According to Gram Research analysis, a 2026 study of 24 rats found that high-sugar diets damage the protective fat tissue around blood vessels in males but not females, through a protein called PTEN. Male rats on high-sugar diets showed reduced blood vessel flexibility and impaired nitric oxide production, while female rats maintained normal blood vessel function despite identical weight gain. Blocking PTEN restored blood vessel health in affected males.
A new study reveals that eating too much sugar damages the protective fat tissue around blood vessels, but only in men. Researchers found that a protein called PTEN becomes overactive in males on high-sugar diets, disrupting the normal function of this protective tissue. Interestingly, women’s bodies seemed to handle the same high-sugar diet better, maintaining healthy blood vessel function even when they gained weight. The findings suggest that blocking PTEN could be a new way to protect men’s heart health when they consume too much sugar. This sex-based difference could explain why men and women sometimes respond differently to diet-related health problems.
Key Statistics
A 2026 study published in the European Journal of Pharmacology examined 24 rats (12 males, 12 females) and found that high-sugar diets for 14 weeks caused blood vessel dysfunction exclusively in males, while females maintained normal vascular function despite developing obesity.
Research showed that PTEN protein expression increased significantly in the protective fat tissue of high-sugar-fed male rats but remained normal in females, suggesting a sex-specific mechanism for diet-related blood vessel damage.
When researchers used drugs to block PTEN or activate Akt in sugar-fed male rats, blood vessel function improved and nitric oxide production returned to normal levels, demonstrating that PTEN is a direct cause of the observed dysfunction.
Female rats on the high-sugar diet gained equivalent weight to males but maintained normal nitric oxide signaling and preserved the protective properties of their perivascular fat tissue, revealing important sex-based biological differences in response to obesity.
The Quick Take
- What they studied: How a high-sugar diet affects the fat tissue that surrounds blood vessels, and whether a protein called PTEN plays a role in damaging this protective tissue.
- Who participated: 24 laboratory rats (12 males and 12 females) were divided into two groups. One group ate a normal diet while the other ate a high-sugar diet for 14 weeks.
- Key finding: Male rats on the high-sugar diet developed damaged protective fat tissue around their blood vessels, while female rats maintained healthy blood vessel function despite gaining weight. A protein called PTEN was overactive in males but not females.
- What it means for you: This research suggests that men may be more vulnerable to heart and blood vessel problems from high-sugar diets than women. Blocking PTEN might offer a new treatment approach, though human studies are needed before any medical applications.
The Research Details
Researchers used 24 laboratory rats split equally between males and females. Half of each sex ate a normal diet while the other half ate a high-sugar diet for 14 weeks. The scientists then tested how well the rats’ blood vessels could relax and contract, which is a key sign of healthy blood vessel function. They also examined the protective fat tissue surrounding the blood vessels and measured levels of important proteins and chemicals involved in blood vessel health. To understand the role of PTEN, they used special drugs to either block PTEN or activate a related protein called Akt, then observed whether this improved blood vessel function.
This approach allowed researchers to identify cause-and-effect relationships. By using both sexes, they could discover whether men and women respond differently to high-sugar diets. The 14-week study period was long enough to see significant changes in body weight and blood vessel function.
The study focused on the aorta, the body’s largest blood vessel, because it’s a good model for understanding how sugar affects the entire circulatory system. By measuring multiple markers of blood vessel health, the researchers could paint a complete picture of what goes wrong when rats eat too much sugar.
Understanding the specific molecular mechanisms, or the step-by-step chemical processes, that damage blood vessels is crucial for developing new treatments. Rather than just knowing that sugar is bad, this research identifies a specific protein target that could be blocked with medication. The discovery of sex-based differences is particularly important because it suggests that men and women may need different dietary recommendations or treatments for heart disease prevention.
This study was published in a peer-reviewed scientific journal, meaning other experts reviewed the work before publication. The researchers used standardized laboratory methods and measured multiple related outcomes to confirm their findings. The use of both male and female animals strengthens the conclusions. However, this is animal research, so results may not directly translate to humans. The study size is relatively small, which is typical for mechanistic research but means findings should be confirmed in larger studies.
What the Results Show
Both male and female rats gained significant weight on the high-sugar diet, confirming that the diet was effective at causing obesity. However, the effects on blood vessel function differed dramatically between sexes. In male rats, the high-sugar diet caused the protective fat tissue around blood vessels to lose its normal beneficial effects. This tissue normally helps blood vessels relax and function properly, but in sugar-fed males, this protective function disappeared.
Female rats told a completely different story. Despite gaining the same amount of weight as males, their protective fat tissue continued to work normally. Their blood vessels remained flexible and responsive, and the important chemical messenger nitric oxide, which keeps blood vessels healthy, stayed at normal levels.
The researchers discovered that PTEN protein levels were significantly elevated in the protective fat tissue of sugar-fed males but not in females. When they used drugs to block PTEN or activate Akt (a protein that works against PTEN), the damaged blood vessels in males improved dramatically. The protective fat tissue regained its beneficial effects, blood vessels relaxed better, and nitric oxide production returned to normal levels.
