Most people probably fear mental decline in old age. Experts assume that 1.5 million people in Germany will suffer from Alzheimer’s dementia by the middle of the century. So it’s no surprise that geriatric psychiatrist Olivia Okereke from Harvard Medical School is convinced that the results of a study in which she participated will attract a lot of attention among seniors. Ultimately, this provides evidence that vitamin supplements could support “better cognitive aging,” according to a press release. According to the study, nutritional supplements could delay the decline in mental performance by two years.
Experts are also paying attention to the result – especially because previous studies have found no protective effect through nutritional supplements, regardless of whether they were multivitamin preparations, minerals or a combination of both. An analysis of eight studies in 2018 found no evidence that such preparations could delay dementia. This was reported at the time by a team led by Naji Tabet from the Brighton and Sussex Medical School in the Cochrane Database of Systematic Reviews.
“So far everything has been negative,” says the President of the German Society for Neurology (DGN), Lars Timmermann, who heads the neurology clinic at Marburg University Hospital. “There was no evidence that such preparations were effective.” Dorothee Volkert from the University of Erlangen-Nuremberg also emphasizes this. “There have been a lot of supplementation studies with a wide variety of nutrients and nutrient combinations,” says the professor of clinical nutrition in old age. “All the results were disappointing. It is difficult to say why an effect was found here of all places.”
“It’s an interesting observation, but nothing more.”
In the current study – the so-called Cosmos study (COcoa Supplement and Multivitamin Outcomes Study) – more than 21,000 participants aged 60 and over received either dummy preparations or pills that contained micronutrients such as vitamins. Over the course of two years, almost 500 of them completed cognitive tests. In the end, the team found a slightly smaller decline in so-called episodic memory in those people who also received multivitamins. It stores memories from your own life such as appointments. “This part of memory is highly relevant to everyday life,” says Timmermann. Other cognitive abilities such as attention did not benefit like the team around Olivia Okereke in American Journal of Clinical Nutrition writes. Nevertheless, the article says: The effect corresponds to cognitive aging delayed by two years.
The team emphasizes that this is now the third study to demonstrate the benefit of dietary supplements in protecting against dementia. However, the other two studies are also parts of the Cosmos study. This was financed, among others, by the food company Mars Incorporated – which, among other things, sells dietary supplements made from cocoa extracts, as are also examined in the Cosmos study.
In each of the other two sub-arms, more than 2,000 people were surveyed about their development either online (Cosmos-Web) or by telephone (Cosmos-Mind) – with generally similar results. The special thing about the Cosmos Clinic study now presented is that it is based on clinical tests, not on unreliable surveys via the Internet or telephone.
The group emphasizes that the evaluation of a total of more than 5,000 people in the three parts of the study clearly shows that memory and mental strength can benefit from dietary supplements. “The meta-analysis of three separate studies provides strong and consistent evidence that daily multivitamins consisting of more than 20 essential micronutrients help to impede memory loss and slow cognitive decline,” lead author Chirag Vyas of Harvard Medical School said in a statement Quoted from his university.
René Thyrian from the German Center for Neurodegenerative Diseases in Greifswald is skeptical about this statement: “A statistically significant effect was found in the study,” says the dementia expert. “But it is questionable whether this has any meaning in everyday life for those affected.” Thyrian is particularly disconcerted by the claim that the effect corresponds to a slowdown of two years: “In my opinion, that is not supported by the data.”
Lars Timmermann is also skeptical: “The test procedures were good,” says the DGN president, “but the number of participants was very low to detect such mild effects.” The cause of the observed effect is unclear. “It’s an interesting observation, but nothing more.” Based on this result, nutrition expert Dorothee Volkert would also not recommend taking multivitamin preparations: “Based on a single study, I would not recommend it.”
The group around Vyas, on the other hand, is convinced that the result is plausible. A lack of nutrients can increase the risk of cognitive loss in seniors, but conversely they could benefit from combinations of vitamins and minerals. However, uninvolved researchers do not interpret the results quite so clearly. After all, even if the exact connections between the development of Alzheimer’s, by far the most common form of dementia, have not been conclusively clarified, people can minimize their individual risk, as Thyrian emphasizes: balanced nutrition, little alcohol, no smoking, exercise and have any high blood pressure controlled. And hearing loss should be compensated for with a hearing aid – not only to avoid social isolation, but also to be able to register acoustic stimuli from the environment.
Lars Timmermann also emphasizes: “If we did more for prevention, we could delay 40 percent of dementia cases.” He also advocates eating a balanced diet, exercising and controlling risk factors. If there are signs of dementia, you should always check neurologically to see whether there is a treatable cause, he says, pointing to Lyme disease or thyroid problems as examples. The expert advises against taking dietary supplements on your own. You should first clarify with your family doctor whether there is actually a nutrient deficiency. “You have to be very careful with too much vitamin,” emphasizes Timmermann. “You can cause yourself significant harm by doing this.”