DNA damage and chemical stress causes cellular aging

Aging explained with Dr. Nick Golinvaux

Aging is more than wrinkles and gray hair—it’s a gradual decline in cellular function. Over time, DNA damage, telomere shortening, and mitochondrial inefficiency contribute to weaker bones, slower memory, and reduced vitality. While aging is inevitable, regular exercise, quality sleep, and stress management maintain health and extend one’s years.

Aging is a complex biological process affecting our cells, tissues, and organs

With each passing decade, researchers uncover additional causes and effects of this seemingly unstoppable process. This visually stimulating video dives into our current understanding of aging, complete with the biological hallmarks researchers use to study aging at the cellular level (biological age).

Cellular aging and deterioration leads to tissue (and overall) aging

Cells are the building blocks of life, forming tissues and organs that keep our bodies working. As we age, cellular changes have progressive consequences on both the structure and function of our organs. This article examines this complex relationship as it relates to the incremental changes associated with aging.

Doctors use three key physical markers to determine biological aging

The length of the ends of chromosomes (known as "telomeres"), the gradual change in collections of DNA molecules called "methyl groups", and the secretion of inflammatory proteins are all used as indicators of biological age.

Epigenetic clock: DNA alterations on cells that predict biological age

Epigenetics refers to a biological process that controls whether certain genes are expressed or not. With a rising interest in the concept of biological age, researchers have discovered a cellular change known as DNA methylation that leaves a fingerprint on our genome as we age.

Stress-induced hormones contribute to gray hair

When the body experiences stress, the sympathetic nervous system releases the hormone norepinephrine. This hormone prematurely activates pigment-producing cells (melanocytes) in hair follicles, which depletes the hair's ability to retain color over the long run.

Red blood, skin, hair, and nail cells destroy their DNA upon maturing

To maximize the amount of oxygen they carry and more easily alter their shape to fit into narrow blood capillaries, red blood cells destroy their own nuclei. Cornified cells found in hair, nails, and the outermost layer of skin destroy their nuclei and other cellular contents to make room for keratin, which provides durability and structural support.

Chronic inflammation can cause cellular damage and could lead to cancer

Over time, this cellular defense system can inadvertently damage cells and tissues when it's in this heightened alarm mode over a prolonged period. This occurs because, when immune cells are sent somewhere without a true target, they may attack healthy cells and tissues.

The average cell's DNA is damaged thousands of times daily

In the case of radiation-induced distortions in a DNA strand, specialized proteins can cut out entire segments and rebuild them using the second strand as a complementary template. If both DNA strands are completely severed, proteins interlace undamaged DNA with the severed DNA and rebuild both using complementary base pairing.

'Old people' smell is real—it's a chemical buildup when fatty acids on the skin oxidize

The chemical composition of body odor seems to change with age. Later in life, we harbor higher concentrations of a chemical compound called 2-nonenal that forms when omega-7 fatty acids on the skin oxidize, and the skin's natural antioxidant defenses weaken. Commonly called "nonenal", it's the smell widely associated with aging, and it's often described as a grassy or greasy odor.

Do people really look younger than they used to?

Why do people today look younger than they used to? From style to science, there are 3 surprising reasons we age differently now.

How burnout alters your brain

Stress is a normal part of everyday life, and it’s not necessarily all bad. But chronic stress—the kind that leads to burnout—can change the size and functioning of parts of your brain. It can alter the ability to make new brain cells and memories and even potentially modify your DNA.

Symptoms of DNA loss may mimic those seen in mushroom poisoning or chemotherapy

Although no organism has ever lost all its DNA, the destroying angel mushroom contains amatoxin, which disrupts DNA transcription and is known to cause death via liver and kidney failure in three days. Doxorubicin, which tangles DNA to disrupt cellular replication, compromises a person's immune system.

