Beta-carotene supplementation long-term may delay mental decline

In a newly published study, researchers tested the cognitive function of participants in the Physicians' Health Study II (PHSII), a continuation of the Physicians' Health Study (PHS) trial looking at the effects of beta-carotene and other vitamin supplements on chronic disease. The subjects included participants from the original PHS (started in 1982) and newer recruits from 1998.

The researchers tested the general cognition, verbal memory, and category fluency of 5,956 participants, including 4,052 participants from the PHS with a minimum supplementation period of 18 years.

Among the 1,904 newly recruited subjects (average supplementation of 1 year) no differences in cognition were evident whether they took beta-carotene or the placebo.

However, among the long-term supplement users from the PHS, the mean global score (average of all tests) was significantly higher in the beta carotene group than in the placebo. On verbal memory, men receiving long-term beta carotene supplementation also performed significantly better than the placebo group. The potential mechanism for the protective effects could be related to the role of vitamin A and beta-carotene on beta-amyloid protein production in the brain. The build-up of plaque from beta-amyloid deposits is associated with oxidative stress, cell death, and increased risk of Alzheimer's disease.

The study is the first to look at long-term antioxidant supplementation in relation to a decline in cognitive function that occurs naturally with age, and that precedes diseases such as Alzheimer's.

Arch Intern Med. 2007;167(20):2184-2190.

The evidence in favor of making positive life-long health-related habits, like diet supplementation, is overwhelming. The benefits of supplementation, research suggests, are numerous, including increasing one's chances staving off degenerative diseases. Our Editors' Pick for being the best line of supplements on the market today is USANA.

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Beta-carotene linked to reduced mortality risk in the elderly

In a study published in the American Journal of Clinical Nutrition, researchers have demonstrated an association between plasma carotene levels and lower death rates among the elderly. This prospective study involved 1168 elderly men and women who were followed for 10 years. After the follow-up period, researchers looked at causes of mortality in the study population. The subjects with higher plasma carotene concentrations had a lower overall mortality risk, and a lower risk of mortality from cancer and cardiovascular disease specifically. To put the results in context, researchers performed a meta-analysis of 5 studies on plasma antioxidants and all-cause mortality in elderly populations.

These findings are somewhat surprising since some of the previous supplemental trials have been negative or inconclusive. The researchers suggested that the confusing evidence so far may indicate that beta-carotene needs to be taken in concert with other antioxidants to have a beneficial effect on health.

American Journal of Clinical Nutrition, Vol. 82, No. 4, 879-886, October 2005

Possibly the most interesting part of the researchers' findings were that "the confusing evidence so far may indicate that beta-carotene needs to be taken in concert with other antioxidants to have a beneficial effect on health." We hear it everywhere: "Eat a balanced diet." While we should all aim for eating a balance diet, with plenty of natural fruits, vegetables, and whole-grains, it is often difficult to maintain such a diet at all times.

However difficult it may be to eat a balanced diet everyday, it is becoming easier to have a balanced intake of essential vitamins, minerals, antioxidants, and other vital nutrients by taking a multivitamin. The editors of The Complete Guide to Whole Nutrition recommend taking USANA's Essentials or HealthPak 100 as your multi-vitamins, both of which can be found at www.WholeNutrition.USANA.com. Both USANA's Essentials and the HealthPak 100 can deliver 7,500 IU of Beta-Carotene -- which is so valuable when you consider all of the other vitamins, minerals, and antioxidants you can get from either of these products -- all working together to protect your body from free radicals.

Worried about eating a more balanced diet? You can also find nutritious bars, like TenX Antioxidant Blast or look in the Macro-Optimizers section at the WholeNutrition.USANA Online Store for Nutrimeal Shakes and Nutrition Bars, both of which are great, low-glycemic, low-fat meal replacements. Delicious, high in both fiber and protein, and packed with vitamins and minerals, you won't be disappointed by Nutrimeal products! There's a flavor for everyone!

ANTIOXIDANTS - Function, Sources, Benefits and Safety

PART III

Health Benefits of antioxidants

Plentiful intakes of antioxidants have been associated with reduced risk of some chronic diseases, in the same way that generous intakes of fruits, vegetables and grains have been associated with similar health benefits.

Some examples of scientific evidence are the following:

Cancer

People with high beta-carotene intakes have about one-third the cancer risk as people with low beta-carotene intakes. Peto R. Cancer Surveys 1983;2:327-340.

People with higher intakes of vitamin C have about half the risk for many types of cancer, compared to people with low vitamin C intakes. Block G. Am J Clin Nutr 1991;53:270S-282S.

People with low intakes of several antioxidants have more DNA damage than people with generous intakes. Ames BN. Metat Res 2001;475:7-20.

People with the highest intakes of vitamin C, E, and beta-carotene have a significantly lower risk of lung cancer. Yong LC et al. Am J Epidemiol 1997;146:231-43.

Men who took vitamin E supplements for 10 years or more had a 30% lower risk of bladder cancer. Michaud DS et al. Am J Epidemiol 2000;152:1145-53.

