Do nutraceuticals really treat?

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Extract of garlic or ginseng, glucosamine, oregano oil: these substances qualified as nutraceuticals are praised for their preventive and curative properties. But are they really effective? The Plaisirs Santé team looked into the matter.

You have certainly read about claims, for example, that ginseng could help alleviate diabetes by asking if it was true. Or heard your best friend repeat that there was nothing like the essence of oregano to deal with the season of colds and flu. Health Canada defines nutraceuticals as a product that “is made from food but sold in the form of pills or powders (potions) or other medicinal forms that are not commonly associated with food, and that are has been shown to have a beneficial physiological effect or to provide protection against chronic diseases “. According to Heather Boon, Director of the Advisory Committee of Health Canada’s Natural Health Products Program and Assistant Professor in the Faculty of Pharmacy at the University of Toronto if, in Canada, nutraceuticals, vitamins and minerals are all classified as natural health products, the former have properties that go beyond the simple framework of nutrition.

It is certainly convenient to swallow a pill that offers the benefits of a food without having to suffer the potential disadvantages, for example, the antioxidants of red wine without alcohol. However, while many nutraceuticals are promising, this category of supplements raises a number of questions. ” Natural substances are complex, ” says Paul Thomas, a registered dietitian and scientific consultant for the US National Institutes of Health’s Office of Dietary Supplements. “Depending on the processing method used, the blend of the finished product ingredients may differ substantially from brand to brand.This means that it is not easy for health professionals to recommend a dosage for a given product.

It must also be borne in mind that nutraceutical studies are only at a preliminary stage. In addition, it is important to emphasize that “natural” does not mean “safe” . ” If the product has a positive effect on the body, it can also have negative effects ,” says Paul Thomas. It’s always best to talk to your doctor about the possible side effects and interactions of a nutraceutical with other medications. “

Clearly, it is not easy to know which of the nutraceuticals are up to the claims of their manufacturers and which are a waste of time and money . The Plaisirs Santé team looked at the most talked about ones. Here are the results of the most recent studies revealing about them.

Conjugated linoleic acid (CLA)

This essential fatty acid is present in dairy products, beef, poultry and eggs. It is usually sold as capsules or tablets.

Claim : It promotes the elimination of body fat and, consequently, weight loss.

Is it effective ?: According to a review of 18 studies published in the 2007 American Journal of Clinical Nutrition, ACL causes a modest loss of fat, about 0.09 kilograms (90 grams) per week compared to the placebo group. This equates to a loss of more than 4.5 kilograms per year, compared to an average of 0.35 kilograms.

Keep in mind: The results of the studies are mixed. In some cases, elevated blood markers of inflammation or deterioration of vascular function have been observed, while others have revealed no such thing. In a study published in the Journal of Lipid Research in 2008, in which mice were given CLA, researchers observed an accumulation of fat in the liver, which is associated with insulin resistance and diabetes. Many experts believe that further studies are required before taking a decision. It should also be noted that CLA may interact with medications prescribed for diabetes and hyperlipidemia (high blood lipid levels).

Conclusion : “Compounds like CLA may have a minor action on weight loss, but no tablet can replace exercise and diet,” says Dr. Mark Tarnopolsky, director of the Neuromuscular and Neurometabolic Unit at the center. McMaster University Medical Center. His studies of CLA indicate that this product is safe, at least when taken over a period of two to six months, at a rate of three grams per day.

Garlic extract

Dehydrated or aged garlic is sold in the form of capsules, powder or oil.

Allegation : It lowers cholesterol and blood pressure.

Is it effective? : The results of animal studies indicate that garlic lowers cholesterol levels. However, those of a more recent study published in 2007 in the Archives of Internal Medicine and in which 192 subjects whose cholesterol level was moderately high were given a supplement of garlic, raw garlic or a placebo , six days a week for six months, indicate that LDL cholesterol (the “bad”) did not change in any of the participants. It is therefore necessary to conduct further studies before deciding on the issue.

With respect to blood pressure, in a review of 11 garlic studies published in 2008 in BMC Cardiovascular Disorders , the researchers concluded that garlic supplements lowered blood pressure. systolic (which is higher) of 8.4 mmHg on average and diastolic (lower) pressure of 7.3 mmHg in subjects with moderate hypertension. These results are comparable to those obtained with hypotensive drugs. Once again, experts believe that further studies are needed to confirm these results.

