Caloric restriction appears to prevent aging in the heart

Eating a very low-calorie yet nutritionally balanced diet is good for your heart. Studying heart function in members of an organization called the Caloric Restriction Society, investigators at Washington University School of Medicine in St. Louis found that their hearts functioned like the hearts of much younger people.

The researchers report their findings in the Jan. 17 issue of the Journal of the American College of Cardiology.

Ultrasound examinations showed that the hearts of people on caloric restriction appeared more elastic than those of age- and gender-matched control subjects. Their hearts were able to relax between beats in a way similar to the hearts in younger people. “This is the first study to demonstrate that long-term calorie restriction with optimal nutrition has cardiac-specific effects that ameliorate age-associated declines in heart function,” says principal investigator Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University in St. Louis and an investigator at the Istituto Superiore di Sanita, Rome, Italy.

Research on mice and rats has shown that stringent and consistent caloric restriction increases the animals’ maximum lifespan by about 30 percent and protects them against atherosclerosis and cancer, but human study has been difficult because the caloric restriction lifestyle requires a strict diet regimen, both to keep the total number of calories low and to insure that people consume the proper balance of nutrients.

The researchers studied 25 calorie-restricted individuals who had voluntarily been consuming a very low-calorie diet for an average of six years (consuming about 1,400 to 2,000 calories per day). They ranged in age from 41 to 65. The study compared their heart function to 25 age- and gender-matched individuals who ate a typical Western diet (about 2,000 to 3,000 calories per day).

In Western countries, heart attacks and strokes are responsible for about 40 percent of all deaths. Cancer causes about another 30 percent. According to Fontana, deaths in both groups can be attributed to what scientists call secondary aging. That’s the term used to characterize health problems that result from conditions such as high cholesterol, diabetes, high blood pressure and other preventable conditions that contribute to premature death. A healthy diet and regular exercise can reduce risks from secondary aging. But this study suggests calorie restriction with optimal nutrition can do even more.

Normal aging causes a decline in cardiac performance. Before it pumps blood to the rest of the body, the heart’s left ventricle fills with blood in a two-phase process. The first phase, which fills the ventricle in healthy hearts to about 80 percent capacity, is a passive, suction-mediated mechanism called early ventricular filling. The second phase is more active because the heart’s atrium contracts to completely fill the ventricle with blood. As we get older, less blood gathers during the passive, diastolic phase, so the atrium has to work harder to increase the amount of blood it forces into the ventricle.

“This decline in diastolic function is a marker of primary aging,” Fontana says. “Diastolic function declines in most people as they get older, but in this study we found that diastolic function in calorie-restricted people resembled diastolic function in individuals about 15 years younger.” It may even be possible that eating a very low-calorie, nutrient dense diet reverses declines in diastolic function. People in the study averaged only six years on the diet, but their hearts looked 15 years younger. So Fontana says it’s possible that the diet has a rejuvenating effect.

He notes that most study subjects had parents, grandparents or siblings who suffered heart attacks or strokes, making it unlikely that their genetic makeup is a contributor to the unusual healthiness of their hearts. In the case of one subject, both parents and younger brother currently take medication for high blood pressure and high cholesterol. Some subjects actually took medicine for high blood pressure themselves before they started on caloric restriction.

Fontana and colleagues previously have found that people on the very low-calorie diet have low blood levels of cholesterol and triglycerides, blood pressure scores equivalent to those of much younger individuals, a lower risk of developing diabetes and reduced body fat. These markers indicate less secondary aging.

In this study, Fontana’s team found that markers of inflammation indicative of primary aging were much lower in the caloric restriction group. Their serum levels of a pro-inflammatory molecule called tumor necrosis factor-alpha (TNFa) were significantly lower. They also had less C-reactive protein (CRP).

In addition, they had lower amounts of a substance called transforming growth factor-beta (TGFb), a molecule that both helps reverse inflammation and activates cells called fibroblasts to produce collagen. If, for example, you cut yourself, your body will work to repair the damage by activating fibroblasts to produce collagen and make scar tissue to heal the wound.

Fontana says the low levels of TNFa, CRP and TGFb, combined with evidence of “younger” hearts in people on caloric restriction, has led his research team to hypothesize that inflammation may play a key role in the aging process.

“Our hypothesis is that low-grade, chronic inflammation is mediating primary aging,” he says. “It’s not the only factor, of course — aging is a complex process. But we found less inflammation in these people — less TNFa, C-reactive protein and TGFb — as well as a more flexible ventricle in their hearts.”

Overweight and obese people also tend to have higher levels of inflammation than lean people. In this study, those on caloric restriction had about 7 percent total body fat. The control group had about 25 percent body fat.

“It’s very clear from these studies that caloric restriction has a powerful, protective effect against diseases associated with aging,” says co-investigator John O. Holloszy, M.D., professor of medicine. “We don’t know how long each individual will end up living, but they certainly have a longer life expectancy than average because they’re most likely not going to die from a heart attack, stroke or diabetes. And if, in fact, their hearts are aging more slowly, it’s conceivable they’ll live for a very long time.”

