The delivery of antioxidants that reduce oxidative injury to tissues, including the brain, is one of the most common ways of combating the effect of aging. Although individual antioxidants are commonly promoted in the marketplace, antioxidant â€œcocktailsâ€ may be more desirable. For example, one recent study indicated that taking antioxidants from different fruits may be more effective than consuming single fruits.1 In the study, pigs were supplemented with linseed oil (25g daily), and then given either apples only (690g), strawberries only (745g), tomatoes only (615g) or a mixture of all three (230g apples, 205g strawberries, 248g tomatoes) daily. The mixture of fruits appeared to completely prevent DNA damage. The authors suggest the most effective reduction in DNA damage may come from a synergistic activity of mixing different types of antioxidants (water- and lipid-soluble), as found from the fruit combination in this study. Apples are a rich source of phenols, tomatoes are rich in lycopene and carotenoids, and strawberries are rich in vitamin C.
Other nutrients with the potential to affect hormonal pathways also are becoming popular. Pathways for which nutrients may affect the aging process are many, as shown by a new research on acetyl l-carnitine.2 In this study, researchers noted that acetyl l-carnitine, already a proposed therapeutic agent for several neuro-degenerative disorders, also â€œmay play a critical role as modulator of cellular stress response in health and disease states.â€ Their paper discussed carnitine and acetyl l-carnitine's role in mitochondrial dysfunction, in longevity and in age-related disorders including the ability of acetyl l-carnitine to modulate redox-dependent mechanisms that would increase brain â€œvitagenes.â€
Many other components have been researched for their benefits with processes and/or conditions associated with getting older. Here are just a few.
Luteinâ€œThese findings suggest that sick eyes may occur in sick bodies,â€ wrote lead author Joanna Seddon in the recently published Age-Related Eye Disease Study (AREDS).3 The study found that the systematic biomarkers for cardiovascular disease, C-reactive protein and homocysteine, are related to dietary intake of antioxidants, such as lutein, and found to be linked to the risk of developing age-related macular degeneration. Essentially, higher lutein intake results in healthier eyes, and lower C-reactive protein. In another study published this year, a number of antioxidants were investigated for their effect on the inflammatory cytokine interleukin-6, which has been associated with poor health outcomes in the elderly, and mortality.4 Among the antioxidants tested in elderly women, it was found that low levels of lutein and zeaxanthin were significantly more likely to have increasing interleukin-6, and this may be related to higher risk of mortality. Research continues to build proving lutein intake not only fortifies the macula of the eye, which filters light that causes oxidation and degeneration of the eye, but also may fortify other areas of our bodies to help guard against age-related conditions and early mortality.
LycopeneWith age comes increased risk of developing certain cancers. Lycopene-containing tomatoes have been shown to reduce the risk of some cancers, as evidenced by the FDA-approved qualified health claim for tomatoes and certain tomato products. However, the wording of health claims (full and qualified) confuses consumers and discourages marketers from using them in the first place, says the Natural Nutritional Foods Association (NNFA) in comments submitted to the FDA earlier this year. Lycopene is a perfect example. Consider its health claim: â€œVery limited and preliminary scientific research suggests that eating one-half to one cup of tomatoes and/or tomato sauce a week may reduce the risk of prostate cancer. FDA concludes that there is little scientific evidence supporting the claim." This health claim sounds more like a warning than a supportive statement and H.J. Heinz Co., the petitioner, is not even intending on using it on product labels.
Beyond its activity in reducing cancer risk, lycopene still is being researched for its effects on other conditions of aging. A recent randomized, double-blind, placebo-controlled study found the DNA of postmenopausal women taking a combination of carotenoids including lycopene was protected from damage.5 The carotenoid combination tested was 4mg each of lutein, beta-carotene, and lycopene, a level that can easily be achieved through diet. The study also found 12mg of each individual carotenoid exerted a DNA protective effect as well.
Saw PalmettoProstate health is one of the more serious issues facing aging American men. It is related to hormonal changes as men age and, possibly, to environmental factors, including pesticides and synthetic organochlorines. An increase of the hormone dihydrotestosterone (DHT) leads to a development in benign prostatic hyperplasia (BPH). Saw palmetto mainly is known as a man's supplement, due to its relatively well-known and well-researched role in helping to improve symptoms of BPH. It does this by preventing the conversion of testosterone to DHT. Other uses of saw palmetto in folkloric medicine have included increasing libido and sperm production; treating chronic cystitis and respiratory tract infections; and preventing hair loss, all of which often are concerns of aging. One recent study found saw palmetto did not improve symptoms or objective measures of BPH, in contrast to many well-designed clinical studies that showed positive support for saw palmetto's benefits.
