Which Health Advice Is Actually True?

Spencer Greenberg, an extremely rational person and ultra synthesizer, posted the below as a public entry on Facebook. I found it interesting. What follows are Spencer’s words…

A query for you about human health: what are dietary/nutrition/health recommendations that are (essentially) universally agreed on by nutrition and health experts of all stripes and schools of thought? Given the incredibly high levels of disagreement in this area, and the poor quality of a lot of the studies, this depressingly short list (below) is all I can come up with. I’m hoping you can help me expand it!

Also, this list probably has some mistakes, so let me know what I’m getting wrong!

-Preliminary List of Universally Recommended Health Interventions-
(1) Don’t consume a lot of sugar (at best, it’s empty calories and probably causes tooth decay, but some claim it’s much worse than that).
(2) Exercise regularly (its best to rotate which type of exercise you do – be very careful to avoid injury, especially when you are getting into new forms of exercise – it’s also unclear what forms of exercise are best e.g. strength training vs. cardio, and how much exercise you should get – also, extremely high levels of exercise are believed to be associated with increasing some health risks).
(3) If you are going to eat a lot of carbohydrates, generally you should choose complex carbs over simple carbs (usually whole grains are also recommended over refined grains, but some argue that whole grains should be sprouted/soaked to remove parts of the seed that are designed to protect it from digestion [HT: Gary Basin]).
(4) Brush your teeth with fluoride toothpaste at least once per day (though perhaps it is not actually a good idea immediately after eating, especially if you’ve been eating acidic foods, the suggestion is to brush before breakfast, or wait an hour after eating – and beware of brushing too often or too vigorously – brushing twice per day may be better than brushing once – and also note that there do exist some very small segment of people in the health field that are against fluoride).
(5) Hydrate regularly throughout each day, especially as soon as you feel thirsty, but even if you don’t (doing so with water is the safest bet, though it’s not clear how much liquid you need in total, and it’s also not clear whether it’s important to do this with water or if other drinks like non-sugary tea are fine replacements. Also, the the 8 cups of water a day thing seems to be bullshit).
(6) Eat plenty of vegetables (preferably not deep fried ones though – note also that there do exist a very small number of people in the health field who advocate an essentially zero-carb or meat only diet).
(7) Don’t eat a lot of deep fried foods in general.
(8) Take Vitamin D3 supplements if you are >60 years old and don’t get a lot of outdoor time, and for the general population, take it if you get very little sunlight.
(9) Avoid frequently drinking large quantities of alcohol.
(10) Avoid frequently consuming tobacco products (but since many of them are addictive, that means it’s safest to avoid them altogether).
(11) If you have the ability to make yourself lose weight and keep it off, prioritize weight and fat loss if you have a very high body fat percentage or a lot of body fat around the gut area [HT: Julia June Bossmann, Ben Hoffman] (the extent to which mild to moderate obesity is bad per se is somewhat debated, as in some studies mild levels of obesity were sometimes even correlated with better outcomes – avoiding metabolic syndrome and poor blood sugar dis-regulation may be more on point than avoiding a very high body fat percentage though the two are significantly correlated [HT: Kara Loewentheil] – however lots of data suggests that three years after a diet most people have regained the weight they lost, and some say that regularly cycling your weight by losing then gaining then losing again could be unhealthy).
(12) If you are going to eat something sweet, fruit is a better bet than candy or sugary baked goods.
(13) Avoid consuming trans fats.
(14) Don’t consume excessive amounts of mercury (which is found in many fish – some say that tuna, king mackerel, marlin, orange roughy, shark, and swordfish are particularly worrisome).
