although most studies have lasted for at least 4 weeks, several studies have demonstrated effects within 1 to 3 hours of administration.

While ginkgo is considered to be relatively safe, 4.4% of patients in 25 clinical studies experienced side effects, including gastrointestinal upset, headaches, sleep disturbances, dizziness, and skin eruptions. Four case studies of adverse events have been reported for individuals who were taking ginkgo extract. Two cases of subdural hematoma, one case of subarachnoid hemorrhage, and one case of spontaneous hyphema (bleeding into the anterior eye chamber) have been reported. Therefore, caution is advised, particularly when taking anticoagulants in addition to ginkgo biloba. As with any medication, herbal or otherwise, side effects should not be ignored.

Other naturally occurring substances with antioxidant effects that have been shown to protect neurons from Я-amyloid toxicity are Vitamin C, Vitamin E, glutathione, melatonin, estrogen, and progesterone. A complex system of antioxidant enzymes, metal chelators, and low molecular weight reductants (Vitamin C, Vitamin E, and glutathione) detoxify free radicals under normal physiological conditions. Under normal conditions, glutathione and Vitamin C replenish each other and Vitamin E from their radicals. During oxidative stress, however, the body’s antioxidant defenses are overcome, low molecular weight reductants are depleted (oxidized), and cellular structures are damaged by free radicals. Administration of antioxidant compounds helps replenish the body’s antioxidant system and boosts scavenging of free radicals.

Ginkgo biloba extract, as well as other naturally occurring compounds with antioxidant activity, may be beneficial in the treatment of Alzheimer’s disease and dementia due to stroke or cerebrovascular insufficiency. Specific precautions should be observed with any of these substances, however. For example, melatonin should be used with caution in individuals with high blood pressure. Since Vitamin E is fat soluble and accumulates in the body tissues over time, doses over 800 IU per day should not be taken without a physician’s supervision. Depending on dose, a two- to three-fold increase in the risk of stroke has been associated with estrogen supplementation. Since the body’s production of progesterone rises from 20 milligrams per day between ovulation and the end of the regular menstrual cycle to 400 milligrams per day during pregnancy, when most women are their healthiest, administration of this hormone appears to have a low risk factor. Considered to be relatively nontoxic, Vitamin C has been administered in doses up to several grams per day. While there is considerable variation with individuals, an excess of Vitamin C can result in diarrhea, which is easily corrected by reducing the dose.

Supplementation with ginkgo, the antioxidant vitamins, and flavonoids such as quercetin, with observation of indicated precautions holds promise as a preventive measure against the debilitating consequences of oxidative stress. Women over 35 may also benefit from progesterone, which is absorbed best transdermally—through the skin. Even more important is the inclusion of plenty of fresh fruits and vegetables in the diet and the avoidance of foods, such as saturated fats, that increase oxidative stress.

Source Article:

S Bastianetto, C Ramassamy, S Dorй, Y. Christen, J. Poirer, and R. Quirion. The ginkgo biloba extract (EGb 761) protects hippocampal neurons against cell death induced by Я-amyloid. European Journal of Neuroscience, 12: 1882-1890, 2000.

Other Sources:

BJ Diamond, SC Shiflett, N. Feiwel, RJ Matheis, O. Noskin, JA Richards, and NE Schoenberger. Ginkgo biloba extract: mechanisms and clinical indications. Archives of Physical Medicine and Rehabilitation, 81: 668-678, 2000.

JX Wilson. Antioxidant defense of the brain: a role for astrocytes. Canadian Journal of Physiology and Pharmacology, 75: 1149-1163, 1997.

Thursday, July 20, 2006

Add pizazz to your daily diet with nutrient-rich fruit and vegetable juices.

Maybe juicing has acquired a mildly inaccurate reputation-the mere word calls forth images of sustained fasting and rigorous deprivation. But juices of late are far from spare, with indulgent offerings ranging from succulent tropical fruits to rich and tangy vegetable combinations. And for good reason: serious health devotees recognize that few foods are as nutrient-rich as fresh fruit and vegetable juices. So if you're in the habit of scrutinizing your meals, you may want to take a closer look at the beverages you're imbibing-and turn to tomato juice instead of coffee for a morning lift.

Fruit and vegetable juices provide a highly concentrated source of nutrients. By breaking down tough, fibrous plant walls, juicing extracts a number of healthful compounds, serving them up in an easy-to-digest form. And besides the better-known vitamins and minerals, fresh juices contain other, harder-to-get substances like enzymes and phytochemicals that offer a variety of specific health benefits.


For those of you who may still think that juicing is a phased-out fad of the hippie generation, consider this: modern science has recognized the value of vitamins in preventing disease, and studies have confirmed the health benefits of other nutrients. And it's not just nutritionists who are urging Americans to up their intake of fresh fruits and veggies: even the Federal government has voiced its opinion, with recommendations that set fruit and veggie consumption at five-plus servings a day.

