In the last blog we began by reviewing how humanOS evolved in 2018. We ended by focusing on what we learned in 2018 about the science of aging. In this post we turn our attention primarily to new developments in the science of nutrition, picking up where we left off as we consider how diet affects aging.
Diet and aging: prebiotics, probiotics, and protein
How diet affects how we age has received a lot of airtime this year. Because humans live for so long and aren’t very good at sticking to lifestyle interventions, most research on diet and longevity has been done on other animals. Dan discussed one of these studies with Susan Westfall, who found that fruit flies that consumed an Ayurvedic supplement plus certain probiotics lived dramatically longer than other flies.
Such preclinical studies are very interesting and can pave the way for research on humans, but we should always be wary of assuming that it’s possible to use other organisms to model how humans respond to various stimuli. I wrote about this a little in a two-part blog (1, 2) in which I shared some of my reservations about making this leap as I discussed the importance of dietary protein as we age. My thoughts on this topic seem to generally converge with those of Stuart Phillips, with whom I had a great time speaking. One talking point that came up was whether eating insects supports skeletal muscle mass and health. Earlier, I wrote about this on the blog, highlighting some noteworthy considerations, foremost among which is the fact that eating insects is much more sustainable than relying on foods such as meat.
How to keep our bodies healthy during strenuous training
Like my conversation with Stuart Phillips, Dan’s conversation with Keith Barr also focused on skeletal muscle mass. Much of their back and forth was about how to ensure that we exercise and eat to support the health of connective tissues such as tendons.
I’ve had first-hand experience of musculoskeletal problems, and as a teenager I experienced back pain intermittently. I was therefore very happy to speak with Stuart McGill about his work on spine health and performance. His research and books have strongly influenced my thoughts on physical activity and exercise training over the years. Stuart drills home the importance of first moving well (don’t “pick the scab”!) and not adding fitness to dysfunction. To give an analogy that might help instil the latter idea, think of the muscles of your torso as a car’s engine and your spine as the vehicle’s chassis. Well, you wouldn’t want a car with a powerful engine and a flimsy chassis, for you’d probably soon write the chassis off. I frequently hear people say things like “back strength is key to avoiding back pain. So, go do some deadlifts!” I enjoy deadlifting as much as the next person, but this advice is often misguided.
Nutritional strategies to boost health and performance
Antioxidants are another topic about which there has been much confusion over the years. Dan’s discussion of antioxidants with Michael Ristow is one of my favorite humanOS Radio episodes of the year. I remember enjoying reading Michael’s 2009 PNAS paper during my undergraduate degree, so it was great to hear his thoughts on a range of interesting matters. In the blog that accompanies the podcast, we included additional information about many of the compounds discussed, should you be interested in more information on them.
This year, we tried to share some simple nutritional strategies to enhance athletic performance on the blog. One of these is taking creatine monohydrate. This blog was necessarily long, for there is simply so much evidence that creatine supplementation improves numerous facets of health and performance. Earlier, I wrote about what I thought was a fascinating study showing that rats fed creatine slept less and had shallower sleep too. What’s truly remarkable is that whereas sleep loss consistently degrades perhaps all aspects of human biology, in many ways creatine supplementation seems to have the opposite effects, despite its effects on sleep.
Creatine supplementation seems to be good for the health and function of the brain, and many people’s interests in compounds with these properties grew this year. I’d noticed that when I consume substantial quantities of cocoa or dark chocolate my mood and productivity surge, and it turns out that there’s a substantial body of evidence showing that cocoa has these effects, as I reviewed here. As I read about other plants with similar effects, Bacopa Monnieri piqued my curiosity given its safety profile and positive effects on cognitive function.
Another nutritional strategy that we reviewed is dietary nitrate supplementation. Dan interviewed Jonathan Burdette about a fascinating study Jonathan’s research team did showing that adding nitrate-rich beetroot 
juice supplementation to a walking-exercise program made the patterns of blood flow in the brains of elderly people more closely resemble the brains of younger people. I then went on to overview the effects of dietary nitrate on exercise performance and general health, including that of the brain. In short, don’t skimp on consuming nitrate-rich vegetables such as beetroot and spinach!