(15) Don’t eat a lot of foods that are burned to the point of being blackened.
(16) Spend some time outdoors in the sun each week.
(17) Avoid getting frequently sunburned.
(18) If you are unusually low in any vitamin then you should consume more of it (but if you have normalish levels, there is not a consensus on whether you should have more of any vitamins as far as I can tell, except perhaps Vitamin D for the elderly which seems to be basically agreed upon – there is also disagreement about whether vitamin pills are as effective as vitamins from whole foods).
(19) If you are a strict vegan, take vitamin B12 supplements.
(20) Don’t get addicted to any drugs (prescription or non-prescription) other than possibly caffeine.
(21) Don’t run a constant sleep deficit (though the amount of sleep each person requires to not have a deficit seems to vary pretty considerably).
(22) Wash your hands with soap regularly [HT: Amy Willey] (though some claim that special anti-bacterial hand soap is not a good idea)
(23) Don’t regularly have non-negligible amounts of caffeine within a few hours of going to bed (though people’s sensitivity to this seems to vary a lot).
(24) Don’t spend your day in very long stretches of sitting without moving (i.e. take breaks where you move around) [HT: Eva Vivalt].
(25) When typing, avoid having your wrists bent at a significant angle for long periods, and avoid having to bend your neck substantially downward or upward to see your computer screen.
(26) Each week spend at least a bit of social time with people you get along well with.
(27) If you have very high levels of anxiety, depression or hopelessness you should seek treatment as soon as possible (e.g. you could try Cognitive Behavioral Therapy with a psychologist or go to a psychiatrist).
(28) Eating a diverse range of healthy foods is usually better than eating a narrow range of foods (of course a diverse range of unhealthy foods is still unhealthy [HT: Bryan Hobart]).
(29) Avoid very high doses of certain vitamin and mineral supplements (e.g. Iron supplements, vitamin A and vitamin B-6, where overdosing is known to happen – beware of mega-dose vitamins unless you know what you’re doing, as they are unlikely to be helpful and could be harmful).
(30) If you have a broken bone or reasonable sized cut or scrape that appears as if it could be infected, go to a doctor immediately (some broken bones require splinting to heal properly, infected wounds may require treatment).
(31) If you have a mole that violates enough of the ABCDE rule, get it checked out by a dermatologist, which means: Asymmetry (if one side of the mole doesn’t match the other), Border irregularity, Color is not uniform, Diameter more than 6 mm (which is about the size of a pencil eraser), and Evolving size, shape or color.
(32) Highly processed meats (e.g. hot dog or bologna) are worse than less processed ones [HT: Claire Zabel].
(33) Do things to keep your brain active, such as learning something new each week or doing something that is mentally taxing [HT: Chad Gracia]
(34) If you have high levels of stress, try to reduce them using whatever techniques you find effective [HT: Jujubee Kang] (high stress has been linked to various negative indicators in the body – techniques that some people find effective to reduce stress include Cognitive Behavioral Therapy (CBT), meditation, progressive muscle relaxation, yoga, walking in nature, and exercise that keeps your heart rate elevated for a reasonably long period).
(35) Keep your sleep cycles at least roughly in sync with the dark/light cycle of the planet (i.e. do most of your sleeping at night, and most of your waking hours during the day).
(36) Don’t regularly drink alcohol before going to bed.
(37) If you think you may be suicidal, or you have made plans for suicide, you should call a suicide hotline immediately, and afterward make an appointment with a therapist or psychiatrist for as soon as is possible.
(38) Keep your living environment at a comfortable temperature, generally in the 65-75°F (18-24°C) range.
(39) Go to a dentist for teeth cleaning and a checkup at least twice per year.

