Our modern lifestyles have turned chronological age into a virtually insignificant number. Aging is not just the number of years you’ve inhabited planet Earth, but rather the degree of wear and tear your body, brain, and vital organs are expressing at a given point in time. When I came out of medical training and started practicing in Southern California, I could easily estimate how old my patients were by looking at them since many of them were working jobs involving physical labor, often outdoors. In fact when we are taught to do physical exams, one of the first things we report is whether patients appear their stated age.
For example, “Mr. Smith appeared older than his stated age.” When I moved up to Silicon Valley to start caring for a mostly sedentary, high-tech workforce, I lost the ability to estimate a patient’s age and often would not even come close, being off by a decade. Yes, 30-year-old engineers looked like they were pushing 40. It wasn’t just the fact that they were overweight. It was their posture, their skin, and their facial expression which lost much of its age-appropriate youthfulness. As I looked at the literature on aging in the context of our current lifestyles, I realized I wasn’t imagining things. I was witnessing an epidemic of accelerated aging in my patients.
Measuring Age: It’s All About Your Genes
A better way to estimate your true health age is to analyze your genetic code or DNA. If your body were a smartphone, the apps and programs are the proteins that run all the basic functions that help your body survive and thrive. Just like writing computer code produces apps for your phone, your DNA or genetic code produces proteins for your body. One particular bit of DNA code may produce a muscle protein, while another code produces a protein for skin elasticity and so on. However having the specific gene doesn’t guarantee that the protein will be built. This is where DNA methylation comes in. There are chemical molecules called methyl groups that attach to your DNA in very specific patterns. These patterns determine whether your genetic code will turn on or turn off production of a specific protein or process. Scientists can read these DNA-methylation patterns (aka “epigenetic clock” or “DNA methylation age”) to accurately estimate your age without any additional information about you. Why am I going into so much detail about DNA methylation? Chronological age is something we have no control over, but our DNA methylation age is something we can influence through our environmental exposures and behaviors. Also tied to DNA methylation is the health of our telomeres. Our genes are packaged into structures called chromosomes and at the tips of these chromosomes are structures called telomeres. When your telomeres are healthy, your cells divide normally, meaning your body’s tissues renew and regenerate properly. When telomeres start wearing away, cells are no longer dividing properly and your body starts exhibiting signs of internal and external aging. My patients who were 40 but looked like they were 50 was not my mind playing tricks on me. If we were to look at their DNA methylation age and the health of their telomeres, their biological age would be closer to 50. Everything from their skin down to their bones, joints, and vital inner organs have functionally aged a decade more than their chronological age. On the other hand, I have some remarkably healthy patients who look 10 years younger than their age with fit bodies, supple joints, smooth skin and that youthful glow we all envy. Their genetic age defies their chronological age
Four Major Age Accelerators
Now that you understand the importance of DNA methylation and the health of your telomeres as a better marker for biological age, let’s discuss the four major age accelerators, a major focus of my book. Each of these factors can be modified to slow down the aging process.
1. Poor nutrition: Those methyl groups we discussed that influence gene expression are actually made directly from the nutrients you eat, such as folate from green vegetables. A nutrient-rich diet with a diversity of plants, healthy proteins and high quality, healthy fats actually feed and nourish your genes which not only manifest in optimal health for you, but also allow you to pass these pristine genes to your children and grandchildren. Most of the patients I see in my clinic are eating highly nutrient-deficient diets that are starving their genes and contributing to accelerated aging. The other major dietary culprit behind accelerated aging is an abundance of glucose. Excess carbohydrate intake (sugar, starches and even whole grains) can damage your proteins by binding directly to form substances called advanced glycated end products, also known appropriately as “AGEs.” Back to our smartphone analogy, even if your genetic code is clean and has produced the right protein or “App,” excess glucose, like a bad software virus, can bind to your protein Apps and cause them to malfunction. So micronutrient deficiencies can disable your genes from producing the right proteins needed for optimal health, while excess glucose from too much sugar and carbohydrates can damage proteins directly.
2. Inactivity: A study done in over 2,000 identical twins that carry the same genetic material showed that the more active twins had longer, healthier telomeres than their genetically identical siblings. (http://www.edinformatics.com/news/exercise_and_aging.htm). The most active twins had genes that appeared 9 years younger than their inactive siblings. So genes are not immutable and can be influenced by behaviors such as exercise, which promotes anti-aging and prevents chronic disease.
3. Stress: A 2004 study (http://www.pnas.org/content/101/49/17312.long) comparing the telomeres of a group of age-matched mothers with healthy children versus mothers who cared for children with a chronic illness (high chronic stress group) showed shorter, unhealthier telomeres in the mothers caring for the sick children. Despite being the same chronological age, the mothers of the ill children genetically looked almost a decade older. Chronic stress promotes inflammation and oxidative damage that is inflicted upon DNA, which increases disease risk and accelerates aging.
4. Low vitamin D: Vitamin D appears to be involved in the process of DNA methylation, promoting telomere length, and in reducing chronic inflammation, all processes critical for halting accelerated aging. Does this mean taking vitamin D supplements is a proven anti-aging strategy? This has not been proven, but getting natural doses of vitamin D with safe sun exposure and physician supervised supplementation based on your blood levels appears to be a reasonable strategy.
How Fast Are We Aging?
Back to my original question stated in the title “Are we aging too fast?” Hopefully I’ve convinced you that the answer in our modern world is a resounding yes. Most of the patients I see in my clinic are sedentary Silicon Valley workers who have all four major age accelerators. They are eating a nutrient deficient and glucose abundant diet, they are completely inactive, they are experiencing high stress and most are significantly vitamin D deficient due to work lives and personal lives confined predominantly to indoor, sun-deprived spaces. Their spines are arthritic and their arteries are becoming blocked with heart-attack causing plaques in their third or fourth decade of life. Formerly known as “diseases of aging,” these conditions are presenting early in life. Even more startling is seeing the effects of these age accelerators on today’s children, who are suffering from conditions like adult onset diabetes, obesity, and fatty liver. If you are planning to have children, realize that future fathers and mothers who are leading unhealthy lives may be passing their sick genes onto their children and grandchildren, increasing their risk of obesity and chronic disease. Your lifestyle decisions are no longer just about you, but can shape the health of future generations.
Ronesh Sinha, M.D. is a physician for the Palo Alto Medical Foundation who sees high risk South Asian patients, he blogs at southasianhealthsolution.org, and co-hosts a South Asian radio show on health.