The Keys to Living 100 or More Healthy Years

The average life expectancy has been increasing every year. We have come to a point in society where living to 100 (centenarians) is not that unusual anymore, a situation largely resulting from the achievements in modern medicine. However, despite society becoming progressively unhealthier as a whole, why is the number of healthy centenarians increasing? What are these centenarians doing differently from the rest of the population to live a century of relatively disease-free years? Could it be lifestyle factors such as diet, exercise, relationships, and environment? Or could it be a specific evolution in their genetic makeup?

A large body of scientific evidence has demonstrated that these centenarians’ longevity is strongly linked to their unique immune cell makeup and response, protecting them from infections and external pathogens. Additionally, multiple studies have noted that the slowing of telomere shortening in centenarians is associated with a slower pace of aging at a cellular level. Moreover, decreased chronic low-grade inflammation has been linked with a reduced risk for several diseases such as cardiovascular disease, cancer, and neurodegenerative diseases, allowing an individual to live an extended and healthier lifespan.

While the immune system plays a crucial and often life-saving role in protecting against serious infections, more recent evidence has demonstrated that it may also play a negative role in the development of metabolic endotoxemia, a systemic immune response to an unhealthy diet. Even though the great majority of the immune system is located in the gut, there are many other sites in the body that can be involved in an immune response, including lymph nodes, bone marrow and spleen. Within the immune system, white blood cells circulate in the blood and lymphatic vessels, forming a network. This network contains lymph, which is a fluid that carries immune-related cells to parts of the network that require them. The immune response to pathogens operates by recognizing signals called danger-associated molecular patterns (DAMPS). These DAMPS or antigens may be part of pathogenic microorganisms or toxins. Once recognized during an infection, the immune system launches an attack on these invaders via white blood cells. The stronger the immune-cell reaction, the stronger the protection the body has against external invaders. A body of evidence suggests that their faster and more effective immune responses to pathogens protects centenarians from undue physiological distress that comes with contracting illnesses.

“It is well known that multiple physiological factors such as nutritional status, hormone levels and infections/inflammation will influence the reactivity of immune cells”

“Inflamm-aging” is a term used to describe chronic low-grade immune activation within the body associated with aging. Even though this process also involves engagement of the immune system, it is a very different mechanism from the response to a pathogen. However, chronic persistence of inflammatory molecules in the body can lead to oxidation of cells, a process thought to favor faster aging. Oxidation is the process when cell membranes become unstable molecules, causing damage to DNA and other cells. Engagement of the immune system can be detected in the blood and other tissues by measuring pro-inflammatory markers, including pro-inflammatory cytokines such as interleukins-6 (IL-6) and TNF-α. Such immune signals have been linked to neurodegenerative diseases such as Alzheimer’s, while also increasing one’s risk for heart disease.

An important anti-inflammatory molecule produced by certain gut microbes such as Faecalibacterium prausnitzi, Roseburia, Bacteroides, and Prevotella, from complex carbohydrates in our diet are short chain fatty acids, in particular butyrate. It has been shown that the microbiota from the oldest group of adults’ (90-100+ years) varied from that observed in young-old adults (60-89 years) in the production of butyrate, suggesting either a greater intake of dietary carbohydrates, the “raw material” for butyrate production, a greater microbial capacity to produce butyrate or both. Current scientific evidence strongly suggest that an increased consumption of dietary fiber, polyphenol-rich foods, and adhering to a largely plant based Mediterranean diet can lead to increased butyrate production, an increase in a subset of anti-inflammatory lymphocytes and increased production of anti-inflammatory cytokines such as Interleukins-10 (IL-10). These diet-induced changes can counteract or prevent inflamm-aging.

“Furthermore, present in fruits such as berries and vegetables, the defensive effect of polyphenols on age related-diseases have been well documented. They have been shown to play a role in the prevention of age-related diseases such as cancer and cardiovascular diseases”

Telomeres are DNA-protein structures that are located at the ends of each chromosome. Telomeres are a set length and decline with age. Each time a cell divides, the telomeres become shorter, and after enough cell division, telomeres can no longer divide, leading to cell death. Faster-paced telomere shortening may be indicative of how fast a person ages overall. Shortened telomeres have been associated with compromised immune system responses and shortened lifespans. Smoking, obesity, lack of exercise, and intake of an ultra-processed, unhealthy diet can increase the pace of telomere shortening. However, there are lifestyle interventions that may preserve telomere length, slow aging, and strengthen the immune system. A meta-analysis suggested that telomere length was positively correlated with dietary fiber and omega-3 fatty acid intake as well as regular physical exercise. Telomere length is associated with biological age, and healthy centenarians exhibit longer telomeres, slowing down the pace at which their cells deteriorate.

“To slow physiological telomere shortening and reduce cancer risk and pace of aging, we may consider eating less; include antioxidants, fiber, soy protein and healthy fats (derived from avocados, fish, and nuts) in our diet…These combined with a Mediterranean type of diet containing fruits, and whole grains would help protect telomeres.”

A prominent example of thriving centenarians can be viewed by examining the Blue Zones regions around the world. The Blue Zones consist of certain communities of different ethnic and racial background that cultivate an environment not only to allow their citizens to remain healthy into old age, but also have been shown to extend the lives of people who previously lived elsewhere. The key characteristics to maintaining a fountain of youth in these regions are their diet, lifestyle, and close and meaningful social relationships. The underlying dietary principals of these regions are to eat locally-grown whole foods, primarily plants, and minimal consumption of animal products. They also adhere to extensive amounts of regular low-impact exercise, as many of them walk an average of 5 miles a day while shepherding or tending to their gardens. Most importantly, the tight-knit communities that they build, sharing meals, and living nearby friends and family are a common denominator between these Blue Zone regions. Although some may attribute longevity to heritability, a meta-analysis showed that only approximately 30% of health and longevity could be linked to genetics, suggesting that lifestyle factors have a much greater influence on gracefully aging. These broad observations illustrate that lifestyle interventions and environment result in an altered gene expression, a process called epigenetics. The benefits of these altered gene expressions in a health-conducive environment result in the preservation of telomere length, reduced systemic chronic inflammation, and the maintenance of a robust immune system.

At first glance, one might say that centenarians won the genetic lottery, but evidence shows that these centenarians boast vitality mainly due to a combination of lifestyle interventions and environment. As observed, a healthy largely plant based diet, such as the Mediterranean diet or some traditional Asian diets combined with ample physical activity, and maintaining healthy relationships can inhibit the proliferation of biomarkers that lead to disease and premature death, allowing people to live and thrive into their 100s and beyond.

Chloe Arzy is a recent graduate from the University of Southern California where she earned her Bachelor of Science in Business Administration. She complemented her studies by receiving her Integrative Nutrition Health Coach certification from the Institute of Integrative Nutrition (IIN).