What else should be on this list that I missed? What am I mistaken about that I should remove from this list (because there is actually some disagreement among experts)?

Also, here are some other health and nutrition questions that didn’t make the list because, while many advocate strongly for one side, there still seems to be a reasonable amount of disagreement (rightly or wrongly):

-List of Important Health Questions Experts Don’t Agree On-
(a) How bad is saturated fat, if at all?
(b) How useful is omega 3 supplementation, if at all?
(c) How bad are carbs versus other macro nutrients?
(d) Is there any benefit (or harm) to getting more than the RDA of protein (0.36 grams per pound of body weight)?
(e) Is flossing effective? (If you like flossing, or at least don’t mind it, it may well be worth it, but the benefits are not as clearly established as one would ideally like, and there have been some claims, possibly false, that it can cause bacteria to escape from your mouth into your body in a way that could be bad)
(f) Does dietary cholesterol lead to high blood cholesterol? (apparently the FDA just released new guidelines on this that say “no” [HT: Romeo Stevens])
(g) Is blood cholesterol correlated enough with bad outcomes that we should care about it, per se?
(h) What types of preventative screening / testing should everyone routinely get?
(i) What dietary supplements (if any) should a healthy person take?
(j) Is there any harm from Aspartame or other artificial sweeteners? (all of the many randomized controlled trials on Aspartame on humans I’ve looked out found no negative effects except headaches in a small subset of people, but other studies in rats show weird effects that are hard to interpret, and a lot of people are anti-Aspartame without providing clear reasons)
(k) Is polyunsaturated fat good for you, bad, or neutral?
(l) How bad is meat for you as a broad category, or is it too broad a category to generalize?
(m) How much should you limit your salt intake?
(n) Which type of cooking oil (e.g. olive oil, coconut oil, avocado oil, etc.) should you use or avoid?
(o) How much exercise is ideal, and of what forms?
(p) Is going into ketosis (by lowering your carb intake dramatically) a good or bad idea?
(q) Is intermittent fasting a good idea?
(r) Is it important to go to bed/wake up at the same time every day?
(s) Is there any real benefit to eating organic foods?
(t) Are “grass fed” animal products healthier than non-grass fed ones?
(u) Is there any real difference (in your body) between sugar and high fructose corn syrup? (common sense about chemical composition and some studies suggest the answer is that there is no difference, but many people think high fructose corn syrup is worse)
(v) What’s the optimal mix of macro nutrients?
(w) Does metformin increase lifespan for (basically) healthy individuals? [HT: Amy Willey]
(x) Are GMO foods actually risky, or are they fine?
(y ) Is the heuristic of eating “natural” or “whole” foods actually accurate, or does it exclude too much?
(z) Are probiotics (like acidophilus) useful to take for a generally healthy person?
(aa) How important is stretching, what type of stretching (static vs. active) is best, and when should you do it (just before you exercise, just after, or at other times)?
(ab) How bad are pesticides on our foods (which types are bad, and how much of them do we have to consume before problems begin)?
(ac) Should you take a multi-vitamin pill? (the tide has been turning against them as repeated studies fail to find a benefit in healthy people, but some experts still recommend them)
(ad) Are there vitamin/mineral deficiencies that a significant proportion of people in developed countries have? (e.g. possibly magnesium, potassium, choline, D3, K2 [HT: Romeo Stevens])
(ae) Is it helpful to wake up when the sun rises each morning?
(af) Do heavily calorie restricted diets improve longevity in humans (like they do in mice)?

RIP Seth Roberts

seth-roberts-headshot-colorNews came today that Seth Roberts, the UC Berkeley professor of psychology, collapsed during a hike near his home. I met Seth through our respective blogs and shared a few meals with him in the Bay Area over the years.

I’ve blogged about him several times. Seth taught me about self-experimentation and science. He taught me about nutrition and fish oil. He taught me about innovation and creative thinking.  Most importantly, he taught me the value of appreciative thinking, which I once summarized thusly:

School teaches us to be proactively skeptical and critical. We’re taught to immediately look for the flaws in experiments or theories. An appreciative approach, by contrast, simply asks, “What’s redeeming about this experiment or idea? What’s done right?”

Some VCs are naturally appreciative, others naturally critical. After an entrepreneur pitch their first feedback will either be, “OK, here’s what I like about what you’re doing” versus “Here’s where I think the problems are.”

I am trying to take a more appreciative approach to people. When I meet someone new at a cocktail party, I am trying to ask myself more regularly, “What’s cool / impressive / interesting about this person?” as opposed to dwelling on their imperfections.

Like many who knew him or read his stuff, I’ll miss Seth. He was a one-of-a-kind thinker. And a deeply compassionate person.

What To Do If You Worry Too Much

Some tips from Ad Kerkhof, a Dutch pyschologist who has worked in the field of suicide prevention for 30 years. I found them in the book Time Warped and quote below from the book.

  • Deliberately imagine the worst-case scenario concerning your worry, followed by the best possible scenario. The real outcome probably lies somewhere in between.
  • If you find yourself awake in the middle of night worrying, with thoughts whirling round repeatedly in your head, imagine there’s a box under your bed. This is your worry box. As soon as you spot thoughts that are worries, imagine taking those individual worries, putting them into the box and closing the lid. They are then to remain in the box under the bed until you decide to get them out again. If the worries recur, remind yourself that they are in the box and won’t be attended to until later on.
  • Your worries relate to real and practical problems in your life, so you cannot rid yourself of them altogether, but you can learn to control when you think about them. Set aside 15 minutes in the morning and 15 minutes in the evening to do nothing but worry about the future. Sit at a table, make a list of all your problems and then think about them. But as soon as the time is up you must stop worrying, and whenever those worries come back into your head remind yourself that you can’t contemplate them again until your next worry time. You have given yourself permission to postpone your worrying until the time of your choice. Remarkably, it can work. It puts you in control.

