Adequate nutrition is crucial for ALS patients. As the disease progresses, patients gradually lose the ability to chew or swallow with ease. At the same time, the abdominal and pelvic muscles weaken, oftentimes resulting in depression. Patients often lose the ability and desire to eat, making malnutrition a common problem. The recognition that aggressive nutritional intervention is paramount among ALS patients has spurred ardent research efforts aimed at elucidating the potential therapeutic value of dietary supplementation (Cameron 2002).
Vitamins and Minerals
Vitamin B12 (methylcobalamin). Whereas ultra-high (25mg daily for 4 weeks) intramuscular doses of methylcobalamin (a form of vitamin B12) have been shown to slow muscle wasting (Izumi 2007), low levels of vitamin B12 have been associated with nerve damage in many different animal models. One of the main problems associated with low levels of vitamin B12 is elevated levels of methylmalonic acid (MMA) which is toxic to neurons (Ganji 2012). Low levels of vitamin B12 are also associated with poorly functioning peripheral nerves which can be exacerbated by ALS (Leishear 2011). Vitamin B12 can also prevent damage to the opthalmic nerves by reducing MMA and homocysteine levels, both being associated with oxidative damage (Pott 2012). Low levels of vitamin B12 have also been associated with neuronal degeneration in other models (Moore 2012).
Zinc. Mutations to the copper/zinc superoxide dismutase gene are responsible for 2-3% of ALS cases. These mutations result in the SOD enzyme having a reduced affinity for zinc (Ermilova 2005). In fact, the loss of zinc from SOD1 results in the remaining copper in SOD1 becoming extremely toxic to motor neurons (Trumbull 2009). Altering zinc levels within the brain is being studied as a method for treating many different nervous system diseases, including ALS (Grabrucker 2011). However, a study conducted at the Linus Pauling Institute found that large doses of zinc inhibit copper absorption, which can lead to anemia. In the study, researchers added a small dose of copper to animal ALS models receiving zinc and found that the copper prevented early death associated with high doses of zinc (Ermilova 2005). In summary, adding a small amount of copper to the subject’s diets prevented this lethal anemia, suggesting that moderate amounts of zinc supplementation combined with small amounts of copper might help prevent neuron death in ALS.
Ginseng. In an animal model of ALS, ginseng was shown to significantly delay the onset of ALS symptoms (Jiang 2000). An extract from the ginseng plant called ginsenoside has also been found to increase the expression of SOD1 (Kim 1996). Ginseng and its extracts may also be able to protect motor neurons from apoptosis and membrane damage, further helping to slow the progression of ALS (Radad 2011).
Ginkgo biloba. Ginkgo biloba has antioxidant properties (Ernst 2002). Additionally, it has been shown to promote healthy mitochondrial function (Fosslien 2001). During an in vitro study, it was found to protect against glutamate-induced excitotoxicity (Kobayashi 2000). Ginkgo biloba also reduced weight loss in a mouse model of ALS (Ferrante 2001). Ginkgo biloba extract has been shown to protect neurons from death due to oxidative stress (Shi 2009).
Coenzyme Q10 (CoQ10) acts as an antioxidant and is essential for proper mitochondrial function (Mancuso 2010). Human studies have found that ALS patients have a higher percentage of oxidized CoQ10 (ubiquinone), a condition the researchers blamed on oxidative stress caused by the disease (Sohmiya 2005). Supplementation with ubiquinol, the reduced (non-oxidized) form of CoQ10 may ameliorate this problem, though no studies have tested this hypothesis. Several animal studies, including the following have supported the benefit of CoQ10 treatment in ALS:
- In an animal model of familial ALS, administration of coenzyme Q10 significantly extended life span and oral administration significantly increased CoQ10 concentrations in the brains and mitochondria of the test animals (Matthews 1998).
As a result of these promising studies in mice, researchers have been testing the benefits of CoQ10 on humans with ALS. One phase II study did not find any substantial benefit of CoQ10 supplementation in patients with ALS (Kauffman 2009). However, more research still needs to be done as CoQ10 plays an important role in mitochondrial function and controlling oxidative stress - two key components of ALS. In addition, it has been noted that high doses of CoQ10 are generally safe (Ferrante 2005).
Acetyl-L-carnitine has been shown to improve mitochondrial function (Carta 1993; Virmani 2002; Jin 2008). Acetyl-L-carnitine appears to increase the growth and repair of neurons (Wilson 2010; Kokkalis 2009) while protecting neurons from high levels of glutamate when combined with lipoic acid (Babu 2009). Acetyl-L-carnitine also protects neuron cell cultures from excitotoxicity, one of the putative mechanisms of disease in ALS (Bigini 2002). Acetyl-L-carnitine has also been found to reduce neuromuscular degeneration and increase life span in animal models of ALS (Kira 2006). In one animal study, the effects of acetyl-L-carnitine were increased when administered in conjunction with lipoic acid (Hagen 2002).
Lipoic acid. Lipoic acid has been shown to have antioxidant properties as well as increase intracellular levels of glutathione (Suh 2004a; Yamada 2011). It also chelates metals both in the test tube and in animal models (Suh 2004b and 2005). As a result, lipoic acid supplementation might protect neurons from some of the changes that lead to ALS (Liu 2008). Furthermore, lipoic acid has been shown to protect cells against glutamate-induced excitotoxicity (Muller 1995). In one study, administration of lipoic acid improved survival in a mouse model of ALS (Andreassen 2001b).
