Keto diet may worsen aggressive breast cancer, new study warns

Scientists find that high-fat diets and elevated lipid levels can accelerate breast cancer growth, prompting caution over keto regimens among patients and survivors

A new study has found that high levels of fat in the blood may fuel aggressive breast cancer, raising concern over popular high-fat diets such as keto.

 

Conducted by scientists at the Huntsman Cancer Institute at the University of Utah and published in Cancer & Metabolism, the research, titled Hyperlipidemia drives tumour growth in a mouse model of obesity-accelerated breast cancer, shows that fatty acids linked to obesity can accelerate tumour growth.

 

The findings suggest that patients and survivors with obesity could benefit from lipid-lowering therapies and should be cautious about following high-fat weight-loss regimens.

What scientists discovered about fats and breast cancer growth

The team discovered that triple-negative breast cancer cells are “addicted” to lipids. These fats are abundant in people with obesity, where a condition called hyperlipidemia, high levels of fat in the blood, is common.

 

 

“When breast cancer cells receive signals to multiply, the abundance of lipids acts like extra building blocks,” explains Amandine Chaix, PhD, one of the study’s lead investigators. “That makes it easier for tumours to grow.”

 

In their experiments, researchers used mouse models that were either fed high-fat diets or genetically engineered to have hyperlipidemia. Even when these mice had normal levels of glucose and insulin, the cancer cells grew faster, proving that lipids alone can drive tumour growth.

How obesity and lipids accelerate breast cancer growth

Obesity changes the body’s metabolic environment, altering hormones, insulin levels, and fat metabolism. The new study narrows this complex relationship to lipids.

 

“People have underestimated the importance of fats and lipids in obesity,” says Keren Hilgendorf, PhD, co-senior author of the study. “Our research shows that breast cancer cells are literally fuelled by lipids, and that’s one of the reasons the disease is more aggressive in people with obesity.”

 

The researchers found that when they lowered lipid levels in obese mice, the growth of breast cancer slowed down, even though the animals’ body weight stayed the same. This suggests that it’s not just weight that matters, but what’s circulating in the blood.

Should breast cancer patients avoid keto and other high-fat diets?

The ketogenic diet, known for promoting rapid weight loss, shifts the body’s energy source from carbohydrates to fat. But in people with breast cancer, this mechanism may actually work against them.

 

“If you already have high cholesterol or triglycerides, eating a high-fat diet like keto could make things worse,” warns Greg Ducker, PhD, a co-author of the study. “It could even provide more fuel for the tumour to grow.”

 

The team recommends that breast cancer patients and survivors with obesity consult their doctors before starting any diet plan and consider lipid-lowering strategies, whether through food choices or medication.

What’s next in cancer research on lipids and obesity link

The Huntsman team now plans to study how anti-lipid drugs might enhance chemotherapy and whether similar mechanisms exist in other cancers, such as ovarian or colorectal cancer.

 

According to the researchers, for individuals with obesity or a history of breast cancer, the safest approach is to:

• Get lipid levels checked regularly
• Avoid extreme diets like keto without medical supervision
• Opt for balanced, whole-food-based eating patterns that improve overall metabolic health

As Hilgendorf puts it, “If we can target the high levels of fat in the blood, the cancer suffers, because the lipids are no longer feeding it.” 

Since you're already here

…and clearly interested in your health, take a moment to explore our varied range of stories on wellness, medical research, and public health insights.

• Caught flu despite the jab?  Why did I catch the flu even after taking the vaccine? Doctor explains
• Mental health help decoded  Psychiatrist vs psychologist: Who does what and whom to approach for help
• First therapy session fears?  Don’t fear therapy: Experts reveal what really happens in the first session
• Safe cough relief for kids  Do kids even need cough syrups? Doctors say they may do more harm than good
• Secrets of a long life  Want to live longer? Science says being active and organised is the key
• Heart under pressure  Financial stress and heart attacks: Why money matters as much as cholesterol
• Myths vs immunity  Vaccines, weather, kadha: What really helps immunity and what doesn’t
• Frown lines and fine lines  From frowns to smiles: These 7 tiny expressions speed up visible ageing
• Caring without crashing  Ageing parents, adult kids: How to grow together without burning out

For more health updates, follow #HealthWithBS 

This content is for informational purposes only and is not a substitute for professional medical advice.