A new case of dementia is diagnosed every seven seconds, according to the paper published in today's Lancet, or 4.6 million each year.
By 2040 the numbers with dementia will have risen to 81.1 million, from 24.3 million today.
The authors, commissioned by Alzheimer's Disease International (ADI), warn that the illness is a 'ticking time bomb' for governments around the globe.
The figures will give further impetus to research into dietary approaches that can help prevent or slow the onset of the disease. A study published this month in the Archives of Neurology found that people who ate two or more fish meals a week had a slower rate of cognitive decline than non-fish eaters.
Further work is needed to understand this association and establish the mechanism if fish, or fish oils, do indeed help prevent the disease.
Other work has looked at the role of B vitamins in lower homocysteine levels that are linked to Alzheimer's disease, and herbals such as gingko biloba are also thought to offer some benefit to the ageing brain.
Preventative approaches would be of major advantage in lowering the costs associated with this disease, which occurs much more frequently in resource-poor countries.
There are 5 million people with dementia in China alone. This compares with 4.8 million in Western Europe and 3.4 million in North America.
And the rate of growth of dementia in the developing world is predicted to be three to four times higher than in developed areas. By 2040 there will be as many people with dementia in China alone as in the whole of the developed world put together, predicts the report.
Sucharithra Narayanan, senior research analyst for Frost & Sullivan, recently told NutraIngredients-USA.com that mental health was emerging as a new health platform being targetted by supplement makers.
But while manufacturers are starting to target the 30+ market, there are still very few mental health products on the market.
"More studies will drive the market," said Narayanan