Beriberi

Beriberi was an epidemic disease that caused the deaths of tens of thousands of people whose diets consisted primarily of polished white rice in the late 19th century. The relationship of this illness to thiamine deficiency was recognized in 1937, allowing for widespread treatment and prevention. It is now a rare disease that is only seen in specific populations. Nonetheless, it must not be overlooked because it may result in permanent disability or even death.

Beriberi is a disorder caused by a deficiency in dietary vitamin B1 (thiamine). Thiamine is commonly found in pork, chicken, fish, eggs, organ meats, wheat germ, beans, peas, nuts, and whole grains. It is a water-soluble and heat-labile vitamin that functions in carbohydrate metabolism. The current recommended dietary allowance (RDA) is one-half milligram per 1,000 kilocalories consumed. For most people, about one serving of a thiamine-rich food daily can fulfill this dietary need.

Early symptoms of thiamine deficiency include fatigue, irritability, depression, poor concentration, and nausea. Over time, individuals can develop so-called dry beriberi or wet beriberi. Dry beriberi manifests primarily as a disease of the nervous system. It is caused by the degeneration of nerve fibers and their surrounding myelin sheaths. Individuals may experience pain, tingling, or numbness in the hands and feet, called peripheral neuropathy. As nerve damage continues, symptoms worsen to include decreased deep tendon reflexes, wasting away of the leg muscles, and eventual paralysis of the lower extremities.

Wet beriberi, on the other hand, is a disease of the cardiovascular system. It is so named because individuals with wet beriberi develop an accumulation of fluid in their tissues. The malnourished heart becomes weak and dilates, leading to poor cardiac pumping and eventually to heart failure. Heart failure leads to fluid accumulation in the tissues and associated swelling, lung congestion, and shortness of breath with minimal exertion. The majority of individuals who die from beriberi do so from heart failure.

Although this was once a widespread problem, beriberi is now seen primarily in select groups of people. Individuals at greatest risk include breast-fed infants of mothers with inadequate thiamine intake, individuals undergoing dialysis or taking high doses of diuretics, people who have undergone bariatric surgery or have been infected with human immunodeficiency virus (HIV), and those in developing countries whose diets are mainly limited to milled rice. Alcoholics are also at risk for developing beriberi because alcohol metabolism requires higher amounts of thiamine and because heavy alcohol intake can lead to poor nutrition and impaired absorption and storage of dietary thiamine.

Individuals with beriberi can easily receive thiamine by injection or in pill form. Most symptoms rapidly improve once the vitamin is given. Nervous system damage is reversible if thiamine deficiency is recognized and treated early, while cardiac damage tends to be completely reversible regardless of how long the person has been symptomatic.