Vegans and vegetarians are at increased risk
by IDW/SRH
(21.09.2022) Vitamin B12 is involved in a large number of important metabolic processes that contribute, among other things, to blood formation, cell division and nerve function. A vitamin B12 deficiency also occurs in western populations, the risk increases with age, so it is estimated that one in five people over the age of 60 has vitamin B12 hypovitaminosis.
Vegans and, to a lesser extent, vegetarians also have an increased risk of suffering from a vitamin B12 deficiency, since vitamin B12 that can be used by humans is mainly found in animal food,” explains Prof. Dr. habil. Marcus Grimm, head of the bachelor’s degree in nutritional therapy and counseling at the Rhineland campus in Leverkusen.
Studies suggest a link between vitamin B12 deficiency and the onset of Alzheimer’s disease. One of the characteristic features of the disease is the accumulation of a special protein called amyloid-β (Aβ). This is also formed from birth in healthy people who are not affected by Alzheimer’s. Here, however, the build-up and breakdown of this protein are balanced. If there is an increased build-up or a reduced breakdown of Aβ, more and more Aβ protein molecules accumulate in the brain, first smaller aggregates are formed, and later larger accumulations, so-called plaques.
The metabolic pathways that lead to the formation or breakdown of Aβ take place on or in the cell membrane, a covering that consists largely of fats. Previous studies, among others by Prof. Dr. habil. Marcus Grimm and colleagues showed that by influencing the fats, the cause of Alzheimer’s disease can be influenced positively but also negatively.
In particular, plasmalogens play a protective role in the disease, reducing the formation of Aβ. At the same time, plasmalogens are significantly reduced in Alzheimer’s patients. Due to their chemical structure, plasmalogens are particularly sensitive to free radicals and oxidative stress, which is greatly increased in Alzheimer’s due to the increased occurrence of Aβ. This leads to a vicious circle. A reduced plasmalogen level leads to an increased production of Aβ protein molecules, which in turn destroy the plasmalogens through oxidative stress, which once more leads to increased production of Aβ.
In the new study by Prof. Dr. habil. Marcus Grimm and colleagues from Saarland University and the SRH Health School were able to show that a reduced supply of vitamin B12 leads to a reduced plasmalog level in the cell membrane. At the same time, it might be shown in cell culture experiments that the altered lipid composition of the membrane directly promotes the formation of harmful Aβ.
In addition to the positive effect on the fat composition of the membrane, vitamin B12 has a positive effect on the detoxification of the cell from free radicals and oxidative stress. These multiple effects of vitamin B12 on mechanisms central to Alzheimer’s disease make the vitamin an interesting target that might play an important role in the prevention and treatment of Alzheimer’s. Even if clinical studies have yet to confirm the results found in neuronal cells, Prof. Dr. habil. Marcus Grimm particularly advises people who are more likely to have a vitamin B12 deficiency to check it and to ensure they eat a diet rich in vitamin B12, possibly with the help of food supplements.