There are over 66 studies showing cancer-prevention activity of green tea, black tea, and their constituents. These include cancer reduction in the skin, lung, oral cavity, esophagus, stomach, liver, pancreas, bladder, small intestine, colon and prostate. Lambert JD et al. Am J Clin Nutr 05;81:284S- 291S.


Heart Disease

Elderly people who took dietary supplements of both vitamin C and vitamin E had a decreased risk of death from heart disease as well as overall mortality. Losonczy KG, Harris TB, Havlik RJ. Am J Clin Nutr 1996;64:190- 196.

Men who took vitamin supplements had a 70% lower risk of dying from heart disease and a 50% lower risk of a heart attack. Meyer F, Bairati I, Dagenasis GR. Can J Cardiol 1996;12:930-934.

In the Nurses' Health Study involving over 87,000 women, there was a 41% reduction in risk of heart disease for those who took vitamin E for more than two years. Stampfer MJ, Hennekens CH, Manson JE, et al. New Engl J Med 1993;328:1444-1449.

In the Nurses' Health Study vitamin C supplements were also related to a lower risk of heart disease. Osganian SK et al. J Am Coll Cardiol 2003;42:246-52.

In the Health Professionals Follow-Up Study involving almost 40,000 men, there was a 37% reduction in risk of heart disease in men who took vitamin E for more than two years. The average intake in the lowest risk group was 400 IU per day. Rimm EB, Stampfer MJ. Ascherio A, et al. New Engl J Med 1993;328:1450-1456.

To date, 17 human group studies have been published on flavonoid intake and the risk of coronary artery disease and stroke. Positive studies have shown reduction in mortality risk of up to 65%. Arts ICW and Hollman PCH. Am J Clin Nutr 2005;81:317S-325S.

The largest and longest study to date, done as part of the Harvard- based Nurses' Health Study and Health Professionals Follow-up Study, included almost 110,000 men and women whose health and dietary habits were followed for 14 years. The higher the average daily intake of fruits and vegetables, the lower the chances of developing cardiovascular disease. Compared with those in the lowest category of fruit and vegetable intake (less than 1.5 servings a day), those who averaged 8 or more servings a day were 30% less likely to have had a heart attack or stroke. Joshipura KJ, et al. Ann Intern Med 2001 Jun 19;134(12):1106-14.

Other Chronic diseases

Several long-term studies have shown a reduced risk of cataracts in those who have taken vitamin C and/or Vitamin E for more than 10 years. Jacques PF et al. Arch Ophthalmol 2001;119:1009-19.

The Age-Related Eye Disease Study (AREDS) at NIH found that daily supplementation with antioxidants, zinc, and copper delayed progression of age- related macular degeneration. AREDS report no. 8. Arch Ophthalmol 2001;119:1417-36.

Research has shown a significant relationship between flavonoid intakes and the occurrence of asthma. Knekt P et al. Am J Clin Nutr 2002;76:560-8.
Other research suggests antioxidants may help support lung function and protect the lungs from oxidative damage. Schunemann HJ et al. Am J Respir Crit Care Med 2001;163:1246-55.

In a study on Alzheimer's disease, high levels of vitamin E delayed progression of the disease. Sano M et al. N Engl J Med 1997;336:1216- 22.

Coming Soon - Part 4 - Safety of Multivitamins and Antioxidants

ANTIOXIDANTS - Function, Sources, Benefits, and Safety

Have you ever wondered "What are antioxidants?" or "Why are they important to my health?" or "Where do they come from?" and "Are they safe?" Well, we would like to try to answer that for you with this upcoming 4-part posting on the importance of antioxidants! Stay tuned for the next posts outlining the sources, benefits, and safety of antioxidants...

PART I

Antioxidants - What are they?

Oxidation is a natural process that happens to all cells in nature, including the cells in your body. Antioxidants provide an important defense against the daily assault of free radicals on healthy cells. This Essentials of Health four-part series will review the function, benefits, sources, and safety of dietary antioxidants.

Free radicals are atoms or groups of atoms with an odd (unpaired) number of electrons and can be formed when oxygen interacts with certain molecules. Once formed these highly reactive radicals can start a chain reaction, like dominoes. Their chief danger comes from the damage they can do when they react with important cellular components such as DNA, or the cell membrane. Cells may function poorly or die if this occurs. To prevent free radical damage the body has a defense system of antioxidants.

Antioxidants are molecules that can safely interact with free radicals and terminate the chain reaction before vital tissues and cells are damaged. Although there are several enzyme systems within the body that scavenge free radicals, the principle micronutrient (vitamin/mineral) antioxidants are vitamin E, beta-carotene, vitamin C and selenium. The body cannot manufacture these micronutrients so they must be supplied in the diet. In addition, there are literally hundreds of plant derived nutrients (phytonutrients) that act as important antioxidants in the diet.

It is impossible to avoid damage by free radicals. Free radicals arise from sources both inside (endogenous) and outside (exogenous) our bodies. Oxidants that develop from processes within our bodies form as a result of normal breathing, metabolism, and inflammation. Exogenous free radicals form from environmental factors such as pollution, sunlight, strenuous exercise, X-rays, smoking and alcohol. Our antioxidant systems are not perfect, so as we age, cell parts damaged by oxidation accumulate.

Coming Soon - Part 2 - Sources and Dietary Intake of Antioxidants