A Guide to Supplements for Seniors

Though supplements containing hormones claim to be the fountain of youth, there have been no well-controlled, long-term studies to bear this out. And using them could be risky because they are, after all, hormones. True, hormone levels drop with age and taking supplemental hormones, such as estrogen for women, can boost them back up.

But the safety and effectiveness of estrogen, progesterone, and now testosterone have been repeatedly scrutinized, checked, and rechecked. And even with these well-studied hormones, the jury is still out on some important safety issues. Much less is known about over-the-counter supplements.

Here's what little is known about these popular hormonal supplements:

DHEA (dehydroepiandrosterone)

Sometimes referred to as the "mother hormone" because it is the precursor of all other hormones, including estrogen and testosterone, DHEA is produced naturally by the body. Production begins to drop off around the age of 30, and that's where supplement claims step in. Claims for its miracle powers range from a purported ability to prevent Alzheimer disease to the power to cure cancer.

But researchers say that while supplemental or replacement DHEA does appear to increase muscle mass and strength and improve immune function, self-dosing could be risky. In fact, recent research found that DHEA could raise the risk of heart disease by lowering heart-healthy HDLs (high-density lipoproteins, the "good" cholesterol) as much as 13 percent. And some scientists have speculated that supplemental DHEA may also increase the risk of prostate cancer.

Moreover, some of what's sold as DHEA is actually an extract of wild yams, which manufacturers claim can be converted by the body to DHEA. We don't know whether this is true, nor do we know about possible long-term side effects of this DHEA wanna-be. There have been some suggestions that using DHEA could cause liver damage. What to do? Don't supplement with DHEA until more is known about its safety and effectiveness.

Using DHEA could be especially risky if you already take hormone replacement therapy or drugs to suppress normal hormone production.

Melatonin

As our bodies age, they produce less melatonin, a hormone that regulates the body's natural biorhythms, including the sleep cycle. The end result is often a problem getting quality sleep. Studies suggest that the drop in melatonin production that occurs with age may partly explain why so many people over the age of 65 experience insomnia.

Some researchers believe that used properly, melatonin can be a non-narcotic way to help you get some much-needed sleep or to jettison jet lag. But there are some caveats before you reach for this supplement: Skip it if you're also taking steroids (check with your doctor if you're not sure), have severe allergies, or have any disease that is affecting your immune system's ability to function. To be effective, melatonin must be taken at the appropriate time in your daily cycle.

Generally it's recommended to take 0.1 to 0.5 milligrams about 30 minutes before going to bed. However, taken inappropriately, melatonin could actually interfere with, rather than improve, your sleep. Moreover, it may be dangerous for people with high blood pressure, since it can cause blood vessels to constrict.

While melatonin appears to be safe over the short term, say to cope with temporary jet lag, don't self-medicate on a regular basis to cope with insomnia. Research, led by the National Institute on Aging, is currently underway to see if melatonin supplements can help people with Alzheimer disease sleep better. Sleep disturbances affect about 45 percent of people who have the disease.

Though melatonin is also claimed to be a powerful antioxidant that can help you fight cancer, that claim has yet to be proven.

Pregnenolone

Though DHEA is often referred to as the "mother hormone," pregnenolone comes closer to that description, since it is the precursor even of DHEA. As with other hormones, body levels decrease with age. It's claimed that pregnenolone can enhance memory and improve concentration.

At least one animal study suggests that is true. Should you supplement? In a word, no. Even less is known about the effects of supplementing with this hormone precursor than is known about DHEA and melatonin. There are no long-term studies of pregnenolone supplementation. And just because it is a substance that the body naturally produces doesn't mean it's safe to use as a supplement.

Continue to the next page to learn about carotenoid supplements for seniors.

These naturally occurring colorful compounds have gained quite a reputation in the health world. Between 500 and 600 carotenoids have been identified; most of them are found in fruits and vegetables, but only a handful are found to any significant degree in your body. The major ones are alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, lycopene, and zeaxanthin.

