Healthy Aging A-Z: Thiamin (Vitamin B1)
Thiamin pyrophosphate (TPP) is the active form of thiamin (Vitamin B1). TPP is an essential cofactor in many enzyme functions including the metabolism of carbohydrates. Alterations in glucose metabolism have been associated with decreased thiamin levels in persons with diabetes. Chronic hyperglycemia in diabetes contributes to damage of the blood vessels in the heart, kidneys, peripheral nervous systems and retina of the eye. A higher daily intake of thiamin has been correlated with better vascular health in diabetes.
Some have called Alzheimer’s disease ‘diabetes of the brain’, as there appears to be impaired metabolism of glucose and insulin in the brain with Alzheimer’s disease. Thiamin is critical for memory formation.Thiamin deficiency and decreased thiamin dependent enzyme activity are linked with Alzheimer’s disease. Thiamin supplementation has been shown to significantly reverse cognitive impairment in animals with thiamin deficiency but the effect of thiamin supplementation needs to be studied in Alzheimer’s disease.
Thiamin may also be helpful in the prevention of cataracts. In a study of 2900 people age 49 and older, those in the highest 5th of thiamin intake were 40% less likely to have cataracts than the lowest 5th of the group. A recent study of 408 women showed a relationship between increased thiamin intake and decreased incidence of cataracts.
Severe thiamin deficiency can lead to impaired cardiac function and congestive heart failure (CHF). The use of the drug furosemide often used in patients with CHF can increase excretion of thiamin, creating a deficiency which can worsen CHF. In one study, CHF patients on furosemide were given thiamin 200mg a day over 6 weeks with an average improvement in left ventricular (heart) function of 22%. Improvement in left ventricular function is associated with improved survival in heart failure patients.
Severe thiamin deficiency can lead to Beriberi, a disease that can attack multiple organ systems including the nervous system. This degree of deficiency is rare in industrialized nations but a variation called Wernicke’s encephalopathy is not uncommon with alcoholism. Chronic alcohol abuse impairs thiamin absorption and is the most common cause of thiamin deficiency in developed nations.
Thiamin levels can drop with excessive consumption of foods that contain thiamin degrading enzymes, such as coffee, tea, alcohol and raw fish, though this is rarely a cause of serious thiamin deficiency. It is important to know if your thiamin levels are sufficient to support good health. This is best done by measuring TPP in the red blood cells, though a serum level can be used, with a goal of having a level comfortably in the midrange.
Regular testing and monitoring of an individual’s nutritional status of vitamin A is advised in order to assure safety and to truly individualize dosing for each person’s unique needs.