Keep in mind : Garlic has the effect of lightening the blood. If you have to have surgery or are on anticoagulants (for example, warfarin), it is best to consult your doctor before taking any. Garlic tablets can also interfere with oral contraceptives and HIV medications.

Conclusion : “Garlic tablets can slightly lower cholesterol and blood pressure, but you still need to lose weight, make changes to your diet, exercise, and take drugs like statins (cholesterol-lowering drugs), “says Toronto cardiologist Dr. Kenneth Melvin. The doses of garlic administered in the blood pressure studies ranged from 600 to 900 mg per day.

Ginseng

Two species of ginseng are used, namely Asian (Panax ginseng) and North American (Panax quinquifolium). The extract is sold in capsule form.

Allegation : Ginseng lowers blood sugar (blood sugar).

Is it effective? : Results of a University of Toronto Study of Asian Ginseng in 2008 Report Improvements in Blood Glucose and Insulin Levels in Drug-Dependent Diabetics Who Have Taken ginseng supplement for 12 weeks; these results were not observed in placebo-treated diabetics. The results of a previous study by the same team indicated that North American ginseng helped lower blood sugar levels in diabetics on medication.

Keep in mind: Diabetics or people taking blood thinners should consult a doctor before taking ginseng. It should also be noted that the results vary depending on the type of ginseng administered, warns Vladimir Vuksan, the researcher who conducted the studies at St. Michael’s Hospital in Toronto and holds a Chair in Medicine and Nutritional Sciences at the University of Toronto. For example, he observed that while North American ginseng (mainly grown in Ontario) and some varieties of Korean ginseng have contributed to a drop in blood glucose, this is not the case for Japanese or North Ginseng. American wild. As for Siberian ginseng and the Chinese species, they rather had the effect of raising it.

Conclusion : “If your diabetes is supported by medication and diet, you can consider ginseng as a complement to both approaches,” says Vladimir Vuksan. We recommend that North American ginseng grown in Ontario be gram-fed three times a day before meals. “

Glucosamine

This amino acid contributes to the development of cartilage that protects the joints. It is derived from chitin (carapace of crab, lobster and shrimp) and sold as capsules or tablets.

Allegation : it relieves pain and stiffness caused by osteoarthritis and delays progression.

Is it effective? : The results are mixed. Those of a large-scale clinical trial published in The New England Journal of Medicine in 2006 indicate that glucosamine / chondroitin supplementation (chondroitin sulfate is also derived from chitin), promotes the retention of water through cartilage) relieved moderate to severe pain in volunteers with knee osteoarthritis, but not mild pain. In an article published by The Cochrane Library researchers analyzing the results of 25 studies between 1980 and 2004 conclude that they are contradictory: in some cases, glucosamine has helped relieve pain and increase joint mobility, in others it has had no more effect than the placebo.

Keep in mind: If you have diabetes, suffer from shellfish allergy, or are following a diet low in potassium or sodium, you should consult a doctor before taking glucosamine.

Conclusion : “I usually advise my patients to try glucosamine for two or three months,” says Joanne Homik, director of the rheumatology division at the University of Alberta. “If it helps, continue taking it, otherwise, stop.” In most studies, the dose was 500 mg three times daily for a period of 30 to 90 days.

Grape seed extract and resveratrol

Grape seed extract contains proanthocyanidin, a powerful antioxidant. Resveratrol is also an antioxidant that is derived from the skin of the grape. Both extracts are sold as capsules or tablets, sometimes in combination in one package.

Allegations : They fight cancer, diabetes and high blood pressure.