All have antioxidant capabilities that protect cells from free radical attack, which has been linked to aging, cancer, atherosclerosis, cataracts, age-related macular degeneration, and a whole host of degenerative diseases. Both animal and human studies suggest that carotenoids also enhance the immune system. There are currently no officially recommended intakes for any of the carotenoids.

Three of the carotenoids mentioned here -- alpha-carotene, beta-carotene, and beta-cryptoxanthin -- are converted by the body to vitamin A. Their role as vitamin A precursors is independent of their role as antioxidants. If you take more than 30 milligrams of carotenoids a day, you may notice your skin turning a yellowish-orange color. It's harmless and will disappear if you cut back on your intake.

Whether you take supplements or choose to get your carotenoids from food, take them with a bit of fat; for example, have orange juice along with breakfast or have pasta sauce with olive oil. Because carotenoids are fat-soluble, the body absorbs them better when oil is in the mix. They are destroyed by light and oxygen, so sliced or cut fruits and vegetables can lose some carotenes if they are stored.

Strange though it may seem, many carotenoids are actually made more available when the carotenoid-containing food is cooked. That's because some of the carotenoids are trapped within the plant cell walls, and cooking breaks them open, releasing the carotene inside.

Alpha-Carotene

A lesser-known relative of the more famous beta-carotene, alpha-carotene is found in many of the same foods, mainly fruits and vegetables. Though not as extensively studied as beta-carotene, it has been linked to a reduced risk of lung cancer.

In fact, some researchers believe that earlier analyses may have misidentified beta-carotene as the beneficial compound reducing disease risk, when in fact it was alpha-carotene. There is no recommended intake for alpha-carotene, but the box above lists some of the richest sources of the carotenoid.

Beta-Carotene

The most well-known of the carotenoid clan, beta-carotene has the greatest vitamin A potential. It is also the most widely studied of the carotenoids. A great deal of research has linked high intakes of foods rich in beta-carotene with reduced risk of several kinds of cancer, including cancer of the skin, cervix, uterus, mouth, stomach, lung, and bladder.

It also appears to increase the activity of natural killer cells, specialized cells of the immune system that help protect against infections and cancer. There is, however, a sour note among all the good news. A few years ago, two clinical trials testing synthetic beta-carotene supplements actually found an increased risk of lung cancer among smokers and former smokers. Would natural beta-carotene, such as that found in foods, have made a difference?

No one knows for sure. What we are sure of is that most of us are getting little beta-carotene in our diets. One estimate says that the average daily intake is only about 1.5 milligrams (mg) a day. While no official recommendations for intake have been made, some experts have suggested that a good goal to strive for would be an intake of 6 mg a day. No safe upper limit has been set for beta-carotene.

However, two large studies found that taking 20 to 30 mg a day for several years actually increased the risk of lung cancer among smokers. It isn't known whether such high doses might be harmful to nonsmokers. Though beta-carotene is converted to vitamin A by the body, the conversion slows down as beta-carotene intake increases. So, you don't have to worry about getting too much vitamin A if you increase your beta-carotene intake.

Beta-cryptoxanthin

Beta-cryptoxanthin is little-known carotenoid that the body can convert to vitamin A and it is probably the least studied of the major carotenoids. But high intakes have been associated with a decreased risk for cervical cancer. There is no recommended intake for beta-cryptoxanthin.

Lutein and Zeaxanthin

Two more of those amazing carotenoid cousins, lutein and zeaxanthin, are found in corn and green, leafy vegetables, such as kale, spinach, broccoli, mustard greens, and collards.

They are the only carotenoids found in the macula of the eye, and it appears that people whose diets contain a lot of lutein-rich foods have as much as a 57 percent lower risk of developing macular degeneration, an eye condition that can lead to blindness, compared to those whose diets contain few.

The antioxidant properties of lutein may help protect the macula from free-radical damage. Research shows that high concentrations of lutein along with zeaxanthin may help prevent macular degeneration and cataracts.

These carotenoids serve as free-radical scavengers and as filters of harmful light that enders the macula. The forms of these two nutrients in the eyes are identical to the forms found in fruits and vegetables.

