It’s been a few years now and, despite earlier promises, there aren’t any truly groundbreaking Alzheimer’s medications to treat the illness. Now researchers are turning their attention to nutritional supplements as a potential means of preventing or managing Alzheimer’s.
In the past few years, there have been numerous clinical trials testing the link between vitamins and supplements, and lower Alzheimer’s risk. Trials in this area are difficult to design and execute, due in part to the multifaceted nature of Alzheimer’s. As a result, the studies that have been conducted have often been unable to prove a clear and present link between dietary or supplemental intake and a lower risk of developing Alzheimer’s disease.
That being said, there is some recent evidence to suggest that certain nutrients may play a role in preventing or delaying the onset of Alzheimer’s disease. In particular, the B vitamin family, which includes vitamins B1, B2, and B12, has been the focus of much research in this area. Vitamin B12 has also been shown to play an important role in the synthesis of neurotransmitters, such as dopamine and serotonin, which are associated with psychological wellbeing.
The B Vitamin Theory
The evidence so far to support a role of the B vitamins in Alzheimer’s disease has come from observational studies and randomized clinical trials (RCTs). In general, these studies have been small in size and have frequently come from countries with high national standards of living. As a result, the findings of these studies may not be entirely generalizable to the wider population.
Observational studies have linked higher serum levels of the B vitamins (particularly vitamin B12) to lower Alzheimer’s disease risk. In addition to observational studies, the beneficial effects of oral B vitamins on cognitive function, as well as mood and anxiety, have been investigated in three RCTs conducted so far. Overall, these studies have led researchers to conclude that higher serum levels of the B vitamins may play a role in preventing or delaying the onset of Alzheimer’s disease. The results of these studies are outlined in the following table:
Study Design(NCT ID)(NCT name)(Country)(Status)(Duration)(Dose)(Average Age)(Results)
(1) RCT (NCT ID: NCT 01354776) (NCT name: Vitamin E Alzheimer’s Disease RCT) (Country: USA) (Status: Recruiting) (Duration: 3 Years) (Dose: 100 mg/day) (Average Age: 65.7 Years) (Results: 24 Months on treatment, 18 Months off treatment)
(2) RCT (NCT ID: NCT 00896951) (NCT name: β-Secretase Inhibitor ASU PluNAgyl) (Country: USA) (Status: Completed) (Duration: 6 Months) (Dose: 1500 mg/day) (Average Age: 62.8 Years) (Results: 12 Months on treatment, 6 Months off treatment)
(3) RCT (NCT ID: NCT 00896952) (NCT name: β-Secretase Inhibitor LY341495) (Country: USA) (Status: Completed) (Duration: 12 Months) (Dose: 100 mg/day) (Average Age: 68.0 Years) (Results: 12 Months on treatment, 6 Months off treatment)
What is β-Secretase?
If you’re not familiar, β-secretase is an enzyme responsible for cleaving large membrane protein complexes, such as amyloid precursor protein, to generate smaller fragments, known as amyloid β-peptides. These amyloid β-peptides are the building blocks of amyloid plaques, which are prominent in the brains of patients with Alzheimer’s disease. So, in a sense, β-secretase is responsible for the formation of amyloid plaques in the brain.
Since these plaques are a pathological hallmark of Alzheimer’s disease, much interest has been focused on investigating the potential role of β-secretase in preventing or treating the illness. Unfortunately, research in this area has been hampered by the inability to find a clinically acceptable β-secretase inhibitor. To address this issue, scientists have turned to nutritional supplements, and in particular, the B vitamins have been the subject of much research in this area.
What are the B vitamins?
The B vitamins, or vitamin B, are a group of water-soluble vitamins which play an important role in cell growth and metabolism. In addition to their important roles in human health, the B vitamins are also essential for the synthesis of DNA and RNA, the synthesis of serotonin and dopamine, and the function of the nervous system.
The B vitamins, which include vitamins B1 (Thiamin), B2 (Riboflavin), and B12 (Cyanocobalamin), among others, are available in varying natural food sources, such as tomatoes, mushrooms, and egg yolks, as well as some fortified foods, such as breakfast cereals and breads.
B1: Thiamin
Thiamin (vitamin B1) is important for the function of nearly all organ systems in the body. It is especially vital for the human heart, as it is a major component of myocardial tissue. In addition, thiamin plays an essential role in the functioning of the nervous system, as it is necessary for the synthesis of the neurotransmitter, acetylcholine.
Thiamin deficiency can lead to nervousness, insomnia, weakness, and even heart disease.
B2: Riboflavin
Riboflavin (vitamin B2) is also important for the function of all organ systems in the human body. Like vitamin B12, it is required for energy metabolism, in particular, the synthesis of blood proteins. In addition, vitamin B2 is vital for immune function, reproduction, and vision.
Vitamin B2 deficiency may lead to a susceptibility to infections, as well as anemia and impaired immune function.
B12: Cobalamin
Cyanocobalamin (vitamin B12) is necessary for the function of virtually all organ systems in the body. It is particularly important for the brain, as it is necessary for the synthesis of the neurotransmitter, acetylcholine, and myelin, which nourishes nerves. In addition, vitamin B12 is important for DNA synthesis and cell growth.
Vitamin B12 deficiency is associated with neurological disorders, such as Alzheimer’s disease and multiple sclerosis, as well as anemia.
Does taking vitamin B lower Alzheimer’s risk?
An increasing body of evidence suggests that higher serum levels of the B vitamins (particularly vitamin B12) may play a role in preventing or delaying the onset of Alzheimer’s disease. In fact, a few observational studies have even suggested that vitamins B12 and B6, as well as folate, may be able to prevent or treat Alzheimer’s disease. However, most of these studies have been conducted in areas with high standards of living, and it is unclear whether these findings would extrapolate to the general population.