In November 2018 researchers from France published their review on dietary supplement intake in the elderly. They stated that studies in older people using multivitamin supplements long-term had shown a potential reduced risk of developing age-related diseases. In addition, older people using omega-3 supplements had increased blood levels of omega-3 polyunsaturated fatty acids which appeared to be associated with fewer cardiovascular deaths. It had also been noted that when older people combined dietary protein supplementation with exercise there was a reduced loss of leg strength. However, some studies involving the use of purified flavonoids showed improved cognitive function, whereas no such effect was observed in a significant number of other studies.
Walrand S et al. Dietary supplement intake among the elderly: hazards and benefits. Curr Opin Clin Nutr Metab Care. 2018 Nov;21(6):465-470.