Lycopene

Tomatoes never looked so good. That's because tomatoes and tomato-based products are the uncontested winners when it comes to lycopene content. Why is that important? Because researchers now believe that lycopene, a lesser-known cousin of beta-carotene, may play an important role in reducing the risk of prostate cancer and heart disease.

A recent review of lycopene research done by a researcher at Harvard University found that high intakes of tomatoes and tomato-based products are consistently associated with a lower risk of several kinds of cancer. The evidence is strongest for cancers of the lung, stomach, and prostate. It is less certain, but still a possibility, that it helps prevent cancers of the cervix, breast, mouth, pancreas, colon, and esophagus.

Lycopene is the main carotenoid in the blood and in the prostate gland. How much is enough? You may need to eat about 5 to 7 servings a week of lycopene-rich foods such as tomatoes, tomato paste, pasta sauce, and tomato juice, though some studies suggest as little as three a week may provide some protection. Other foods with lesser amounts of lycopene include red and pink grapefruit, red peppers, and watermelon.

But you need to take your lycopene with a little bit of fat, which aids in its absorption. Drinking a cup of tomato juice in between meals, for example, may not provide you with much absorbable lycopene, despite the fact that tomato juice is one of the richest sources of the carotenoid. Here's another tip: Cooked tomato products, like tomato sauce and tomato paste, provide more lycopene than raw tomatoes.

That's because heat breaks open the plant's cell walls during cooking or processing, releasing more lycopene. There are also a number of lycopene-based supplements available to choose from. If you just can't stomach tomatoes and decide to go the supplement route, bear in mind that all the research so far has been done with tomatoes and tomato-based foods, not supplements.

Many of the supplements are just concentrated sources of lycopene, with none of the other phytochemicals found in tomatoes that may be important for their cancer and heart-disease fighting powers. Your best bet is to look for a lycopene supplement that contains tomato extract or tomato oleoresin. These should contain the full phytochemical portfolio found in tomatoes.

Ellagic Acid

This naturally occurring plant compound is especially concentrated in raspberries, grapes, and nuts. It is also found in strawberries, pomegranates, and cranberries. Several studies have found that it may possess cancer-fighting potential. Studies suggest it inhibits the growth of tumors and actually triggers cell death in cancer cells.

In the next section, learn about the different types of flavonoid supplements for seniors.

You may have heard these natural nutrition factors called vitamin P. The more than 800 flavonoids in plants, better known as phytochemicals, may help fight cancer and heart disease. A recent study of almost 10,000 men and women in Finland found that the risk of lung cancer went down as intake of flavonoid-rich foods went up.

Red wine and grape juice, for example, contain significant levels of flavonoids that act as antioxidants, protect against LDL oxidation, and inhibit platelet aggregation, thereby providing protection against heart disease. The following are some of the most studied flavonoids.

Wild blueberries are exceptionally rich in this group of flavonoids, which is responsible for their intense blue color.

They are also found in the reddish pigments in many fruits, such as strawberries, cherries, cranberries, raspberries, grapes, and black currants. More than 100 studies worldwide have looked at the potential health benefits of anthocyanins. They appear to have the ability to inhibit cholesterol synthesis, thus providing protection against heart disease. And proanthocyanin, another flavonoid component of wild blueberries, inhibits an enzyme involved in cancer promotion.

This is the most abundant flavonoid in grapefruit. It may provide protection against cancer by triggering cancer-fighting enzymes in the body. But it can also have strong interactions with some prescription drugs. Researchers have discovered that drinking grapefruit juice with certain drugs prescribed for the heart and for high blood pressure can trigger some pretty frightening side effects, including rapid pulse, irregular heartbeat, dizziness, and flushing.

They believe it's the flavonoids, most likely naringin, that increase the drugs' potency and make them potentially dangerous. But there's an easy solution -- don't take your meds with grapefruit or grapefruit juice. This phytochemical is found in many fruits, vegetables, and grains. Quercetin is the major flavonoid in the western diet. Rich sources are red and yellow onions, kale, broccoli, red grapes, cherries, apples, and cereals.

Like its flavonoid relatives in red wine and tea, it is thought to protect against heart disease via its antioxidant powers. Translation: It prevents the damage to LDLs (low-density lipoproteins, the "bad" cholesterol) that makes them dangerous to artery walls. It may also have anticancer activity.

