Alzheimer’s is the most common type of dementia and is the sixth leading cause of death in the U.S. It is also the third leading cause of death among older adults. This deadly disease is associated with memory decline and brain shrinkage.
Comprehensive reviews on the progression of Alzheimer’s disease suggest that low levels of folic acid and vitamin B12 and high levels of homocysteine – an amino acid obtained from eating meat – are associated with an increased risk of Alzheimer’s disease. A review of 77 cross-sectional studies that included 34,000 participants and 33 prospective studies with more than 12,000 participants showed that the levels of homocysteine and B vitamins are associated with cognitive impairment or the development of dementia. Elevated blood levels of homocysteine are caused by inadequate dietary intakes of vitamins B2, B6, B9, and B12, so taking vitamin B supplements can lower homocysteine levels and the risk of Alzheimer's.
Researchers from Harvard University discovered that high homocysteine levels can triple the risk of heart attack. Homocysteine also increases the risk of stroke and is associated with other health problems, such as atherosclerosis, erectile dysfunction, kidney disease, peripheral vascular disease, and retinopathy.
When homocysteine is present in large amounts, the excess spills out of the cells and enters the bloodstream. From there, it can damage the arteries by increasing the risk of plaque buildup and the onset of atherosclerosis – the narrowing and hardening of the arteries. Vitamins B6, B12, and B9 can regulate homocysteine levels and lower the risk of cardiovascular disease.
In addition, vitamin B2, also known as riboflavin, works as an antioxidant that combats free radicals and prevents the onset of heart disease. This B vitamin is also linked to red blood cell production which is important for the proper distribution of oxygen throughout the body.
Another B vitamin called niacin (vitamin B3) is known to support heart health by promoting the production of high-density lipoprotein (HDL) or "good" cholesterol. (Related: B vitamins lower homocysteine levels and provide significant stroke risk reduction.)
B vitamins are water-soluble, which means they cannot be stored in the body. Because of this, a person's diet must be able to supply these vitamins every day. While B vitamins are available in supplements, it is best to get them directly from food sources.
Vitamin B5 helps the body obtain energy from food and aids in hormone and cholesterol production. Vitamin B7 or biotin is important for carbohydrate and fat metabolism and the regulation of gene expression. Vitamin B7 can be obtained from foods like salmon, eggs, and yeast.
Pregnant and breastfeeding women, older adults, vegetarians and vegans, and people with medical conditions like cancer, celiac disease, Crohn’s disease, anorexia, or hypothyroidism are more likely to be deficient in B vitamins, so taking B-complex supplements is a must for them.