The importance of concentrated nutrients is evident when we look at the nutritional lineup of the average American. While most of us get sufficient vitamin B to hold beri beri at bay, it's difficult to consume enough food to acquire the therapeutic doses of nutrients which have been shown to prevent disease. Juicing provides a dramatic concentration of nutrients: instead of trying to cram seven carrots into a salad, you can get the same vitamins, minerals, and phytochemicals in a single glass of carrot juice.

Vitamins extracted from plants play a major role in maintaining health, especially the antioxidant vitamins A, C, and E. In plants, vitamin A is found in the form of carotenoids. Vitamin A helps improve night vision, ensures healthy skin, and promotes the growth of bones and teeth. Vitamin C, found in citrus fruits, strawberries, tomatoes, mangoes, dark leafy greens, and other fruits and vegetables, boosts immune function, protects against blood clotting and bruising, promotes healing, and regulates adrenal gland function. Vitamin E, found in dark leafy greens and cabbage, helps repair damaged tissues and is a potent heart-healthy antioxidant.

Fruit and vegetable juices are packed with minerals as well, in a balanced and highly bioavailable form. The combination of minerals in juices boosts energy and calms nerves, maintains a healthy balance of electrolytes, and ensures the proper function of muscles,including the heart.

Freshly squeezed juices also contain enzymes, complex protein compounds produced in living cells, which speed biochemical reactions. The typical American diet centers around lots of cooked and processed foods. Since they're quickly destroyed by heat, live enzymes from raw foods are limited in most diets. Raw fruit and vegetable juices are packed with live enzymes.


Juicing itself is a relatively simple procedure. All you need are fresh, preferably organic fruits and vegetables, a good-quality juicer, and a little patience and imagination. Using organic fruits and vegetables is especially significant in juicing. If you don't, you'll be concentrating everything in the plant, including pesticides and chemicals. Additionally, if you're using organic and locally grown produce, they will have ripened to maturity on the vine, thus boosting their nutrient content.

Before you toss a handful of berries into your blender, remember that blending or pureeing isn't the same as juicing: you're getting the whole fruit, not the concentrated extraction of nutrients. Which is not to say a blended berry smoothie is a bad thing: you do get lots of fiber, and fruits like avocado and banana, which can not be juiced, can be blended and added to juiced fruits and veggies. But for the highest concentration of nutrients, extracted juices are your best bet. Juicers range in price from $90 to upwards of $1,500.

There are two basic types of high-speed juicers, centrifugal and masticating. A centrifugal juicer chops the fruit or vegetable and spins it in a basket at high speed, separating the juice from the pulp. The pulp is then ejected out the back, if the juicer has a pulp ejector. If not, you must remove the pulp yourself. A good centrifugal juicer costs between $150 and $300, and will last essentially forever. A masticating juicer mashes fruits or vegetables into a paste and then squeezes the juice through a screen in the bottom. Some masticating juicers come with a hydraulic juice press. This unique feature automatically places the pulp in a cotton bag, and hydraulically presses every last bit of juice out of the pulp. Masticating juicers tend to be more expensive than centrifugal ones.


The combination of juices you choose is limited only by your imagination. There are a few traditional rules of thumb, but these are mildly controversial. Some say it's best to avoid combining acidic citrus juices with other, more alkaline juices, since the acid/alkaline environment in the stomach is upset and can make digestion more difficult. The same applies to melons: it's said that they should be consumed separately for the best digestion. The best advice? Experiment with combinations to see what works for you.

To get the most out of your fresh juice, drink it right away. Also, the best time to drink juices is before or between, not with, meals. Any kind of liquid taken with a meal will slow the digestive process, and the high concentration of sugars in juices, can create gas and cause an upset stomach in some people. Just think of them as food, rather than beverages: they're perfect for fast breakfasts and mid-day knoshes to stave off energy slumps. Because they're so easy to digest, they're also great pre- and post-workout snacks.

You can boost the flavor and health power of your juices with quickie additions. A spoonful of ginseng extract, an ounce of wheat grass juice, or a teaspoon of concentrated green food powder will up the nutrient value and add intriguing flavors. Juice-based smoothies benefit from the addition of a little soy protein powder to add texture and nutrition. And since juicing at home may not always be an option, keep a supply on hand of organic, fresh-squeezed juices for times when you're in a rush. Get your juices from the health food store, and check the label even 'natural' juices sometimes contain lots of grape juice to add sweetness, and may offer fewer amounts of the featured fruit or vegetable.


More good news: some of the most popular fruits and vegetables used in juices contain phytochemicals that have been shown to help prevent-and even treat-specific health problems.