On the next page, learn about phytonutrient supplements and their role in preventing disease.

Study after study has found that people whose diets contain a lot of fruits and vegetables are significantly healthier than those whose diets contain few. While most produce is packed with vitamins and minerals, they are not the only nutritional components responsible for fighting disease.

In recent years, research has begun to focus on the phytochemicals (phyto=plant) they contain. These naturally occurring plant compounds, which are not found in animal-based foods, may help the body fend off heart disease, diabetes, and cancer. The following are a few of the most intensely studied.

Indoles

These compounds are produced in vegetables of the cruciferous family, including cabbage, broccoli, and brussels sprouts. Several studies have found that indoles can delay the onset of tumors and even prevent the formation of malignancies. They are believed to work, in part, by stimulating enzymes in the body that defuse carcinogens before they have a chance to cause harm.

Isoflavones

Found mainly in soy, soy products, and red clover, isoflavones are estrogenlike substances, also known as phytoestrogens, that may block breast cancer, lower cholesterol, slow bone loss, and ease the symptoms of menopause, especially hot flashes. Isoflavones may also be responsible for the decreased incidence of breast, colon, and prostate cancers in populations that regularly consume soy foods.

Studies have also found that postmenopausal women who take isoflavone supplements have more supple arteries, allowing blood to flow freely and thus theoretically lowering the risk for heart disease. After carefully considering several studies, The Food and Drug Administration has even decided that soy protein, which contains isoflavones, can lower blood cholesterol.

The official word from the FDA is that diets that contain at least 25 grams (g) of soy protein a day -- as part of a diet low in saturated fat and cholesterol -- might reduce the risk of heart disease. A proposal is now being considered by the agency that will allow foods containing a minimum of 6.25 g of soy protein per serving to make a cholesterol-lowering claim on the label.

The two main isoflavones believed to be responsible for soy's amazing range of health benefits are daidzein and genistein. These phytoestrogens have weak estrogen-like effects and can take the place of more potent estrogens in the body; in essence, they act as anti-estrogens. In addition, genistein is a proven antioxidant -- another characteristic that may contribute to its potential as a cancer fighter.

Researchers point to the fact that in Asian countries, where consumption of isoflavone-rich soy is high, the incidence of breast and prostate cancer is low. The average isoflavone intake throughout Asia is about 25 to 45 milligrams (mg) a day. In Japan, estimates have gone as high as 200 mg a day. In the United States and other Western countries, however, the average daily intake is only about 5 mg a day.

For postmenopausal women who can't or choose not to take estrogen replacement therapy, isoflavone supplements may be a reasonable alternative, though experts aren't 100 percent sure of their long-term safety. They do offer one distinct advantage -- unlike estrogen replacement therapy, they do not increase the risk of uterine cancer.

A dose of 50 to 100 mg of isoflavones a day may be enough to offer the same health benefits as estrogen replacement therapy, but no one knows exactly how much isoflavones it takes to provide the same effect.

Also, bear in mind that if you've recently upped your intake of soy foods or soy-based supplements, you're already getting supplemental isoflavones. Don't take isoflavone supplements if you're already taking estrogen replacement therapy without checking first with your doctor. The same holds true if you're taking prescription drugs for the prevention of breast cancer or osteoporosis.

Start Slow

Before you start seeking soy, be aware that soy products contain oligosaccharides, a type of sugar that your body can't digest and that causes gas and bloating. Not everyone is affected. But if you're not used to soy, take it easy in the beginning to allow your body time to adjust. For the future, look for soy products made from low-oligosaccharide soy. They're in the works.

Lignans

This group of phytochemicals has weak estrogen and anti-estrogen effects that may change the actions of sex hormones, such as estrogen and testosterone. Flaxseeds from the flax plant (Linum usitatissimum) are the richest source. You won't find much in flaxseed oil, however, since lignans are removed during processing.