The Problem With Walking Meetings

Walking meetings are all the rage.

Steve Jobs and Larry Ellison, best friends for years, went on walks together around Palo Alto. Jeff Weiner wrote that he’s converting many 1:1 meetings to walking meetings. Brad Feldsays his best meetings are walking meetings. Mark Zuckerberg supposedly walks with key candidates he’s recruiting to Facebook.

Walking meetings are awesome for obvious reasons. Exposure to sun and fresh air lifts your mood. Walking counts as exercise, which is important for health and cognitive function. A physical atmosphere that’s different from the normal white walls of an office — trees, sun, a beautiful landscape — can spark creative trains of thoughts.

My favorite reason for walking meetings? They enable a different kind of social bonding. People open up more outside the office. You can cover personal topics more easily.

Yet walking meetings involve trade-offs, and before you propose them, you should be sure the topic you want to discuss is well-suited to a walking format.

See, while some walking meeting proponents pitch the activity as refreshingly distraction-free, there are distractions while you walk. Namely, having to put one foot after the other and undergo the physical act…of walking. You have to watch where you’re going, even if it’s a familiar path. You have to control your speed and match it with your meeting partner’s pace: not too fast, not too slow. These distractions are cognitively taxing — they draw away your attention and deplete your well of self-control.

See Nobel prize winning economist Daniel Kahneman, in his book Thinking, Fast and Slow:

It is normally easy and actually quite pleasant to walk and think at the same time, but at the extremes these activities appear to compete for the limited resources of System 2. You can confirm this claim by a simple experiment. While walking comfortably with a friend, ask him to compute 23 x 78 in his head, and to do so immediately. He will almost certainly stop in his tracks. My experience is that I can think while strolling but cannot engage in mental work that imposes a heavy load on short-term memory. If I must construct an intricate argument under time pressure, I would rather be still, and I would prefer sitting to standing….

Accelerating beyond my strolling speed completely changes the experience of walking, because the transition to a faster walk brings about a sharp deterioration in my ability to think coherently. As I speed up, my attention is drawn with increasing frequency to the experience of walking and to the deliberate maintenance of the faster pace. My ability to bring a train of thought to a conclusion is impaired accordingly. At the highest speed I can sustain on the hills, about 14 minutes for a mile, I do not try to even think of anything else. In addition to the physical effort of moving my body rapidly along the path, a mental effort of self-control is needed to resist the urge to slow downSelf-control and deliberate thought apparently draw on the same limited budget of effort.

Bottom Line: Walking meetings are fantastic. Beyond exercise, it’s a great format for social bonding and perhaps for creative thinking. Yet, I believe on average you are less likely to think big thoughts and solve difficult problems while walking. Furthermore, the faster and harder the walk, the worse the ideas you generate. So for serious analytical work or high stakes conversation, consider the old fashioned routine of sitting in an office or conference room.


Some other musings on physical activity and thinking:

  • Our brains are associative. Associate certain physical places, positions, or activities with certain kinds of thinking. Have a desk where you do hard, analytical thinking; have a desk where you do light email. Have a walk you do where you’re trying to be as creative as possible; have a different walking route that’s more for social catch up. Train your brain.
  • Standing desks vs. sitting desks: There’s a parallel to walking meetings. Standing desks are great for “exertion” — it tires my legs, which helps me sleep better, and sleep’s the key to everything. I stand about half the day; while standing I do email, web browsing, and other lightweight tasks. But serious thinking and writing? I have to sit.
  • I generate some of my best ideas while on the telephone, pacing in a confined space (like a living room). Being on the phone while walking in an open yard is not the same; I need to be able to pace back and forth.

(Image: FlickrOriginally published on LinkedIn)

A Life Worth Ending

Michael Wolff wrote an incredibly honest essay over the summer about his mother’s last years in hospital beds, and having to endure endless sessions with doctors where no one was willing to confront the elephant in the room: his mother was a vegetable. Hers was a life worth ending. It’s a personal story I expect we’ll be hearing more frequently, as the rate at which we develop technologies to lengthen life outpaces the development of the corresponding ethics / norms / expectations within families and the healthcare system. Worth reading.

