Generally, what's harmful to your heart also is also harmful to your brain. Make no mistake about it: While fried potato skins are busting your buttons, there's also a portion that gets shuttled up through your arteries to your gray matter.

Saturated fats, for example, clog arteries that lead to your brain, putting you at risk of stroke, while omega-3 fatty acids—the good fats found in fish—are helpful for your brain because they help keep your arteries clear. They also alter your neurotransmitters and reduce depression.

These are the best foods to keep your brain and your RealAge young:

Nuts
Nuts contain monounsaturated fats to keep your arteries clear, as well as levels of precursors of serotonin to boost mood.
Recommended Amount: 
1 ounce of nuts a day is just right. (More is fine, but be careful of calorie overload.) An ounce is about 12 walnuts or 24 almonds.

Fish (especially wild salmon, whitefish, tilapia, catfish, flounder, mahi mahi)
Fish contain artery-clearing omega-3 fatty acids.
Recommended Amount: 
Aim for 13.5 ounces of fish a week, or 3 servings, each about the size of your fist.

Soybeans 
Soybeans contain heart- and artery-healthy protein, fiber, and fats.
Recommended Amount: 
1 cup of soybeans a day.

Tomato juice and spaghetti sauce
Tomatoes contain folate, lycopene, and other nutrients to keep arteries young.
Recommended Amount: 
8 ounces a day of juice or 2 tablespoons of spaghetti sauce a day.

Olive oil, nut oils, fish oils, flaxseed, avocados
All of these foods contain heart-healthy monounsaturated fats.
Recommended Amount: 
25 percent of daily calories should be healthy fats.

Real Chocolate (at least 70 percent cocoa)
Real chocolate increases dopamine release and provides flavonoids, which keep arteries young.
Recommended Amount: 
1 ounce a day (to replace milk chocolate).