Lignans are also found in small amounts in barley, buckwheat, millet, oats, legumes, broccoli, carrots, cauliflower, and spinach. It should come as no surprise, then, that vegetarians tend to have higher levels of lignans in the body than meat-eaters. Populations with high-fiber diets and high intakes of phytoestrogens such as lignans tend to have lower rates of hormone-dependent cancers such as breast cancer than Western populations with low fiber intakes.

The plant lignans in flaxseed are converted by the bacteria in the colon to mammalian lignans, which may protect against hormone-sensitive cancers by inhibiting certain enzymes involved in hormone metabolism, reducing estrogen levels and interfering with tumor growth. The lignans in flaxseed and other plants are actually converted into a different form of lignans in the colon by the bacteria that normally reside there.

Limonene

The name gives it away. This compound is a natural component of oil from citrus fruits like lemon, but it is also found in oils from mint, caraway, thyme, cardamom, and coriander. It is one of a group of phytochemicals known as terpenes and is commonly used as a flavor and fragrance.

It has been intensely studied for its ability to suppress cancer and has been found to cause complete reversal of breast cancer in animals and inhibit the growth of skin cancer. Limonene is believed to fend off cancer by activating cancer-fighting enzymes naturally produced by the body. There are actually about 40 limonoid compounds found in citrus fruits, all of which may be involved in the fight against cancer.

Resveratrol

Purple grapes are your richest source of this heart-healthy phytochemical. Research from Holland has hinted that resveratrol may be the reason that those who drink red wine every day have a lower risk of heart disease. Resveratrol appears to have anticancer effects as well. If you want the resveratrol without the alcohol, go for purple grapes or purple grape juice. They're concentrated sources, too.

Salicylates

The active ingredient in aspirin and a common additive in foods, this compound is also found in several fruits and vegetables, such as prunes and raisins. It's believed to mimic the anticlotting effects of the chemically related aspirin, which is routinely prescribed to prevent heart attacks. Research suggests it may also reduce the risk of cancer.

SulforaphaneThis phytochemical is found in broccoli, cauliflower, brussels sprouts, and cabbage -- foods that have long been known as cancer fighters. A few years ago, researchers at Johns Hopkins University School of Medicine uncovered a clue as to why. It seems that when sulforaphane jump-starts the activity of protective, detoxifying enzymes in the body, it disarms carcinogens, lowering the risk that cancer cells will develop.

Continue to the next page to learn about anti-aging supplements for seniors ranging from alpha-liopaic acid to MSM.

In addition to vitamins, minerals, botanicals, and phytochemical supplements, there is a growing number of other, hard-to-classify supplements that might slow the aging process that deserve mention. Many are gaining popularity, despite the lack of solid evidence to back their use.

Some have been used for years in Europe, but you'd be hard-pressed to find an American doctor who's ever heard of them, much less feels comfortable counseling you on their safety and effectiveness. Here's some of what we know.

Alpha-Lipoic Acid

This supplement claims to be a super antioxidant that protects cells from free-radical damage. It is found in spinach, broccoli, and a variety of other foods and is also synthesized by body tissues. Alpha-lipoic acid supplements have been used in Germany to treat nerve damage in people with diabetes.

The typical amount in supplements -- many are standardized to 50 milligrams (mg) per tablet -- can't realistically be obtained from food. And anywhere from 100 to 1,200 mg a day have been used in studies. Studies show alpha-lipoic acid is taken up by the central nervous system and peripheral nerves, suggesting it is needed there. It seems to protect cell membranes, in part by interacting with vitamin C.

In animals, alpha-lipoic acid has been found to be beneficial in the treatment of diabetes, cataracts, radiation injury, and damage to brain cells. Though it appears to be safe, low blood sugar may be a side effect -- a particular concern for people with diabetes, the group found to possibly benefit the most.

Choline and Phosphatidylcholine

These compounds are critical for sustaining life itself. Choline regulates signals sent between cells, and it's a structural component of all the body's cells. You get some from your diet (cauliflower, iceberg lettuce, peanuts, peanut butter, and whole-wheat bread contain high amounts), and the body produces it as well.

One of the most important roles it plays, and there are many, is in the production of phosphatidylcholine, which is essential for the production of the neurotransmitter acetylcholine. Some research has suggested that supplementation with phosphatidylcholine can boost brain levels of acetylcholine and help fight memory loss, including that experienced by Alzheimer patients.

