Boosts the immune system, and is believed to be great for cognitive functions, reducing both stress and memory loss. In January 2017, the Independent newspaper ran an article with the headline, “A diet rich in thiamine can reduce your risk of getting Alzheimer’s disease, but some groups, such as the elderly, aren’t getting enough”. Levels of vitamin B1 are often deficient in individuals who consume too much alcohol, as it blocks its absorption. Vegetables, meat, fish, seeds and nuts are all good sources of thiamine.