Citrus fruits contain limonoids, which stimulate the production of enzymes that may help prevent cancer, especially lung cancer. And grapefruit contains a type of fiber in the membranes and juice sacs that may help reduce cholesterol.

Dark, leafy greens include dandelion greens, kale, turnip greens, arugula, spinach, beet greens, mustard greens, Swiss chard, endive, collard greens, escarole, watercress, and parsley. They're rich in folic acid and may help reduce the risk of heart disease. Folic acid helps regulate blood levels of homocysteine, a naturally occurring amino acid that, at elevated levels, contributes to atherosclerosis and heart disease.

Red-orange fruits and vegetables have been celebrated of late because of their high content of carotenoids, compounds that have been shown to decrease the risk of heart disease and cancer, boost immunity, prevent cellular damage, and protect the body from a variety of age-related disorders. Fruits or veggies with a deep red, orange, or yellow hue-including carrots, red peppers, raspberries, apricots, cantaloupe, watermelon, papaya, mango, and red grapefruit-have a high content of carotenoids.

Tomatoes contain high concentrations of lycopene and other carotenoids that can help prevent colon, rectal, and stomach cancer, and may even slow the progression of already-developed cancers. Lycopene, a member of the carotenoid family that's relatively rare in foods, helps boost immunity, and may help prevent macular degeneration, the leading cause of blindness among older Americans.

Cruciferous vegetables, including cabbage, broccoflower, and bok choy, are rich in sulforaphane, indoles, and other phytochemicals that may help prevent various types of cancer, especially colon cancer. Since some of the cancer-preventive compounds in crucifers are easily lost in cooking, juicing is especially important for members of this family.


Get creative with your combinations. Experiment with the unexpected. Tomato and apple, for instance, has a wonderfully tangy and refreshing flavor, and adding a little ginger to any vegetable juice gives it an extra lift and helps combine the flavors. Try pureeing non-juiceable fruits like banana and adding them to extracted juices.

Tropical Breeze

1 medium papaya
2 medium peaches
1 medium mango

Peel and pit fruits. Cut into chunks, and blend in blender until smooth.

Makes about 2 cups.

VPER 1 CUP: 164 CAL (3% from fat), 2g PROT, 1g FAT, 42g CARB, 7mg SOD, 0mg CHOL, 6.5g FIBER

Cabbage Patch

1/2 medium cabbage head
2 medium red peppers
1 small bunch parsley
1 medium cucumber

Wash all vegetables. Cut cabbage head into wedges and remove stem from pepper. Juice and serve.

Makes about 3 cups.

VPER 3/4 CUP: 39 CAL (11% from fat), 2g PROT, less than 1g FAT, 8g CARB, 25mg SOD, 0mg CHOL, 0g FIBER

Berry Blush

2 medium apples
2 medium pears
1 cup raspberries
1 medium banana

Wash apples, pears, and berries, and peel banana. Juice apples and pears. Combine juice in blender with raspberries and banana. Puree on high and serve.

Makes about 4 cups.

VPER 1 CUP: 131 CAL (6% from fat), 1g PROT, 1g FAT, 33g CARB, less than 1mg SOD, 0mg CHOL, 3g FIBER

Tangerine Dream

4 small tangerines
1 small pink grapefruit
1 medium orange

Peel fruits. Juice and serve.

Makes about 2 cups.

V PER 1 CUP: 146 CAL (4% from fat), 2g PROT, 1g FAT, 37g CARB, 2mg SOD, 0mg CHOL, 0g FIBER

Ruby Slippers

2 medium tomatoes
1 medium beat
1 large bunch watercress
3 medium scallions

Wash all vegetables. Juice and serve.

Makes about 2 cups.

V PER 1 CUP: 49 CAL (10% from fat), 3g PROT, 1g FAT, 10g CARB, 55mg SOD, 0mg CHOL, 0g FIBER

Some Like It Hot

8 radishes
1/2 cup radish sprouts
4 ribs celery
1/2 medium fennel bulb

Wash all vegetables. Juice and serve.

Makes about 2 cups.

V PER 3/4 CUP: 28 CAL (12% from fat), 1g PROT, less than 1g FAT, 6g CARB, 87mg SOD, 0mg CHOL, 0g FIBER

Popeye's Delight

2 cups spinach
2 cups kale
2 medium carrots
2 large stalks celery
1 1-inch segment ginger

Wash all vegetables. Juice and serve.

Makes about 2 cups.

V PER 3/4 CUP: 175 CAL (9% from fat), 10g PROT, 2g FAT, 37g CARB, 268mg SOD, 0mg CHOL, 0g FIBER

High-power nutritional aspects of juice and which are best suited for activities.

The message is out: Eat more fruits and vegetables to help fight disease and maintain optimum health. With slogans like "Strive for Five' and "Five a Day," Americans are getting the message to eat at least five servings of fruits and vegetables a day.

