People with severe mental disorders who drink up to four cups of coffee a day can look about five years younger in their cellular age than people who don’t drink coffee. Recent research has identified an optimal period of moderate coffee consumption associated with the longer protective caps at the ends of chromosomes. The study was published in the journal BMJ Mental Health.
People with severe mental health conditions, such as schizophrenia and bipolar disorder, often have a lower life expectancy compared to the general population. This early mortality rate often leads to higher rates of cardiovascular disease, certain cancers, and other physical health problems. Researchers believe that these health problems may be indicative of an accelerated biological aging process within the body.
To track this biological aging, scientists often look at structures called telomeres. Telomeres are DNA sequences located at the ends of human chromosomes. They function similar to the plastic tips at the end of shoelaces, preventing genetic material from fraying and deteriorating.
During cell division, the biological machinery that copies DNA cannot reach the tips of the chromosomes. This mechanical restriction causes small sections of telomeres to be left behind and lost with each division. When these caps retract to a very short length, cells either stop dividing or die.
This natural process allows telomere length to serve as a reliable marker of cellular aging over a person’s lifetime. Previous clinical trials have shown that patients with severe mental illnesses tend to have shorter telomeres than healthy people of the same chronological age. The exact biological reason for this difference is an ongoing research topic.
Scientists suspect that environmental and lifestyle factors may have a major impact on telomere degradation over time. Diet is a major environmental factor that can alter biological aging. Coffee is one of the most widely consumed nutritional drinks worldwide and contains a variety of bioactive compounds.
Because of these potential health benefits, a team of scientists decided to investigate the relationship between coffee consumption and biological aging in populations with mental illness. The study was led by researcher Vid Mlakar from the Institute of Psychiatry, Psychology and Neuroscience at King’s College London. Mlakar et al. pointed out that people with severe mental disorders often consume large amounts of caffeine, but previous studies have not examined how this habit relates to their telomere length.
Public health authorities, such as the United Kingdom’s National Health Service, recommend that healthy adults limit their caffeine intake to no more than 400 milligrams per day. This amount is equivalent to about 4 standard cups of coffee. Consuming amounts above this recommended limit can cause insomnia, gastrointestinal upset, and increased heart rate.
Studies examining coffee and telomeres in the general population have yielded mixed results. Some studies suggest that coffee protects cell membranes, while others link heavy consumption to increased shortening. Murakar and his team aimed to chart this relationship, particularly for patients surviving severe mental illness.
The research team designed a cross-sectional study using data from 436 participants previously recruited in Norway. Participants included 259 people diagnosed with schizophrenia spectrum disorders. An additional 177 people had been diagnosed with an affective disorder, such as bipolar disorder or major depressive disorder with psychosis.
During the clinical interview, a doctor and psychologist asked patients about their daily coffee habits. Participants chose from four intake categories: 0 cups, 1–2 cups, 3–4 cups, or 5 or more cups per day. Clinicians also recorded details about patients’ smoking, specific psychiatric medications, age, and biological sex.
To measure cellular aging, the research team extracted DNA from the participants’ white blood cells. They used a laboratory technique called quantitative real-time polymerase chain reaction. Using this method, scientists can estimate the average length of telomeres across blood samples by comparing them to standard reference genes.
This analysis revealed an inverted J-shaped relationship between coffee intake and telomere length. This particular shape means that as coffee intake increased from zero, the length of the cap that protects the chromosomes also increased up to a certain point. Beyond four drinks per day, the protective relationship reversed and telomere length began to decrease.
Participants who drank three to four cups of coffee each day had longer telomeres than any other group. The greatest differences in chromosome length appeared between this moderate intake group and the no-coffee drinking group. Groups that consumed five or more cups did not show similar cytoprotective effects.
The researchers calculated that the telomere length of moderate coffee drinkers was equivalent to about five years younger in biological age than the non-coffee drinkers. The statistical analysis took into account age, smoking history, and medication dosage, meaning that these variables cannot explain the findings. Results did not vary by diagnostic category, indicating that this pattern holds for both schizophrenic and affective disorder patients.
The researchers proposed several biological mechanisms that may explain why moderate coffee consumption protects cell membranes. Coffee contains high levels of chlorogenic acid and other natural antioxidant compounds. Antioxidants help neutralize unstable molecules in the body called free radicals, which typically cause oxidative stress and damage DNA.
People with severe mental illness often exhibit chronically high levels of systemic inflammation and oxidative stress. The antioxidants in coffee may help calm this inflammatory condition, preserving telomeres in the process. Chlorogenic acid specifically activates subtle pathways that act as the body’s natural defense system against cell damage.
Another explanation points to a biological chain reaction that controls cell survival. Caffeine interacts with this system to increase the production of a specific genetic component called TERT. TERT is a key component of telomerase, the enzyme responsible for returning lost DNA to short telomeres.
Moderate coffee intake may physically encourage the body to expand the safe upper limit of chromosomes by promoting the production of TERT. However, in excess, caffeine itself can cause cellular stress. This negative response may explain why the biological benefit disappeared in patients who consumed five or more cups per day.
The research team also noted the importance of assessing smoking habits in patients with this mental illness. People diagnosed with severe mental illness often smoke at much higher rates than the general population. Nicotine stimulates the liver to produce certain enzymes that rapidly break down caffeine.
Smokers often consume larger amounts of coffee to process the caffeine more quickly. This habit can easily push you over the protective 4-cup threshold and shorten your telomeres. The data showed that the people in the study who drank the most coffee also had the longest history of smoking.
This study relied on a cross-sectional design, providing only a single snapshot of participants’ health status. A single snapshot cannot prove that drinking coffee directly causes telomere lengthening. It only indicates a strong statistical association that occurs between two variables at the time of measurement.
Another limitation involves the self-reported nature of dietary data. Participants estimated their daily cup count, which may introduce memory bias. The researchers also lacked details about the type of coffee consumed, such as whether participants preferred filter coffee, espresso, or instant.
Dietary questions did not track other common sources of caffeine intake, such as energy drinks, soda, and tea. The exact caffeine concentration per cup of coffee can vary widely between participants depending on the brewing method. This result was not statistically significant in determining whether biological benefits differ strictly between men and women.
Future studies will need to track participants’ habits and cellular changes over multiple years to establish a reliable chain of events. Scientists also want to assess multiple markers of biological aging simultaneously. Combining telomere length measurements with other epigenetic clocks may provide a broader understanding of how diet supports cellular health in patients with mental illness.
The study, “Coffee consumption is associated with telomere length in severe mental disorders,” was conducted by Vid Mulakkar, Marta Di Forti, Els F. Halff, Deepak P. Srivastava, Ibrahim Akkou, and S. Lujan Jurovic, Carmen Martin-Ruiz, Daniel S. Quintana, Viktoria Birkenes, Nils Eyer Steen, Monika BEG Ormerod, Ole A. Andreassen, Monika As.
