The 'Anorexia of Aging': What is It?
The "anorexia of aging" is a term describing the age-related reduction in appetite and food intake, prevalent in 15% to 30% of older adults. It's distinct from the eating disorder anorexia nervosa. While some appetite decline is normal, severe loss can cause malnutrition, frailty, and increased mortality risk. This condition has multi-factorial causes, including physiological, pathological, and social elements.
Physiological Factors That Influence Appetite
Natural age-related physiological changes affect appetite and digestion.
Slowed Metabolism and Digestion
- Metabolism slows with age due to decreased muscle mass and physical activity, reducing calorie needs.
- Digestion also slows, with delayed gastric emptying leading to prolonged fullness.
Hormonal Shifts
- Hormones regulating hunger and fullness change with age.
- Ghrelin (hunger hormone) levels may decrease, and the body can become less responsive to its signal.
- Leptin (satiety hormone) may increase or resistance to it may develop, extending feelings of fullness.
- Increased sensitivity to Cholecystokinin (CCK), which inhibits food intake, might also suppress appetite.
Sensory and Oral Health Changes
Declining senses impact the enjoyment of food.
Diminished Taste and Smell
- Taste bud sensitivity decreases after age 60, and the sense of smell declines, especially after 70, affecting flavor perception.
- Food may taste bland, reducing the desire to eat.
Oral and Dental Issues
- Dental problems, ill-fitting dentures, dry mouth (due to reduced saliva), and difficulty swallowing (dysphagia) can make eating uncomfortable or difficult.
Psychological and Social Factors
Psychological and social aspects significantly influence appetite.
Depression and Isolation
- Depression and anxiety can suppress appetite.
- Social isolation and loneliness, often following the loss of loved ones, can make eating alone less enjoyable and decrease intake. Loss of interest can extend to eating.
Cognitive Decline and Dementia
- Conditions like dementia can alter eating habits directly.
- Memory issues may cause forgetting to eat or indifference to food.
- Brain changes can affect food preferences and recognition of hunger cues.
Medical Conditions and Medications
Health issues and their treatments can impact appetite.
Chronic Illnesses
- Conditions like cancer, heart disease, and diabetes can cause appetite loss and fatigue.
- Inflammation can also suppress appetite.
Polypharmacy and Side Effects
- Taking multiple medications (polypharmacy) is common and increases the risk of side effects that affect appetite.
- Medications can cause nausea, constipation, or change taste perception, making food unappealing.
Comparison of Appetite Factors: Young vs. Old Adults
| Factor | Younger Adults | Older Adults |
|---|---|---|
| Metabolism | Higher energy expenditure and higher calorie needs. | Lower energy expenditure and reduced calorie needs due to decreased muscle mass. |
| Hormonal Signals | Responsive to ghrelin and leptin, maintaining a robust hunger/satiety cycle. | Altered ghrelin and leptin sensitivity, leading to weaker hunger signals and prolonged satiety. |
| Taste & Smell | Strong and sensitive sense of taste and smell, contributing to high enjoyment of food. | Diminished taste and smell, causing food to seem bland and less appealing. |
| Digestion | Efficient gastric emptying, leading to faster hunger signals after eating. | Delayed gastric emptying, resulting in feeling fuller for a longer duration. |
| Social Eating | Often involves a wide social network and variety of dining experiences. | May be reduced due to isolation, grief, or mobility issues, diminishing mealtime pleasure. |
Management Strategies to Support a Healthy Appetite
Strategies can help address age-related appetite changes.
- Smaller, Frequent Meals: Offer 5-6 smaller, nutrient-dense meals/snacks daily to be less overwhelming for those with delayed gastric emptying.
- Enhance Flavors and Visuals: Use herbs/spices to boost flavor without excess salt/sugar. Present colorful, textured meals visually appealing.
- Promote Social Interaction: Encourage eating with others or at community meals; social dining improves enjoyment and intake.
- Address Underlying Issues: Manage chronic conditions, review medications for side effects, and screen for depression or cognitive decline with a healthcare provider.
- Focus on Nutrient Density: Prioritize nutrient-rich foods like healthy fats, proteins, and fortified products since calorie needs are lower.
Conclusion
Aging's impact on appetite is complex, involving physiological, sensory, psychological, and medical factors. While some calorie reduction is normal, "anorexia of aging" can cause serious health issues. Understanding causes like hormonal changes, dulled senses, isolation, and medication side effects is crucial. Implementing strategies focused on flavor, portion control, and social engagement can enhance nutrition and well-being, helping prevent malnutrition and ensure enjoyable eating in later life. National Council on Aging: Nutrition for Older Adults
