Great Food for Your Body, Heart and Brain

By Lauren Aaronson

When I was 7 years old, I read in the sequel to Little Women that oatmeal made you smart. So I demanded that my mother feed me oatmeal on the day of my spelling test. I ate oatmeal before every test I ever took from elementary school through grad school. I even made my mother mail me oatmeal when I had a big exam during my semester abroad; later, I thanked both my mom and Quaker Oats: I got a perfect score.

My mother chalked up my success to superstition. But I still believe that the oatmeal itself made a difference. And now it looks like science will prove me and the book's heroine, Jo March, right.

Like just about anything we eat, oatmeal influences the way our brains function. Food, after all, gives our bodies the raw materials to build everything from noses to neurons and the ability to operate them efficiently. Some materials make for better outcomes than others, as a flood of recent studies attest.

Fibrous oatmeal, for instance, slowly and steadily ushered the cereal's cargo of carbohydrates into my system as glucose. My brain snapped up that sugar from the bloodstream and deployed it both as fuel to power its operations and as a component of key chemical messengers, the very neurotransmitters that carry thoughts and memories. Oatmeal revved up my brain and stabilized my mood, memory and concentration -- all without the spiky highs or crashing lows of foods like candy bars that dump their payload of sugar quickly.

Unbeknownst to me, my morning oatmeal also supplied ferulic acid. A potent antioxidant lurking in the germ and bran of grains, ferulic acid appears to be a general protector of brain cells, keeping them supple and responsive by nullifying toxins that stiffen them with age -- and possibly even reversing some of the cognitive decline of aging.

A bowlful of gruel is hardly the fashionable food of choice. But oatmeal sits, however lumpily, at the cutting-edge of a revolution in the way we think about food. Nutritional science is demonstrating that some edibles -- call them functional foods -- do far more than provide essential nutrients for normal maintenance and development. They furnish biologically active components that create high-class physiologic effects, such as disarming toxins, and impart health benefits. They have the capacity to reduce disease risk -- ''with minimal involvement of health professionals,'' the nation's food scientists say.

"Food has a greater impact on health than previously known," declares a report released in March 2005 by the Institute of Food Technologists. "New evidence-based science linking diet to disease and disease prevention" has "blurred the line between food and medicine." Nutrients influence body processes at the molecular level, turning our very genes on and off. The emerging understanding of molecular nutrition, says the IFT, "has the potential to revolutionize diet, nutrition and food products, and health care."

Scarcely a week goes by now when scientists don't make some discovery about the health-enhancing properties of food, from the cancer-fighting abilities of brussels sprouts to the anti-Alzheimer's effects of anchovies. For the nation's nutritional scientists, that presents a significant problem: There's no longer a clear boundary between foods and drugs. In some cases -- antioxidant-rich cranberry juice, for example -- the health claims for nutrients actually have to be soft-pedaled, lest they trigger regulations that require foods to undergo the same approval process as drugs. The IFT is urging the Food and Drug Administration to adopt reasonable procedures for demonstrating safety and efficacy of foods that are, well, more than foods -- what some people call "nutraceuticals."

Oatmeal in fact inspired one of the earliest drug-like claims for a food. In 1997, the Quaker Oats box began touting the cholesterol-lowering effects of the cereal after the FDA evaluated studies linking whole grains to reductions in the blood fat.

Food-boosted health now goes way beyond the heart, all the way to the head. Of course, brain virtuosity also hinges on physical and mental activity, as well as on factors not yet understood. But there's no question that proper feeding primes our brains to reach their fullest potential and maintain their wits for a lifetime.

Everyday nutrients are involved in a dazzling array of sophisticated actions at the molecular level. Nevertheless, the latest research on functional foods highlights six strategic lines of defense on the route from mouth to mind. Some functional food superstars make use of more than one mechanism.

The Telltale Heart: Jogging the Mind
Food doesn't have to reach your head to improve your memory. "There's getting to be a general consensus that what is good for your heart is good for your brain," says James Joseph, a neuroscientist at the Human Nutrition Research Center at Tufts University in Massachusetts.

Your brain accounts for just 2 percent of your body weight, but it eats up about 20 percent of your oxygen intake. Since it's such a hungry organ, your brain depends on a strong cardiovascular system to ferry in supplies. Healthy blood pressure and cholesterol levels keep your arteries clear, leaving them free to transport nutrients to your brain. Clear arteries also reduce risk of stroke, which kills neurons when a blocked or ruptured vessel cuts off blood flow.

