LENGTHENING YOUR LIFE,
ONE BITE AT A TIME
Every year, more and more Americans are joining a special group: those who’ve lived to age 100. In the year 2000, only about 72,000 Americans were 100 or older. But by the middle of this century, that number could skyrocket to 834,000!
While most of us probably won’t join this group—on average, we can expect to live to our mid-to late-seventies—we certainly have a much longer life expectancy than people did in the early 1900s, when the average person didn’t live to be 50.
People are living longer partly because of our success in preventing childhood diseases like polio, as well as finding new treatments and prevention strategies for adult conditions such as heart disease. But it’s also because scientists are unlocking the secrets of aging itself. We’re finding out why our bodies break down and how to put the brakes on our own destruction. In the process, we’re expanding not only our life spans but also what scientists call our health spans—the number of years that we can expect to live in robust good health.
Researchers now know that one of the most important contributors to heart disease, wrinkles, cancer, arthritis, and many of the other problems of aging is the same process that causes a variety of objects around us to deteriorate. It’s called oxidation. The same air that gives us life is what causes iron to rust, fruit to turn brown, and your body’s cells to break down and age. Through a series of chemical changes, oxygen molecules in our bodies lose electrons, making them unstable. These unstable molecules are called free radicals.
In frantic attempts to stabilize themselves, free radicals pillage electrons from healthy cells throughout your body. Every time they steal an electron, two things happen: A healthy molecule is damaged, and more free radicals are created. Free radicals can damage vital genetic information within your cells, proteins in tissues throughout your body, and other components that keep you running properly. Unless this process is stopped, more and more cells are damaged every day, and your health pays the price.
To keep this destructive process under control, nature provides an enormous arsenal of antioxidants, which are compounds in foods that can stop free radicals from doing harm. Antioxidants come between free radicals and your body’s healthy cells, offering up their own electrons and preventing yours from being pillaged.
Even though your body naturally maintains its own antioxidant system, the antioxidants in foods give you a powerful boost of additional protection against free radicals. Three of the best known antioxidants are beta-carotene and vitamins C and E. Each of these nutrients has been shown to help protect you from age-related illnesses like cancer and heart disease. Although you can get some protection by taking antioxidant supplements, most doctors agree that the antioxidants in foods are a better choice and should be your first line of defense. That’s because fruits, vegetables, and other plant foods are brimming with antioxidants and other components that may work together as teams to protect you from disease. Some studies have found that vitamin E may help protect you from heart disease, and beta-carotene and selenium (a mineral that’s an ingredient in some of your body’s antioxidant enzymes) may help lower your risk of some cancers, but a lot of questions remain about the best ways to get these nutrients. As you’ll see in the antioxidants section (page 18), supplements of vitamins C and E are a good idea, but they shouldn’t take the place of a diet rich in fruits and vegetables. As far as beta-carotene is concerned, you should just get it from plant foods and skip the supplements.
The quickest way to get vitamin C is to have a glass of grapefruit juice, an orange, or a half-cup of red bell pepper slices—each provides more than 100 percent of the Daily Value (DV). For beta-carotene, deep green or bright orange fruits and vegetables are best. One sweet potato or a large carrot delivers between 12 and 15 milligrams, more than the 6 to 10 milligrams that some experts recommend we get.
Unlike vitamin C and beta-carotene, vitamin E is a bit trickier to get from foods because it’s found mainly in high-fat foods, such as vegetable oils, which we’d rather avoid. Still, you can get quite a bit of vitamin E from dry roasted almonds, with 1 ounce providing 7 milligrams, or 40 percent of the DV. Other nuts and seeds are also good sources of vitamin E. And some breakfast cereals offer nearly 100 percent of the vitamin E that you need each day in each serving.
Even though vitamins C and E and beta-carotene are important antioxidants, they’re hardly the only ones. Fruits and vegetables are loaded with plant compounds called phytochemicals, which can also have antioxidant abilities.