CalciumCalcium is an important mineral in the body used in many of our â€œhomeostasisâ€ mechanisms, and for maintaining healthy bones and teeth, blood clotting, transmission of nerve impulses, as well as the regulation of the heart's beat. A few recent studies questioned calcium supplementation's benefits in regards to bone health. However, many others, including a recent one by Shrank, et al. indicate calcium supplementation actually may help prevent osteoporosis, as well as associated risks, like the risk of fracture in elderly women.7 Another study found women consuming dietary or supplemental calcium of greater than 1,200mg daily had a 21% lower risk in developing type 2 diabetes, compared to women getting less than 60mg daily.8 A combination of 1,200mg calcium and over 800mg vitamin D resulted in a 33% decrease in risk of developing type 2 diabetes. For both vitamin D and calcium, intake from supplements rather than from diet was more significantly associated with lower risk of type 2 diabetes.
Chromium PicolinateChromium intake has been shown to help prevent a number of conditions relating to heart health and diabetes, including insulin sensitivity, glucose tolerance, and the ratio of high-density lipoprotein to low-density lipoprotein cholesterol. The link between chromium and heart health still is being confirmed, but one study found men with the highest levels of chromium (as measured in toenail clippings) were 35% less likely to suffer heart attacks than those with the lowest levels.9 Last year, the FDA approved a qualified health claim for chromium picolinate and type 2 diabetes. In vitro research in the past has shown chromium picolinate may be helpful for type 2 diabetes by improving receptor signaling. A new in vivo animal study shows chromium picolinate improves the muscle sensitivity to insulin in obese, insulin-resistant rats.10
SoySoy is among the most popular functional foodsâ€”due to its numerous health-benefiting effects. Soy isoflavones have been found to play a role in cancer prevention, slowing down the aging process in peri-menopausal women, and they serve as a complementary supplement or alternative to hormone replacement therapy. As research has mounted on the benefits of soy isoflavones, knowledge on the bioavailability of soy isoflavones present in foods is lacking. Thus, a new study investigated the availability of isoflavones daidzein and genistein in cookies, chocolate bars and juice. Juice with soy isoflavones (455mg) had the highest absorption of isoflavones (as measured by total urinary recovery of genistein), indicating it is a better food matrix than cookies or chocolate bars.11 This research has implications on the formulation of functional foods, and the determination of the food matrix form best suited for soy isoflavones.
FlaxMany people supplement with flaxseed oil for its content of the essential fatty acids linolenic acid and linoleic acid, as it is about 57% omega-3 fatty acids and about 17% omega-6. Linolenic acid and other omega-3 fatty acids are precursors to anti-inflammatory and anti-atherogenic prostaglandins. Another beneficial ingredient in flax is lignan, which has benefits for cancer, menopause and other conditions. Daily supplementation of lignans, such as those found in flax or spruce, has been confirmed to be effective in helping women manage the effects of menopause. In the body, plant lignans are converted to enterodiol and enterolactone in the colon. In one recent study, the consumption of lignans was linked to better cognitive function.12 In postmenopausal women who consumed the lignans, cognitive function was better preserved, and their risk of developing Alzheimer's disease also was reduced. NS
References1 Pajk T, et al. 2006. Efficiency of apples, strawberries, and tomatoes for reduction of oxidative stress in pigs as a model for humans. Nutrition, 22:376-384 Epub 2006 Jan 18.
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3 Seddon JM, Gensler G, Klein ML, Milton RC. C-reactive protein and homocysteine are associated with dietary and behavioral risk factors for age-related macular degeneration. Nutrition. 2006 Apr;22(4):441-3.
4 Walston J, et al., 2006. Serum antioxidants, inflammation, and total mortality in older women. Am J Epidemiol. 163(1):18-26. Epub 2005 Nov 23.
5 Zhao X, et al. 2006. Modification of lymphocyte DNA damage by carotenoid supplementation in postmenopausal women. Am J Clin Nutr. 83(1):163-9.
6 Bent S, et al. 2006. Saw palmetto for benign prostatic hyperplasia. N Engl J Med. 354(6):557-66.
7 Shrank WH, et al. 2006. The implications of choice: prescribing generic or preferred pharmaceuticals improves medication adherence for chronic conditions. Arch Intern Med. 166(3):332-7.
8 Pittas AG, et al. 2006. Vitamin D and calcium intake in relation to type 2 diabetes in women. Diabetes Care. 29(3):650-6.
9 Guallar E. et al., 2005. Metals and Myocardial Infraction Study Group. Low toenail chromium concentration and increased risk of nonfatal myocardial infarction. Am J Epidemiol. 162(2):157-64. Epub 2005 Jun 22.
10 Wang ZQ, et al. 2006. Chromium picolinate enhances skeletal muscle cellular insulin signaling
in vivo in obese, insulin-resistant JCR:LA-cp rats. J Nutr. 136(2):415-20.
11 de Pascual-Teresa S, et al. 2006. Absorption of isoflavones in humans: effects of food matrix and processing. J Nutr Biochem. 17(4):257-64.
Franko, OH, et al. 2005. Higher dietary intake of lignans is associated with better cognitive performance in postmenopausal women. J Nutr. 135:1190-1195.