This section lists products and treatments that *seem* inexpensive and effective at first glance. Yet once you look at the original research, their benefits are practically nonexistent — or even negative. They’re arranged based on two factors: how much money people spend on them and how strong the supporting evidence actually is. The items near the top of the list are the ones you should stop using first.
English text comes from the independent translation maintained by dlgrv. New entries without a translation appear in Chinese. The author's Chinese original is authoritative for the latest content. Translation snapshot: dlgrv/HowToLiveBetter · 11818c6
Don’t take multivitamins for longevity or heart protection
Over 14,000 male doctors took multivitamins for eleven years. The number of serious heart and vascular problems, as well as deaths, was virtually identical between those who took them and those who didn’t. When nine separate trials involving more than 50,000 participants were pooled together, there was no measurable effect on mortality at all. Skipping them saves you between 200 and 700 yuan each year. This does not apply to people who have been medically diagnosed with specific nutrient deficiencies, nor to pregnant women needing folic acid.
Cost
They cost roughly 0.5 to 2 yuan per day, or 200 to 700 yua…
Benefit
The PHS II trial enrolled 14,641 male doctors and followed them for a median period of 11.2 years (some longer…
02Evidence A
Don’t take regular fish oil capsules to prevent heart disease
Two large trials enrolled 26,000 and 15,000 people with diabetes respectively. For those who took 1 gram of fish oil daily, the rates of major cardiovascular events and death were identical to those who did not take it. The fact that eating fish is beneficial does not mean fish oil capsules are equally helpful. Skipping them saves you 400 to 1,000 yuan each year.
Cost
It costs roughly 1 to 3 yuan per day, or 400 to 1,000 yuan…
Benefit
The VITAL trial included 25,871 participants who took 1 gram of fish oil daily for a median follow-up of 5.3 y…
03Evidence A
Don’t give vitamin D supplements to people who already have enough
Two large trials looked at this issue. One involved 26,000 participants who took supplements for five years; the other included 21,000 older adults on supplements for the same period. For people who already had adequate vitamin D levels, there was no change in cancer rates, cardiovascular problems, or overall mortality — the death rates were 5.3% versus 5.1% respectively. This does not apply to people who truly lack vitamin D, those with osteoporosis, or anyone who rarely gets sunlight; they should follow their doctor’s advice.
Cost
Roughly 0.2 to 0.5 yuan per day, or 100 to 200 yuan per ye…
Benefit
The VITAL trial followed 25,871 participants who took 2,000 IU of vitamin D daily for 5.3 years on average. No…
04Evidence A
Don’t take antioxidant supplements to prevent cancer (beta-carotene, vitamin E, vitamin A)
This isn’t just ineffective — it’s actually harmful. A review of 78 randomized controlled trials involving nearly 300,000 people found that those taking antioxidant supplements had a slightly higher overall mortality rate. Two large trials focused on smokers showed that beta-carotene raised the likelihood of developing lung cancer by 18% to 28% and increased death rates by 8% to 17%. Smokers and people exposed to asbestos should absolutely avoid these supplements.
Cost
Roughly 0.5 to 2 yuan per day. For smokers, the real cost…
Benefit
Cochrane analyzed 78 randomized controlled trials with 296,707 participants. Overall, those taking antioxidant…
05Evidence A
Don’t expect glucosamine/chondroitin to treat knee osteoarthritis
The GAIT trial involved 1,583 participants with knee osteoarthritis who took the supplements for 24 weeks. In the placebo group, 60.1% reported reduced pain. Glucosamine only improved this rate by 3.9 percentage points (P=0.30), while chondroitin added 5.3 percentage points (P=0.17). Taking both together yielded a 6.5 percentage point improvement (P=0.09). All these differences are so small they could easily be due to chance. Spending 700–1,800 RMB yearly essentially buys you the same placebo effect seen in 60% of participants.
Cost
Roughly 2–5 RMB per day, or 700–1,800 RMB per year.
Benefit
As noted above, glucosamine and chondroitin showed minimal benefits compared to placebo. The real active drug…
06Evidence A
Don’t rely on vitamin C to prevent colds
A combined analysis of 29 controlled trials involving 11,306 participants shows that daily vitamin C intake hardly reduces the likelihood of catching a cold. Taking it after symptoms appear also yields inconsistent results. It can shorten the duration of a cold by about 8%, which equals roughly half a day of reduced discomfort. The absolute number of people who benefit from this effect is 500. Whether this half-day of relief is worth spending several hundred yuan per year is a personal calculation. Marathon runners and soldiers stationed in cold climates form the exception: among them, daily vitamin C intake cuts cold incidence roughly in half.
