Nutrition in the 21^st Century: Navigating Myth from Reality

It seems that every time we open social media, we are bombarded with a new health trend that promises us glowing skin, weight loss, and unlimited energy. But what evidence exists to back up these claims? In this article, we’ll examine three popular trends to see whether they are worth incorporating into our daily routine.

Juice Cleanses

Juicing is portrayed as the ultimate regimen for optimal health, marketed to detox, reboot and reenergize the body. Juicing in essence, is an extraction process that separates the liquid from fruits and vegetables while simultaneously discarding the fibrous pulp. While it is a great way to increase daily consumption of fruits and vegetables, particularly for individuals that don’t enjoy the taste of these foods, is it worth the cost and extra effort?

Let’s do some simple math. One medium apple contains approximately 4 g of fiber, whereas an 8 oz. glass of apple juice contains approximately 3-4 apples, and virtually no fiber. This is 12-16 g of fiber we are missing out on by choosing the liquid equivalent! Fiber is important to regulate blood sugar, activate satiety responses, and works to promote gastrointestinal health¹. Moreover, daily fiber consumption reduces the risk for stroke, hypertension, cardiovascular heart disease, diabetes, and obesity¹. Interestingly, high fiber whole foods have been shown to increase thermogenesis, thus increasing postprandial energy expenditure by 50% relative to refined food consumption of equivalent caloric content². So because of the fiber, whole foods require more work to digest, thus burn more energy during the digestion process. By removing the fibrous pulp through juicing, we miss on all of the additional benefits fiber has to offer!

Juices are often promoted as a temporary cleansing program whereby other food groups are restricted for a period of time. Some plans incorporate small snacks or meals in addition to the juices while others promote a liquid-only diet that lasts anywhere from three days to three weeks. Although this may seem like an enticing way to reset your body after overindulging in calories, there is little scientific evidence that shows any real benefit to following such programs (see below). Instead, doing so may cause blood sugar spikes throughout the day and leave you feeling moody, irritable, and hungry. Moreover, because they often limit caloric intake, if used over a prolonged period of time, they can slow down your metabolism.

While prolonged juice fasts are not recommended, and juices should not comprise the entirety of your daily fruit and vegetable intake, they are fine if used in moderation. At the end of the day, smoothies remain as a superior option if you prefer to drink your spinach.

Detox Teas

A trend with similar claims to juicing are detox teas, which have gained extreme popularity over the years. Detox teas are often advertised as part of a week or even a month regimen, to be incorporated with healthy eating and exercise. Where detox teas differ, however, is that they often contain large amounts of caffeine, which as a diuretic, causing you to expel water. Two cups of liquid approximates to a pound on the scale, so even without any fat loss, you will look and feel lighter. What’s more, many also have a laxative effect, increasing bowel movements to temporarily give you a flatter abdominal region (a common ingredient that mediates this is senna). Although laxative teas are fine if used for a short period of time, continual use can cause electrolyte imbalance, dehydration, and diarrhea. Moreover, the specific ingredient ratios in different detox blends are not well studied, so it’s difficult to assess effectiveness, possible interactions, and safety of prolonged use.

For any product, whether it is juices or teas, the general concept of detoxification is not backed up by science—we have an internal detoxification mechanism mediated through the digestive tract, liver, lungs, and kidneys. As such, it is important to support this natural process by drinking plenty of fluids, eating a diet rich in fiber, and exercising regularly. A temporary fix cannot undue a bad lifestyle, and like most products that seem too good to be true, specialty teas cannot perform miracles. Having said that, tea in general is a great addition to one’s diet if used as a supplement. Studies suggest that green tea may help lower cholesterol and even prevent stroke and cardiovascular disease³. To learn how to incorporate green tea in baking, check out our “Matcha Muffin” recipe at the end of this issue!

Turmeric

Another popular trend you may have come across is turmeric (Curcuma longa), a rhizome part of the ginger family. Used for centuries in food preparation and traditional Ayurvedic Medicine, turmeric has gained popularity in Western culture in recent years.

