Scientists worldwide have been searching for a cure for Alzheimer's for decades with little success. The devastating disease, which is the most common form of dementia, robs victims of their memories and makes them shells of their former selves. But research shows that common foods can offer protection.
A recent study published in the Journal of Agricultural and Food Chemistry found that blueberry vinegar restored cognitive function in mice. After scientists gave blueberry vinegar to mice with induced amnesia, they analyzed the rodents' performance in mazes and in an avoidance test, in which the mice would receive a low-intensity shock in one of two chambers.
The blueberry vinegar improved the animals' performance in both tests, suggesting that their short-term memory was improved.
Measurements of molecules in their brains showed that the vinegar reduced the breakdown of acetylcholine and also boosted levels of brain-derived neurotrophic factor, a protein associated with maintaining and creating healthy neurons.
But it's not the first study to indicate that blueberries are powerful weapons against Alzheimer's. A study at the University of Cincinnati Academic Health Center gave older adults with mild cognitive impairment either freeze-dried blueberry powder equivalent to a cup of fresh berries, or a placebo powder. After 16 weeks, those taking the blueberry powder showed an improvement in cognitive abilities when compared to those who took the placebo.
"The blueberry group demonstrated improved memory and improved access to words and concepts," said research leader Robert Krikorian, Ph.D. In addition, functional magnetic resonance imaging (fMRI) showed increased brain activity in those who took the blueberry powder.
Other foods that appear to offer protection against Alzheimer's include:
• Strawberries. A natural compound found in strawberries called fisetin reduces the mental effects of aging, say researchers at Salk's Cellular Neurobiology Laboratory. They fed 3-month-old mice that age prematurely a daily dose of fisetin with their food for 7 months. Another group of the prematurely aging mice was fed the same diet without fisetin. At 10 months, mice not treated with fisetin had difficulties with cognitive tests and also showed elevated markers of stress and inflammation, while those treated with fisetin weren't noticeably different from a group of untreated 3-month-old mice.
• Coffee. Caffeine in coffee boosts an enzyme in the brain that protects against dementia, say researchers from Indiana University. The enzyme, called NMNAT2, reduces the damage caused by harmful proteins in the brain.
Researchers found that NMNAT2 plays two protective roles in the brain: guarding neurons from stress and fighting misfolded proteins called tau that are linked to Alzheimer's and other neurodegenerative disorders. Tau proteins accumulate in the brain, forming plaques that are caused by aging. Earlier research found that mice altered to produce misfolded tau also produced lower levels of NMNAT2.
When researchers gave caffeine to mice modified to produce lower levels of NMNAT2, they began to produce the same levels of the enzyme as normal mice indicating that increased levels of NMNAT2 in the brain could create a "blockade" against neurological disorders.
• Alcohol. People who regularly consume moderate amounts of alcohol have a better chance of reaching the age of 85 free of dementia and other age-related cognitive impairments than those who don't drink, according to a study lead by the University of California San Diego School of Medicine.
Researchers found that among men and women 85 and older, individuals who consumed "moderate to heavy" amounts of alcohol five to seven days a week were twice as likely to be cognitively healthy than non-drinkers.
"This study shows that moderate drinking may be part of a healthy lifestyle to maintain cognitive fitness in aging," said lead author Erin Richard.
• Tea. Drinking a cup of tea every day cuts the risk of dementia in half in people aged 55 and older, says a study from the National University of Singapore. But in people who carry the APOE e4 gene, which raises the risk of developing Alzheimer's, risk is reduced by as much as 86 percent.
The researchers also discovered that the ability of tea to protect the brain isn't limited to a particular type of tea, as long as the tea is brewed from tea leaves, such as green, black or oolong tea.
"Tea is one of the most widely consumed beverages in the world," said researcher Feng Lei. "The data from our study suggests that a simple and inexpensive lifestyle measure such as daily tea drinking can reduce a person's risk of developing neurocognitive disorders in late life."
• Mushrooms. Several studies have found that mushrooms may have the ability to reduce or delay the development of age-related neurodegeneration. A study published in the Journal of Medicinal Food found that an extract of lion's mane mushroom (H. erinaceus) had positive effects on brain cells without being toxic, and also helped brain cells recover from damage and injury. Another study found that taking H. erinaceus extract for four months improved the cognitive function of aging Japanese men and women who suffered with mild cognitive impairment.
• Brussels sprouts. Retonic acid, a nutrient created in the body from vitamin A that's found in vegetables such as Brussels sprouts, tomatoes, and carrots, interacts with specific receptors in the brain, and may slow the formation of brain-destroying beta amyloid deposits.
• Fish. A study conducted at the University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine found that eating baked or broiled fish once a week improves brain health and cuts the risk of developing mild cognitive impairment (MCI) and Alzheimer's disease. Those who ate fish regularly showed almost five-fold increases in the volume of gray matter in several areas of the brain. The study also found increased levels of cognition in people who ate broiled or baked fish.
• Maple syrup. Researchers from the University of Toronto discovered that an extract found in pure maple syrup prevents the misfolding and clumping of two types of proteins prominent in Alzheimer's and other neurodegenerative diseases. The neuroprotective effects were similar to resveratrol, a compound found in red wine.