Protein and Amino acids. Adequate protein intake is essential for patients with amyotrophic lateral sclerosis. Protein supplementation may help improve the nutritional status of ALS patients, thereby slowing the progression of the disease. A 2010 study found that patients with ALS taking whey protein supplements had improved nutritional and functional parameters as compared to the control group (Carvalho-Silva 2010). Some preliminary data suggests that whey protein may also directly protect motor neurons from oxidative stress, thus delaying the progression of ALS (Ross 2011). A Portuguese study suggested that dietary supplementation with amino acids may have some beneficial effects on the course of the disease (Palma 2005).
Creatine. In cells, creatine aids in the formation of adenosine triphosphate (ATP), the primary source of cellular energy. In multiple animal studies, creatine has been shown to provide protection against neurodegenerative diseases. For example, it has been suggested that creatine helps to stabilize cellular membranes (Persky 2001). Creatine may also lessen the burden of the excitotoxin glutamate in the brain, thus improving survival time in animals with ALS (Andreassen 2001a). In human ALS patients, there is evidence to suggest that creatine may improve mitochondrial function (Vielhaber 2001). In addition, a small preliminary study found that creatine supplementation improves muscle strength in ALS patients (Mazzini 2001). More recent research has confirmed that creatine can protect neurons from toxic processes such as those that drive the progression of ALS. Creatine, due to its antioxidant and anti-excitotoxic properties, has been found to have a significant therapeutic effect in mouse models of ALS (Klopstock 2011; Beal 2011). However, human studies have yielded mixed results (Pastula 2010) which may be due to insufficient sample size (Klopstock 2011). Creatine can cross the blood-brain barrier and gain access to the brain, a treatment which lowered levels of glutamate in the cerebrospinal fluid which may help to protect the brain (Atassi 2010).
Glutathione and N-acetyl-cysteine (NAC). Glutathione is an antioxidant which is naturally synthesized by the body. Increasing glutathione levels could help prevent free radical damage to cells (Exner 2000). The glutathione precursor N-acetyl-cysteine (NAC) boosts blood levels of glutathione (Carmeli 2012). Patients with ALS tend to have higher levels of oxidized glutathione (glutathione that has already been used to protect the body from free radicals) (Baillet 2010). Increased levels of glutathione can also protect neurons from degeneration in models of ALS (Vargas 2008). Interestingly, cell culture models have shown that ALS is associated with reduced glutathione levels due to mitochondrial dysfunction, and that reduced glutathione levels can result in elevated levels of glutamate (D’Alessandro 2011). Along with being a glutathione precursor, NAC has antioxidant activity of its own. In animal models of ALS, NAC administration has been shown to decrease motor neuron loss, improve muscle mass, and increase survival time and motor performance (Andreassen 2000; Henderson 1996). In addition, NAC supplementation can help thin mucous secretions in the oral cavity which may make swallowing easier (Kuhnlein 2008).
Green tea. Green tea contains high concentrations of catechins, flavonoids with strong antioxidant properties (Hu 2002). Green tea extract has been demonstrated to have anti-inflammatory properties as well (Hong 2000). One of these catechins known as epigallocatechin-3-gallate (EGCG) is of particular interest in the context of ALS. EGCG and other catechins may be able to protect neurons from a variety of diseases (Mandel 2008). EGCG has been found to protect cultures of motor neurons from death due to excessive levels of glutamate (Yu 2010). Motor neurons can also be protected from mitochondrial dysfunction with the addition of EGCG in culture (Schroeder 2009). EGCG can also bind to and inactivate iron, which may help protect motor neurons from the effects of ALS (Benkler 2010). Epidemiological data further supports the following role of tea in its potential protection of neurons: green tea consumption reduces the risk of neurodegenerative diseases (Mandel 2011) and people who drink tea may have a lower risk of developing ALS (Morozova 2008).
Pycnogenol® is an extract of marine pine bark that includes procyanidins and phenolic acids (Packer 1999). It has been shown to have antioxidant properties (Packer 1999) as well as protective effects against glutamate excitotoxicity (Kobayashi 2000). Pycnogenol® is a common complementary therapy option among ALS patients (Cameron 2002). In addition, pycnogenol® increased the levels of SOD produced in an animal study (Kolacek 2010).
Resveratrol is a powerful antioxidant found in red grape skins and Japanese knotweed (Polygonum cuspidatum). Resveratrol has been found to suppress the influx of excitatory ions into some cell types which is associated with reduced glutamate-induced cell toxicity (Wu 2003). Another way resveratrol may target neurodegenerative diseases is by reducing oxidative stress, both on its own and by increasing the expression of SIRT1 (Sun 2010), a stress-response gene associated with longevity and protection against a number of cellular assaults. Although it is not known what role this gene plays in ALS, increasing SIRT1 expression via resveratrol administration helps protect motor neurons from ALS in cell culture (Kim 2007; Wang 2011). In addition, resveratrol can increase the activity of SOD in cells and protect them from apoptosis and oxidative stress (Yoon 2011). Adding the cerebrospinal fluid from ALS patients to rat motor neuron cell cultures causes the cultured cells to die. One of the intriguing aspects of resveratrol is that it can protect the motor neuron cell cultures from death which is something that riluzole, the only FDA approved drug for ALS, cannot do (Yanez 2011).