⭑ Retraining your body to burn fat helps you live longer ✔ Try this
⭑ Omega 3 slows aging, says large validated study ✔ Worth a try with real food
⭑ The brain cleanup crew - ketones! ✔ Here's how it’s not too hard
⭑ Brief bursts of exercise yield disproportionate gains - WHO research

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Hello,

I trust you are well and active.

I found one myth-debunking piece of research this week, which always grabs my attention, and then lo and behold another popped up. Both make sense to me.

Item #1 is about metabolic flexibility. I knew about this because of my running. But I hadn’t realised that it is especially good to focus on developing it when we're older - say 60-plus. The research debunks the myth that carbs are your only energy lifeline and that the carb-crash cycle - read more below.

Omega 3 - please no more ads! But wait, real systematic research found it slowed aging, for real. A small dose. Looks real to me, but I'd still prefer to get it in real food, see item #2.

Then the second myth-debunker popped up on my screen. Ketones. Another subject where I grit my teeth until I can hit the "Skip" on the ads. But this research found for sure that ketone release helps clean up the metabolic waste in our brains, and how you do it is the same way you promote metabolic flexibility, almost. See item #3.

Then in item #4, our usual "exercise of the week", I turn to research on "exercise snacking" which has unexpected benefits for longevity pathways that can literally slow down the aging process. Read on.
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Your podcast of this newsletter is here (14 min).

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01 Why Boosting Your Metabolic Flexibility Matters

I'm a big fan of boosting our metabolic flexibility. What does that even mean, you ask? In a nutshell it is about retraining your body to get better at burning fat, something which it did naturally when you were younger.

Recent studies comparing different dietary approaches have revealed something fascinating: while keto diets excel at short-term blood sugar control, Mediterranean-style eating patterns show better long-term metabolic health outcomes. But here's the twist - it's not about choosing one over the other, it's about understanding when to use each approach.

Aging slows us down—specifically, an enzyme called pyruvate dehydrogenase stalls, making energy production sluggish. You feel it: dragging by noon, crashing after meals, or fading on stuff you used to crush.

But metabolic flexibility isn’t jargon—it’s fact. It debunks the myth that carbs are your only energy lifeline and that the carb-crash cycle—spike, drop, repeat—is just “how it is.” That cycle hits harder after 60, when our insulin sensitivity dips and glucose control gets wobbly. Flexibility breaks it by training your body to tap fat, not just carbs, keeping you steady without the roller coaster:

• Steady Energy, No Burnout: Your glycogen (carb fuel) tank shrinks with age. If fat-burning's rusty, you’re wiped mid-day. Flexibility lets you use fat for long hauls—think gardening or a day out—saving glycogen for when you need a burst. Athletes train this to preserve reserves; for you, it’s no naps to survive.
• Less Aches, More Bounce: Stuck in carb-only mode piles on oxidative stress and muscle damage. Switching fuels cuts soreness and speeds recovery—less creaking after chores.
• Dodge the Slump: That enzyme slowdown betrays you, but diet tweaks push back. You stay sharp, not sluggish.

⇒ The goal: flexibility, honed by cutting carbs to burn fat, steadies glucose—no wild highs or lows from carb hits. That’s fewer shaky spells, less diabetes risk, more freedom.

What this means for you: Mediterranean eating (fish, veggies, olive oil) steadies your metabolism; low-carb stints (like keto days) boost fat-burning. Blend them, and you thrive. Try ditching pastries for nuts over 24 or 48 hours—slump gone. Studies on insulin sensitivity agree: this works.

Your Move:

• Try: One day a week, go low-carb—eggs, avocado, meat. Rest of the time, Mediterranean—salmon, greens, olive oil.
• Test: Add in shorter ending windows e.g. breakfast later and dinner earlier, and see if you start to feel less sluggish and even more evenly active.

⇒ Forget “aging means slowing.” Metabolic flexibility puts your body back in the race, enjoy it.​​​​​​​​​​​​​​​​​

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02 Here We Go Again? Or Do We - Omega 3

Because of the incessant promotion of such things I am always a little skeptical about claims for Omega 3. A study published in Nature Aging in February 2025 investigated the effects of omega-3 supplementation on biological aging at the cellular level.

Conducted over three years with 777 participants aged 70 and older, the research found that taking one gram of omega-3 daily resulted in a modest slowing of biological aging, as measured by DNA methylation clocks.The effect was more pronounced when omega-3 was combined with vitamin D supplementation and regular exercise.

Specifically, the combination of all three interventions led to an additive protective effect on biological aging, with a reduction equivalent to three to four months over the study period.

The numbers? Just 1g a day (330mg EPA + 660mg DHA) slowed aging by nearly 3–4 months over three years. It may not sound huge, but in the aging world, that’s a big deal.

And here's the kicker: when omega-3 was paired with vitamin D and regular exercise, the anti-aging effect got even stronger.

⇒ It's the combo—supplementation, movement, and micronutrients—that really moves the needle.

What this means for you: Add omega-3 to your daily stack, but don’t stop there. Layer it with vitamin D and consistent exercise to amplify the effect. Small changes, big long-term payoff.