Book Review: Why We Get Fat

I found Gary Taubes’ Why We Get Fat to be provocative and persuasive. It challenged my long held assumption that the way to lose weight is to eat less and exercise more. Taubes’ hypothetical exposes the oddity of the “eat less, exercise more” maxim:

Imagine you’re invited to a celebratory dinner. The chef’s talent is legendary, and the invitation says that this particular dinner is going to be a feast of monumental proportions. Bring your appetite, you’re told—come hungry. How would you do it? You might try to eat less over the course of the day—maybe even skip lunch, or breakfast and lunch. You might go to the gym for a particularly vigorous workout, or go for a longer run or swim than usual, to work up an appetite. You might even decide to walk to the dinner, rather than drive, for the same reason. Now let’s think about this for a moment. The instructions that we’re constantly being given to lose weight—eat less (decrease the calories we take in) and exercise more (increase the calories we expend)—are the very same things we’ll do if our purpose is to make ourselves hungry, to build up an appetite, to eat more. Now the existence of an obesity epidemic coincident with half a century of advice to eat less and exercise more begins to look less paradoxical.

I also liked this sentence:

To ‘explain’ obesity by overeating is as illuminating a statement as an ‘explanation’ of alcoholism by chronic overdrinking.

The thesis of the book is that what you eat determines weight loss. Namely, what kind and how many carbohydrates. Taubes advocates the Atkins diet — low carb, high protein, high fat. Taubes is a science journalist, not a researcher himself, so he positions himself as a syntheizer of the literature. Here’s his recent podcast interview with Russ Roberts on Econtalk. For a more skeptical take, here’s a blog post from Scientific American.

I reccomend Why We Get Fat to anyone interested in nutrition, diet, and health. Thanks to Saar Gur and Tod Sacerdoti for the recomendation.


Also from the book: diet and disease:

Eat Western diets, get Western diseases—notably obesity, diabetes, heart disease, and cancer. This is one of the primary reasons why public-health experts believe that there are dietary and lifestyle causes for all these diseases, even cancer—that they’re not just the result of bad luck or bad genes.

To get a feel for the kind of modern evidence supporting this idea, consider breast cancer. In Japan, this disease is relatively rare, certainly not the scourge it is for American women. But when Japanese women emigrate to the United States, it takes only two generations for their descendants to experience the same breast-cancer rates as any other local ethnic group. This tells us that something about the American lifestyle or diet is causing breast cancer.

Colon cancer is ten times more common in rural Connecticut than in Nigeria. Alzheimer’s disease is far more common among Japanese Americans than among Japanese living in Japan; it’s twice as common among African Americans as among rural Africans. Pick a disease from the list of Western diseases, and a pair of locations—one urban, say, and one rural, or one Westernized and one not—compare people in the same age groups, and the disease will be more common in the urban and Westernized locations and less common outside them.

The Fragility of Health

I came down with food poisoning last night. Twice during the night, I got out of bed, went into the bathroom, and threw up.

I bent over the toilet, hands on knees, and did the violent act for 45 seconds.

After the second time, I looked up from the toilet and faced the mirror in my bathroom. My eyes were bloodshot. Face grey. I was shivering all over. In that moment, I felt frail and vulnerable in a way I hadn’t felt for many years.

Today, I’ve been reflecting on how a single piece of bad food, in a matter of hours, could make me go from youthful, energetic, and ready to do anything, anywhere to bedridden, weak, depressed. My physical health is so good most of the time that I take it for granted.

Jimmy V’s classic ESPY speech from 1993, delivered two months before his cancer killed him, talks about cherishing every moment of good health. Obviously, a simple bout of food poisoning is not comparable to life-ending cancer, but his message, which I re-watched tonight, resonated anew. Hopefully it will stick for longer this time.

Mike Moritz is Chasing Daylight — The Adjustments He’s Making As a Result

Mike Moritz, one of the most successful VCs in Silicon Valley history, announced he’s been diagnosed with an incurable illness and has been told his quality of life will likely decline significantly in the next 5-10 years. Very sad. Moritz says he will continue to do investing but also make some changes in his life:

I will use twelve to fourteen weeks – sprinkled throughout the course of each year – for various pursuits, diversions and trivial indulgences.

