Bone broth, detoxes, and other wellness fads that won't quit

Some wellness trends are a blip on the radar, fading into the recesses of the internet as quickly as they appeared. (Celery juice, anyone?) Others have serious staying power. Here’s a handful of potions, powders...and one reputed poison...that have secured a foothold in the wellness zeitgeist.

Apple cider vinegar

What makes apple cider vinegar different from other vinegars? All vinegar is diluted acetic acid. But apple cider vinegar is often sold unfiltered, so it has an intact “mother”​—a cloudy mixture of yeast and bacteria. 

While there’s no evidence that the mother does anything for your health, the acetic acid in any vinegar might.

Take vinegar’s touted ability to lower blood sugar. In several small studies, pre-meal vinegar blunted the rise in post-meal blood sugar. For example, when 12 volunteers drank about 1½ tablespoons of vinegar diluted in water before a high-carb meal, their post-meal blood sugar rose roughly 30 percent less than when they drank just water before the meal.

Can vinegar help lower blood sugar over the long term? That’s an open question. Only a handful of studies have looked, and they were either too short, too small, or not well designed.

Bottom line

Vinegar might help lower blood sugar after meals, but longer and larger studies are needed. Just keep in mind that undiluted vinegar can burn the esophagus and diluted vinegar can erode tooth enamel. So if you try it, mix a tablespoon of vinegar in one cup of water and drink it through a straw.

Detoxes and cleanses

Want to shed pounds, flush away toxins, boost your energy, and eliminate cravings? Try a detox or cleanse, say some websites.

Most detoxes involve consuming only fruit and vegetable juices, or limiting food to just soups (or some solid foods while cutting out ingredients like gluten, soy, dairy, and more), or taking supplements like niacin, probiotics, and/or digestive enzymes, or mixing those tactics for a few days to a few weeks.

But no randomized trials have tested detox or cleanse diets. And don’t kid yourself; they’re not weight-loss magic. You may lose a few pounds because you’re taking in so few calories for a short period. But you’re likely to regain any lost weight once the cleanse is over.

What about flushing out toxins? Our kidneys, liver, gut, skin, and lungs have impressive detoxifying systems. It’s true that our bodies can store some pollutants and heavy metals like lead, mercury, and cadmium. But there’s no evidence that a cleanse can bolster the body’s ability to purge any of those.

In fact, getting enough minerals like calcium, zinc, iron, and selenium in your usual diet can blunt your absorption of heavy metals. But even if juices were rich in those minerals—they’re not—that wouldn’t get rid of whatever you’ve already absorbed. 

Bottom line

Skip the detoxes and cleanses. Your body doesn’t need a detox assist.

Bone broth

“Bone broth contains collagen and gelatin, which help seal the gut lining and promote proper digestion,” says Google’s AI overview. Not quite.

Bone broth is the stock made from simmering animal bones (often with meat, vegetables, or herbs) for 24 hours or so. The result: a liquid rich in gelatin that’s touted not just for gut health but also to boost the immune system.

No trials have tested gelatin on the gut lining in people. Nor have studies tested other claims about bone broth’s healing or immune-boosting potential. And the animal evidence on gut health isn’t encouraging.

Gelatin tannate is a powder made of gelatin and tannins that’s marketed in Europe for the relief of short-term diarrhea. Animal studies suggest that it reinforces the lining of the gut. In one (partially company-funded) study, when researchers used a toxin to make the gut lining of rats more permeable, gelatin tannate did protect and reinforce the lining. But gelatin alone didn’t.

Bottom line

Like bone broth? Great! Just don’t expect it to “seal the gut lining” or do much else.

Raw milk

When you buy milk at the supermarket, you can trust that it’s been pasteurized—that is, briefly heated to kill dangerous microbes. Pasteurization is one of the world’s greatest public health successes.

In 1938, before the widespread adoption of pasteurization, roughly 25 percent of food poisoning outbreaks in the U.S. were due to raw (unpasteurized) milk. By 2018, that number had plunged to less than 1 percent.

Still, raw-milk enthusiasts insist that unpasteurized milk is a wellspring of health and vitality, capable of curing lactose intolerance, asthma, and allergies while boosting the immune system.

In fact, none of that is true. Nor is raw milk richer in nutrients than pasteurized milk.

