Is there a connection between nutrition and physical therapy outcomes?

Whether a patient presents with an acute injury, be it iatrogenic or accidental, or a condition that has led to gradual tissue degeneration, part of the intervention program created by the physical therapist includes appropriate unloading and loading of these tissues to stimulate regeneration, healing and hypertrophy. While the evaluative process often also includes assessing psychosocial factors that may negatively affect this process, physical therapists do not consistently assess pertinent metabolic and nutritional factors that may more directly slow progress.

Put simply, bodily tissues, whether due to their ongoing regenerative processes, physical adaptation to exercise or due to regeneration following injury, require and are made up of various nutrients. Nutrients are also needed for the formation of neurotransmitters. The nutrients need to be included in the diet or supplementation regimen in sufficient amounts and subsequently absorbed and utilized in order to make possible the regeneration of these tissues. Nutritional needs vary depending on age, gender, activity level and type, degree of injury, use of pharmaceutical drugs etc. However, patients are typically not exposed to relevant information, or guidance about whether additional steps might be helpful, during their journey through the healthcare system.

Physical therapists have over the years increasingly started to take psychosocial factors into account, understood the importance of meeting the patient as an individual with varying psychological needs, learning styles, value systems and aspirations. However, the target of our interventions, the intersection of our nervous and musculoskeletal systems, may rest on a shakier foundation than we imagine if the body isn’t supplied with the necessary nutrients.

Nutrients that are of importance for the patient seeking physical therapy may include proteins, both for the building of bone, muscle and connective tissue. Minerals, including macro minerals such as calcium and magnesium, as well as micro minerals such as zinc, copper, silica are of importance for structural integrity, but minerals also play a role in the correct function of actin and myosin and thus in the maintenance of normal muscle tone. Proteins and fats are important structural building blocks, and vitamins are needed for normal cell function, growth, and development. According to the U.S. Department of Health and Human Services many Americans do not obtain Estimated Average Requirement (EAR) or Adequate Intake (AI) levels of several nutrients in their diet. This is largely due to a high intake of energy-dense and nutrient poor (EDNP) foods resulting in marginal micronutrient intake. If we accept that nutrient intake can vary from merely adequate to ideal, from merely avoiding symptoms of frank deficiency to prevention and improved health, a person wishing to optimize health and performance might actually require a micronutrient intake somewhat above the EAR.

Many individuals may also suffer from nutritional deficiencies due to decreased absorption due to infection or metabolic disease, increased loss of nutrients, increased need due to illness, stress or recovery or the use of pharmaceutical drugs. Poverty, lack of nutritional information, the desire to maintain a lower body weight and adherence to restrictive diets may all, especially in susceptible individuals, contribute to nutritional deficiencies. Individuals in lower socioeconomic groups with insufficient access to fresh produce, individuals with high stress levels and subsequently higher need for certain nutrients and vegans at risk for B12 deficiency are examples of such groups.

Prescription drugs and nutrient levels

The use of prescription and OTC (over-the-counter) drugs can induce subclinical and clinically relevant micronutrient deficiencies, which may sometimes develop gradually over months or years. Despite the large number of medications currently being prescribed, the number of research studies examining potential drug–nutrient interactions is quite limited.

Pharmaceutical drugs, especially when used long-term, can be an important cause of nutritional deficiencies. As an example, proton-pump inhibitors (PPIs) raise the pH of the stomach by reducing gastric acid production. Therefore, decreased absorption of micronutrients that depend on low pH for uptake into intestinal cells may occur with PPI use. PPIs may contribute to osteoporosis in susceptible patients and, especially in patients over 60 or in patients with certain co-morbidities such as H.Pylori, they can contribute to B12 deficiency which can manifest as fatigue and cognitive decline. PPIs may also decrease plasma levels of vitamin C. Vitamin C levels are of interest to physical therapy patient populations because of this vitamin’s potential to accelerate bone healing after fractures and increase type I collagen synthesis supporting repair of soft-tissue injuries.

Examples of common drug-nutrient interactions

Nutrients in aging, illness and recovery from injuries

Many acute and chronic illnesses can decrease nutrient absorption or increase nutrient need. The muscles of the elderly tend to be more resistant to anabolic stimuli such as amino acids and resistance exercise. This resistance can be overcome with higher levels of protein or essential amino acid consumption. Aging individuals therefore need higher protein intakes than individuals older than 65 years of age in order to maintain lean body mass, and yet about a third of older Americans do not ingest the basic RDA for protein. The Australian recommended dietary intake (RDI) for protein for people aged 65 years and older is about 25% higher than the recommendations for younger adults, but in the US and the UK government recommendations do not reflect the increased need for protein in this population. Overall food intake among older adults also tends to be decreased due to decreased energy expenditures as well as loss of appetite and thirst, while nutrient absorption may be decreased due to age-related factors and the use of drugs. Older individuals should therefore in addition to engaging in resistance training be encouraged to eat a nutrient dense diet and be aware of common signs of deficiencies, such as fatigue as a result of B12 deficiency, or sarcopenia due to inadequate protein intake and low vitamin D levels.

Injured patients also have higher protein requirements, and as mentioned other nutrients such as vitamin C and D are also needed in sufficient quantities to counteract the negative effects of immobilization, prevent sarcopenia and promote muscle hypertrophy. Tissue repair processes are dependent on the synthesis of collagen and other proteins and insufficient protein intake will therefore impede wound healing and tissue repair. A protein intake of 2–2.5 g/kg/day may be warranted for this population. Sufficient calcium, K2 and vitamin D during healing from fractures and joint replacement surgery is important for optimal bone formation.

Examples of common nutrient deficiencies

Pain and nutrition

Inflammatory pain is a common form of chronic pain, and levels of inflammation also play a role in acute pain. Diet plays a very important role in inflammation and attenuation of oxidative stress, but modern dietary practices are often skewed in a pro-inflammatory direction. A diet high in vegetables, legumes, fruits and berries and whole grains contains micronutrients and phytochemicals important for immune function, while the reduction of omega 6 containing seed oils and the inclusion of fats, fish and meats high in omega 3 fatty acids has been shown to have anti-inflammatory effects. Chronic pain patients may also require supplemental levels of certain nutrients such as vitamin B12, vitamin D and n-3 fatty acids. Both physicians and physical therapists treating patients with chronic pain would do well to be aware of the role that diet, like other lifestyle factors, plays in either attenuating or increasing pain.

Conclusion

While every physical therapist may not be inclined to guide the patient towards even the most basic facts of pertinent nutritional science, their patients may still benefit from receiving information about the need to correct any such deficiencies.

The typical physical therapy patient does not, during the course of their rehabilitative process, encounter any other professional that would see to this need. Therefore physical therapists should, at the very least, include an assessment of risk factors for nutritional deficiencies in their ongoing evaluative process, just as we do with other so called red and yellow flags, in order to appropriately refer patients to a nutrition professional as needed. This would decrease the risk that such deficiencies contributing, unchecked, to slow healing, recurring injuries, decreased motor function, neurological dysfunction or incidental findings such as cognitive decline.

Physical therapists, and consequently their patients, can benefit in many ways from enhancing their understanding of the role of nutrition in health and disease. Such an understanding could lead to appropriate and timely referrals and improved patient outcomes. Specific courses and certifications are also available for healthcare professionals wishing to improve their nutritional know-how.There can also be great benefit in offering nutritional counseling in an existing physical therapy practice. In the vast majority of the cases, patients benefit from simply being made aware of the fact that we not only are what we eat (as the adage goes), but we also feel and live a great deal better, and often longer, when we eat wisely.