While it is currently being studied -- and research suggests that the more choline that is present, the more acetylcholine is produced -- there is no conclusive evidence that supplementing with either choline or phosphatidylcholine will improve brain function. Phosphatidylcholine is also found in foods such as beef, egg, margarine, and cauliflower.

Creatine

Found in meat, poultry, and fish, this nitrogen-containing compound is also produced by the body. As a supplement, it is sold as creatine monohydrate and is promoted as a way to increase muscle mass and enhance exercise endurance. It has been tested mainly in athletes, and studies show it does offer them some advantage. But it isn't known if a nonathlete taking creatine supplements will get any benefit.

Coenzyme Q10

This antioxidant compound, produced by all cells of the body, is claimed to do everything from enhancing the immune system to reversing aging, but there's only strong evidence for its role in protecting the heart. Research has found that coenzyme Q10 (CoQ) minimizes small injuries to the heart that are caused by inflammation or a limited oxygen supply.

On a day-to-day basis, CoQ helps the body produce energy for all the body's cells to work properly. The heart is a reservoir for CoQ because it is packed with energy-producing cells. CoQ works together with vitamin E, which helps prevent LDL cholesterol (low-density lipoprotein, the "bad" cholesterol) from damaging arteries. The body manufactures CoQ, and it is found in a wide variety of foods. So why would you need more?

Illness and chronic use of medications (ironically, those prescribed for heart conditions, such as beta-blockers and cholesterol-lowering drugs) can deplete the body's natural reserves. CoQ deficiencies are common among people with cardiovascular disease, and the more serious the disease, the lower CoQ levels are likely to be. The people most likely to benefit from CoQ supplementation are those with cardiomyopathy or congestive heart failure.

In Japan, CoQ has been an approved treatment for congestive heart failure for years. How much helps? Some researchers suggest 100 to 120 milligrams a day. While CoQ seems to benefit people with cardiovascular disease, there's little evidence it can prevent it.

And claims that CoQ can treat cancer and periodontal disease, help you lose weight, and delay aging are far from proven, although it is being studied for a possible role in treating breast and prostate cancers.

Selenium and vitamin E are important nutrients for maintaining adequate levels of CoQ in the heart. Low intakes of either of these nutrients can affect levels of CoQ.

Glucosamine Sulfate

This is a synthetic version of a compound your body normally produces. Several proponents say supplementation of glucosamine sulfate combined with chondroitin sulfate, another collagen-promoting compound, restores lost and deteriorating cartilage and alleviates arthritis symptoms.

Unlike conventional treatments, which only treat symptoms, these two supplements are supposed to help rebuild and prevent further breakdown of collagen, the stuff that cushions joints.

Several studies in Europe and Asia have found positive results from supplementation. And it's a well-established treatment for arthritis in animals. While no drug or supplement has proven to get rid of arthritis, trying this combo is unlikely to cause you any harm, and it just might help.

MSM

The full name is a mouthful -- methylsulfonylmethane -- and it's claimed to have remarkable pain-relief power. MSM is a sulfur-containing compound found naturally in the body and in green vegetables. It's a relative of DMSO, another more well-known prescription sulfur compound that's long been said to relieve pain. If MSM works, its main advantage over DMSO is that it is odorless.

Its proponents claim that it can provide pain relief for 70 percent of patients who take it, and it is used in more than 100 countries. But very little well-controlled research has been done on its use in people, and no one seems to know if it does work, how it works, or why. It is, however, commonly used topically by veterinarians to relieve muscle pain and inflammation in horses.

The amount of sulfur in the cartilage of animals suffering from arthritis may be only one-third that of cartilage found in healthy animals. MSM is sold in capsules or crystals, and it can be applied on the skin in lotion, cream, or gel form. Most experts consider MSM a safe compound even when taken internally in amounts up to 2 grams a day on a long-term basis.

It doesn't work as quickly as prescription pain medications, and it may take several weeks before you experience pain relief, if at all. MSM can, however, cause stomach upset. If you decide to give it a try, break your daily dose into two or three smaller doses during the day.