Cost
Each effervescent tablet costs roughly 1–2 yuan;
Benefit
Cochrane’s pooled analysis of 29 trials with 11,306 participants indicates that regular vitamin C consumption…
07Evidence A
Don’t get a whole-body PET-CT or tumor marker panel if you have no symptoms
Screening completely healthy people most often yields false alarms. In one study, 86% of 1,192 symptom-free individuals had at least one “abnormality” on a whole-body CT; 37% were called back for further tests, yet the vast majority of findings turned out to be benign. In large trials of ovarian cancer markers, the screened group actually had a slightly higher death rate. In some studies, 0.2%–3.25% of people underwent unnecessary surgery simply because of false positives.
Cost
A whole-body PET-CT costs roughly $7,000–$10,000 per scan…
Benefit
The USPSTF, which evaluates preventive measures in the U.S., assigned a D rating to CA-125 testing and ultraso…
08Evidence B
Don’t expect fitness trackers or smartwatches to help you lose weight
471 overweight adults followed the same diet and exercise plans. The group wearing fitness trackers lost just 3.5 kilograms over two years, while the group without devices actually lost 5.9 kilograms. Trackers do not aid weight loss; regular exercise itself is what makes the difference.
Cost
Devices cost between 200 and 2,000 RMB. Plus, you have to…
Benefit
The IDEA trial involved 471 overweight or obese adults and lasted 24 months. All participants followed identic…
09Evidence B
Don’t pay a premium for organic food just to be “healthier”
When we combine 17 studies done on humans with 223 studies analyzing food composition, there’s no solid evidence that organic food is significantly more nutritious. Only 3 of those studies actually looked at health outcomes after people ate it, and no difference was found between organic and conventional foods. The proportion of organic produce found to contain pesticide residues is indeed 30 percentage points lower, but detection does not mean those levels exceed safety limits. Eating more fruits and vegetables is beneficial regardless of whether they’re organic or not.
Cost
Typically 1 to 3 times the price of regular versions of th…
Benefit
One systematic review brought together 17 human studies and 223 studies on food composition. Its conclusion: “…
10Evidence C
Don’t spend a lot of money on health supplements, herbal pastes, or tonics to “rebalance your body”
The agency responsible for regulating health foods mandates that packaging must carry a specific statement: these products are not medicines and cannot replace medical treatment. Even the regulators themselves do not believe they can cure diseases. The most common ingredients — multivitamins, fish oil, vitamin D, antioxidants, glucosamine, and vitamin C — have all been examined in the first six sections of this chapter, and none demonstrate any meaningful effect. Most of the money spent on these products isn’t aimed at any therapeutic benefit; it’s meant as a gift for parents or relatives. The intention behind such gifts is perfectly fine; the problem lies solely in the products themselves.
Cost
Prices range from a few hundred to tens of thousands of yu…
Benefit
According to regulations set by the State Administration for Market Regulation, at least 20% of the front surf…
11Evidence B
Don’t take probiotics long-term if you have no gut problems
A review of 45 trials conducted on healthy adults shows that probiotics don’t bring about lasting changes in gut bacteria; once you stop taking them, the gut flora returns to its original state, and there’s no improvement in blood lipid levels either. Separate evidence exists for situations such as antibiotic‑induced diarrhea, but that isn’t covered here.
Cost
Roughly 2–5 RMB per day, or 700–1800 RMB per year.
Benefit
This review concludes that there’s no solid proof that probiotics can produce lasting alterations in gut micro…
12Evidence B
Don’t force yourself to take cold showers just to “boost immunity”
In a trial involving 3,018 participants, those who took cold showers had 29% fewer sick days. However, the total number of days they took off for illness remained the same as in the control group, so it doesn’t mean they got sick less often. A 2025 systematic review combining 11 trials found that cold showers temporarily raised markers of bodily inflammation without any noticeable change in immune function. Feel free to take cold showers if you enjoy them, but don’t treat them as a worthwhile health investment.
Cost
No cost at all. It requires enduring discomfort for 30 to…
Benefit
A randomized controlled trial conducted in the Netherlands enrolled 3,018 participants. After a hot shower, th…
13Evidence C
Don’t buy products marketed for detox, colon cleansing, enzymes, or alkaline water
One review examined whether there is any evidence supporting detox diets. It concluded that while the detox industry is huge, there is very little clinical evidence to back it up, and no randomized controlled trials have ever been conducted on commercial detox diets. As for the claim that an “acidic body pH causes cancer,” a search of 8,278 research papers yielded just one study that met the criteria — and even that showed no link.
