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Healthy Aging

By Yousry Naguib, Ph.D.
Vitamin Retailer magazine, May 2005 

Health-related quality of life is a key element of successful aging. “Anti-aging” dietary supplements have become a popular topic in the lay press. They hold promise to halt age-related diseases. Numerous products on the market are claiming to support a healthier, longer and youthful life, and to slow down the “normal” problems of aging.

As we grow older, some hormones begin to decline gradually and progressively. These hormones include human growth hormone (HGH), insulin-like growth factor I (IGF-I), melatonin, dehydroepiandrosterone (DHEA), testosterone, and estrogen. The age-related hormonal changes may contribute to muscle weakness, urinary incontinence, loss of cognitive function, and sexual dysfunction, which can be partially reversed in elderly people with hormone treatment.
The results of placebo-controlled trials showed that in healthy older men with low-normal to mildly decreased testosterone levels, testosterone supplementation increased lean body mass and decreased fat mass and improved sexual function and mood. The study suggested that testosterone supplementation cannot be recommended for older men with normal or low-normal testosterone levels.1

DHEA is a weak androgen used to elevate testosterone levels. Both the steady decrease of DHEA production from age 40 on and evidence of the beneficial effects of DHEA supplementation in rodents, have suggested the possibility that this steroid is involved in cognitive, vascular, and sexual functions in the aging process.

Menopausal women not only lack estrogen resulting from cessation of ovarian activity, but also other hormones such as DHEA and androstenedione. In fact, serum DHEA decreases by about 60 percent between the maximal levels seen at age 30 to the onset of menopause. Administering DHEA to postmenopausal women for 12 months resulted in increased bone formation and higher bone mineral density and stimulated vaginal maturation.2 Long-term supplementation with DHEA in women over 60 significantly increased bone mineral density, and increased sexual desire.3

HGH is one of the most frequently used hormones in anti-aging strategies. It is responsible for stimulating the growth of tissues, skin muscles, nerves, and bones. In a 26-week randomized, double-blind, placebo-controlled trial, 57 healthy women and 74 men ages 65 to 88 received HGH or placebo. At the end of the trial, the women’s lean body mass (LBM) increased by 1.0 kg in the GH group and 0.1 kg in placebo; and fat mass decreased significantly in the GH group. In men, LBM increased by 3.1 kg in the GH-group and 0.1 kg in placebo; and the fat mass decreased significantly with GH.4

Sexual Function
Aging is most often associated with impotence. About 5 percent of men at age 40 and 15 to 25 percent at age 65 experience impotence, which is defined as a consistent inability to achieve or sustain a penile erection sufficient for sexual intercourse.

Impotence is treatable in all age groups. Treatments of impotence include psychotherapy, drug therapy, vacuum devices, surgery, and dietary supplements.

Research showed that animals receiving horny goat weed (Epimedium breviconum) had an elevated level of dopamine which helps release leutenizing hormone from the pituitary gland, which in turn, stimulates the testes to produce testosterone.5

The herb Corydalis yanhusuo has been traditionally used to invigorate blood, and alleviate all types of pain, including menstrual and abdominal. The primary active component of Corydalis yanhusuo is claimed to be dehydrocorydaline (DHC), a quaternary ammonium hydrate. A 1999 study found that Weige, composed of several Chinese herbs with DHC as the main bioactive constituent, effectively cures male and female erectile dysfunction and sex frigidity.6

Yohimbe has been shown in several double-blind studies to help treat men with impotence.7 Yohimbe is not recommended for excessive or long-term use, and it may potentiate MAO inhibitors and hypotensive drugs.

