One of the food-related trends in modern society is that of nutraceuticals, that is, people seeking foods that will enhance some physical characteristic or another that they value. From foods to boost brain power to foods to aid weight loss, or foods to boost immunity. The quest goes on for the quick food fix, usually as an alternative to a healthy lifestyle.
Some of the popularly published articles touting the benfits of various foodstuffs have no scientific support at all, and simply invoke “scientific evidence” like some sort of magic to support their claims. Others cite the tangible biochemical properties of the fruit, vegetable or substance and hypothesize the benefit that these chemicals will have on a person. Worst of all are self-reported, long-term studies that often confuse coincidence with causality and draw sometimes ridiculous conclusions from analysis of their constituent surveys, such as ‘high peanut butter consumption linked to longevity in nurses’.
In truth, rigorous trials with living animals or people are the only way to really see if any of these foods or their constituent chemicals have any affect whatsoever on immune response, healing or other characteristic in a living system. The reason for this is because living systems are very complex. Just because a food is rich in phytochemicals or some other property doesn’t mean that it will help your overall health when eaten. This is because of the complicated picture of overall health, metabolism, bioavailability and competing factors.
That bit of skepticism voiced, there is a growing body of scientific evidence, largely coming out of Asia, that lends support to the claims that some Asian spices and ingredients have anti-inflammatory effects and will function as immune modulators or that they prevent injury or even speed healing in response to direct injury.
Very roughly speaking immunity is modulated in part by a large selection of chemicals call cytokines. Some of these substances are “pro-inflammatory” that is they increase the number of cells that engulf foreign particles (phagocytes) or increase the fluid content of tissues to help stop the spread of injury. Others are “anti-inflammatory” and have to opposite effect. Others are fibrogenic and help speed tissue replacement (however imperfect) of damaged tissues. Still others have other functions.
In addition to cytokines, we’ve all heard that antioxidants are good things that bind with “free radicals” produced by an over abundance of reactive oxygen and nitrogen chemical compounds and thus reduce the oxidative stress on tissues. Well, another way that Asian spices are shown to have specific health benefits on living systems is in their function as antioxidants.
Turmeric
Turmeric, the lovely root, originating on the Indian Subcontinent, which when ground and dried forms the bright orangey-yellow powder that is used to color curries and stews and to offer a thick blanket of flavor that calms the extremes of other spices and unites them into a gentler whole. Also known as curcumin, systemic turmeric has been found to reduce both acute and chronic radiation-induced skin injury in animals after they received a single 50 Gray exposure to the hind leg. This reduction of injury comes about because the curcumin downregulates both inflammatory and fibrogenic cytokines. The coolest part of this testing, which began in China and is now being continued with US-NIAID funds, is that similar effects were noted when the curcumin was administered both before and after exposure. This means that this experimentation could lead to preventatives AND treatments for radiation-induced skin injury. (Int J Radiat Oncol Biol Phys. 2006; 65(3):890-898.)
Marigold
Marigold petals, also known as Calendula officinalis, originated in western Asia and are still widely used in Black Sea and Caspian regions as well as in Southern Russia. The spice that is used to color foods and unite straining flavors in a way similar to the southern Asian use of turmeric, is also used as an ingredient in many teas. Used for centuries as a medicinal herb, modern science is just beginning to find that marigold is also a powerful antioxidant in concentrations as low as .20 micrograms per milliliter.
Additionally, marigold flower extract acts to prevent deliberately induced chemical damage to the liver and kidneys in a dose-dependent manner when given before the insulting injection in doses of 100 and 250 milligrams per kilogram of body weight. The mechanism of this protection is still being studied in India, but is believed to be due to marigold’s inherent antioxidant activity. (Pharmacology. 2009;83(6):348-55; Indian J Exp Biol. 2009 Mar;47(3):163-8.)
Coriander
The spice that is ubiquitous in Asian cooking – whether as a seed, a powder, fresh leaves or roots – coriander or Coriandrum sativum seems to have a multitude of benefits on specific systems. Like marigold, its antioxidant properties help to protect against oxidative injury to the liver when administered in doses of 100 to 200 milligrams per kilogram of body weight in animals. Additionally, when studied in India in living animals, coriander has a strong diuretic effect which may make it useful in the treatment of hypertension. (Food Chem Toxicol. 2009 Apr;47(4):702-8. Epub 2008 Dec 29; J Ethnopharmacol. 2009 Feb 25;122(1):123-30.)
Black Cumin
The tiny scimitar shaped seed with the smoky bite that hails from the northernmost reaches of the Indian subcontinent or possibly Central Asia has recently been shown to protect animals against lung injury. Administration of black cumin – nigella sativa – in the form of volatile oil was shown to decrease the amount of fibrotic tissue, granuloma and necrosis in the lung after injury. The mechanism of this protection is still under investigation, but might be related to suppression of inducible nitric oxide synthase and an increase in surfactant protein D in the lungs. (Acta Histochem. 2009 May 8.)
Bay Leaves
Here’s a spice with real wow factor! Laurel nobilis, bay leaves, which hail from Asia Minor, are now found widely all around the Mediterranean and were associated with the God Apollo by the Greeks also seem to have some fantastic effects on glucose and lipid profiles in people with type 2 diabetes. Pakistani researchers mounted a small, placebo controlled, clinical trial in which they administered 1, 2 or 3 grams of ground bay leaves per day to diabetics for 30 days. They found that all three doses reduced serum glucose from 21 to 26%; total cholesterol decreased, 20 to 24%; and low density lipoprotein (LDL) cholesterol fell 32 to 40%. High density lipoprotein (HDL) cholesterol increased 29 and 20%, and triglycerides also decreased 34 and 25% after 30 days. These results need to be repeated in larger trials and examined carefully for toxicity profiles etc, but as a first shot across the bow, modern science seems to have found a real winner in bay leaves. (J Clin Biochem Nutr. 2009 Jan;44(1):52-6.)
As you can see, modern science is beginning to confirm the facts that subcontinetal cooks have known for millenia – many of the spices in your average curry are really quite good for you. So, as the lines between food and medicine continues to blur – the next time you are feeling a bit peaked, take two curries and call me in the morning. (Words by Laura Kelley. Photo of Nutritious Curry © Mayangsari | Dreamstime.com)