Portugal Study: 40% Calorie Cut Boosts Chemo and Shields Healthy Cells in Mice

The Portugal-based research network RISE Health has shown that deliberately eating about 40% fewer calories in the days surrounding chemotherapy can shrink sarcoma tumours in mice and shield healthy tissue—a discovery that could one day rewrite hospital nutrition protocols.

Why This Matters

• No human trial yet – results come from animal models; Portuguese oncologists are urging caution before patients self-prescribe diets.

• Potential to strengthen doxorubicin – the standard drug for many soft-tissue sarcomas could become more potent without higher doses.

• Lower side-effect burden – early data hint at fewer DNA lesions in healthy cells, meaning shorter recovery time and possibly lower hospital bills.

• Check with your oncologist – drastic calorie cuts can backfire, especially in already frail patients; individual assessment remains crucial.

The Science in Plain English

When food supply drops, a tumour’s notoriously high energy appetite is starved. The Portuguese-Brazilian team recorded a cascade of changes: suppressed Insulin/IGF-1 signalling, dampened mTOR activation, heightened AMPK alerts and a wholesale rewiring of lipid metabolism. Tumour cells, stripped of their preferred fuel—cholesterol and triglycerides—enter a state of metabolic stress that amplifies the punch of doxorubicin. In contrast, normal cells flip into a protective mode dubbed differential stress resistance, improving DNA repair and slashing oxidative damage.

Where Portugal’s Hospitals Stand

Oncologists at IPO-Porto and Lisbon’s Santa Maria acknowledge the promise but emphasize that no Portuguese centre is yet running a calorie-restriction protocol for sarcoma. The only active clinical study, listed simply as “Caloric Restriction Diet for Sarcoma,” is recruiting abroad. Local specialists instead direct patients to the ClinicalTrials.gov filter or the Portuguese portal Clinical Trials Portugal to watch for upcoming enrolment notices.

What This Means for Residents

Speak first with a registered dietitian before trimming meals; cancer-related weight loss already affects roughly 35% of Portuguese chemotherapy patients.

Expect new nutritional screening forms at major oncology units as hospitals prepare for eventual human trials.

Health insurance policies may evolve; if calorie restriction truly lowers drug dosage or hospital stay, some insurers could incentivise medically supervised diets.

Investors tracking health-tech should note that fasting-mimicking meal kit start-ups could find a regulatory foothold once clinical data mature.

Nutritional Red Flags

Portuguese dietitians warn that unsupervised cuts can lead to cachexia, lower immune cell counts, and derail the country’s progress on meeting EU malnutrition targets. The safe middle ground favoured by most clinicians is an intermittent 12-hour overnight fast combined with the Mediterranean diet, which already aligns with national guidelines and provides the antioxidant-rich olive oil, fish and legumes that reduce inflammation.

The Road Ahead

RISE Health scientists are drafting a Phase 1 protocol they hope to lodge with Infarmed by early 2027. If approvals follow, a small cohort of Portuguese sarcoma patients could be the first in Europe to test whether a three-week, physician-monitored calorie deficit enhances chemotherapy. Until then, the takeaway is simple: stay informed, but don’t slash your plate without hospital sign-off.