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Gwyneth Paltrow's Snake Oil

— The science behind actress-turned-wellness guru's iffy deprivation diet

MedpageToday

Actress Gwyneth Paltrow is well known for her lifestyle brand, , that promotes and sells products related to her .

Once again, it's that time of year when Ms. Paltrow's fancy turns to promoting detox diets. As :

"2018 was a year of incredible, nourishing, healing food here at goop, but in the spirit of balance, we also indulged in some less-than-clean favorites (like lasagna, schnitzel, waffles, and so many fun cocktails). Again, striving for balance, we're recalibrating this month with our annual January detox program."

As in the past, Gwyneth depends on her detox guru, Dr. Alejandro Junger, who is well known in the "detox market" for his . Dr. Junger's basic elimination diet rules include "no caffeine, alcohol, dairy, gluten, corn, nightshades (tomatoes, eggplants, peppers, potatoes), soy, refined sugar, shellfish, white rice, or eggs. The no's are replaced with nutrient-dense leafy greens, cruciferous veggies, hearty grains, seeds, and lean proteins."

"The 5 Day Detox Plan" starts each day with warm water with lemon. For breakfast, there is grain-free granola, smoothies with coconut and chia, or a cauliflower/black bean scramble. "Portable" lunches include soup (borscht, beans and greens) or salad (leftover salmon patty salad, kale caesar, or detox bun). The dinner menu features salmon Patties with turmeric cauliflower rice, beans and greens soup, roasted chicken with cauliflower, tom yum soup, and blackened trout with roasted sweet potatoes and arugula salad. Snacks range from apple with almond butter, date balls, brown rice cakes and "toum with crudités" (a Lebanese garlic sauce -- which the : "This condiment -- along with the process of making it -- is not for the faint of heart").

The plan comes with a shopping list, a menu plan with helpful hints such as making some of the items on the Sunday before you start and buying your trout the day before or the day of to ensure its freshness, as well as the recipes for each meal.

Oh, and if that seems like it would take too much time to prepare, don't worry, Gwyneth's got you covered. Meet "The Working Girl Detox!"

"Many of us could use a good detox but simply don't have the time for the full Monty. Or even the half Monty. Enter the Working Girl Detox -- an abbreviated, streamlined version of our annual five-day goop detox, this three-day reset can really make a difference in how you feel, with much less work. Breakfast is a simple but inventive DIY instant oatmeal, lunch is a packable vegan puréed soup, and dinner happens all in a single sheet pan, in around thirty minutes. Every recipe is healthy, delicious, and so easy, even the busiest person can pull it off. For at least three days."

What are Detox Diets and Cleanses and Does Anyone Need Them?

Whether it's called a detox diet or a cleanse, it doesn't really matter. Neither has a clear-cut definition but both have similar goals -- to rid/cleanse the body of supposedly harmful substances (usually referred to as "toxins").

According to from the U.S. National Library of Medicine, "Toxins are substances created by plants and animals that are poisonous to humans. Toxins also include some medicines that are helpful in small doses, but poisonous in large amounts. Toxins also include metals, such as lead, and certain chemicals in the environment." However, in the context of commercial detox diets, the meaning of the term "toxin" is often vague or obscure.

In 2009, a group of early career scientists called The Voices of Young Science, created "." They went to the manufacturers of 15 representative detox products and asked what toxin their product targeted and what evidence they had to support that claim. They came to the following conclusion:

"No one we contacted was able to provide any evidence for their claims or give a comprehensive definition of what they meant by 'detox'. We concluded that 'detox' as used in product marketing is a myth. Many of the claims about how the body works were wrong and some were even dangerous."

Weight loss is often a secondary goal of detoxes or cleanses. All use a restrictive diet, often in conjunction with a variety of supplements (including herbs, vitamins, seasonings, and so on). For example, , also called the Lemonade Diet, is a liquid-only diet consisting of water, lemon juice, maple syrup, and cayenne pepper taken for 10 days. It is essentially a starvation diet. Unfortunately, most of the weight loss in a detox diet is water, and the weight returns just as quickly as it left as soon as a normal diet is resumed.

Detox diets claim that they can help chronic conditions that occur when the body becomes victim to a buildup of "toxins." As Dr. Junger puts it: "When our systems are overtaxed, they begin to break down in a multitude of ways. Allergies, headaches, depression, irritable bowel syndrome, fatigue, weight gain, and insomnia are just a few of the symptoms that can result. The majority of these common ailments are the direct result of toxin build-up in our systems that has accumulated during the course of our daily lives." Dr. Junger's book Clean currently is number 7 in Amazon sales rankings for alternative medicine books.

"But the science behind the detox theory is deeply flawed," says , an internal medicine specialist at Cedars-Sinai Medical Center in Los Angeles. "The body already has multiple systems in place -- including the liver, kidneys, and gastrointestinal tract -- that do a perfectly good job of eliminating toxins from the body within hours of consumption."

Detox dieters often report a variety of benefits, but most of these improvements may be due to changes in the diet unrelated to any change in "toxin levels." For instance, a decrease in headaches could be related to elimination of caffeine or alcohol in the diet. Decreased bloating just from eating less. Clearer skin may be related to better hydration.

Is there any scientific evidence to support the dubious claims of detox proponents? Almost none. There is a 2015 study by . "Eighty-four premenopausal women were randomly divided into 3 groups: a control group without diet restriction (Normal-C), a pair-fed placebo diet group (Positive-C), and a lemon detox diet group (Lemon-D). The intervention period was 11 days total: 7 days with the lemon detox juice or the placebo juice, and then 4 days with transitioning food." Women in the Lemon-D and Positive-C groups had significantly greater changes in body weight, BMI, and percentage of body fat than the control group. In addition, serum insulin levels, leptin, and adiponectin levels decreased in the Lemon-D and Positive-C groups. But there was no significant difference between the Lemon-D and Positive-C groups in any of these measurements- suggesting that the main contributing factor was caloric restriction.

A 2015 review by , in the Journal of Human Nutrition and Dietetics, pointed out a study on UltraClear (Metagenics Inc), the only commercial detox product to have been evaluated clinically. UltraClear is a medical food supplement that purports to detoxify the liver. A study, by , gave 25 naturopathy students UltraClear for 7 days. There was no placebo control group. They reported a "statistically significant (47%) reduction in the Metabolic Screening Questionnaire [MSQ] scores." The MSQ is a series of questions used to gauge the severity of a variety of health conditions -- from acne, mood swings, and even dark circles under the eyes.

Klein reported that there were (at the time of his review) no current rigorous scientific studies that investigated the effectiveness of commercial detox diets for losing weight.

Are detox diets safe? Possibly, for otherwise healthy people, if used for only a brief period of time. However, the diets can be stressful because of feelings of hunger and deprivation. But prolonged use of these diets can lead to electrolyte imbalances and protein and vitamin deficiencies. Occasionally, there have been reports of potential risks such as kidney damage from green smoothies (, 2018) or liver failure from detox teas (, 2017).

Despite the lack of evidence that detox diets have any real health benefits, they remain incredibly popular due to celebrity endorsements and intensive marketing of the diets and related products. Have any of your patients discussed these diets with you? What has been your reaction or advice?

Michele R. Berman, MD, and Mark S. Boguski, MD, PhD, are a wife and husband team of physicians who have trained and taught at some of the top medical schools in the country including Harvard, Johns Hopkins, and Washington University in St. Louis. Their mission is both a journalistic and educational one: to report on common diseases affecting uncommon people and summarize the evidence-based medicine behind the headlines.