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Welcome to Weekly.health’s 26th issue. Every week, we explore cutting-edge research, actionable advice, and science-backed nutrition insights to help you live longer and healthier.

Our aim is to help you live another 10 healthy years and cut your risk of age-related disease.

🗒️ In This Issue:

• 📚 A brief note on sustainability

• 📚 Books We’re Reading Right Now

• 📈 Research Digest: What’s new in nutrition science

• 🔥 Calculate your BMR (try our free tool)

• 💊 Supplement Deep Dive: Ashwagandha

• 🛍️ Recommendations

• 📘 Glossary of Terms: Definitions for technical terms in this issue

📚 A brief note on sustainability

This week marks six months of Weekly.health, and we wanted to share a quick, honest update.

From the outside, it’s reasonable to assume that a newsletter like this — with affiliate links, book recommendations, and now educational tools and courses — comfortably pays for itself.

In reality, it doesn’t. In practice, each issue currently generates only a small amount of revenue and costs significantly more to produce.

Each issue takes several hours of research, reading, and synthesis, and while revenue has slowly increased, Weekly.health still runs at a net loss per issue once platform costs and research tools are accounted for. We’ve worked hard to streamline production and keep costs sensible, but growth itself increases those costs.

Nothing about the newsletter is changing, and we’re committed to keeping it independent, evidence-based, and accessible. But if you find value in the work and would like to help make it sustainable, one simple way to do so is via Buy Me A Coffee. Even a single coffee genuinely makes a difference.

There’s absolutely no expectation — your time and attention already mean a great deal. We’re grateful you’re here.

You can still support us by selecting from our recommended books and products below.

📚 Books We’re Reading Right Now

📈 Research Digest: What’s New in Nutrition Science

Here’s the best of recent nutrition research:

🥗 Mediterranean-style eating may reduce inflammation after cancer treatment
In 132 people in cancer remission, a 6-month personalised Mediterranean, low-GI diet led to weight and belly-fat loss, plus better insulin control and lower inflammation. The plan focused on plenty of vegetables and wholegrains, fish or legumes at least three times a week, olive oil daily, red or processed meat just once a week, and desserts only occasionally. Colorectal cancer patients benefited even without weight loss. (source)

❤️ Healthy habits can slow heart ageing
Using data from over 250,000 UK adults, this study found that healthier lifestyles were linked to a “younger” heart, measured by cardiovascular biological age. The biggest drivers were diet and alcohol habits. Eating a balanced diet (regular fruit, veg, wholegrains, fish and limited processed foods) and avoiding heavy drinking mattered most, especially diet for women, and alcohol moderation for men. Small daily choices really add up. (source)

🧠 Intermittent fasting may help protect the ageing brain
This narrative review analysed 12 peer-reviewed studies (mainly animal studies plus a few small human trials) on intermittent fasting and brain health. Results suggest fasting patterns like time-restricted eating or 5:2 may improve memory and attention and support brain “clean-up” processes linked to Alzheimer’s and Parkinson’s. Practical takeaway: a gentle overnight fasting window (12–14 hours) may be a sensible, low-risk place to start—pending stronger human evidence. (source)

🥗 A daily drizzle of olive oil may improve heart health
In this 4-week randomised trial of 50 people with high cholesterol, daily extra virgin olive oil improved blood vessel function and slightly lowered blood pressure and heart rate. Just 8 g per day of high-polyphenol olive oil worked better than a larger dose of standard EVOO. Takeaway: use a good-quality, peppery EVOO daily, as small amounts seem to deliver real vascular benefits. (source)

🔥 Calculate your BMR (try our free tool)

Do you know how many calories your body needs just to exist?

Your basal metabolic rate (BMR) is the number of calories your body burns each day at complete rest — breathing, circulating blood, maintaining organs, repairing cells. No steps. No workouts. Just staying alive.

Why does this matter?

Because BMR is the foundation of almost every nutrition decision:

• Trying to lose fat without under-fueling

• Eating enough to support muscle, hormones, and recovery

• Avoiding “mystery plateaus” where weight or energy stalls

• Understanding why two people of the same size can need very different intakes

If you don’t know your BMR, you’re guessing, often by hundreds of calories per day.

I’ve just calculated mine using our BMR calculator over at The Healthspan Academy BMR calculator (screenshot above). It takes less than a minute and gives you a personalised baseline you can actually use, whether your goal is fat loss, muscle, or long-term health and longevity.