The study revealed that the Akt/eNOS/NO signaling pathway, a chain of chemical signals that keeps blood vessels healthy, was disrupted in males but not females on the high-sugar diet. This pathway is like a communication system that tells blood vessels to stay flexible and healthy. In males, PTEN was blocking these important signals. The research also showed that nitric oxide bioavailability, meaning how much of this protective chemical was actually available to work in the blood vessels, was significantly reduced in males but remained normal in females.
Previous research has shown that obesity damages the protective fat tissue around blood vessels, but this study provides new insight into how and why this happens. Earlier work suggested that PTEN might play a role in various metabolic problems, but this is among the first studies to directly link PTEN to blood vessel dysfunction from high-sugar diets. The finding that women are protected from this damage despite obesity is particularly novel and contradicts the assumption that obesity affects all people equally. This aligns with growing evidence that sex hormones and biological differences significantly influence how the body responds to unhealthy diets.
This research was conducted in laboratory rats, not humans, so the results may not directly apply to people. The study used only one type of rat breed and only examined one blood vessel type, the aorta, so results might differ in other vessels or populations. The 14-week study period, while reasonable for rats, is relatively short compared to human lifespans. The study did not investigate whether female rats’ protection is due to hormones like estrogen, which would be important for understanding whether postmenopausal women might lose this advantage. Additionally, the study examined only one potential mechanism, so other factors contributing to blood vessel damage were not explored.
The Bottom Line
Based on this research, men should be particularly cautious about consuming high-sugar diets, as they appear more vulnerable to blood vessel damage than women. Reducing sugar intake remains the most practical recommendation. The findings about PTEN suggest that future medications targeting this protein might help protect men’s heart health, but such treatments are not yet available for human use. This research is preliminary and should not change current medical practice, but it provides a foundation for developing new therapies.
Men concerned about heart disease risk should pay special attention to these findings, particularly those with family histories of cardiovascular disease or those who consume high amounts of sugar. Women should not assume they are completely protected, as the study was conducted in rats and other factors beyond PTEN may affect their health. Anyone with existing heart disease or high blood pressure should discuss their diet with their doctor. Researchers and pharmaceutical companies developing new heart disease treatments should find these results particularly relevant.
In laboratory rats, the protective fat tissue dysfunction developed over 14 weeks on a high-sugar diet. In humans, similar changes might take months to years depending on individual factors like genetics, overall diet quality, and exercise levels. If a PTEN-blocking medication were developed, benefits would likely take weeks to months to become apparent, similar to other cardiovascular medications. Prevention through diet changes could show benefits in blood vessel function within weeks to months.
Frequently Asked Questions
Why do men seem more affected by sugar’s effects on blood vessels than women?
A 2026 rat study found that a protein called PTEN becomes overactive in males on high-sugar diets, disrupting blood vessel function. Female rats’ bodies appear to suppress PTEN even with obesity, protecting their blood vessels. This suggests biological sex differences influence how sugar damages cardiovascular health.
Can blocking PTEN help treat heart disease caused by high-sugar diets?
Research shows that blocking PTEN restored blood vessel function in male rats on high-sugar diets. However, this is early-stage research in animals. Medications targeting PTEN do not yet exist for human use, though these findings may guide future drug development for cardiovascular protection.
Does this mean women don’t need to worry about sugar and heart health?
No. This rat study shows women’s protective fat tissue resisted damage from high-sugar diets, but other mechanisms may still cause harm. Women should continue limiting sugar intake, as obesity and high-sugar diets increase disease risk through multiple pathways beyond PTEN.
How long does it take for sugar to damage blood vessels?
In this rat study, significant blood vessel dysfunction developed within 14 weeks of high-sugar diet consumption. In humans, the timeline likely varies based on genetics, overall diet quality, and exercise. Damage probably develops over months to years of consistent high-sugar intake.
What is nitric oxide and why does it matter for blood vessels?
Nitric oxide is a chemical messenger that tells blood vessels to relax and stay flexible, preventing heart disease and high blood pressure. The study found that high-sugar diets reduced nitric oxide in males but not females, explaining why males’ blood vessels became less flexible and functional.
Want to Apply This Research?
- Track daily sugar intake in grams, aiming to stay below 25-36 grams per day (the recommended limit). Log sources of added sugars including beverages, desserts, and processed foods to identify patterns.
- Set a specific goal to replace one sugary beverage per day with water or unsweetened tea. Use the app to log this swap and track consistency over two weeks to establish the habit.
- Monitor weekly average sugar intake and create a trend chart. Set monthly goals to reduce sugar by 10-15% increments. For users with access to health data, track blood pressure or other cardiovascular markers to correlate with sugar reduction efforts.
This research was conducted in laboratory rats and has not been tested in humans. The findings are preliminary and should not be used to change medical treatment or dietary recommendations without consulting a healthcare provider. PTEN-blocking medications do not currently exist for human use. If you have concerns about your cardiovascular health or sugar consumption, speak with your doctor or a registered dietitian. This article is for educational purposes only and is not a substitute for professional medical advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.