Are they effective?: One of the first clinical trials we conducted on grape seed extract focused on high blood pressure. “We discovered that red wine stimulates the endothelium (layer of cells lining the blood vessels) and relaxes the blood vessels,” says Dr. C. Tissa Kappagoda, director of the University of California’s Preventive Cardiology Program. in Davis. “Then we tried to find out what would happen if we eliminated alcohol. We then conducted two trials on grape seed extract, the first on the metabolic syndrome (a set of factors including high blood pressure, high blood sugar, excess abdominal fat and hypercholesterolemia), the second on prehypertension. In both cases, the blood pressure dropped. “

Most of the more recent studies have been conducted in animals or in vitro. In a study published in 2008 in Cancer Prevention Research, it was found that resveratrol inhibited the formation of abnormal cells associated with breast cancer in vitro. In another in vitro study published in 2008 in Diabetes, Obesity and Metabolism , it was found to protect blood vessels from cell damage resulting from diabetes complications.

Keep in mind: Grape seed extract and resveratrol are considered safe but their potential drug interactions have not been well studied.

Conclusion : “People who plan to exercise and monitor their diet in order to lower their pressure could take a grape seed extract to increase the effects of both approaches,” advises C. Tissa. Kappagoda. In the study he conducted, subjects took 150 to 300 mg of extract daily for a month. Resveratrine, a concentrated form of resveratrol, is sold in the form of 50 mg capsules.

Essence of oregano

This essential oil is derived from wild oregano. It is usually sold in liquid form.

Allegations : It helps fight viral, bacterial and fungal infections.

Is it effective ?:Aromatherapy enthusiasts swear by it for the prevention of colds and flu, but there are few, if any, clinical studies to prove these claims. It is mainly studied in the nutrition sciences because it has the property of preventing microbial multiplication on chilled meats. In a laboratory study, Harry Preuss, a professor of physiology at Georgetown University in Washington, DC, found that relatively low doses were as effective as antibiotics commonly used to prevent the spread of staphylococcus, a harmful bacteria. . It has also been discovered in recent laboratory studies that it inhibits various strains of Candida (a microorganism that can cause vaginal fungal infections) and E.

Keep in mind : Although there are no known side effects or drug interactions, the essence of oregano has not been studied thoroughly. Therefore, do not give up your medications. In addition, do not take this essence if you are allergic to plants of the mint family, including thyme, sage and basil.

Conclusion : There is no problem taking oregano oil once or twice a week during the winter for the prevention or treatment of colds or flu, says Iva Lloyd, a practicing naturopath in Markham. (Ontario) and Past President of the Canadian Association of Naturopathic Doctors. “However, I do not recommend taking it all year round.” Depending on the brand of the product, the dosage varies from 5 to 15 drops a day, 2 or 3 times a day. If concentrated, mix with water.

Psyllium

Under this name is sold the dietary fiber which is extracted from the seed coat of Plantago ovata. It is in capsule or powder form; it is also added to certain cereals.

Claim : Psyllium lowers cholesterol levels and reduces inflammation, thereby promoting heart health.

Is it effective ?: The results of studies, including one that was published in 2008 in the European Journal of Clinical Nutrition(EJCN), indicate that psyllium contributes to lowering LDL cholesterol (the “bad”) without altering LDL (the “good”) level. On the other hand, the results of studies concerning its action on the reactive protein C (CRP), an inflammatory marker whose presence in the blood indicates a risk of heart attack, are contradictory. In a 2007 study at the Medical University of South Carolina, it was found that regular consumption of psyllium fiber in the form of foods or supplements had the effect of significantly lowering CRP levels. On the other hand, in another study conducted in 2008 by the same researcher who, this time, had given subjects only psyllium supplements, there was no decrease in CRP levels,

Keep in mind : If you have diabetes or a digestive tract disorder, such as irritable bowel syndrome (IBS), you should have a doctor before taking psyllium. This fiber is useful for some people suffering from IBS, but not all.

Conclusion : “By eating a whole grain cereal enriched with psyllium, you also get iron, B vitamins, zinc and magnesium,” says Bonnie Conrad, a dietitian in Halifax. Patients in the study published in the EJCN took 3 to 20 grams of psyllium a day.

Find the letters NPN

Before you buy a nutraceutical, make sure the label has the letters NPN (Natural Product Number) followed by an eight-digit number (for example, NPN 12345678). This is a guarantee that the product has been evaluated by Health Canada, which has determined that it is safe and effective when taken according to the indicated directions for use and has authorized its sale in Canada. You can also check Health Canada’s Licensed Natural Health Products Database(LNHPD).

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