6. Take the salt shaker off the table
Doctors have warned for years that too much salt is bad for the heart. Now, a study by Canadian scientists has found that older people who eat too much salt and also fail to exercise are at increased risk for cognitive decline. According to the U.S. Department of Agriculture, if you're 50-plus, or suffer from high blood pressure, your salt intake should max out at no more than 1,500 milligrams a day.
Tip: Liven up your dishes with herbs and spices instead of processed gravies, condiments and sauces, which tend to be high in sodium. Many herbs and spices — including ginger, parsley, oregano, basil and black pepper — are not only flavorful but high in antioxidants.
Curcumin, a key component of turmeric, found in curry powders, is believed to reduce amyloid plaque buildup. The brain benefits of these haven't been confirmed, but they're all better sources of flavor than salt.
7. Reduce sugar and simple carbs
So many studies have shown a link between dementia and obesity and high blood sugar at midlife that Alzheimer's disease has been dubbed "diabetes Type 3." Last fall, Mayo Clinic scientists found that people age 70 and older who ate a lot of simple carbohydrates (found in refined flours and rice) and sugar were nearly four times more likely to develop mild cognitive impairment than those who ate a healthier diet.
Your body does need a certain amount of sugar (glucose) to function properly. But a diet packed with sugar and the simple carbs regularly sends blood glucose soaring. High glucose levels, in turn, block blood flow to the brain, depriving it of the energy it needs to generate new neurons. Too much glucose has also been implicated in the formation of the tangles of Alzeimer's disease.
Tip: You're already likely eating more sugar than you need, since it's added to many beverages and foods during processing, so don't add it to your coffee or sprinkle it on already sweet fruits. Instead of sodas, sports drinks and sweetened coffee drinks, drink water. If you eat canned fruit, make sure the label says "in its own juice," not sugary syrup.
The easiest way to cut down on simple carbs is to opt for whole grain rice, breads and pastas. Whole grains are digested more slowly, so glucose also is released more slowly into the bloodstream, keeping you mentally alert longer. "Whole" or "whole grain" should appear on the label before the name of the grain.
Don't be fooled by phrases on labels that sound healthy but don't really mean much, such as "100 percent wheat,'' "cracked wheat," "multigrain" or "stone ground." Even better: Buy wheat berries, bulgur or farro — whole grains that haven't yet been ground into flour.
Next page: Can supplements make you smarter? »