Cost
Several hundred to several thousand yuan. Fasting as a way…
Benefit
That same review reiterated that despite the rapid growth of the detox market, there is almost no clinical evi…
14Evidence C
Don’t force yourself to drink water just to hit “8 glasses a day”
Some people have tried to trace the origin of the “8 glasses a day” rule, but no studies supporting it have ever been found. On the contrary, surveys of thousands of adults’ diets and fluid intake show there’s no need for that much water at all, since food and other drinks already provide plenty. Just drink when you’re thirsty, and use the color of your urine as a guide — that’s all you need to do. People working in hot environments, those doing intense exercise, people who’ve had kidney stones, and older adults who no longer feel thirsty as readily should make a conscious effort to drink more water.
Cost
No cost at all. It does require some time and effort to re…
Benefit
One literature review specifically examined the “8×8” rule — that is, 8 glasses a day, each glass holding 8 ou…
15Evidence B
Don’t spend money on fortune‑telling, tarot, or astrology to make decisions
There is a classic classroom experiment: students receive a “personality analysis tailored just for them,” yet every student gets exactly the same text, and most still find it very accurate. This is precisely why fortune‑telling seems so reliable. The price isn’t limited to just a few dollars: in Xixian County, Henan Province, a fortune‑telling ring collected “offering fees” and even sold “donation packages” priced up to 3,888 yuan; the ringleader was sentenced to eleven years in prison.
Cost
There is no monetary cost. The real challenge is giving up…
Benefit
In that same classic experiment, after taking a personality test, students were given an “individual analysis”…
16Evidence A
Don’t buy blue-light-blocking glasses to “protect your vision,” and don’t believe claims that staring at screens for months will ruin your eyes — but eye pain, swelling, and redness require urgent medical care.
Blue-light-blocking lenses provide no real benefit; you simply save the extra cost of purchasing them. A review of 17 studies found no difference in eye fatigue or visual clarity compared to regular lenses, nor any evidence that they protect the retina. While screen use can cause temporary eye strain and dryness, this does not mean your eyes are being permanently damaged. The only factors that can cause irreversible eye damage in a short time are welding arcs, ultraviolet light, lasers, and acute angle-closure glaucoma.
Cost
These glasses cost nothing, and you’ll also avoid paying t…
Benefit
A 2023 Cochrane systematic review analyzed 17 randomized controlled trials involving 5 to 156 participants eac…
17Evidence A
Don’t treat blood donation as a health habit: claims that it “detoxifies, lowers cholesterol, and prevents heart attacks” lack randomized trial support, while frequent donation truly causes iron deficiency
The idea that donating blood helps “detoxify,” lowers cholesterol, or prevents heart attacks is not reliable. Those conclusions stem from observational data, and people who regularly donate are generally healthier to begin with. When this baseline difference is accounted for, the original claim that “each additional yearly donation lowers mortality by 18.6%” drops to just 7.5%. One actual randomized trial found no difference in death rates between donors and non-donors. On the other hand, donating too often does make people feel weak and cold — precisely because of iron loss.
Cost
There is no monetary cost. A single donation — including r…
Benefit
The Kuopio study in Finland followed 2,862 men aged 42–60 for nearly nine years. In the 24 months prior to tra…
18Evidence A
Don’t rely on generic health checkup packages to prevent disease; only get those evidence‑based screenings appropriate for your age and gender.
Researchers divided 230,000 people into two groups — one that regularly underwent generic health checks and one that did not. Across 11 trials, mortality rates were virtually identical between the groups, with a difference of less than 3%. The same held true for deaths from cardiovascular disease and cancer. The Cochrane authors concluded that such generic checkups are unlikely to provide any benefit. The only screenings that truly lower mortality are those performed for specific medical reasons.
Cost
There’s no cost at all, and you even save hundreds to thou…
Benefit
The 2019 update of the Cochrane systematic review included 17 randomized controlled trials. For overall mortal…
19Evidence A
Don’t start taking uric‑acid‑lowering drugs just because a checkup shows high uric acid but you’ve never had symptoms
People whose uric acid levels are high but who’ve never had gout attacks or tophus deposits mainly gain peace of mind from taking uric‑acid‑lowering drugs. According to calculations by the American College of Rheumatology, you’d need to treat 24 people for three full years just to prevent a single gout episode. These drugs also won’t protect your kidneys; in randomized trials the rate of kidney‑function decline was identical in patients taking them and those on a placebo. What truly helps is keeping weight, alcohol, and sugary drinks in check — and only treating gout after an actual attack occurs.
