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The human body experiences major changes at two specific times, research shows. RZCREATIVE/Stocksy
  • As we age, the body undergoes a number of changes, both externally that you can see and internally that you cannot see.
  • Researchers at the Stanford University School of Medicine have discovered that humans undergo two major changes in their molecules and microorganisms around ages 44 and 60.
  • Scientists found these age-related molecular changes are associated with certain health risks, including cardiovascular disease.

Everyone knows that as we age, our bodies go through a lot of changes. While changes will occur every year, past research shows that, at the protein level, the most notable changes take place around ages 34, 60, and 78.

Although some of these aging body changes you can see — such as graying hair and skin wrinkles — many of these alterations are not visible as they happen inside the body to organs, tissues, and even on a cellular level.

A new study recently published in the journal Nature Aging adds to what we know about how aging affects the inside of the body. Scientists from the Stanford University School of Medicine have discovered that humans undergo two major changes in their molecules and microorganisms around ages 44 and 60.

Researchers say these changes can potentially have a major impact on a person’s health, including cardiovascular health.

For this study, researchers analyzed data from 108 people living in California between the ages of 25 and 75. Study participants were tracked for an average of 1.7 years with a maximum of about 7 years.

Throughout the study, participants donated blood and other biological samples every few months, which allowed scientists to track changes in their bodies’ molecules and microbiomes.

The research team tracked age-related changes in more than 135,000 different molecules and microbes for almost 250 million distinct data points.

“We are tracking people in incredible detail — measuring as many molecules as possible (tens of thousands) and their microbes to get a detailed picture of their health,” Michael P. Snyder, PhD, professor of genetics at Stanford University School of Medicine and senior author of this study explained to Medical News Today. “In the process, we can also see how they age.”

As Snyder and his team looked at the data more closely, they noticed that about 81% of the molecules and microbes they identified change more at certain ages than at other times of a person’s life span. The two ages with the largest molecule and microbe changes, scientists found, occur when a person is in their mid-40s and early 60s.

“We expected the changes in the 60s because this is when disease risk increases for nearly all diseases and people’s immune system decreases (and) we found additional changes,” Snyder said. “The changes in the 40s were unexpected although in hindsight it is a time when people hit their ‘mid-life crisis’ and often injured themselves.”

“We think people are undergoing biological changes throughout their lives but (there are) two periods where lots of changes occur. The reason is not clear, but it might be because their lifestyle is not ideal — exercise and nutrition — or their cells are undergoing senescence in their 60s.”
— Michael P. Snyder, PhD

Additionally, the scientists found that the most noteworthy age-related molecule and microbe changes were linked to potential health concerns.

For example, with people in their 40s, Snyder and his team discovered significant changes in the number of molecules related to alcohol, caffeine, and lipid metabolism, as well as cardiovascular disease and skin and muscle.

At the age of 60, the biggest molecule changes were related to cardiovascular disease, immune regulation, kidney function, carbohydrate and caffeine metabolism, and skin and muscle.

Snyder said it is important for researchers to continue to examine what happens to the body during biological aging because we can then take action to reduce many of the problems associated with aging.

“The goal is to have people live long healthy lives. You (can) track these changes and take action with this information. For example, get on statins as you hit your 40s or just before, (and) make sure you exercise through life. In your 60s, drink plenty of water for keeping healthy kidneys, eat immune boosters, and antioxidants,” he said.

“Be aware of your health changes so that you can take action and live a long and healthy life,” Snyder added.

After reviewing this study, Cheng-Han Chen, MD, a board certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, told MNT that this study establishes that changes in various classes of molecules involved in human health seem to happen at specific time periods in a person’s life, rather than gradually throughout someone’s life.

“This is an important finding that will help us better understand the biochemical changes that underlie aging, and potentially provide targets for therapy depending on someone’s stage in life,” Chen continued.

“It is unclear why there are such large changes specifically around the ages of 40 and 60. Further research will be necessary to identify the mechanisms and potential biological rationale for the changes around those time periods.”
— Cheng-Han Chen, MD

“Science is only beginning to understand the biological mechanisms involved in aging. Studies like this help us to identify the basis of normal aging and, in turn, provide insight into how deviations in normal biology led to diseases such as cardiovascular disease. Ultimately, this will help us understand how to keep our patients healthy and aging well. It may also help us to develop new therapies for diseases that result from abnormal aging,” he added.

MNT also spoke with Manisha Parulekar, MD, FACP, AGSF, CMD, director of the Division of Geriatrics at Hackensack University Medical Center, co-director of the Center for Memory Loss and Brain Health at Hackensack University Medical Center, and associate professor at Hackensack Meridian School of Medicine in New Jersey, about this study.

“We are all trying to understand the aging process and chronic conditions. Some of the diseases like diabetes and Alzheimer’s are also suggesting that we have to start preventive interventions early on. It is interesting to see that this study is showing findings at these two age groups, around age 40 and 60. This may help us have a better conversation with our patients regarding various lifestyle modifications early on.”
— Manisha Parulekar, MD, FACP, AGSF, CMD

Parulekar said an abundance of most molecules and microbes in our bodies undergo periods of rapid change throughout our life span due to a complex interplay of factors, including development and growth, environmental factors, lifestyle factors, physiological changes, genetic factors, and disease and illness.

“It’s important to note that these factors often interact and influence each other. For example, diet can impact the gut microbiome, which in turn can influence the production of hormones and immune cells. Understanding the dynamic fluctuations of molecules and microbes across our life span is crucial for maintaining health and preventing disease. We can use these data points to help our patients understand the importance of certain interventions. It is always helpful to have data to support these conversations,” she said.