Reading this sentence gave me pause and caused me to reflect.

Among other things, I was reminded of the classic 2005 Alex Tabarrok post about travel. To paraphrase: If someone told you you were going to live for 10 additional years (say, living until 110 instead of 100) and ask what you would do with that extra time, you would probably say (among other things), “I’d travel more.” If someone told you were you going to die in the next 5 years and ask what you would do with your time remaining on planet earth, you would probably say (among other things), “I’d travel more.” Those were Alex’s answers, and mine too. As Alex says, “Given that I would travel more if I was to live either less or more, the probability that I was at just that level of mortality that I should not be traveling now must be vanishingly small.” And so he set off for Peru.


The phrase “chasing daylight” from the title of the post comes from the touching book by the same name. I finished the book in tears. My book review is here.

What Doesn’t Kill You Makes You Stronger?

Whether you think of Nietzsche or Kanye West when you hear the line "what doesn't kill you makes you stronger"–you probably think of it as true. Or at least I did. Short term struggle builds long term strength. Even life's toughest experiences have a redeeming quality inasmuch as it instructs or inspires or hardens or softens a person in the right away. Etc.

Christopher Hitchens is dying of cancer. He's undergoing radiation. In Vanity Fair he reflects on the maxim that I took as fact–and finds it false.

In the brute physical world, and the one encompassed by medicine, there are all too many things that could kill you, don’t kill you, and then leave you considerably weaker.

On the pain he felt:

To say that the rash hurt would be pointless. The struggle is to convey the way that it hurt on the inside. I lay for days on end, trying in vain to postpone the moment when I would have to swallow. Every time I did swallow, a hellish tide of pain would flow up my throat, culminating in what felt like a mule kick in the small of my back. I wondered if things looked as red and inflamed within as they did without. And then I had an unprompted rogue thought: If I had been told about all this in advance, would I have opted for the treatment? There were several moments as I bucked and writhed and gasped and cursed when I seriously doubted it.

He ends:

So far, I have decided to take whatever my disease can throw at me, and to stay combative even while taking the measure of my inevitable decline. I repeat, this is no more than what a healthy person has to do in slower motion. It is our common fate. In either case, though, one can dispense with facile maxims that don’t live up to their apparent billing.


Here's a touching book trailer about dying. I've rarely seen someone on camera who appears truly at peace in life. Lee Lipsenthal does. He passed away a couple months ago. His book, Enjoy Every Sandwich, came out last month.

The Effects of Going Off the Grid and Exploring Nature

Is going off the grid and retreating into nature sure to be relaxing and rejuvenating? Not for Rob Horning, who spent some time in Idaho for a nature trip awhile back. He reports:

Contra Thoreau, retreating into nature, instead of bringing me back to myself, made me feel like less of a self and a bit more like one of the many undifferentiated bison one encounters out there. I don’t feel replenished for the assault on the backlog of posts I intend to read and write. Instead, as I was out hiking, I would think of this dormant blog and wonder how I’ll ever manage to catch upa nagging thought that filled me with vague, unshakable uneasiness.

Being adrift in the natural world had come to feel very unnatural; the serenity seemed like a taunt. This seems to me the inverse of the interconnected feeling I take for granted in the time I spend online, and I understood for the first time why people would do something as inane as Twitter their hikes from their iPhones or something. I tried to feed this anxiety by taking lots of pictures with the idea of sharing them later, but this only aggravated the feeling. I couldn’t possibly take enough pictures. Eventually I had to try the opposite tack and take no pictures at all.

There are two points here. The first is that if you take a vacation but spend the vacation time worrying about all the work that's piling up, it may cause more stress than you had in the first place. A valid point, which is why off-the-grid vacations need to be long enough so that you pass by that anxiety, so that you get you a point where so much work has piled up that you essentially say, "Screw it, time to relax." 6-7 days a couple times a year seems a good number for formal vacation; a couple days of stress, a few days of relaxation.

His second point is that being disconnected from technology–and out in nature–makes you feel adrift, perhaps lonely. I think this is a benefit from unplugging for stretches of time. Something that feels unnatural in the modern age is not necessarily a bad thing.

I wish I spent more time in nature and off-the-grid. That, and meditating, are two things I aspire to do more of in the year ahead in order to lower stress, improve health, and improve clarity of thought.