More than 9,000 phytochemicals have been identified to date, and many more are still unknown, experts say. Research has found that phytochemical extracts taken from fruits demonstrate anticancer power, and the combination of these chemicals in fruits and vegetables adds to their antioxidant and cancer-fighting ability.
While it’s important to eat well to prevent aging, you also need to adjust your eating habits as you age. As the years pass, your nutritional needs can change dramatically.
“As we age, we produce less saliva, and our swallowing reflexes slow down, so food may not be as easy to digest and swallow,” says Susan A. Nitzke, PhD, RD, professor in the nutritional sciences department at the University of Wisconsin in Madison. “Many of us experience changes in taste and appetite as we get older, so we may eat less. We also have less stomach acid, which means that we don’t digest foods or absorb some nutrients as well as we used to.”
An Israeli study that looked at 414 elderly patients in hospitals found that less than 20 percent were well nourished. The study also found that those with poor dietary habits had less successful outcomes from their visit to the hospital. But even with information from this and other studies available, doctors don’t always think to check for nutritional deficiencies in older adults. This is unfortunate because a simple lack of nutrients can easily be mistaken for a more serious illness. Nutritional deficiencies in older people can even be misdiagnosed as dementia.
Vitamin B12 is essential for maintaining healthy blood and nerve function. It’s also one of the nutrients that requires adequate amounts of stomach secretions in order to be absorbed. When acid levels decline, getting enough vitamin B12 can be a problem, says Dr. Nitzke. This is of particular concern for people who use antacids, she adds. You can get plenty of vitamin B12 in meats and other animal foods. Clams are the top performers: One small steamed clam provides an astonishing 9 micro-grams of vitamin B12, more than 100 percent of the DV.
In addition to a B12 deficiency, many people in their late fifties and older may be deficient in vitamin B6. Chickpeas and potatoes are great bets for bringing in the B6. A cup of chickpeas contains 1.1 milligrams, or slightly more than half of the DV. A baked potato provides 0.6 milligrams, or about one-third of the DV.
Another B vitamin that’s important for protecting the cardiovascular and nervous systems is folate, which is found in green vegetables, beans, and whole grains. A cup of canned pinto beans, for example, provides 144 micrograms of folate, or more than 33 percent of the DV. Asparagus is another good source of folate, with 1 cup of cooked fresh asparagus containing 263 micrograms of folate.
As bones get older, it’s essential to get extra calcium and vitamin D to prevent them from becoming brittle, says Dr. Nitzke. “Many older people believe that they can’t eat dairy foods because they’re ‘lactose intolerant,’ but in fact, most people can eat moderate amounts of dairy without trouble,” she says. Low-fat and fat-free (skim) milk, cheese, and yogurt are your best sources of calcium. One cup of fat-free yogurt contains 415 milligrams of this bone-building nutrient, or 41 percent of the DV. One glass of fat-free milk provides 302 milligrams, or 30 percent of the DV.
Iron is one of several minerals that can be tough to get in the correct amounts. Some people don’t get enough, while others get too much, says Dr. Nitzke. In fact, women’s need for iron declines in their later years after they stop menstruating.
To ensure that you’re getting the right amount of nutrients for your particular needs, Dr. Nitzke recommends talking to your doctor to find out whether or not you need to take supplements of certain nutrients, such as iron, calcium, vitamin D, and vitamin B12.
As you get older, make extra sure that the foods you eat are as nutrient-dense as possible, advises Susan A. Nitzke, PhD, RD, of the University of Wisconsin in Madison, and make empty-calorie foods like candy and sodas an even smaller part of your diet. Nutrient-dense foods are those that are loaded with vitamins, minerals, and phytochemicals, and relatively low on calories. As people get older, they tend to lose muscle mass, and consequently, they burn off fewer calories each day. Thus, if you eat the same amount of calories as you did when you were younger, you’ll gain weight! So, it’s more important to make sure that the foods you eat carry plenty of nutrients into your body, without extra calories.