The problem is that some people struggle to consume enough fruits and vegetables to meet their nutrient needs and gain all of these benefits. A convenient and tasty way to address this is by making smoothies, and Ginny has done great work on this topic this year. First, we made a series of smoothie recipes that is available to Pro members. Next, Ginny walked you through our principles for how to make healthy smoothies in our smoothie guide. Most recently, she published a course on the myriad reasons that it’s smart to make smoothies if you seek better health!
Hot topics in nutrition
Has there been a hotter nutrition topic in the online health and fitness community this year than ketosis?
If there has, I’ve somehow missed it.
Interest in ketosis has spiked for many reasons, one of which is its potential efficacy in treating metabolic diseases. In this podcast, I think Dan and Stephan Guyenet did a tremendous job of dissecting a recent study that showed that ketogenic diets can help treat type-two diabetes. In a later episode of humanOS Radio I spoke with Tommy Wood about another therapeutic use of ketones – treating brain injury. But people aren’t only interested in using ketones for medical purposes, and there’s also been some hype about whether ingesting ketone supplements enhances athletic performance. I wrote about this here. Regardless of your reasons, if you’re keen to try a ketogenic diet, Dan made a guide on ketogenic diets that Pro members can access here.
What did we learn about diet in 2018? This blog reviews hot topics in nutrition and more Click To TweetNow, interest in some dietary approaches waxes and wanes dramatically. But people are always interested in alcohol. Back in August The Lancet published a paper provocatively entitled “No level of alcohol consumption improves health”. This predictably caused a stir, and in this blog Ginny coherently strung together her thoughts on this contentious subject. At the same link you’ll also find Dan’s interview with Todd White from Dry Farm Wines. If you’re going to drink, wines made without added sugar are often an excellent choice.
There’s marked variability between people in how well they detoxify alcohol, so while some people appear to suffer no ill effects from a few drinks here and there, others quickly become disorderly. Just visit England if you want to see this for yourself. Anyway, this exemplifies the importance of personalizing nutrition, and new companies providing tests designed to provide bespoke dietary guidance are emerging left, right, and centre. Personalized nutrition is a complex research field, and Dan briefly explored one corner of it in this conversation with Alon Keinan about genetic variation in how efficiently people’s bodies construct certain fatty acids.
Turning heads at the beach
One of the reasons many of us became interested in diet was to feel better about how we look. In truth, much of what we’ve shared this year can help you if your goal is to improve your body composition. But three blogs that Ginny wrote are particularly relevant to those of you wanting to shed fat.
The first of these reviewed a study that showed that despite their high calorie density, walnuts are very satiating and may therefore be a smart choice for those of you who wish to stay lean. Ginny’s next post critiqued a study that reported that drinking sparkling water considerably increases blood concentrations of ghrelin, a hormone that typically increases food-seeking behavior. The careful student that she is, Ginny didn’t take the authors’ conclusions at face value though, pointing out some noteworthy limitations of the study. And in the last blog I’ll mention here, Ginny summarized findings that while after people do cognitively demanding work they’re liable to eat more at a buffet, doing strenuous exercise in the period between the cognitive task and the buffet offsets this effect in the short-term. One more reason to build physical activity into your day!
Finally, one behavior common among people who sustain substantial weight loss is that they weigh themselves regularly. But is the way that most of us weigh ourselves optimal? Well, Dan spoke with Dan Ariely about Shapa, a novel weighing scale that may help people rid themselves of unwanted pounds by overcoming some limitations of traditional scales. You may want to tune in if you’ve been overindulging over the festive period!
The fast track to better health
Fundamentally, changes in how fat you are depend on fat balance, the difference between how much fat your body stores and how much it burns. So, a simple way to tip this balance in favour of fat loss is to simply not eat! But while fasting can certainly be a useful strategy for people who wish to rid themselves of inches off their waists, intelligent use of fasting may have numerous other favourable effects on health too. The question is, what are some smart ways to implement fasting?
In our guide to fasting, Jeff Rothschild (lead developer of our fasting program) and Dan summarized a variety of different fasting protocols, including a method used to mimic the effects of fasting without enforcing a true fast. And if you aren’t a Pro member, you can still read more about one of these approaches in this blog that Ginny wrote.
Closing
That’s all for now. In the final part of this series we’ll review what we’ve learned about circadian rhythms, sleep, and the brain, ending by looking ahead to what’s on the horizon for humanOS in 2019.
Watch this space!
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