Tribulus (Tribulus terrestris) has been used widely in Ayurvedic medicine for treatment of sexual dysfunction and various urinary disorders. Tribulus terrestris extract containing protodioscin has been shown to improve sexual function in rats, perhaps due to the release of nitric oxide (NO) from the nerve endings innervating the corpus cavernosum.8

Ginseng is one of the most popular herbal remedies, and is commonly included in herbals used for the treatment of sexual dysfunction. The efficacy of Panax ginseng for erectile dysfunction was demonstrated in a recent double-blind, placebo-controlled study. Mean International Index of Erectile Function scores were significantly higher in patients treated with Korean red ginseng than those who received placebo.9

Zallouh (Ferula hermonis) has been used in Lebanon as an aphrodisiac for many years. In a recent study, researchers in Italy found that acute administration of Zallouh extract (30 and 60 mg per kg body weight) stimulated sexual motivation in potent rats and improved copulatory performance and increased serum testosterone levels in sluggish/impotent rats.10

The dietary supplement l-citrulline is a new activator of the NO pathway. L-citrulline is recycled by the body into l-arginine. L-citrulline is an amino acid found in melons and stimulates the body to produce more l-arginine, which in turn produces more NO. A combination of l-arginine and Pycnogenol was found in a recent clinical study to significantly improve sexual function in men with erectile dysfunction.11

Maca (Lepidium meyenii), a Peruvian hypocotyls, is traditionally used for its aphrodisiac and fertility–enhancing properties. In an animal study, oral administration of a lipid extract from Lepidium meyenii enhanced the sexual function of mice and rats.12

Eurycoma longifolia Jack has been traditionally used in Malaysia as an aphrodisiac. Recent research studies showed that E. longifolia Jack enhanced the sexual qualities of middle-aged male rats by increasing mount frequency as compared to controls.13

Cognitive Health
A significant concern associated with growing old is the loss of cognitive function, resulting in dementia. Fortunately, the current research on aging indicates that cognitive decline is not an inevitable function of the aging process; individuals can take steps to maintain cognitive health throughout life. A growing body of research suggests that social engagement, intellectual stimulation, and physical activity play a key role in maintaining cognitive health and preventing cognitive decline. In addition, specific nutrients such as vitamin B complex, vitamin E, ubiquinone (coQ10), ginkgo biloba, and phospholipids, can support cognitive health.

Severe niacin insufficiency can cause dementia, and researchers at the Centers for Disease Control examined whether dietary intake of niacin was associated with incident Alzheimer’s disease (AD) and cognitive decline in a large, prospective study. Nutrient intake of 6,158 people aged 65 years and older was determined by food frequency questionnaire. Subjects with the highest quintiles of total niacin intake over six years had the slowest annual rate of cognitive decline.14

Phosphatidylserine (PS) is enriched in the brain. It has been demonstrated in clinical trials to improve memory, concentration, word recall, and mood in middle-aged and elderly subjects with dementia and age-related cognitive decline. PS also relieves symptoms of anxiety and depression in elderly women.15

Sixty percent of the human brain is fat, 25 percent of which is the omega-3 docosahexaenoic acid (DHA).  Depression has been associated with significantly low levels of EPA and DHA in cell tissue contents (red blood cell membrane, plasma). In an eight-week, double-blind, placebo-controlled trial, comparing omega-3 PUFAs (polyunsaturated fatty acids, 9.6 g/day) with placebo in 28 patients with major depressive disorder, patients in the omega-3 PUFA group showed a significant improvement in the symptoms as compared to those in the placebo group.16

Ginkgo is thought to be helpful for preventing or treating dementia because it improves blood flow in the brain. A review of studies on ginkgo and mild memory impairment (dementia) found that ginkgo was significantly more effective than placebo in enhancing memory and cognitive function.17

Vinpocetine, derived from vincamine (an alkaloid found in the periwinkle plant Vinca minor), is an excellent vasodilator, acting by direct relaxation of the vascular smooth muscle; and cerebral blood flow enhancer in patients with cerebrovascular disorders.18 In clinical trials involving patients suffering from mild-to-moderate vascular dementia, vinpocetine benefited memory and cognitive performance.19

Huperzine A, an alkaloid isolated from a club moss (Huperzia serrata), is currently in phase III trials in China for the treatment of patients with Alzheimer’s disease.20

Heart Health
Heart health is a major area of concern among baby boomers. The two most common contributors to heart problems are high cholesterol and high blood pressure.
Supplements known to help improve circulation include: l-arginine, garlic, ginkgo, hawthorn berry, bioactive peptides, and coenzyme Q10 (coQ10).