Even though we may need to eat more of certain foods in order to live longer, researchers are finding that the opposite can also be true: People who eat less may live more years.
Researchers have long known that a concept called “calorie restriction”—essentially, taking in fewer calories—extends the lives and helps slow down age-related diseases in a variety of creatures, including worms, flies, and mice. It’s also been shown to improve some markers of aging in monkeys, such as their body-fat percentage and levels of free-radical damage.
Now scientists are working to learn more about how calorie restriction may help humans age better, says George Roth, PhD, a gerontology researcher and CEO of the Maryland-based company GeroScience.
Human research is taking two approaches, he says: observations of people who voluntarily restrict their calories for many years for the potential life-lengthening results, and controlled experiments in which subjects are instructed to restrict their calories for a shorter period.
A Louisiana State University study followed 48 people for 6 months as they either followed a normal diet or different types of calorie-restricted diets. It found that prolonged calorie restriction can lower people’s fasting insulin levels and their body temperature, which are both markers of longevity.
Experts think that calorie restriction “resets” your metabolism so it works more efficiently, and your body shifts its focus from growth and reproduction to long-term survival, says Dr. Roth. And when you take in fewer calories, your body naturally produces fewer free radicals as it turns food into energy. Thus, you have less oxidative damage.
However, it’s hard for humans to reap the benefits from calorie reduction that lab animals have shown. Tests on rodents have cut back their calories by more than 30 percent, and tests on monkeys lower their calorie intake by about 30 percent, says Dr. Roth. “For those of us who like to eat, that’s probably not going to be a viable strategy.” In addition, drastically reducing your calories without medical supervision can leave you malnourished.
For now, a good way to potentially get some benefit from calorie reduction is to make sure that you eat a “prudent” diet that provides the nutrients you need without excessive calories, he says. If you do decide to restrict your calories, talk to your doctor to make sure your diet meets your nutritional needs.
A 2004 study in the Journal of the American Dietetic Association listed common foods and the amount of advanced glycation endproducts (AGEs) they contained. Here’s a quick look at some foods high and low in AGEs to give you some sense of how to steer your diet to cut down on the amount you consume. They’re measured by AGE kilounits per serving.
| High Foods | AGE per Serving |
| Frankfurter, broiled for 5 minutes | 10,143 |
| Chicken breast with skin, breaded and oven-fried for 25 minutes | 8,965 |
| Whiting fish, breaded and oven-fried for 25 minutes | 7,897 |
| Pizza, thin crust | 6,825 |
| Pork sausage, microwaved for 1 minute | 5,349 |
| Low Foods | AGE per Serving |
| Canned red kidney beans | 191 |
| Raw onion | 36 |
| Canned corn | 20 |
| Bran flakes | 10 |
| Banana | 9 |
Researchers are discovering that substances called advanced glycation endproducts—or AGEs—may be linked to a variety of age-related problems including wrinkles, cataracts, and atherosclerosis (fatty deposits blocking your arteries). AGEs result from sugar attaching to proteins, which causes proteins in your tissues to develop unwanted linkages between them, altering their ability to function normally. They also contribute to extra inflammation and oxidative damage in your body.
AGEs can develop within your body, particularly when you have high blood sugar, and you can also take them in through the foods you eat. Research has shown that foods that are particularly high in AGEs include meats that have been cooked at high temperatures by methods such as frying or broiling.
To cut down on AGE-related damage in your body, it’s a wise idea to keep your blood sugar in a normal range. If you have diabetes, be sure to keep your blood sugar well controlled. If you have prediabetes, talk to your doctor about using diet and exercise to lower your risk of developing full-blown diabetes.
And be sure that your diet relies heavily on foods that are low in AGEs, such as fruits, vegetables, whole grains, fish, and low-fat dairy. Be careful with foods high in AGEs, such as meats cooked at high temperatures, processed foods, and full-fat cheeses, and eat them more sparingly.