Dear Mark: PUFA/SFA Swap, Ticks and Meat Allergy, HIIT for Older Men

For today’s edition of Dear Mark, I’m doing three quick topics. First, what are we to make of the studies in which replacing saturated fat and trans-fat with omega-3 and omega-6 polyunsaturated fat seems to reduce heart disease? Second, although red meat is nutrient dense and generally a more interesting option than plain chicken breast, some people have legit red meat allergies (tick-induced or otherwise). What do I think about that and the tick situation in general? And third, is HIIT an effective (and safe) option for middle-aged men?

Let’s go:

Larry pointed out an interesting quote from the PUFA article I linked to on Sunday.

Quote from the heart disease explanation article-a reason to be wary of ‘PUFA Paranoia’:
“Summarising the clinical studies, Ramsden and colleagues performed a meta-analysis of randomised controlled trials comparing mixed omega-3/omega-6……-When saturated fat plus trans-fat was replaced by omega-3 and omega-6, there was a significant 22% reduction in non-fatal MI plus CHD death“

Still a good idea to choose seed oils wisely, though.

Nice catch, Larry. Of course, this illustrates the difficulty and downright impossibility of making perfect nutrient-for-nutrient swaps.

The meta-analysis you describe in the quote wasn’t exploring every potential option for a person. They combined saturated fat and trans-fat into one group, and omega-3 with omega-6 into another, then swapped one group for the other. They never mingled, they never explored a little from here, a little from there. They “replaced” one group of fats with another group.

What does it say about removing trans-fat and leaving saturated fat? Nothing.

What does it say about removing trans-fat, leaving saturated fat, and including omega-3s and omega-6s? Nothing.

What does it say about adding some omega-3s to the saturated fat in your diet, eliminating both trans-fat and omega-6 seed oils? Nothing.

Those three scenarios are far more realistic than wholesale fatty acid replacement. Unfortunately, they’re very difficult to study at scale to produce nice, neat headlines. The best thing to do is for each individual to eat, live, and experiment with full presence, an open mind, and an inquisitive disposition. Be subjective, be objective. How you feel, look, and perform are valid biomarkers, as are more traditional biomarkers like lipids, CRP, waist circumference, glucose, and insulin.

Article about allergy to red meat due to tick bites. Increased incidence of heart attack and stroke as well as 30% more arterial plaque. That is me. Off red meat 2 months ago and feel so much better 4 years after stents the 1 year later double bypass. Needed more but too much plaque for more bypass grafts so had TMR procedure. 2 tics in Jr. High and High School. Sister had beef and pork allergies in elementary school and took allergy shots for years. We must remember we are all different and what works for some doesn’t for others.
Hope links are allowed here. If not google “tics, red meat and atherosclerosis”.

I love links. Bring ’em on.

Very good, valid point: We are all different and what works for some doesn’t work for others.

The tick issue is really quite concerning, especially for a group of people like Primal Blueprinters. We love the outdoors, where ticks thrive. We love wearing minimalist footwear, which ticks can easily surmount and get at our bare skin. Sometimes we don’t even wear shoes at all, which makes it even easier for them. We enjoy exerting ourselves, breathing hard, and working up a sweat, and ticks are drawn to the carbon dioxide we exhale and the ammonia we produce in our sweat. I bet we even taste better.

Growing up in Maine, ticks were around, but not like they are these days. And in Malibu, ticks were pretty few and far between. I never had a single one in all my time there. My dogs? Maybe once or twice. That’s with frequent exposure, too. They’re everywhere now.

Be careful out there, folks. And not just because you like your red meat.

Hey Mark,
I’ve heard others mention HIIT as a must for older guys.
You failed to mention it in the how to fix it section and I was wondering if that was intentional or just an oversight. Thoughts?

HIIT is fantastic for older guys. The problem many people have is the “high intensity” part scares them off. They worry they’re too frail, or their better days are behind them, or that they’ll break or twist or pull something. Or maybe it’s just because the older you are, the (generally) slower you are, and you figure you’ll never be able to approach true “intensity.” Well, intensity is relative. What matters is that you are doing something that’s intense for you, something that stresses and forces your body to adapt.

Let’s look at some research.

In middle-aged men, high intensity interval training had a stronger, more positive, and faster-acting effect on heart rate variability than classic aerobic endurance training. The HIIT consisted of 4-6 30 second all out cycling sprints with 4 minutes rest—extremely intense, this is the Wingate test which famously provides puke buckets. The endurance training was 40-60 minutes at 60% peak workload. Improved heart rate variability is a powerful marker for improved health, stress resilience, and cardiovascular health in particular (one of the big ones for older men).

Even untrained middle-aged men can handle HIIT. A cool version called 15-10-5 (15 seconds of slow movement, 10 seconds of moderate running, 5 seconds of all out sprints, done continuously for the time allotted) helped middle aged men cut body fat and increased both muscle mass and bone mineral density.

Older patients with heart failure who are still in the hospital can do it, too. A group of them performed a few sessions of one minute high intensity aerobic intervals at 80% peak Vo2max with 4 minutes rest in the hospital, improving muscle power along the way.

Cycling is the classic HIIT movement employed in these populations, since they’re relatively “low-impact” while still being intense as hell. You can do anything you’re comfortable doing. If you want to tackle straight sprinting but worry about your joints, try uphill sprints. They’re my go-to option, because they’re incredibly hard but easier on the joints than running on flat ground. Also check out these alternatives.

That’s it for today, folks. Have a great rest of the week. Be sure to let me know your thoughts down below.


Kiviniemi AM, Tulppo MP, Eskelinen JJ, et al. Cardiac autonomic function and high-intensity interval training in middle-age men. Med Sci Sports Exerc. 2014;46(10):1960-7.

Ravnholt T, Tybirk J, Jørgensen NR, Bangsbo J. High-intensity intermittent “5-10-15” running reduces body fat, and increases lean body mass, bone mineral density, and performance in untrained subjects. Eur J Appl Physiol. 2018;118(6):1221-1230.

Taya M, Amiya E, Hatano M, et al. High-intensity aerobic interval training can lead to improvement in skeletal muscle power among in-hospital patients with advanced heart failure. Heart Vessels. 2018;33(7):752-759.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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