In the next section, we will discuss the different types of anti-cancer supplements for seniors.

While cancer must be treated by a physician, there is a growing body of studies that suggest the following supplements may help fight this dreaded disease.

Grapeseed Extract

Grapeseed extract is high in proanthocyanidin phytochemicals, which act as antioxidants and are thought to help protect against heart disease and cancer. Clinical trials with grapeseed phytochemicals have found that they improve peripheral circulation, improve the condition of the retina in the eye, and have anti-inflammatory effects on the skin.

Grapeseed extract supplements are generally considered safe, though some animal studies have shown liver toxicity at high doses. It is typically a cheaper alternative to pycnogenol, a trademark product that has no generic equivalent.

IP-6

Promoted as a cancer-fighter, this supplement is said to improve immunity by boosting the cancer-fighting activity of the body's natural killer cells. It is also claimed to fight heart disease and prevent kidney stones. It contains the compounds inositol and inositol hexaphosphate (the IP-6), which are extracted from rice bran.

IP-6 also goes by the name phytic acid and occurs naturally in all animal and plant cells. Cereal grains and legumes are especially rich sources of it. Though animal and laboratory studies show that IP-6 reduces the frequency of tumors or beneficially alters levels of chemicals in the blood that are indicative of cancer, there's no research in humans to indicate that IP-6 has the ability to fight cancer cells.

Moreover, even the product's promoters caution against taking it if you already take a blood thinner (preventing blood clotting is one of the ways IP-6 is said to fight heart disease) or if you're undergoing chemotherapy, which can also affect blood factors. IP-6 can also bind to several essential minerals and prevent or reduce their absorption.

Until we know more, your best bet is to eat the healthful foods already recommended, including brown rice, whole-grain cereals, and legumes.

Shark Cartilage

Despite promoters' claims that sharks don't get cancer and the supplement's widespread fame as a cancer fighter, there's actually little evidence that shark cartilage can beat cancer. In fact, the largest study done so far to test the effectiveness of shark cartilage found it did little for people suffering from advanced cancers of the breast, colon, lung, and prostate.

But there may still be some life in this supplement. Researchers have found a compound in shark cartilage that blocks the development of blood vessels. What does this have to do with fighting cancer? A lot. Tumors grow because the body develops new blood vessels to feed them. Shark cartilage contains a substance that, at least in laboratory studies, appears to block the development of these tumor-feeding blood vessels.

There's no proof that the same happens in people. But even if there were, scientists don't know if taking the supplements in pill form would produce the same effects (perhaps it would need to be injected) or if the supplements you find at the health food store actually contain enough pure shark cartilage to do the job.

In the final section of this article, learn about the various cholesterol-lowering supplements for seniors. Continue to the next page to read more.

Diet and exercise are the most effective tools to lowering your cholesterol, but these supplements may also lend you a helping hand.

Conjugated Linoleic Acid

Also known as CLA, this supplemental fatty acid has been extensively researched in animals, where it shows promise as a way to lower cholesterol, fight cancer, and even reduce body fat. In laboratory studies, CLA uses its antioxidant powers to slow the growth of cancerous cells in the skin, breast, colon, and lung.

Some animal studies even suggest it reduces body fat and increases muscle mass. But there's no proof so far that the same holds true for people. Two recent studies in humans had conflicting results.

Ironically, high-fat meats, such as ground beef and lamb, and full-fat dairy products -- foods generally viewed as dietary bad guys -- are the richest natural dietary sources of CLA. The body doesn't make it; CLA comes only from the foods you eat.

Does that mean you should eat more high-fat meat and dairy products? Hardly. There's too much confirmed bad news about high-fat foods. What about CLA supplements? Despite the fact that CLA supplements claim to make you slimmer and healthier, there's no solid evidence, at least in humans, that this is true.

Gamma Linolenic Acid

This appears to be an exception to the recommendation to limit omega-6 fats in your diet. Also referred to as GLA, it is found in plant seed oils, such as borage and primrose oil. Animal studies show GLA can relieve both acute and chronic inflammation, such as that from arthritis.