Arginine relaxes the arteries, including coronary arteries that supply blood to the heart, helping to maintain healthy blood pressure and blood flow. Arginine also assists in promoting healthy blood flow to the sexual organs necessary for sexual function.21

Garlic has been used throughout the history of civilization for treating a wide variety of ailments associated with aging. Garlic has strong antioxidant properties and it has been suggested that garlic can prevent cardiovascular disease, inhibit platelet aggregation and thrombus formation, and improve blood circulation.

Ginkgo has also been studied in people with intermittent claudication. An analysis of eight published studies revealed that people taking ginkgo tend to walk roughly 34 meters farther than those taking placebo.22

The berries and flowers of hawthorn (Crataegus oxycantha) are widely used as a cardiac tonic, and recommended as a treatment option for congestive heart failure (a disease in which the heart does not adequately maintain circulation). Research in patients with hypertension indicates that treatment with coQ10 decreases blood pressure, possibly by decreasing oxidative stress.

Vitamin C, vitamin E, niacin, and grape seed extract, all of which are believed to have a dilating effect on blood vessels, may help to get the blood flow. Magnesium supplements may help dilate vessels and alleviate arterial spasms.

Cholesterol-lowering supplements, such as red yeast rice, phytosterols, policosanol, guggul, polymethoxylated flavones, and tocotrienols, help prevent atherosclerosis and associated diseases. For example, a study published in the American Journal of Clinical Nutrition found that healthy subjects (46 men and 37 women, ages 34 to 78) with hyperlipidemia who received 2,400 mg daily of red yeast rice containing, by weight, 0.4 percent HMG-CoA reductase inhibitor, had a significant reduction of total cholesterol (16 percent), and LDL cholesterol (22 percent) after 12 weeks of treatment, as compared to placebo.23

Eye Health
With the aging population, the number of Americans with major eye diseases is increasing, and vision loss is becoming a major public health problem. Blindness or low vision affects 3.3 million Americans age 40 or over. This figure is projected to reach 5.5 million by the year 2020.

Recently, interest has been directed at dietary supplements that might prevent loss of vision caused by degenerative conditions that become more common as we age.
Oxidative damage to the retina has been proposed as a risk factor for age-related macular degeneration (AMD) and its associated vision loss. And it is proposed that antioxidants may play a protective role.

By far the most biologically plausible micronutrients to have a potential protective role in AMD are the carotenoids lutein and zeaxanthin, which are potent antioxidants. They are abundant in the retina of the eye, and found in high concentration in the macula.
A case-control study involving 56 subjects with AMD and 56 without AMD showed that people with the highest quartile of lutein and zeaxanthin level had an 82 percent lower risk for AMD compared with those in the lowest quartile.24

Bilberry extracts have been used in ophthalmology for their properties in enhancing night vision acuity. Research studies confirmed these effects, although other studies cast doubt on the proposition that bilberry supplementation, in the forms currently available and in doses recommended, is an effective treatment for the improvement of night vision in young males with good vision.25

Skin health
As we age, fine lines start to bracket our mouth and radiate out from the corners of our eyes. These early aging signs get more noticeable as our skin gets dryer and less elastic over time. To address skin aging, skin creams containing antioxidants such as Coenzyme Q10, vitamin E and vitamin C, DMAE (dimethyl amino ethanol), astaxanthin, and alpha-lipoic acid have been developed. In addition, supplements containing hyaluronic acid (HA) are becoming increasingly popular in recent years. HA is a ubiquitous polysaccharide present at high concentrations in the cornea, skin, and joints.

HA possesses two major molecular characteristics that contribute to its physiological functions: its unique ability to retain water, and its instructive effects on cell signaling and behavior (adhesion, migration and proliferation). HA has been widely used for osteoarthritis, ophthalmology, and cosmetics for skin care.

Hormones play a central role in skin appearance and are implicated in skin aging. The anti-aging properties of a date palm kernel extract rich in phyto-hormones was examined in ten healthy women volunteers, ages 46 to 58, who applied either a cream containing 5 percent date palm kernel or placebo on the eye area twice a day for five weeks. Clinical evaluation showed that topical application of date palm kernel reduced the total surface of wrinkles by 27.6 percent, and reduced the depth of wrinkles by 3.52 percent26.

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