Is there an association between weight loss and Alzheimer’s disease?
Weight loss is frequently seen in individuals with Alzheimer’s disease. Weight loss may occur throughout the course of Alzheimer’s disease, but becomes more common as the disease progresses.
From a scientific standpoint, there is growing evidence that weight loss later in life can be an early warning sign of mental decline and the development of Alzheimer’s disease. Because the brain regulates so many of the body’s functions – including hunger and satiety – scientists say it makes sense that the effects of Alzheimer’s disease in the brain would affect many different aspects of bodily function including weight.
There are many causes of weight loss in the elderly and in persons with Alzheimer’s disease. These are addressed in the Q & A below.
Can certain medical conditions in the elderly or persons with Alzheimer’s disease also cause weight loss?
Yes. Conditions that can lead to weight loss include:
- Chronic infections
- Thyroid disease
- Not drinking enough liquids
- Swallowing difficulties (dysphagia)
- End-organ disease (congestive heart failure, kidney disease, chronic obstructive pulmonary disease, liver failure)
- Gastrointestinal disorders (celiac disease, inflammatory bowel disease, pancreatic insufficiency, peptic ulcer disease, gastroesophageal reflux disease)
- Dry mouth
- Dental issues, including poorly fitting dentures, bad teeth, mouth sores/ulcers
Are there certain medications that an elderly person or person with Alzheimer’s disease may be taking that are known to cause weight loss?
Weight loss is a side effect of many medications that an elderly person or person with Alzheimer’s disease may take. The types of medications include:
- Cardiac drugs. Including drugs to treat cholesterol (statins) heart failure, high blood pressure (hypertension), chest pain (angina), and drugs to reduce fluid buildup (edema)
- Neurologics and psychotics. Including drugs used to treat depression, anxiety, seizures, bipolar disorder, schizophrenia, Parkinson’s disease and Alzheimer’s disease
- Bone and joint and pain drugs. Including drugs to treat osteoporosis, arthritis, gout, pain (opiates), and lupus
- Endocrine drugs. Including drugs to treat thyroid disease and diabetes
- Others. Including aspirin, some antibiotics, cold products, allergy products, iron, potassium, alcohol and nicotine, drugs used to treat involuntary muscle movement
Besides the presence of other health problems and medication side effects, are there other reasons persons with Alzheimer’s disease lose weight?
Other reasons for weight loss in persons with Alzheimer’s disease include:
- More calories being burned. Individuals with Alzheimer’s disease may lose weight because they may burn more calories than elderly people without the disease. People with dementia frequently pace, wander, and are more likely to be in motion – activities that burn more calories.
- The effects of Alzheimer’s disease itself and aging. Food preferences may change as dementia progresses. Favorite foods may no longer be favorites. Certain food types may become more desired (for example, sweets). Vision or sense of smell or taste may become impaired, which makes finding the food and stimulating the appetite more difficult. If the individual with Alzheimer’s disease is delusional, they may not eat because they fear something, hear voices, or may be distracted during dining and leave the table before finishing the meal. People with advanced Alzheimer’s disease may lose the ability to recognize foods or forget how to use utensils to bring food into the mouth (a condition called food apraxia) even though they may be hungry. They can also forget how to chew and swallow food. In addition, patients can also lose weight if they can no longer communicate health problems that are making it less desirable to eat, such as gastrointestinal pain and discomfort.
Other events in the lives of the elderly, such as grief and mourning the loss of a spouse or life-long friends as well as social isolation, can also lead to weight loss.
How are patients with Alzheimer’s disease who are losing weight evaluated?
The doctor will gather the patient’s medical history and conduct a physical exam to look for the medical issues that often underlie the cause of the weight loss and need treatment. Many doctors review a patient’s medications as the first step since they are often the cause of loss of appetite and weight. All current prescription and over-the-counter medications and supplements should be reviewed.
A speech pathologist may be consulted to determine if the patient has any swallowing problems.
How can weight loss in patients with Alzheimer’s disease be treated?
Treatment should be focused on the identified causes of weight loss. If other health problems are suspected to contribute to weight loss, they need to be identified and treated. Current medications that are no longer required should be discontinued. Prescription medications, over-the-counter products and supplements that are thought to be a source of weight loss should be discontinued and replaced (if needed) with medications that are not associated with weight loss. An appetite stimulant, such as megestrol acetate (Megace®), dronabinol (Marinol®), mirtazapine (Remeron®), or growth hormone secretagogues may be prescribed.
A speech therapist may recommend a feeding strategy if there are reversible causes for the eating problems.
In individuals with advanced Alzheimer’s disease in their final stages of illness, oral feeding by hand (by an assistant) or placement of a feeding tube are the two main options. The goal of hand feeding is to continue to provide food and beverage as long as still pleasurable and comfortable for the patient. Hand feeding requires a caregiver’s assistance for approximately 45 to 90 minutes per day. The goals of long-term tube feeding (usually through a PEG tube [percutaneous endoscopic gastrostomy]) are to improve malnutrition, prevent aspiration (food, drink, secretions, stomach content that enter the airways [lungs] instead of the digestive tract), and extend life. Tube feeding is not without its risks, which include dislodgement of the tube, blockage, leakage, and development of pressure sores. The decision to place a feeding tube in a person with end-stage Alzheimer’s disease is difficult and requires understanding, careful thought, and counseling of family members by the healthcare team, religious personnel, hospice personnel and other responsible individuals.