How long-term keto diet may raise hidden risks for liver and cancer health

As the ketogenic diet becomes more popular, new studies warn of potential long-term risks-from liver dysfunction and metabolic strain to possible cancer-linked pathways-highlighting the need for medic

 

As the popular high-fat and protein, very low-carbohydrate ketogenic diet (KD) gains traction for weight loss, fresh studies are raising serious questions about its long-term safety, especially in relation to liver health, cancer risk and how men and women may respond differently.

 

What are the emerging liver-related concerns with long-term keto?

 

According to Dr Surakshith TK, Senior Consultant, Gastroenterology & Hepatology at Fortis Escorts, Okhla, “Long-term ketogenic dieting causes changes that may involve increased liver fat in some, changes in liver enzymes, shifts in the metabolism of ketones, reduced glycogen stores, and variable effects on insulin sensitivity.”

 

A recent study published in Science Advances, titled A long-term ketogenic diet causes hyperlipidaemia, liver dysfunction, and glucose intolerance from impaired insulin secretion in mice, found that male mice developed severe fatty liver and metabolic dysfunction, while female mice did not show comparable fat accumulation.

 

Clinical experience echoes similar patterns. Dr Nirmal Raut, Senior Consultant, Medical Oncology, HCG Cancer Centre, Borivali, notes that the most common liver-related changes in long-term keto users include elevated liver enzymes and worsening or new-onset fatty liver, especially in those consuming high saturated fat. He adds, “Few patients also develop gallbladder issues, as the diet increases bile production,” and poorly balanced keto plans may, in rare cases, precipitate NASH.

 

Experimental findings also point to deeper metabolic strain. Researchers observed significant stress on pancreatic beta cells, which produce insulin. High-fat exposure disrupted protein handling in these cells, contributing to unstable blood sugar and impaired insulin secretion.

 

How do men and women respond differently to the ketogenic diet?

 

Dr Surakshith explains, “Recent data have pointed out that there are some sex differences in the response to KD, at least with regard to liver fat handling, insulin dynamics, and lipid metabolism.”

 

Dr Raut adds that emerging data suggest women may experience more pronounced adverse metabolic responses, including dyslipidaemia and impaired glucose handling, on strict ketogenic plans. “Men, on the other hand, often show more favourable short-term metabolic responses,” he says.

 

What evidence is emerging on cancer-related risks linked to keto?

 

A study in Cancer & Metabolism, titled Hyperlipidaemia drives tumour growth in a mouse model of obesity-accelerated breast cancer, found that high-fat diets and elevated circulating fatty acids may accelerate aggressive breast cancer.

 

The ketogenic diet, often promoted for quick weight loss, may therefore pose specific risks for individuals with breast cancer, as cancer cells may rely heavily on lipids for fuel.

 

Dr Surakshith notes, “Such studies indicate that clinicians should consider lipid profiles when counselling ketogenic dieters, especially those with cancer risk factors.” Dr Raut agrees, warning that people with active cancer, a history of cancer or high-risk profiles should avoid extreme high-fat diets unless medically supervised.

 

Why is long-term safety data on keto still limited?

 

Dr Surakshith highlights a lack of multiyear trials and limited data in people with fatty liver, obesity, insulin resistance or past cancer. Dr Raut adds that long-term safety data among cancer survivors, post-menopausal women and individuals with keto-induced dyslipidaemia are especially scarce.

 

What practical precautions do experts recommend for keto users?

 

For those who wish to continue keto, experts recommend:

 

• Regular monitoring of liver enzymes, lipid panels, kidney function, HbA1c, thyroid markers and, where relevant, menstrual function.
• Prioritising unsaturated fats and avoiding heavy reliance on saturated fat.
• Ensuring sufficient fibre from low-carb vegetables and seeds.
• Watching for red flags such as rising LDL, elevated liver enzymes, persistent fatigue or unexplained weight changes.

 

Experts agree that while keto may offer short-term benefits, it is not risk-free and requires personalised assessment, careful monitoring and cautious long-term use.     

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