Medical foods often are confused with dietary supplements and nutraceuticals. Each is very different and serves different purposes. Dietary supplements are intended to enhance wellness among healthy adults and consist of vitamins, minerals, and/or herbs and botanicals. Nutraceuticals are nutrients, foods, or parts of foods that provide health benefits and combat disease. Like dietary supplements and nutraceuticals, medical foods are composed of combinations of vitamins, minerals, and botanicals, but they’re formulated specifically to manage nutritional deficiencies that affect disease progression. While many nutrients contained in medical foods are also commonly taken as supplements, medical foods contain specific formulations designed to improve risk factors associated with disease.
Evidence supporting the effectiveness of supplements and nutraceuticals may vary widely; there’s no legal distinction between the two, and the terms often are used interchangeably. In contrast, medical foods are tested for effectiveness in clinical trials and deemed safe by panels of experts before they’re brought to the marketplace.
Medical foods used for managing metabolic syndrome, type 2 diabetes, and cardiovascular disease are designed to improve lipid profiles and blood sugar levels, combat insulin resistance, and support favorable changes in body composition (ie, increased lean body mass). These products generally have a low glycemic index and often contain folic acid, vitamin B6, and soy fiber, nutrients that help normalize serum homocysteine levels, a known risk factor for cardiovascular disease. In addition to these nutrients, medical foods promoting cardiometabolic health may contain formulated blends of plant sterols, dietary fiber, herbal extracts, and soy protein. They also may consist of single nutrients, such as folic acid or chromium, known to be effective in improving cardiovascular risk factors.
A randomized double-blind clinical trial demonstrated that use of a medical food containing extracts from the herb hops (Humulus lupulus) and the acacia plant (Acacia nilotica) significantly decreased serum triglyceride and insulin levels in individuals with metabolic syndrome (defined as a BMI of 25 to 42.5, hypertriglyceridemia, and fasting insulin levels greater than 71.74 pmol/L) compared with those in the placebo group.9 Phytochemicals present in these plant extracts (rho-iso-alpha acids and proanthocyanidins) appear to improve cardiovascular and diabetes risk factors by exerting favorable effects on lipid and glucose metabolism.
Medical foods also may improve other cardiovascular risk factors. Deficiencies of the omega-3 fatty acids EPA and DHA have been implicated in an increased risk of sudden death from myocardial infarction.10 An open clinical trial that involved subjects with clinical deficiencies of omega-3 fatty acids showed marked improvement in blood levels of omega-3s after two weeks of using medical food consisting of 680 mg of EPA and 110 mg of DHA derived from fish oils four times per day.
Medical foods used to treat osteoporosis aim to return bone metabolism to a normal balance of resorption and formation to improve bone mineralization.12 Typically, they’re composed of vitamin D, zinc, and genistein, an isoflavone derived from soy that’s been found to repress the activity of osteoclasts (cells responsible for bone loss) and stimulate the development of osteoblasts (cells that build bone matrix).12 A randomized double-blind controlled clinical trial of postmenopausal women with osteoporosis found that those who received genistein in conjunction with calcium and vitamin D had significantly greater rates of bone mineralization, compared with subjects taking a placebo, calcium, and vitamin D.
Mitochondrial disorders result from mutations in mitochondrial DNA and affect about one in 4,000 to 8,000 people. Mitochondrial diseases present diverse symptoms and clinical manifestations, including neurological, hematological, cardiovascular, respiratory, and autoimmune disorders, which appear early in life and are sometimes fatal. The underlying pathology often involves disturbances in creatine metabolism.
Medical foods used to manage mitochondrial disorders are composed primarily of ubiquinol, a form of coenzyme Q10, which is found in high concentrations in mitochondria and is responsible for energy production. Other components include B complex vitamins, vitamin E, lipoic acid, biotin, L-carnitine, and zinc picolinate.16 This formulation has been found to increase muscle strength and exercise tolerance, inhibit free radical production, and boost glycogen, amino acid, and lipid metabolism via stimulation of mitochondrial activity.
A randomized double-blind multicenter clinical trial investigating the safety and effectiveness of coenzyme Q10 in improving motor and neurological symptoms among children aged 12 months to 17 years with mitochondrial energy metabolism disease is under way at the University of Florida.
