Second Pass
They’ve become two of the scariest words in the English language: Alzheimer’s disease (AD). Recent surveys show that loss of mental ability is the aspect of aging that many people fear most. But fortunately, there are simple measures that everyone can take – starting in middle age – that may significantly reduce the chances of developing AD or other forms of dementia.
Nearly two years ago I sent you the e-Alert “Stockholm in July” (7/24/02) that detailed several new studies that emphasized AD prevention. Now a new research project from the National Institute on Aging (NIA) confirms some of the important findings reported in the summer of 2002.
Return to Stockholm
One of the most promising studies presented at the 2002 International Conference on Alzheimer’s Disease and Related Disorders in Stockholm, Sweden, was conducted by a team from the University of Kuopio in Finland. Researchers examined nearly 1500 subjects over 21 years, giving special attention to several Alzheimer’s risk factors.
The Kuopio team found that the risk of AD was greatest for those with two treatable risk factors: high cholesterol and high blood pressure. Their conclusion: people who are able to control their cholesterol and blood pressure levels throughout their lives (especially during middle age) are less likely to develop Alzheimer’s, even if they are genetically inclined toward the disease.
Another report presented in Stockholm was a study conducted by researchers at Johns Hopkins Alzheimer’s Disease Research Center. The JH team wanted to determine if there was an inverse association with AD risk and an intake of the antioxidant vitamins E and C. They studied the dietary and vitamin supplement records of 579 volunteers, aged 60 or older, for a period of more than 7 years.
After adjusting for sex, education, and age (all factors that come into play with AD risk), a diet high in vitamin E was strongly associated with a significant reduction of Alzheimer’s risk. Intake of vitamin C was somewhat useful in reducing AD risk, but not nearly as effective as vitamin E.
One thing leads to another
The new NIA Alzheimer’s research expands on the Kuopio conclusion about cholesterol, and the Johns Hopkins results on the preventive benefits of vitamin E.
The NIA research was conducted in two phases. In one phase the NIA scientists examined the brains of deceased patients with AD as well as deceased subjects with normal neurology. When levels of fats in the brain were measured, the lipids ceramide and cholesterol were found to be significantly greater in the AD brains. Oxidative damage to the brain was also assessed and found to be considerably higher in those patients who had suffered the greater severity of Alzheimer’s.
In the other phase of the study, researchers evaluated the brains of young and old laboratory rats to compare the advancement of oxidative stress, as well as levels of cholesterol and ceraminde. They observed that the presence of beta amyloid peptide (typical in the brains of Alzheimer’s patients) triggers oxidative stress, which disrupts ceramide and cholesterol metabolism, creating an accumulation of the two lipids. This accumulation eventually sets off a “neurodegenerative cascade” that leads to the death of nerve cells in the brain, and eventually Alzheimer’s disease.
In addition, when researchers treated cultured rat nerve cells with vitamin E, the levels of cholesterol and ceramide dropped, and the amount of neurons killed by oxidative stress was reduced significantly.
Strength of E
In the e-alert “Taking History” (9/18/03), I told you about research from the University of Florida College of Nursing (UFCN) that revealed specific vitamin E benefits that have clear ties to the NIA study, as well as the two Stockholm studies.
The UFCN researchers recruited 60 men and women in a retirement community. Subjects were split into two groups. One group participated in supervised exercise for one hour twice each week for 16 weeks while the second group refrained from exercise. Half of the subjects of each group were randomly selected to receive 800 international units (IU) of vitamin E daily (considerably higher than the RDA of 30 IU per day), while all others received a placebo.
Using blood samples, the researchers measured blood serum concentrations of lipid hydroperoxide (LH); a marker that indicates levels of oxidative stress. The results: There were no significant changes in the group that didn’t exercise and received the placebo. But the LH levels indicated that those who received the daily dose of vitamin E had only half as much antioxidant damage as they had when the trial began; and this was true for both the exercise and non-exercise groups.
In addition, the group that didn’t exercise and took vitamin E showed an average reduction in their systolic blood pressure of nearly seven points. Meanwhile the exercise/vitamin E group lowered their systolic BP reading (on average) by nearly 15 points, and their diastolic BP by about five points. This group also experienced other healthy results such as improved cardiovascular health and weight loss.
Seedy advice
The lead researcher of the UFCN study, James Jessup, PhD, RN, told the University of Florida News that when we reach our 40s, most people begin to naturally produce fewer amounts of antioxidants, but larger amounts of free radicals. Therefore, it becomes progressively more difficult to get the amounts of vitamin E necessary to fight free radicals through diet alone.
Good dietary sources of vitamin E include spinach, eggs, nuts and seeds, avocado, tomatoes, peaches, and blackberries. But based on his study results, Dr. Jessup suggests that older adults will benefit from a vitamin E supplement, “because of its clear benefits to aging and systolic blood pressure.”
Dr. Jessup’s opinion is in line with previous information I’ve shared with you about vitamin E. In the e-Alert “C-ing Double” (6/12/03), HSI Panelist Allan Spreen, M.D., recommended 400 IU of vitamin E daily, as well as 200 mcg of selenium for general antioxidant protection. And while it is possible to get too much selenium, a range of 200-400 mcg daily is considered quite safe.
The necessity for daily intake of vitamin E isn’t news to HSI members. But as the NIA study confirms, a high intake of E may provide considerable benefits in keeping the advancement of Alzheimer’s at bay.
“Involvement of Oxidative Stress-Induced Abnormalities in Ceramide and Cholesterol Metabolism in Brain Aging and Alzheimer’s Disease” Proceedings of the National Academy of Science, Vol. 101, No. 7, 2/17/04, pnas.org
“Why Diet Could be Effective Prevention for Alzheimer’s” NutraIngredients.com, 2/16/04, nutraingredients.com
“New Study May Explain How Fats Damage Neurons in Alzheimer’s Patients” Press Release, American Association for the Advancement of Science, 2/15/04, eurekalert.org
“The Effects of Endurance Exercise and Vitamin E on Oxidative Stress in the Elderly” Biological Research for Nursing, 2003, July; 5(1): 47-55, ncbi.nlm.hih.gov
“Vitamin E Pill with Exercise Regime could Slow Aging” NutraIngredients.com, 8/4/03, nutraingredients.com
“UF Researcher Finds Vitamins and Exercise May Slow the Harmful Effects of Aging” University of Florida News, 7/29/03, napa.ufl.edu