Dear Mark: Garcinia Cambogia, Ultra Pasteurization, Getting Better All the Time, and How Much Walking is Enough

MangosteenFor today’s edition of Dear Mark, I’ve got a four-parter for you. First, I address the popular new supplement being touted as a powerful fat-burner: garcinia cambogia. Does it measure up to the hype? Next, I discuss the effects of ultra pasteurization on the proteins, vitamins, and health effects of milk. Is ultra pasteurization a dangerous practice, or does it just produce milk that is less than optimal? After that, I explore the question of what to do when you’ve seemingly achieved your initial health goals but still want more. Do you keep tweaking things to make them even better, or do you make the attempt to be content? And finally, I tell a reader how much walking is actually enough.

Let’s go:


I’m seeing a lot of advertisments (facebook recommended ads, pop-up, etc) for Garcinia Cambogia. I tried searching and don’t find that you’ve written anything about it. As a person that tries to follow paleo eating (not perfect) and still carries a few extra pounds (5 feet 10 inches and 188 lbs, some flab) I was wondering if it’d be worth trying either the fruit or supplements. The supplements are made from the rind of the plant and that isn’t something I’m used to eating. Maybe I could juice it.

Your thoughts would be greatly appreciated.


Dr. Oz lauded garcinia cambogia on a recent episode of his show. Like all the other supplements he’s touted as incredible fat-burners before it, garcinia camboiga has experienced an explosion of interest. But does it work?

In rats, garcinia cambogia (a fruit related to the mangosteen) extracts ameliorate the metabolic disturbances caused by obesogenic diets, reduce visceral fatsuppress fat accumulation (while being highly toxic to the testicles), and even selectively inhibit gene expression related to abdominal fat gain without affecting genes necessary for fundamental support of the tissue. It sounds wonderful, but looking through a number of humans trials, we see a different pattern emerge:

Unfortunately, as a “fat-burner” or appetite suppressant, garcinia cambogia extract just doesn’t seem very effective in humans. Rats are a different story. If you raise show rats and need a little help slimming down the tubbier ones before competition, garcinia cambogia might help. For everyone else, I’d skip the supplement unless you can try it for free. Cause hey, it might defy the evidence and work for you (just don’t pay for it). At least it’s safe. It may also slightly enhance glycogen synthesis in skeletal muscle after exercise. That’s something, I guess.

That said, I’d definitely eat the (native to Indonesia) fruit if you can get your hands on it. Trying new fruits is always worthwhile, and fruits tend to be pretty healthy, tasty foods with interesting nutritional benefits. There’s no magic bullet out there of which I’m aware. Only healthy foods that contribute (sometimes a huge amount) to an overall healthy way of eating.

I hope like heck you will take on this subject, because there’s way too much rhetorical finesse going on when it comes to the rapidly increasing use of Ultra Pasteurization of milk. Finding articles condemning the process is relatively easy, and if you want justifications for its use (or an “apologist’s” reply), just email any organic dairy and ask for some. I get all that…but you are a source of nutritional expertise, and you’ve appeared to have staked out a rational, non-confrontational territory when it comes to issues like dairy. So I’d love to hear from you – is ultra pasteurization a problem…or isn’t it? And why?



Just so people know, ultra pasteurization involves exposing milk to 280 ºF temperatures for two seconds. This kills all microbes and makes the milk so shelf-stable that it can sit out, unrefrigerated, for months.

This is a tough one. You’ve got claims that ultra pasteurizing milk “flattens” the proteins, makes them unavailable to our digestive enzymes, and allows them unfettered access in their intact state to our blood stream via our permeable intestinal lining (which the milk may or may not have had something to do with).

The “protein flattening, digestion inhibiting” argument is commonly attributed on a number of websites to Lee Dexter, a goat farmer and microbiologist. While I was unable to find any references in the literature supporting this specific claim, the heating of milk can actually reduce allergenicity of milk proteins in people with milk protein allergy, according to some research. There’s even research suggesting that kids with milk allergy can use baked milk (which they tolerate) to develop widespread tolerance of unheated milk, too. Another study found that ultra high heat treatment of milk made the proteins more digestible, not less – although this is only true for recently treated milk; storage appears to reduce digestibility, and most ultra-pasteurized milk you encounter is “in storage.” These seem to oppose the claims that ultra pasteurized milk is indigestible as a rule, although storage may be problematic (is most milk technically “stored”?).

However, heating milk does alter the proteins and this can definitely have unwanted effects. Raw milk proteins – the whey, specifically – are uniquely stimulatory of glutathione, the body’s master antioxidant. Heating the milk denatures the whey and drastically reduces its stimulation of gluathione secretion, with ultra pasteurization denaturing up to 100% of the beta-lactoglobulin (the whey component responsible for glutathione synthesis). This is probably the likeliest reason for the protective effects of raw milk consumption on asthma and allergies demonstrated in studies. Ultra pasteurization also reduces B12 and thiamine levels in milk. It affects the folate binding protein as well, which could reduce folate bioavailability.

What about all the people who prefer raw milk and report improved digestion and health from consuming it? I’d definitely put myself in that category; on the very rare occasion that I consume milk, I definitely prefer and “feel better” with raw. Are we just imagining things?