Human studies have found significant relief of the pain and inflammation of arthritis with doses of about 3 grams a day. Because it is not an approved treatment for arthritis, most experts are cautious about recommending it as a regular, long-term treatment for the condition.

Prebiotics and Probiotics

Friendly bacteria is not a contradiction in terms. At least not when it comes to your colon. Your intestinal tract is home to hundreds of different kinds of bacteria, some good, some bad. Bad bacteria, such as Staphylococci, can cause diarrhea and infection. Good, or friendly, bacteria, such as Lactobacilli, inhibit the growth of bad bacteria, improve digestion and nutrient absorption, lower cholesterol, and enhance immune function.

As a result, health experts are beginning to realize there is a connection between maintaining intestinal health and maintaining overall health. It's a fight to the finish going on in your intestinal tract -- a battle of good against bad. If the number of beneficial bacteria drop, the intestinal environment becomes more attractive to pathogens. The toxins produced by pathogens can irritate the lining of the intestinal tract and gain entry into the bloodstream.

How to shift the bacterial balance in the right direction? Through the use of prebiotics and probiotics. Prebiotics are nondigestible food ingredients, such as fructooligosaccharides (FOS for short), a type of carbohydrate, which are a favorite food for the good bacteria and promote their growth and activity. If you eat lots of fruits, vegetables, and grains, you get some from your diet.

If not, FOS come in capsule or powder form. Considerable animal research has shown that regular consumption of FOS has wide-ranging health benefits. The typical dose is about 1 teaspoon a day of powder. FOS are widely used in Japan as a health-promoting food ingredient in more than 500 food products. You may be most familiar with probiotics, which are products or supplements that contain live, active, beneficial bacterial cultures.

The most common, of course, is yogurt. Many animal studies and some population studies have found that eating yogurt can help fight infection, control diarrhea, decrease food allergies, and possibly reduce the risk of cancer. Though no recommended dose has ever been established for probiotics, it is known that you must eat yogurt regularly to maintain the population of good bacteria in the intestinal tract and have a beneficial effect.

Red Yeast Rice

For thousands of years, this has been a Chinese remedy. Now it is a main ingredient in several over-the-counter supplements in this country. And, according to the latest research, it's an effective, low-risk way to lower cholesterol -- significantly better than a cholesterol-lowering diet could do on its own. It also costs a fraction of what similar prescription drugs cost.

Red yeast rice just happens to contain a cholesterol-lowering compound that's chemically identical to lovastatin, one of the most popular prescription drugs for lowering cholesterol. Recently, the Food and Drug Administration had banned the import of red yeast powder, saying it was a drug, not a supplement.

But a federal court judge overturned the FDA's ban, saying it was a supplement after all. It's best used by people who have borderline cholesterol levels (200 to 240), with no other known risk factors for heart disease. If your cholesterol is higher than that, you should consult your doctor first.

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ABOUT THE AUTHORS:

Elizabeth Ward, M.S., R.D., is a nutrition consultant and writer. She is the author or coauthor of five books, including Super Nutrition After 50 and The Complete Idiot's Guide to Feeding Your Baby and Toddler. Ward is the nutrition editor of Muscle & Fitness Hers, a contributing editor for Environmental Nutrition, and a contributing writer for WebMD.com.

Jeffrey Blumberg, Ph.D., F.A.C.N., C.N.S. is a professor of nutrition science and policy and is the director of the Antioxidants Research Laboratory in the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. In addition to publishing more than 180 research articles in peer-reviewed scientific journals, he has served on the Surgeon General's Workshop on Health Promotion and Aging, the Sports Medicine Committee of the U.S. Olympic Committee, the Board of the American Aging Association, the WHO/FAO Consultation on Preparation and Use of Food-Based Dietary Guidelines, the Food Advisory Committee of the FDA, and the WHO Expert Consultation on the Development of Nutrition Guidelines for the Elderly. He serves on the editorial board of several scientific journals, including the Journal of the American College of Nutrition, the Journal of Nutrition for the Elderly, the Journal of Medicinal Food, and Antioxidants & Redox Signaling.