Malnutrition in Substance Use Disorders: A Critical Issue in Their Treatment and Recovery

Abstract

Substance use disorders (SUDs) are widely prevalent in many countries, with the highest rates observed in nicotine and alcohol use, followed by opioid and cannabis use disorders. Within the field of SUDs, nutrition has become an increasingly important area of focus in both epidemiology and public health, as malnutrition is frequently observed among individuals affected by these disorders. Research indicates that people with SUDs are more likely to experience malnutrition than the general population; however, this issue remains an often-overlooked consequence that can impact disease progression and recovery outcomes. SUDs disrupt brain metabolism, leading to changes in brain function and disturbances in glucose, protein, and lipid metabolism. Evidence shows that individuals with certain SUDs often suffer from poor nutritional status, marked by high sugar consumption and insufficient intake of key micronutrients like iron, as well as vitamins D, C, A, and B-likely due to prioritizing drug use over adequate food intake. Importantly, diet can alter the metabolism and effects of drugs, potentially amplifying or diminishing their impact. While nutrition should play a central role in SUD treatment and rehabilitation, current research-both in animal models and human studies-on the role and benefits of specific nutrients in this context remains limited. This literature review aims to synthesize the available findings on the impact of malnutrition in human and murine models of SUDs, with the goal of identifying which nutrients may provide the most support for treatment and recovery.

Keywords: addictions; craving; drugs; eating behavior; malnutrition; nutrients; nutrition; substance use disorders.

Figure 1

The impact of substance abuse on eating behavior, metabolism, and digestion. (a) Low nutrient intake (proteins, vitamins and minerals) influenced by appetite suppression and taste changes. (b) Digestive system alterations: damage to the digestive system mucus and barrier membranes (that causes an increase in the intestinal permeability, dysbiosis, risk of cancer), and delayed gastric emptying. (c) Alteration in absorption of nutrients such as thiamine (by reducing the transcription factors of THTR1 and THTR2, and limiting the production of thiamine pyrophosphokinase) and vitamin D (decreasing its absorption, hepatic calcidiol synthesis, and renal calcitriol synthesis). (d) Body composition changes: in the early stages of alcoholism, it increases BMI and fat mass. Later, chronic alcohol consumption is inversely correlated with BMI and fat mass (greater elimination of toxic substances by the liver leads to increased thermogenesis and reduces lipogenesis). (e) Heroin addiction: subjects with this condition present deficient levels of protein and vitamins, and elevated zinc and copper levels (due to inflammation, stress, and malnutrition). (f) Reward sensitivity is associated with substance abuse and a high-fat diet; several brain pathways involved in pleasure, reward, and motivation can influence addictive behaviors. Arrows ↑ and ↓ indicate increase and decrease, respectively. THTR: thiamine-absorbing transporters; BMI: body mass index. Created in biorender.com.