And raw milk isn’t harmless. Between 2013 and 2018, it was linked to 75 outbreaks caused by bugs like Campylobacter jejuni, Cryptosporidium, and Salmonella. Hundreds of people were sickened and nearly 100 were hospitalized.

Bottom line:

There are no health benefits—and plenty of risks—from drinking raw milk.

Seed oils

Seed oils—like canola, corn, soy, sunflower, and safflower—have gotten a bad rap in some circles. 

They’re “toxic” because they cause inflammation that leads to obesity, heart disease, type 2 diabetes, and more, critics charge. 

The main villain: linoleic acid, an omega-6 fat found in seed oils. The logic goes like this: The body converts linoleic acid into arachidonic acid, which then gets converted into prostaglandins. And prostaglandins set off inflammatory responses throughout the body.

The problem? Only about two-tenths of 1 percent of the linoleic acid we consume is converted to arachidonic acid.

What’s more, in an analysis of 30 studies that tracked roughly 70,000 people, those with the highest blood levels of linoleic acid—and arachidonic acid—had a lower risk of car­dio­vascular disease. (The analysis was partly funded by Unilever, which makes mayo and margarine. Both are rich in omega-6 fats.)

Most seed-oil critics recommend swapping them for butter and olive, avocado, or coconut oil. Olive and avocado oils are fine, but coconut oil and butter are loaded with saturated fat. Replacing saturated fat with omega-6 fats not only lowers LDL (bad) cholesterol; it slashes the risk of cardiovascular disease by roughly 30 percent.

Bottom line

Ignore the seed-oil-is-toxic hype.

Alkaline water 

Alkaline waters have been a mainstay in the bottled-​water aisle for years. Are they worth the higher price tag? No. 

On the pH scale of 0 to 14, which measures how acidic or alkaline a substance is, water sits smack in the middle, with a neutral pH of 7. Alkaline water typically has a pH between 8 and 9.

Most claims hinge on the idea that alkaline water can neutralize acid. For example, you might have heard that alkaline water can neutralize stomach acid and ease gastric reflux. 

Stomach acid has an extremely acidic pH (1.5 to 3.5). Sure, you might be able to briefly and slightly raise that pH if you gulp down, say, a liter of alkaline water. But would that translate to less reflux? Who knows? No randomized trials have looked.

And don’t expect alkaline water to change the pH of your blood. The average adult body contains about 30 to 50 liters of water, so drinking a liter or two of mildly alkaline water is trivial. But more importantly, your body is incredibly good at keeping your blood’s pH within a very tight range (7.35 to 7.45), regardless of what you eat or drink.

Bottom line

There’s no evidence that you can—or reason why you should try to—change your body’s pH.

Probiotics

From “probiotic-boosted popcorn” to hydration powders, dried fruit, bars, cereals, and more, the flood of new pro­biotic-spiked packaged foods seemingly knows no bounds.

Are probiotics a magic wellness wand? Nope. They’re a stellar marketing tool.

To start with, many people assume that probiotics are interchangeable and that all are equally good for you. In reality, different bacteria have different effects. What’s more, the evidence that specific strains can treat or ease symptoms in people with health problems is skimpy.

And in a recent industry-funded review, after experts combed through the research on probiotics for the prevention of disease in healthy people, they concluded that “The evidence is not yet sufficiently robust for recommendations for prevention in the general population.”

Bottom line:

Don’t assume that a granola bar—or any other food—with added probiotics is healthier than one without.

Greens powders

Interested in hacking your way to wellness? Look no further than the latest magic fairy dust: powdered greens.

Depending on which pricey powder you purchase, you can expect promises to support digestion and immunity, relieve bloat, or boost energy.

Many companies also sprinkle in, for good measure, a mix of powdered fruits and other vegetables, probiotics, prebiotics, adaptogens, and antioxidants.

But there’s no evidence (or reason to believe) that powdered greens, other powdered vegetables, or powdered fruits hold a candle to the real deals. All are low in the unprocessed fiber and the potassium you’d get in whole greens, fruits, and veggies. And despite claims like “2 servings of fruits and vegetables,” the powdered stuff doesn’t fill you up or help lower blood pressure like a hearty salad or a bowl of stir-fried broccoli.

We’d love to see a head-to-head trial pitting powdered versus intact greens on all those promised health benefits. Odds are, we’ll be waiting a while.

Bottom line

Powdered greens are a sad substitute for the real things.