Once you know your number, everything else - protein targets, calorie ranges, even meal planning - becomes clearer and far easier to get right.

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💊 Supplement Deep Dive: Ashwagandha

Should you be taking taking ashwagandha supplements?

Often supplemented for stress, research supports a small but meaningful reduction in circulating cortisol levels - the stress hormone. High-stress individuals may benefit most.

1-minute verdict

Try (short-term, with cautions) — Best evidence supports modest reductions in perceived stress/anxiety and small improvements in sleep over 6–12 weeks; performance outcomes (VO₂max/strength) show early promise but are less consistent. Long-term safety is unclear and rare cases of liver injury have been reported, so cycle use and avoid if high-risk.

• Outcomes that matter according to research;

  • Stress/anxiety ↓ (small–moderate)

  • Cortisol ↓ (small)

  • Sleep quality ↑ (small)

  • Possible VO₂max/strength ↑ (mixed)

• Time to benefit: 2–8 weeks in trials.

• Who should avoid / adjust: Pregnancy/breastfeeding; active liver disease; thyroid disorders or diabetes meds (monitor/seek advice); those on sedatives/immunosuppressants.

• Upper limit: No established UL; UK FSA currently conducting a risk assessment and has not set a safe level.

Does it actually do anything?

Across nine RCTs (n≈558), a meta-analysis shows reduced perceived stress/anxiety and lower cortisol vs placebo using 125–600 mg/day for 30–90 days. Effects are small–moderate and clinically meaningful for some, especially in higher-stress samples. (source)

Sleep: pooled RCTs show modest improvements in sleep quality and latency, with larger effects at ≥600 mg/day and ≥8 weeks. (source)

Performance: a systematic review suggests VO₂max may increase and strength/recovery markers can improve, but heterogeneity and small samples limit confidence; consider this promising but provisional. (source)

The NIH Office of Dietary Supplements’ 2025 fact sheet concludes evidence supports short-term benefits for stress/anxiety and sleep, while emphasising the need for larger, longer trials and careful attention to safety. For safety they suggest “Ashwagandha appears to be well tolerated for up to about 3 months of use, but its long-term safety is not known.” (source)

Dose & form

• Effective dose range (adults): 300–600 mg/day of root extract standardised to ~5% withanolides; or 125–250 mg/day of higher-potency root+leaf extracts (~10% withanolide glycosides).

• Best forms / standardisation: Choose clearly standardised extracts (state % withanolides and plant parts); root-only extracts are common, while some products use root+leaf to achieve higher withanolide glycosides at lower mg.

• Absorption / timing: Take with meals to reduce GI upset; for sleep focus, evening dosing; for stress, split AM/PM.

Our pick - what to buy

Mechanism minute (for the curious)

Withanolides may modulate the HPA axis and GABAergic signalling, dampening stress responses and improving perceived stress/sleep. Anti-inflammatory and antioxidant effects are also proposed, which could underlie small improvements in recovery and cardiorespiratory performance seen in some trials.

Safety & cautions

Generally well-tolerated short-term, but rare cases of drug-induced liver injury (often cholestatic, sometimes severe) are documented; discontinue and seek care with jaundice, dark urine, severe itching, or marked fatigue.

Potential effects on thyroid hormones and blood glucose mean extra caution if on thyroid or diabetes medication.

Avoid in pregnancy/breastfeeding and in active liver disease; use clinician guidance if autoimmune conditions or on sedatives/immunosuppressants.

The UK FSA is assessing safety and has not set a safe level; several EU agencies (e.g., BfR, RIVM) flag uncertainties and advise high-risk groups to avoid.

Consider limiting continuous use to ≤12 weeks pending more data.

🛍️ Recommendations

Discover the products, services, and retailers we’ve mentioned in past Weekly Health issues, all in one place so you can explore at your own pace.

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🙏 Thanks for Reading!

That’s the end of this issue of Weekly.health.

This newsletter is written by a small, independent team, led by James — who’s been following nutrition science for nearly 20 years and is now working towards a formal, industry-recognised qualification.

We’re based in England, so if you’re over the pond, you might notice a few strange spellings.

Our goal is to make cutting-edge, evidence-based nutrition advice simple, useful, and genuinely applicable to everyday life.

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We’ll keep improving with every issue. If you’ve got any feedback or suggestions, we’d love to hear them (just reply to this email).

See you next week!

📖 Glossary of Terms in This Issue (Alphabetical Order)

A–Z Glossary of Technical Terms

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