Or, to​ match the daily intake of 1 gram of combined EPA and DHA from supplements, you can incorporate the following real food options (my preference) into your diet:

• Mackerel: Approximately 70 grams (about 2.5 ounces) of mackerel provides around 1 gram of EPA and DHA. ​
• Salmon: Roughly 100 grams (about 3.5 ounces) of salmon offers a similar amount of these omega-3s.
• Sardines: Consuming about 90 grams (approximately 3 ounces) of sardines delivers close to 1 gram of EPA and DHA.

Related: ​Brain Health Is Boosted By Eating Less, Often — Here’s How To Start​​​​

@Medium - Follow me on Medium ↗, covering ⭑food, ⭑brain, ⭑body, ⭑life

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03 Ketones and Your Brain—New Tricks for Old Dogs

I suppose chance occurs to a prepared mind, as Louis Pasteur is reputed to have said (during an 1854 lecture at the University of Lille, in French: "Dans les champs de l'observation, le hasard ne favorise que les esprits préparés.").

I noticed yet another myth debunking piece of research, related to item #1, and equally fascinating I think. Ketones. I thought ketones are just about shedding pounds?

Think again. New research flips that old myth—ketones, those molecules from fasting or low-carb eating, aren’t just fuel. They’re like a cleanup crew for our brain, clearing out damaged proteins and junk that pile up with age.

Here's how - when carbs dip, ketones kick in and trigger autophagy—our body’s recycling system. In your brain, it’s a targeted scrub-down, keeping neurons healthy.

Studies show this cuts through the gunk linked to aging and brain decline—think Alzheimer’s or that annoying forgetfulness. People swear by the mental clarity on keto or fasting; now science says it’s not just energy—it’s repair.

⇒ This is more gold for staying sharp.

What this means for you: The simplest advice is to "skip carbs one morning—eggs and avocado instead. Or fast ‘til lunch twice a week." This sounds awfully like item #1 doesn't it.

We don't trust such simple truths, and perhaps there is a little more too it. Here's a slightly bigger move, which I think will pay more dividends:

⇒ Once a week, cut carbs (under 30 grams)—think eggs, nuts, no toast. ‘Til noon (skip breakfast) or ‘til dinner (full day) works; longer ramps ketones more. Once a week won't kill you it will make you feel better once you adjust to it. In fact, you'll start looking forward to it, I promise.

Related: ​Walking Backwards Benefits So Much More Than Your Knees​​​​​​​​​​​​

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04 The New Science of Movement for Longevity

Our exercise of the week is ... movement.

If you think exercise is just about burning calories or building muscle, the latest research will make you think again. The WHO's updated physical activity guidelines reflect a revolutionary understanding of how movement affects our biology at the cellular level.

⇒ It turns out that physical activity isn't just about fitness - it's about triggering longevity pathways that can literally slow down the aging process.

If would make absolute sense to you if you are a fan of yoga or Tai Chi.

Here's what's fascinating: research shows that different types of movement activate different cellular signaling pathways.

For instance, resistance training triggers mechanisms that preserve muscle mass and bone density, while moderate-intensity activities like brisk walking activate genes involved in DNA repair and cellular maintenance.

Even more interesting is how brief bursts of movement throughout the day can help counteract the negative effects of sitting - it's like hitting the reset button on your metabolic processes.

The most exciting finding is about something called "exercise snacking" - short bursts of activity spread throughout the day. These mini-workouts are on track to potentially be more beneficial for metabolic health than one long session, especially for we older folk.

Think of it like feeding your cells small, regular doses of anti-aging medicine, rather than one big weekly dose. This is particularly relevant for those of us who spend long hours at desks or in sedentary activities - that's me (at the desk that is).

What this means for you: Aim to structure your weekly activity to include:

Core Movement Strategy:

• 150-300 minutes of moderate activity (broken into manageable chunks)
• Two to three strength training sessions (focus on major muscle groups), bodyweight exercises are great if you can’t get hold of weights.
• Daily balance exercises (especially important after 50)
• Movement breaks every 30-60 minutes of sitting

Implementation Approach:

1. Daily Foundations:
   • Morning mobility routine (5-10 minutes)
   • Lunchtime walk (15-20 minutes)
   • Evening stretching (5-10 minutes)
2. Strength Focus:
   • Full-body workouts twice weekly
   • Emphasis on compound movements i.e. not isolation exercise on a machine, unless you are in rehabilitation
   • Progressive overload principle
   • Recovery days between sessions
3. Cardiovascular Health:
   • Mix of moderate and vigorous activities
   • Include both structured and incidental exercise
   • Focus on activities you enjoy
   • Build intensity gradually

⇒ Pro Tips:

1. Start each workout with joint mobility exercises
2. Use everyday activities as exercise opportunities (take stairs, park further away, stand on one foot while brushing your teeth)
3. Track your progress but focus on consistency over perfection
4. Listen to your body and adjust intensity as needed
5. Find movement partners to maintain motivation

Remember: The goal isn't to become an athlete - it's to maintain function and vitality as you age. Every bit of movement counts, and it's never too late to start.​​​​​​​​​​​​

Thanks for reading!

>> My Latest Blog Post: Energise Your Golden Years: Boosting Your Desire to Exercise with Gut-Healthy Foods​

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