Members of the Caloric Restriction Optimal Nutrition Society try to consume between 10 and 25 percent fewer calories than average Americans while still maintaining proper nutrition. Fontana says that’s a very important point. People on this type of diet don’t simply consume less food. “Caloric restriction does not mean eating half a hamburger and half a pack of French fries and drinking half of a sugary beverage,” he says. “These people have very good nutrition. They eliminate calories by eating nutrient-dense foods.”

He says caloric restriction tends to resemble a traditional Mediterranean diet, which includes a wide variety of vegetables, olive oil, beans, whole grains, fish and fruit. The diet avoids refined and processed foods, soft drinks, desserts, white bread and other sources of so-called “empty” calories.

But Fontana and Holloszy don’t believe that caloric restriction is for everyone. Instead, they recommend a moderate reduction in calories, combined with moderate, regular exercise.

“If you change the quality of your diet by increasing the servings of nutrient-dense food and reducing — actually, it would be better to slowly eliminate — all of the servings of ’empty’ calorie foods, you improve your chances of living a healthier and longer life,” Fontana says.

Source: Washington University School of Medicine

Original article: Meyer TE, Kovacs SJ, Ehsani AA, Klein S, Holloszy JO, Fontana L. Long-term caloric restriction ameliorates the decline in diastolic function in humans. Journal of the American College of Cardiology, vol. 47:2, pp. 398-402, Jan. 17, 2006.


5 thoughts on “Caloric restriction appears to prevent aging in the heart

  1. kill your tv

    To realisitically sustain a low calory diet, supermarkets need to stock the right products at the right prices, and this should be urged by governments imo.

  2. My friend just told me about this. It turns out her father has actually been working on an experiment that’s related to this at the University of Wisconsin. It’s been going on for 30 years now. She also told me that there’s an island off Germany whos inhabitants, for the most part, live on a restricted calorie diet and they also have the highest percentage of people in the world who live to be over 100.

  3. flo

    This theory and kind of experience is not new, which by the way does not diminish the interest and value of it. I read Roy Walford years ago and was very interested in this theory. Overeating and overstimulating digestion metabolism is now related to oxydative process. cf the “Okinawa diet”. It consists in eating in small amounts things that are compatible with our metabolism. Which is after all only reason…

    It has occurred to me that with inapropriate food we have reduced our natural potential ; and we are now discovering that with a bit of sense we might recover it.

    I have personnally taken the habit of having 2 meals per day with healthy*, mainly raw food, and I feel really energetic and comfortable, even with less calories and fewer intakes. I don’t know how longer I might live, but this experience is very satisfying as for now!! I found out you can be greedy and eat things that are good for the body. By the way, althouh I am not a scientist, I read you with great pleasure. thanx for this blog.

    *I realize that the notion of “healthy” food demands to be a bit more specific. I think healthy and have : a veggie diet, with no dairy products, including seaweed, organic things. And some reading to learn how to have all the amino acids, fatty acids and stuff that we need, but that industrial food does not bring.

    In fact, reducing quantities should always be combined with enhancing nutritive quality, of course. 2 criteria that are impossible to separate. Will send you an email as soon as I rech the age of 100. 😉

  4. Eias

    I take this article with a bit of slat. A lower calorie diet isn’t beneficial for the heart just because it’s low in calories. The most significant variable in relation to health (and to improve all the markers of health eg Insulin Sensitivity, blood pressure etc) Is the quality of the food you eat. These people had better hearts not because they reduced calories, but because they made better food selections. I’m sorry calorie is not a calorie. 100 kcal from Broccoli is going to be far beneficial for you than 100Kcal form greasy fried chips. Calories are important up to a certain point. But the most important variable in regards to Health a body composition would be the food selections you chose. Of course switching to 1400-2000Kcal of healthy natural food will do your heart better than the 2000Kcal of the typical western diet (Fried food, high amounts of saturated fat, high amounts of processed carbohydrates and all the usual culprits). Not because of the drop in calories but because the food selection were much better. For example there plenty of information that has been back up by research that the antioxidants in vegetables and fruit will reduce the amount of free radicals in the blood stream. A lower intake of Trans fats and Saturated fat by omitting fried foods and replacing them with other good food chooses will also protect the heart.

    The Drop in calories is not the main reason. It’s the better overall food selections they made.

    Eat 1400Kcal of a typical western diet and believe me body will suffer just as much.

    1400kcal diet is not healthy in any way and should not be continued for long periods of m due to the sever restrictions of calories to the body. Instead eating 2500kcal (Or whatever your daily energy expenditure happens to be) would be better for the heart.

    It all boils down to eating your fruits and vegetables in the end.

  5. Pingback: Caloric Count by Nutrition and Vitamins

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s