Reduced intake of the B vitamin niacin may predispose elderly people to develop Alzheimers disease, according to a study presented at the 2002 Gerontological Society of Americas 55th Annual Scientific Meeting.
In the study, the researchers determined food intake by use of a questionnaire in which 815 healthy participants indicated the frequency with which they consumed niacin-rich foods. The researchers then determined how much niacin the subjects, who were at least 65 years old, consumed. The researchers followed up to determine which subjects developed Alzheimers over the next 4 years.
The findings indicate that people who received the most niacin in their diets were 79% less likely to develop Alzheimer’s than those who consumed the lowest intake of niacin. Half of the subjects who fell into low risk for Alzheimer’s consumed more than 22 mg of niacin daily. Of those subjects who consumed the lowest amount of niacin, half received less than 13 milligrams per day.
Niacin is used to help lower high cholesterol and fat levels in the blood. This may help prevent medical problems caused by cholesterol and fat clogging the blood vessels.
Even a small increase in niacin dosage appeared to offer benefits. The subjects who consumed the second-lowest amount of niacin were 70% less likely to develop Alzheimers during the study than those who consumed the least.
A severe deficiency of niacin, or vitamin B-3, in your diet may lead to cognitive changes, including memory loss, disorientation and confusion. Most Americans get enough niacin from dietary sources to prevent dementia related to a niacin deficiency, according to the Linus Pauling Institute. However, an inadequate intake of niacin may still cause symptoms of cognitive decline, the MayoClinic.com.
The dietary needs of people in their fifties or sixties are different from those who are younger. For most vitamins and minerals, needs are higher; although for some nutrients they actually fall. The needs of people in their seventies and eighties are different again. Mainstream nutrition is beginning to recognize these differences and some of the new RDAs take into account the needs of those who are older.
Energy intakes and energy expenditure vary widely among elderly people, and are very different in those who are healthy, sick or institutionalized. Older people tend to consume fewer calories than younger people, probably due to loss of muscle, reduced activity levels and lower metabolic rates. As total food intake decreases, individual nutrient intakes also decrease, making it more important to eat nutrient-dense foods and leaving less room for sweets and other empty calorie foods.
Deficiencies of many nutrients are common in elderly people. Normal changes associated with aging, some medications for chronic disease, and relatively common disorders such as diabetes, high blood pressure, constipation and diarrhea can result in higher requirements for some nutrients. Many social and physiological factors such as loneliness, limited income, reduced interest in food, decreased sense of smell and taste, difficulty in chewing or swallowing and reduced vision may also lead to changes in an older person’s diet.
New research findings are being published all the time but relatively little is known about how the aging process affects the ability of the body to digest, absorb and retain nutrients. The diets of elderly people are often deficient in several nutrients including vitamins A, C, D, E, B12, thiamin, riboflavin, pyridoxine, niacin, folic acid, calcium, iron, magnesium and zinc. These deficiencies may be due to lower dietary intake, decreased absorption, altered metabolism or increased excretion. They often develop slowly and may mimic the normal changes of aging. Elderly people are particularly at risk of marginal vitamin and mineral deficiencies and early recognition of malnutrition is very important in preventing diseases, maintaining a healthy immune system and increasing lifespan.
The B-complex vitamins perform key roles in maintaining healthy brain and nerve function. Niacin also affects blood circulation by dilating blood vessels, increasing blood flow to the brain and other vital organs. A niacin deficiency may cause dementia, a set of mental status or personality changes that may include confusion, wandering, agitation, memory loss and disorganized thought. Dementia is a characteristic sign of pellagra, a vitamin deficiency disorder caused by inadequate intake of foods that contain niacin. However, pellagra has become uncommon in developed countries, where breads, cereals and other grain products are often fortified with niacin. The University of Maryland Medical Center notes that an adequate intake of dietary niacin has been associated with a lower incidence of Alzheimer’s disease, a neurodegenerative disorder that causes a form of dementia. Clinical research has not established a clear connection between Alzheimer’s-related dementia and niacin deficiency.
If you have high cholesterol, your first steps should be to improve your diet, lose weight if needed, and get more exercise. If these steps don’t help enough, you may be prescribed a statin drug. But another option is high-dose niacin.
Known as B3 or nicotinic acid, niacin is found in meats, beans, and whole grains. At high doses of 1 to 3 grams daily—far more than you can get from diet alone—niacin becomes a drug. There are prescription versions, such as Niaspan (for extended release), but you can buy it over the counter as a dietary supplement. You should not take high-dose niacin without medical supervision. As with other cholesterol-lowering drugs, you will need to be monitored to make sure you are getting the desired results.
Niacin’s beneficial effect on blood cholesterol has been recognized for at least half a century. It does not reduce LDL (“bad”) cholesterol as much as statins do, but one advantage of niacin is that it raises HDL (“good“) cholesterol substantially; statins raise HDL only modestly. No one is sure exactly how niacin works, but it does change the proportion of LDL to HDL in a favorable direction. It also decreases triglycerides, fats in the blood that can increase the risk of heart disease. In clinical trials niacin has proved to reduce the risk of heart attacks, perhaps because it boosts HDL so much. Niacin may raise blood sugar slightly, but it is now considered safe for people with diabetes.
Dr. John Guyton of Duke University, in a review of studies, emphasizes the safety and efficacy of niacin, taken alone or with a statin. Niacin does not cause muscle disorders, as statins can in rare cases. Combining niacin with a statin when either drug by itself fails to have sufficient effect is a relatively new idea. Studies in people who already have heart disease have shown that the combination improves blood cholesterol levels more than either drug alone. And a review by Dr. Guyton, in Current Opinion in Lipidology, concluded that “the addition of niacin to moderate doses of statin may be favorable for stable, high-risk patients with low HDL and perhaps those with progressive atherosclerosis and average HDL levels.”
High-dose niacin can produce stomach upset and, in rare cases, liver damage. But the chief problem with niacin is that it often causes flushing (a kind of hot flash). This is not harmful or long-lasting, but many people find it hard to put up with. Sometimes the flushing decreases with time. Taking aspirin before the niacin helps reduce flushing, as may taking it with food and avoiding hot drinks or alcohol near the time you take it. Extended-release niacin usually produces less flushing—but avoid nonprescription extended-release formulas, as those are more likely to cause liver damage.
In conclusion, if you need medication to improve your cholesterol levels, ask your doctor about your choices, including niacin.
Gerontological Society of Americas 55th Annual Scientific Meeting, Boston, Massachusetts, November 22 – 26, 2002.