Mineral and chemical sunscreens protect differently but both guard against UV damage

UVA rays age the skin, while UVB rays are more directly linked to skin cancer. Mineral sunscreens, with ingredients like zinc oxide, physically block rays, while chemical ones absorb UV and turn it into heat.

Age, stress, and neurological disorders can prevent memory formation and recall

Neurons transmit signals between one another at sites called synapses. Repeated interactions at these sites improve the efficiency of signal transmissions, making memories involving sensory data associated with those neurons easier to recall. Biochemical factors impacting these synaptic interactions affect memory quality.

Alzheimer's can cause brain shrinkage of between 10% and 30%

While the exact cause of Alzheimer's is debated, the buildup of amyloid plaques and tau protein tangles is instantly recognizable in post-mortem examinations. The atrophy of brain cells caused by this molecular pileup leads to noticeable physical changes, including significant shrinkage in affected brain regions.

Sleep deprivation leads to buildup of danger molecules in the gut

Fruit flies genetically engineered to be awake for as long as they live tend to live half as long as their well-rested brethren. Analysis shows these modified flies suffer from a buildup of DNA-destroying reactive oxygen species in their guts. When enabled to sleep, the flies live as long as their counterparts.

Cancer rates are on the rise among GenXers and Millennials

Cancer rates are rising among Gen X and Millennials, with more cancer diagnoses being made in their 30s and 40s than previous generations. Factors such as prenatal exposures, environmental toxins, and lifestyle choices may contribute to this trend. Memorial Sloan Kettering Cancer Center's experts discuss these issues, exploring how these insights could reshape cancer risk understanding.

Age-related macular degeneration is the primary cause of blindness in older Americans

Around 20 million Americans suffer from macular degeneration, and it's the leading cause of blindness in older Americans. Risk factors for age-related macular degeneration include aging, genetics, smoking, hypertension, obesity, and diet.

Gradual chemical build-up reduces the effectiveness of rechargeable batteries

During charge cycles, small chemical deposits gradually form a film on the electrodes where they make contact with the electrolyte, trapping ions that would otherwise facilitate the flow of electricity. Mechanical degradation from electrode wear and electrical shorting from structural instability can also reduce battery capacity.

Explore how cells respond to signals from their environment

In "Dropping Signals," users can drag stimuli, such as hormones and light, into various cellular environments to observe cellular responses. These include changing their shape, enabling the transport of chemicals into or out of the cell via the cell membrane, or dividing to compensate for surrounding damaged cells.

Some data links schizophrenia to older paternal age and birth complications

Yet both associations are not yet considered firm enough to definitively be causative. Schizophrenia is a multi-causal syndrome and a mixture of factors, including genetics, are widely believed to be behind its development.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

The five most common chemicals found in modern food

Most modern processed foods rely on a number of preservatives to stay fresh from production to our plates. The most common include citric acid (preservative and flavor), sodium benzoate (preservative), xanthan gum (thickening and stabilizing), carrageenan (thickening), and red dyes 3 and 4 (for color).

Modern conveniences may be contributing to allergy increases

A combination of genetics and how the environment changes our genes are likely contributing to the rise in allergies. But daily conveniences, such as dishwashers and packaged baby food, also change the level of bacterial exposures in early life, with potential implications for allergy development, experts from Mount Sinai Health System state in this video discussion.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

The original copy of the Declaration of Independence is not a pristine document, and even features a smudged anonymous handprint in the bottom left corner.

Tattoos remain visible on your skin thanks to immune cells called macrophages

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Watch what the Ebola virus does inside our cells and organs in order to spread and survive.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

Poison ivy can cause rashes year-round since all parts of the plant contain urushiol, the oil that triggers our allergic response.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

Dorothy's famous entrance into Oz in 'The Wizard of Oz' relied on analog tricks, including a body double and sepia-toned paint, as much as it did on technology

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.

Use this tool to calculate the dollar value of your parental mental load, from meal planning to coordinating after-school care, then see resources that help generate solutions.