A likely explanation is that while many consumers either have no issue digesting denatured, heat-altered milk proteins or don’t notice a difference, many do – and the ones who do have a sensitivity (either from previous health issues or perhaps elevated intestinal permeability) are the ones who notice huge benefits from consuming raw milk and/or avoiding ultra-pasteurized milk. Now, maybe the people without issues simply don’t know any better. Maybe they’ve accepted poor digestion and all the health issues that accompany it as just “part of life.” Maybe if they did switch to raw milk, or even vat pasteurized milk, they’d be converts (I suspect it’s likely). We can’t know for sure, though, especially since the actual evidence is inconclusive.

One more thing: it’s often claimed that ultra pasteurized milk cannot be used to make yogurt. I don’t know what to make of this, seeing as how ultra pasteurized milk is more susceptible to bacterial contamination (with raw milk being far more resilient with its strong arsenal of resident bacteria to oppose incursions). Yogurt is just “contamination” with the right species, so ultra pasteurized milk should work. This guide to yogurt-making seems to agree, and this source suggests that the denatured proteins in ultra pasteurized milk even improve the texture of yogurt.

To sum up as best I can, I don’t see any ironclad evidence that ultra-pasteurization renders milk especially dangerous, and even though I don’t drink the stuff and vastly prefer raw dairy, many of the claims about ultra pasteurization have been greatly exaggerated.

New Year… Not looking for the healthiest weight loss lifestyle…Not looking for ways to incorporate exercise into my daily life . Where does a healthy, fit individual find new ways to keep improving? Most articles geared towards individuals who need help to lose weight and/or to exercise more. Where do others like myself find information to improve an already healthy individual?


I’m maybe going to give you the answer you weren’t looking for or expecting, but I think it’s the right one in this case: you don’t.

If you’re healthy and fit enough to have to rack your brain to come up with some way to improve those facets of your life, you’re fast approaching the realm of diminishing returns. In fact, in my experience it’s the folks who get overly bogged down in details and micromanage everything that create problems for themselves. People come to Primal with a laundry list of health issues and, with a standard approach, are able to check most of them off. They lose weight, get off the meds, see their numbers in the gym improve, and are just feeling good overall. They think “Why not feel even better?” and start tweaking things here and changing things there. They dig deep into the health blogs, using most of their free time actively thinking about improving their health.

And yet their health degrades. The new diet tweaks don’t take. Their previously basic but consistent workout routine is replaced by a constantly shifting rotation of exercises they read about on a lifting forum that will only end when they find The One True Lift (which doesn’t exist, of course). Late nights on the Pubmed database reading about the debilitating health effects of sleep deprivation ironically lead to chronic sleep deprivation.

At some point, we have to stop the relentless pursuit of… what? What are we looking for, really? How much healthier can we get? We aren’t corporations whose continued success depends on endless growth to satisfy investors. We’re the investors in our own health. We profit when we’re happy, healthy, and fit. As humans, it’s good enough being good enough.

So don’t go looking for a problem that probably isn’t there. It can get in the way of maintaining your good health and fitness levels, which should be your main goal. If you want to improve, focus on other aspects of your life. Explore your creativity, take up a craft, learn an instrument, travel more, read a book a week, learn a language – that sort of thing. There’s way more to life than just health and fitness (although those are the foundation for everything).

What is considered “enough” walking? I know everyone is different but would like a round number. I try to do 3 miles a day.


It’s tough to pin down hard numbers, since it really depends on multiple factors like size, weight, leg length, fitness level, age, and goals. We have a few rough ideas, though.

Our hunter-gatherer ancestors frequently moved around at a slow pace, as a rule. Studies on extant hunter-gatherers like the Hadza support this, showing that women walk about 6 km/day (3.7 miles/day) and men a bit over 11 km/day (or 6.8 miles/day). Earlier research put the numbers a bit lower but still in the same general realm.

For weight loss, current research indicates that 10,000 steps (0r about 5 miles) a day seems to be best. One study found that a 10,000 step/day target helped obese and overweight adults improve body composition. The average improvement in steps/day was just 4,000 and the mean body fat reduction was 2.7 kg. Those who adhered to the plan and actually got close to 10,000 steps a day had even better results with more fat loss, since the averages also included those participants who got nowhere near the 10,000 step goal.

Getting those steps in becomes even more important for general health as we age. A recent study found that among healthy older people, a two week reduction in daily step count resulted in lower leg mass and a reduced ability for the leg muscles to synthesize protein to build themselves back up. So not only did they lose muscle by walking less, gaining muscle actually became more difficult. Another analysis examined the association of various daily step counts with improvements in areas of health among elderly men and women. Here are their results:

  • 4000-5000 steps/day: Improvements in mental health and indices of depression.
  • 7000-8000 steps/day: Improvements in aortic arteriosclerosis, osteoporosis, physical fitness, and muscle wasting.
  • 8000-10000 steps/day: Improvements in markers of metabolic syndrome, particularly hyperglycemia and hypertension.

I’d shoot for 10,000 steps, or about 5 miles. Since it’s total steps that seems to matter most, and not just the amount of steps you take throughout your planned walks, you’re probably close to 10,000 steps a day with your “three miles a day” habit plus whatever other steps you take on a given day. But go ahead and take longer walks some days and shorter walks others. Aim for 10,000/5 miles as an average.

That’s it for today, folks. Thanks for reading!

TAGS:  dear mark

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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