Hypogeusia (diminished taste) and dysgeusia (altered taste) can cause distaste for food and reduced food intake, resulting in weight loss. Causes can include head and neck radiation therapy, diabetes mellitus, Sjögren’s syndrome, and zinc deficiency. Medications used to treat systemic disease can provoke dygeusia and smell irregularities, hypogeusia (decreased sensation in taste perception), or ageusia (total loss of capacity to taste). Although total taste loss is rare, dysgeusia or hypogeusia can be triggered by altered salivary quantity and/or chemical composition, secondary to diabetes. Medication can also influence actions on trace metals such as copper, zinc, and nickel. Decreased salivary flow can concentrate salivary electrolytes causing a salty or metallic taste

Medications that frequently alter taste perception are: griseofulvin, metronidazole (Flagyl®), capoten (Captopril®), pencillamine, and metformin (Glucophage®). Up to 40% of individuals treated with angiotensin-converting enzyme (ACE) inhibitors have dysgeusia, it is usually a self-limiting, reversible effect; taste returns to normal within a few months, even with continued therapy. Lansoprazole (Prevacid®) therapy for Helicobacter pylori infection, terbinafine, pentamidine, and isotretinoin (Accutane®) can cause some loss or altered taste perception.

Medications that can alter taste and smell are: antihistamines, anticonvulsants, antidepressants, antihypertensives, anti-inflammatories, antimicrobials, antineoplastics, asthma medication, bronchodilators, lipid-lowering drugs, muscle relaxants, and vasodilators.

Dietary recommendations for altered taste perception are:

Use flavor enhancing agents during food preparation, substitution of protein sources if meat is intolerable, and a salivary substitute as needed. Plastic utensils can minimize metallic taste in food. Tart foods can help overcome metallic taste. If red meat tastes unusual, use other protein sources and dairy products. Addition of sugar can improve the flavor of salty food.  (Warning: Some diets and medical conditions have salt and sugar restrictions).

Conventional and nutritional therapeutics may include taste tests to find out which taste sensations remain. Diets should be modified to highlight the remaining taste sensations and limit offensive tasting foods and flavorings.