Aging Well: Diet and Science
I received a lot of feedback and interest on the recent articles about diet and aging. Thank you for your calls. What else can we do to keep our brains in good shape as we age? As we know, diet and stress have both been shown to have a significant effect not only on our health in general, but specifically on the health of our brains. Let's explore some of the current research on diets and how we got to the understanding of the implications of diet on our aging well.
Does consuming fewer calories lead to a longer, healthier life? We do not know for sure because human experiments on calorie restriction are very difficult to perform, but there have been a number of animal experiments that have found that significantly restricting the number of calories that an animal eats does significantly extend their lifespan- sometimes by a lot.
In addition, there are a number of scientific studies suggesting health benefits from eating the way people living around the Mediterranean Sea in the 1960s did. The Mediterranean diet focuses on fruits and vegetables, nuts and legumes (such as beans, peas, and lentils), olive oil, fish, and whole grains, as well as moderate amounts of alcohol, particularly red wine.
One of the most famous studies was the so called Seven Countries Study started in the late 1950s at Minnesota University with the help of a number of scientists from around the world. The study investigated the diets and lifestyles of more than 10,000 people in seven countries and followed them over time to examine associations with cardiovascular disease. The study found that dietary patterns were associated with lower rates of heart disease and longer life. When they looked specifically at the elderly in the sample, they found that older people eating a Mediterranean style diet lived the longest and also suffered the least cognitive decline and depression. The study also found that over time, the lifestyle and diet of the people in the Mediterranean countries began to change. They began to eat a diet that was more similar to people in the United States and became less physically active. As their lifestyle changed, their risk of heart disease began to rise. Similar results have been reported in a number of other studies. Basically, people who ate a Mediterranean diet tended to live longer, healthier lives than people who did not. The diet and health study also reported that eating a Mediterranean diet was associated with less cardiovascular disease and cancer.
Similar results have been reported for a related style of eating known as the DASH (Dietary Approaches to Stop Hypertension) diet, which was specifically designed by doctors in an attempt to prevent and control high blood pressure. Compared with a typical American diet, the DASH diet involves a lot more fruits and vegetables, low fat dairy products, whole grains, fish, poultry, and nuts. It is also significantly lower in red meat, sweets, and sugary drinks.
The DASH diet was tested in a large multicenter controlled study in the 1990s. The DASH diet led to significantly lower blood pressure than in a control group diet. In fact, differences in blood pressure were starting to be seen after just two weeks on the diet. A subsequent experiment found that reducing the sodium content in the DASH diet led to even greater reductions in blood pressure. Like the Mediterranean diet, the DASH diet has also been shown to improve cognitive function.
Recently, a group at Rush University in Chicago studied a related diet called the MIND diet, which is a hybrid of the Mediterranean and DASH diets. The researchers found that people eating a MIND-like diet were more than 50% less likely to develop Alzheimer's disease than people who ate other diets. Even people who only followed the diet moderately were still about 35% less likely to develop the disease.
Most scientists agree on some parts of why these diets work but not others. For example, scientists often point out that fruits and vegetables contain lots of vitamins and minerals and are high in antioxidants which can help neutralize free radicals, which are thought to cause a lot of cellular damage associated with age. But what is undoubtedly more important is what people following these diets do not eat. Most Americans eat a lot of processed food. Eating this way is associated with heart disease, stroke, diabetes, and cancer. Naturally, it is also associated with a shorter life.
There are things we can do to change our environments so that they nudge us to eat in healthier ways. One of the most important changes is based on what we bring home from the grocery store. If we bring home soda, potato chips, and ice cream, then that is what we will tend to eat; conversely, if we bring home fresh fruits and vegetables, fish, beans, and other healthy foods, then we will tend to eat better.
Another idea is to only make as much food as you intend to eat at each meal. Americans often make more food than they need and then save the rest for leftovers. But doing so also makes it easy to eat more than you actually want. You might also consider using smaller plates at meals.
One of the most important ideas might be the most basic: eat when you are hungry, but then stop eating when you are full. Do not eat when you are not hungry. This is much more difficult than people truly realize. This is where we need to address the role stress plays in the equation.
Next time, we will pick up on this last point and talk about the effect stress has on our aging minds and bodies and the concept of being "mindful."
|Nora DeVoe is a Gerontologist specializing in Eldercare and Caregiver issues. She may be reached at (716) 667-7299.|
Dr. Nora is a ....