Dr. Carol L. Jong, PhD, RD, is a graduate of the UCLA School of Public Health, has a doctorate in nutrition from the University of California, Davis, and is a Registered Dietitian. Dr. Jong is an educator and speaker, and has served as a television nutrition expert, call-in radio show host, national seminar speaker and university professor. (cj@drjong.com)
You’ve said that calorie restriction is the single most important dietary change that increases life expectancy. Why?
In controlled animal and laboratory experiments, caloric restriction has been consistently shown to extend life span across several species: rodents, primates, fruit flies and fish, to name a few. Gerontologists recognize calorie restriction as the single most effective dietary change that can enhance longevity. Eating less, animal studies indicate, can increase life expectancy by one-third—the human equivalent of 40 years to a mammal’s life. It can also delay age-related declines in immune responses and diminish the risk of developing diseases associated with aging such as heart ailments, cancer, kidney disease and arthritis. Instead of becoming ill, many of the animals on restricted diets eventually simply die of old age.
Although anecdotal, there are personal testimonials, such as a 2009 interview with Montana resident Walter Breuning, who at 113 years was the oldest man in the United States. Breuning revealed his secret to longevity as eating just two meals a day, which he had done for the past 35 years. As Breuning told USA Today in 2009, “I think you should push back from the table when you’re still hungry.”
There is epidemiological evidence for the power of calorie restriction. The Okinawans, citizens on the southern tip of Okinawa, Japan, are the longest living population in the world, with a life expectancy of 79.0 for males and 86.1 for females. In addition, this population boasts the largest number of centenarians than anywhere in the world (37 per 100,000—twice the occurrence compared to the U.S.). Among their many healthy holistic practices (e.g., regular green tea and fish consumption, spirituality, family relations and low-stress living), Okinawans practise Hara hachi bu, the convention of eating until 80 per cent satisfied. The widely practised cultural custom derives from the Confucian philosophy to value simplicity and turn from excess.
Mechanistically, why would calorie restriction contribute to longevity? Beyond the obvious—less overweightness and obesity and related disease consequences such as hypertension, cancer and coronary heart disease—there may be a greater underlying mechanism at work. Researchers have recently discovered that calorie restriction enhances the activity of sirtuin, a protein that repairs damaged genetic material or DNA. One could extrapolate that a long-term benefit is to reduce the body’s risk of mutations and precancerous events, thereby enhancing longevity.
One of the main components of the Okinawan diet in Japan is grazing (eating six small meals a day). Is it practical or possible to change retirement residence meal planning to incorporate this model? What is the benefit of it?
Unfortunately, the opportunity for grazing within an retirement residence creates a larger labour burden upon the food service staff, particularly for facilities with a large population of high-assistance residents. With more independent residents, the idea of self-serve snacks, which serve as small meals, may help resolve the additional labour issues. The adoption of the grazing model could result in better diabetic glucose control, reduced obesity and improved overall health, an investment that can ultimately reduce medical needs and services of staff.
Seniors don’t always eat enough (or enough of the right foods) due to things like illness or decreased sense of smell or taste, so some can be malnourished. How could the idea of eating only until 80 per cent satisfied be adapted successfully for North American seniors, many of whom have not grown up with this concept?
An often-overlooked principle of nutrition is that it is not absolute. Rather than black-and-white rules, nutrition is interwoven with shades of grey, exceptions and caveats. Likewise, the longevity calorie restriction model is not appropriate for all populations. Infants, children, adolescents and teens would be excluded from this recommendation, since we do not want to compromise growth or development. Furthermore, individuals experiencing catabolic illness or other disease states would consider calories and protein as their nutritional priorities, rather than calorie restriction. Similarly, the elderly population at risk for malnutrition should consider the calorie restriction model on an individual basis.
My mentor and renowned gerontologist, Roy Walford (UCLA School of Medicine, pathology), was a highly respected researcher in the area of longevity and calorie restriction. Realizing that the recommendation to restrict calories by 30 per cent could compromise the nutriture of certain populations, Dr. Walford carefully described the calorie restriction practice as “undernutrition without malnutrition” in his book Maximum Life Span In other words, a longevity diet contains all required nutrients, but about one-third fewer calories than are needed to maintain “normal” body weight. We see something similar in the Okinawan diet—foods that are high in nutrient density become ever more significant—after all, they have a smaller budget of fewer calories through which to satisfy their nutritional needs.
What is the most important thing that retirement residences can do to improve the dining experience for their residents?
We often lose sight of the fact that food is trendy, and the customs and familiarities we grew up with are more likely to be accepted. For instance, many of today’s elderly population were raised with traditional comfort foods—for instance, pot roast, potatoes and macaroni and cheese. When food is familiar, and generationally/culturally relevant, it is more likely to be enjoyed. Moreover, sensitivity to these details is much appreciated by the consumer. Traditional fare tends to be high in sodium, fat and cholesterol, but these recipes can be “nutritionized” to be healthier, but without losing the fundamental character and cultural iconicity.
What advice do you have for retirement residence executives as they plan their food service operations for the next five years?
The challenge of food service is to marry food science with the food arts, all while keeping the customer—with such varied tastes and expectations—happy. View the trends in the food industry—increased use of novel spices, emphasis upon colours (for presentation and nutrition), global cuisine, support of local purveyors, and fresh ingredients—and you’ll see that industry trends often become consumer expectations. I find it wonderfully professionally edifying to see the industry continually renewed and refreshed with new ideas, reflective of culture, economics and legislation. My advice is to embrace the creativity and dynamics of the food industry—for this is what makes our industry and us so very unique!
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