Cost
There’s no cost at all;
Benefit
The 2020 gout guidelines from the American College of Rheumatology address asymptomatic hyperuricemia, defined…
20Evidence A
Don’t undergo preventive gallbladder removal just because an ultrasound reveals gallstones but you’ve never had any pain
Most people with gallstones who have never felt any pain will continue to stay symptom‑free. An Italian study followed 580 such individuals for nearly nine years; 78 % never developed any symptoms. In the U.S., a group of 135 people was tracked for about four years, and only 7 % ended up needing surgery. The UK’s clinical guidelines state plainly: if gallstones are found incidentally and cause no symptoms, no treatment is required.
Cost
There’s no cost at all — in fact, you avoid the expense of…
Benefit
The Italian MICOL population survey examined 11,229 people aged 29–69 using ultrasound. Gallstones were detect…
21Evidence A
Don’t cut calcium out to prevent kidney stones
People who’ve had calcium oxalate stones are often advised to limit calcium intake, but randomized trials show the opposite. A study with 120 men who repeatedly developed stones divided them into two groups: one ate a normal amount of calcium while cutting back on animal protein and salt; the other followed a traditional low‑calcium diet. After five years, recurrence rates were 12 out of 60 versus 23 out of 60 — meaning the normal‑calcium group had half the risk. UK guidelines also advise against restricting calcium.
Cost
No cost at all. In fact, it’s easier — no need to constant…
Benefit
This five‑year randomized trial enrolled 120 men with recurrent calcium oxalate stones and high urinary calciu…
22Evidence B
Don’t buy crystals, bracelets, or Pixiu figurines for “good luck,” “wealth attraction,” or “health benefits”
There is absolutely no verifiable evidence supporting claims that wearing such items can change one’s fate, attract wealth, or improve health. These assertions work on the same principle as fortune-telling: they are phrased so vaguely that people naturally interpret them as applying to themselves. Any explicit health or fortune-related claims made by sellers would constitute illegal false advertising; in 2026, several livestream shops were penalized for exactly this reason. Buying them purely as decorative accessories is perfectly fine, but allocating extra funds specifically for “luck enhancement” is what this guidance aims to prevent.
Cost
There is no monetary cost involved. The only requirement i…
Benefit
Classic classroom experiments demonstrate that when participants receive the same generic “personality analysi…
23Evidence B
Don’t expect shopping to lift your mood or boost your sense of self-worth
On average, people who place a higher value on money and material possessions report lower levels of happiness. This conclusion comes from a meta-analysis of 259 separate studies, though the link between the two is fairly weak and it’s unclear which factor drives the other. Other research comparing spending on experiences versus physical goods found that money spent on experiences tends to bring more satisfaction. So when you’re in a bad mood, reallocating your budget toward a day out or a meal with friends is far more likely to help than adding more items to your shopping cart.
Cost
No cost at all. The hard part is resisting the urge to buy…
Benefit
This meta-analysis combined data from 259 independent studies, covering a total of 753 effect sizes. The resul…
24Evidence B
Don’t spend extra money on a new house, car, or social circle just to “move up a notch” among peers
When comparing people with similar incomes, those whose neighbors earn more report lower happiness levels. This effect appears only among neighbors with comparable education and frequent interaction. Thus, spending extra to move into a neighborhood where everyone is wealthier actually pushes you down the social ladder. Yet when incomes rise across the board, people still feel better off — absolute levels still matter.
Cost
Zero. All you have to do is ask one extra question before…
Benefit
The National Survey of Families and Households (NSFH) in the U.S. followed the same individuals over two waves…
25Evidence A
Don’t believe that “willpower is like a muscle that runs out after use”
The popular idea is that after doing something that requires self‑control, it becomes harder to resist temptations later, so we should “save” our willpower. Yet 23 laboratories and 2,141 participants ran the same experiment, and the results showed almost no effect. Stop using “I’ve run out of willpower today” as an excuse, and don’t spend money on courses that promise to help you conserve it.
Cost
No cost at all. Only a change in wording is needed.
Benefit
In a multi‑lab preregistered replication study, 23 labs with 2,141 participants followed Sripada et al.’s stan…
26Evidence A
Don’t expect skipping breakfast or the 16:8 intermittent fasting schedule to help you control your weight; pick a meal timing you can stick with long‑term.
Popular belief holds that skipping breakfast leads to overeating at lunch and dinner, ultimately increasing total daily calorie intake. Randomised trials tell a different story: people who skip breakfast actually consume roughly 200 fewer kilocalories per day and tend to weigh slightly less. Compared with simply eating less, the 16:8 schedule makes no difference in weight after a year. Long‑term breakfast skippers do have about a 17% higher risk of cardiovascular disease; overall mortality shows no notable change. The absolute number of excess cardiovascular events is 1.42 per 100,000 people per year.
Cost
No cost at all. What you save is the mental energy you’d o…
Benefit
Let’s examine the claim that skipping breakfast makes you eat more later. One meta‑analysis combined results f…