For fruits, the Food Guide Pyramid recommends we eat at least 2-3 servings per day, with a serving counting as one whole piece of raw fruit, 3/4 cup of juice, 1/4 cup of dried or 1/2 cup of canned fruit. Nutritionally speaking, fruits are a nearly perfect food-they're loaded with vitamins, minerals, fiber and phytochemicals, while low in calories, extremely low in fat and cholesterol-free.

Supplementing your intake of whole fruits and vegetables with juices is an ideal way to quench your thirst while providing your body with valuable nutrients. Though not quite as nutritious as the whole, fresh fruit (processing and storage may lessen the vitamin content slightly and eliminates much of the fiber found in the whole fruit), juices are still an excellent choice over beverages like soft drinks and coffee, both of which are devoid of beneficial nutrients.

The Counterfeits

When purchasing juices, remember to pay attention to the percentage of actual juice contained in the product. Under the new labeling law, all beverages claiming to contain juice must clearly state the total percentage on the information panel. Products labeled "drink," "beverage," "cooler," or "punch" will often contain water, corn syrup and flavorings, with very little actual juice and little more nutrition than a can of soda. Exotic "blends" such "Raspberry Peach Juice Blend" may contain a single raspberry and sliver of peach mixed with less expensive apple, pear or white grape juice. You're still getting a 100% juice product but maybe not the quality of juice you were expecting.

Choice Explosion

Canned, boxed, bottled, frozen, reconstituted or refrigerated, juices can be conveniently stored for ready availability. It's estimated that Americans are drinking twice as much juice as they did 40 years ago.

Besides choices in packaging and processing, consumers now have a huge variety of mixtures from which to choose. Not only are traditional grape, orange and apple juices available, dozens of juice-blend selections are crowding the store shelves. Some are fairly straight-forward blends (like cranberry-apple juice), while others are more exotic (pineapple-banana-strawberry-kiwi juice).

You can also choose juices that are now fortified with extra vitamins and minerals. For people who need to increase their calcium intake, an eight-oz. glass of fortified orange juice can easily provide 30% of their Reference Daily Intake for that mineral; an extra 280 mg more than you'll get from a regular glass of orange juice and as much calcium as you'll get in a glass of milk. But don't waste your money on juice "drinks" that are fortified with vitamins A and D but contain only a minuscule percent of juice in a concoction of sugar and artificially colored water.

Not All Created Equal

Although most juices are a good source of several vitamins, like C, A and folate, and minerals like potassium, some choices are far better than others.

Referring to the juice table (opposite) which gives a nutrient profile for twelve of the most common, available fruit juices, you can pick the best of the crop when it comes to meeting your particular needs.

The calories in juice are predominantly from naturally occurring fruit sugar, with fat and protein contributing an insignificant number of calories. In fact, the sugar content, and thus calories, of juices is similar to soft drinks. However, unlike fruit juices, soft drinks provide no beneficial vitamins, minerals or phytochemicals.

As mentioned earlier, primarily fiber is lost from processing fruit into juice. On our list, prune juice is the highest in fiber, although it's loaded with calories (181 for an eight oz. serving). If you're concerned about calories, tomato, apricot nectar and vegetable juice don't come in too far behind prune juice as good sources of dietary fiber.

The biggest disappointment among juices is apple, followed by grape and pear juices. Apple juice provides insignificant amounts of vitamin C and beta carotene, barely any fiber and a tiny amount of iron. Unfortunately, apple juice is very popular, especially among the pre-school set. Parents frequently select apple juice for their children because of its mild taste and inexpensive cost, and kids like apple juice because of its high sugar content. (Remember the comparison to soft drinks?) If you're looking for more nutrition in your juice, just about every other choice will be better than apple. Blends that mainly contain apple, pear or grape may also be short on nutrition.

For vitamin C, the richest sources are the citrus juices, including orange, grapefruit, lemon and lime. Orange juice, the most frequently consumed citrus juice, provides 97 mg, or 162% of the RDI for vitamin C for an eight oz. glass. Other juices that exceed 100% of the vitamin C in one glass are cranberry, vegetable and grapefruit.

Though beta carotene, or vitamin A, can be found in plentiful quantities in some juices, these are generally not as popular with consumers. For example, carrot juice is more of a specialty juice found in some stores and may be quite expensive when compared to orange juice. However, carrot juice, to no one's surprise, is loaded with beta carotene-one eight oz. glass provides 12 times the RDI for the nutrient!

But if you're interested in boosting the beta carotene level of your diet, tomato and vegetable juices are easily found and fairly reasonably priced. They also contain significant amounts of vitamins A and C in addition to contributing fiber and some iron. One word of advice: These juices may be very high in salt content so look for the reduced sodium or salt-free varieties. Also, these two juices, for the calorie-conscious, are good bets because they have the lowest number of calories per glass compared to all the other juices.