The turmeric plant contains a polyphenol called curcumin, which gives it its signature yellow colour and is associated with a wide range of health properties⁴. Studies suggest that curcumin blocks NF-kB, a signaling molecule that turns on pro-inflammatory genes⁵ and has comparable therapeutic potential to some anti-inflammatory drugs without any side effects⁶. It also serves as a powerful antioxidant, both by neutralizing free radicals and by enhancing the activity of antioxidant enzymes in the body^7,8. Moreover, it boosts brain-derived neurotrophic factor (BDNF), a type of neurotrophic factor that supports neuronal health and development⁹. Interestingly, low levels of BDNF are associated with depression and Alzheimer’s disease^10,11; therefore, supplementing with turmeric may have some neuro-protective properties. Clinical studies have reported that daily consumption of turmeric is not associated with toxicity, with no significant adverse effects seen following a prolonged oral dose of up to 8 g/day¹². Given this data, it seems that turmeric is worth a try. If you are up to the challenge, you can try adding this spice to smoothies, soups, stir-frys or even consume it as a hot beverage with milk or water.

At the end of the day, with every health trend we come across, it is important to take time to critically assess the literature instead of passively accepting marketing as gospel. Objectivity and social media are often contradictory, so the onus falls on the consumer to filter through the “fluff” and make conscious decisions that best suit individual needs.

References:

1. Anderson JW, Baird P, Davis RH, Ferreri S, Knudtson M, Koraym A, Waters V, Williams CL. Health benefits of dietary fiber. Nutrition reviews. 2009 Apr 1;67(4):188-205.
2. Barr S, Wright J. Postprandial energy expenditure in whole-food and processed-food meals: implications for daily energy expenditure. Food & nutrition research. 2010 Jan 1;54(1):5144.Schneider C, Segre T. Green tea: potential health benefits. American family physician. 2009 Apr 1;79(7).
3. Singletary K. Turmeric: An overview of potential health benefits. Nutrition Today. 2010 Sep 1;45(5):216-25.
4. Singh S, Aggarwal BB. Activation of transcription factor NF-κB is suppressed by curcumin (diferuloylmethane). Journal of Biological Chemistry. 1995 Oct 20;270(42):24995-5000.
5. Lal B, Kapoor AK, Asthana OP, Agrawal PK, Prasad R, Kumar P, Srimal RC. Efficacy of curcumin in the management of chronic anterior uveitis. Phytotherapy Research: An International Journal Devoted to Pharmacological and Toxicological Evaluation of Natural Product Derivatives. 1999 Jun;13(4):318-22.
6. Menon VP, Sudheer AR. Antioxidant and anti-inflammatory properties of curcumin. InThe molecular targets and therapeutic uses of curcumin in health and disease 2007 (pp. 105-125). Springer, Boston, MA.
7. Agarwal R, Goel SK, Behari JR. Detoxification and antioxidant effects of curcumin in rats experimentally exposed to mercury. Journal of Applied Toxicology. 2010 Jul;30(5):457-68.
8. Xu Y, Ku B, Tie L, Yao H, Jiang W, Ma X, Li X. Curcumin reverses the effects of chronic stress on behavior, the HPA axis, BDNF expression and phosphorylation of CREB. Brain research. 2006 Nov 29;1122(1):56-64.
9. Phillips HS, Hains JM, Armanini M, Laramee GR, Johnson SA, Winslow JW. BDNF mRNA is decreased in the hippocampus of individuals with Alzheimer's disease. Neuron. 1991 Nov 1;7(5):695-702.
10. Shimizu E, Hashimoto K, Okamura N, Koike K, Komatsu N, Kumakiri C, Nakazato M, Watanabe H, Shinoda N, Okada SI, Iyo M. Alterations of serum levels of brain-derived neurotrophic factor (BDNF) in depressed patients with or without antidepressants. Biological psychiatry. 2003 Jul 1;54(1):70-5.
11. Hatcher H, Planalp R, Cho J, Torti FM, Torti SV. Curcumin: from ancient medicine to current clinical trials. Cellular and molecular life sciences. 2008 Jun 1;65(11):1631-52.

Edited by Zsuzsa Lindenmaier & Jeffrey Lynham