Any steps you take to improve the delivery of oxygen to your heart -- that two-mile jog, for example -- automatically pump up your brain. The steps include well-known dietary cardiovascular strengtheners like fiber-rich foods, which lower cholesterol; leafy greens rich in B vitamins and folate, which reduce levels of vessel-harming homocysteine; omega-3 fatty acids, which may prevent arrhythmias; and exercise, which reduces blood pressure, helps control blood-fat levels, and keeps weight in check.

Brain-boosting steps may also include downright counterintuitive measures. Women who have one alcoholic drink a day -- be it wine, beer or that cosmopolitan -- have a much lower risk of cognitive decline than either teetotalers or heavy drinkers, according to a recent study at the Harvard School of Public Health. It's the effect of alcohol on your blood. By elevating levels of "good" cholesterol, thereby lowering the risk of stroke, small amounts of alcohol may protect both your cardiovascular system and the brain it serves.

Sweet Memory: Oat Cuisine
Your brain is the only organ that draws nearly all its energy from glucose, the sugar in ripe grapes and honey, for example, and produced in quantity from pasta and other starchy carbohydrates. That sweet substance also fuels the formation of sweet memories, or at least reliable ones.

Lab experiments reveal that a dose of glucose-sweetened lemonade boosts recall of events, words, movements, drawings and faces, among other things, with effects lasting long enough to get you through a two-hour exam. Other research extends these findings from doctored drinks to regular food. Any carbohydrate-rich dish, such as a bagel or a thick slice of bread, may prompt similar memory enhancements for healthy adults.

While a candy bar provides a burst of brain energy, that flash quickly subsides and your blood-sugar level plummets, fueling the desire for another ride on the blood-sugar roller coaster. Both body and brain may do better with foods that score low on the glycemic index, a rating that measures how fast and how high a food increases blood glucose levels after it's consumed. Because they surrender their starches slowly, such fiber-rich foods as barley, beans and Jo March's oatmeal all provide a steadier -- and less fattening -- stream of energy than a Snickers bar.

Over the long term, less-fattening foods benefit body, blood and brain. A healthy weight helps prevent diabetes and impaired glucose tolerance, conditions associated with a decline in cognitive capacity. Compared to glucose-intolerant adults, people with a well-maintained energy supply hang on longer to their memories.

Signal Savers: Salmon Tales
Neurons, the main cells in your brain, are a bit like New York City: bustling with activity but walled off from the outside by rivers and membranes, respectively. For neurons to survive and contribute to the world, their walls need to let vital goods pass in and out.

A healthy cell in its prime has a supple membrane that allows important molecules to cross unimpeded, as if over the Brooklyn Bridge at midnight. As a cell ages, though, the materials in the membrane stiffen and make it less pliable. With bridges and tunnels closing down, toll booth-like receptors on the surface of the membrane don't collect as many incoming signals from message-carrying neurotransmitters as they should. You might feel such effects as sluggishness in learning the new and recalling the old, poor sleep, lowered pain threshold. Impaired body-temperature regulation could make you uncomfortable in ordinary settings.

The neuronal membrane is made up primarily of fats, the very same fats that you fork into your mouth. In fact, your brain has your body's second-highest concentration of fat, right after actual fatty tissue -- think butt and belly -- itself.

The kinds of fats in the foods you eat influence the character of your cell membranes. Cholesterol and saturated fats harden membranes, while essential polyunsaturated fatty acids -- omega-3s and omega-6s -- render them supple. A healthy mix of essential fatty acids seems to enhance learning by facilitating the smooth passage of signals through neuronal membranes.

Most Americans take in plenty of omega-6 fatty acids, via nearly ubiquitous soy and corn oils. But the typical American diet lacks sufficient omega-3s, notes David I. Mostofsky, a neuroscientist at Boston University. Within days after you add omega-3s to your diet, membranes are rejuvenated in composition.

Salmon and other coldwater fish and (perhaps less appetizingly) algae are rich sources of the omega-3 fats that your body can utilize directly from food -- known as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Walnuts and flaxseed are rich in a related substance, alpha-linolenic acid, which can be converted more or less efficiently to EPA and DHA in the body. Human breast milk is rich in all three fatty acids, and DHA provides critical insulation for an infant's developing nervous system.

Under the direction of Gregory Cole, the Alzheimer's Disease Research Center at UCLA, is preparing to test whether omega-3 fatty acids can deter Alzheimer's disease, the No. 1 cause of cognitive decline. So far, the fats have successfully fended off dementia in lab rats.

Tests of omega-3s are underway for a variety of other conditions, ranging from sleep disorders and anxiety to depression and impaired immune responses.

"Nobody fully understands why they should have so many different functions," muses Mostofsky. Perhaps it's because the neuronal membrane controls access to all other nerve-cell functions.

Next: Meat and milk, the power-makers >