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)?