Healing of surgical wounds, chronic foot ulcers caused by diabetes, and pressure ulcers due to prolonged bed rest often is difficult because of increased metabolic needs and poor dietary intake. Nutrition intervention for wounds and pressure ulcers involves increasing intake of protein and energy and other nutrients known to promote healing.
Medical foods used to treat wounds and pressure ulcers generally contain 1.2 to 1.5 g of hydrolyzed collagen protein per 1 kg of body weight, along with vitamin C, zinc, copper, and the amino acids arginine, glutamine, proline, hydroxyproline, glycine, and cystine, which are essential for tissue repair.19 Some also contain citrulline, an arginine precursor that’s converted to nitric oxide in the body.20 Formulas containing nitric oxide have been shown to facilitate healing by increasing the transport of oxygen and stimulating collagen synthesis at wound sites.2
A randomized prospective controlled multicenter trial conducted among elderly residents in long-term care facilities found that the use of a collagen protein hydrolysate formula significantly increased healing of pressure ulcers when compared with those who received the placebo.
Acute and chronic pain affects millions of Americans and can be difficult to manage. Typical treatment involves the use of nonsteroidal anti-inflammatory drugs, which may have serious adverse effects such as liver damage and renal complications, or potentially addictive narcotic drugs.
Research has shown that individuals experiencing chronic pain often have depressed serum levels of choline, tryptophan, arginine, glutamine, and histidine, nutrients that serve as precursors to neurotransmitters involved in the control of inflammation and pain.24 Medical foods developed to alleviate pain and inflammation from disorders such as fibromyalgia, arthritis, headache, and back and joint problems contain specialized formulations of these nutrients as well as gamma-aminobutyric acid, an inhibitory neurotransmitter that slows pain response; antioxidants (gingko biloba, grapeseed extract, and cinnamon); and anti-inflammatory peptides (provided by whey protein hydrolysate). Researchers found that this formulation significantly reduced pain symptoms in a crossover study of patients with fibromyalgia, trigeminal neuralgia, back pain, headache, osteoarthritis, and tendonitis.
Inflammatory bowel disease (Crohn’s disease and ulcerative colitis), irritable bowel syndrome, and leaky gut syndrome are chronic debilitating disorders associated with pain, diarrhea, weight loss, and nutrient malabsorption. During acute stages, these diseases usually are treated with low-residue diets as well as corticosteroid and antibiotic therapies.
Medical foods designed to lessen the symptoms of gastrointestinal disorders contain specialized blends of soluble fibers, vitamins, minerals, amino acids, and/or hydrolyzed protein.26-28 Other ingredients may include extracts of ginger, rosemary, turmeric, hops, plantain (herbs and plants containing phytochemicals with anti- inflammatory properties), medium-chain triglycerides (MCTs), rice, and oats. Formulations with these ingredients are developed to strengthen the intestinal mucosa, lessen free radical formation, and boost the immune response.
Probiotic medical foods also are used to relieve the symptoms of gastrointestinal disease. These products are composed of select strains of beneficial bacteria (eg, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus acidophilus) in a formulation and potency designed to restore optimal levels of normal gut flora. Emerging studies are providing evidence that the components of these medical foods are effective in managing the symptoms of gastrointestinal disorders. In addition, clinical trials are under way to evaluate the effectiveness of these products in easing the symptoms of ulcerative colitis and Crohn’s disease.
Medical foods have been developed to treat various neurological and psychological disorders, including Alzheimer’s disease and depression.
Alzheimer’s disease is characterized by the death of brain cells due to the formation of plaques (deposits of a protein called beta amyloid) and tangles (clumps of a protein called tau) in the brain.30 The accumulation of plaques and tangles is linked with the loss of cognitive ability and memory seen in Alzheimer’s disease.30 Two medical foods (one consisting of EPA, DHA, uridine, choline, B vitamins, vitamin E, selenium, and vitamin C; the second containing MCTs), significantly increased cognitive scores in two randomized, double-blind clinical trials involving elderly subjects with early Alzheimer’s disease.
Folic acid deficiency has been linked with the onset of depression because of its positive effect on the biosynthesis of the neurotransmitters serotonin, dopamine, and norepinephrine.33 A medical food consisting of methylfolate, the active form of folic acid, significantly improved symptoms of depression in a retrospective study of clients at an outpatient psychiatric clinic.