Turmeric from Curcuma longa which is the best variety is known as the orange ingredient used liberally in Indian curries, turmeric has a long history of use in both Indian and Chinese traditional medicine, and has also been used as a textile dye. Much of the effects are attributed to the component curcumin which is about 3 to 6% in the better varieties but there are many other synergistic compounds in the whole rhizome that work together in the metabolism and it is best consumed cooked with an oil like coconut, olive or butter and importantly black pepper.
In September 2012 I started the Facebook group Turmeric User Group https://www.facebook.com/groups/415313751866609/ to document the therapeutic use of turmeric in humans and all animals. As of December 2019, group membership has exceeded 270,000 worldwide.
The active ingredients are notoriously difficult to absorb and when that is achieved they are quickly eliminated. The addition of fresh cracked black pepper (Piper nigrum), apart from its own positive effects, is used to markedly slow the excretion of the active curcuminoids and prolong their effect in metabolic pathways, and it itself pepper is a good food and not just a condiment. Pepper was correctly revered as a food additive a few hundred years ago.
Turmeric needs to be cooked in boiling water to make the starchy compounds much more soluble and better absorbed in monogastrics digestion. Using it raw, like grating on salads, is not going to be digested at all. For humans and dogs the famous Golden Paste is made by boiling turmeric powder in water, then adding freshly ground black pepper. A healthy oil can be added at the same time, or later when the paste is used.
These components are not soluble in water but dissolve in oils, short chain fatty acids and alcohol. Unless one or more of those are present when consuming turmeric, absorption does not happen. And absorption is far better in monogastrics (single stomach species) when turmeric is consumed with a good whole food and healthy gut biota present, and less so when gut biota is poorly diversified and compromised as the result of a poor diet, high in processed foods and added sugars.
Even so 100% absorption will never be achieved and the best is more likely to be 10%. Luckily, curcuminoids are very powerful and you do not need very much to have effect.
Regular daily intake is the rule, and humans and dogs probably need to consume two to 4 times daily. Ruminants like cows and sheep, with their efficient storage type digestive systems, may need it only once. Horses, camelids and other herbivores also digestive turmeric efficiently and may not need as much as carnivores and omnivores.
Ruminants like cattle, sheep, llamas and alpacas have a very effective fermentation vat: the rumen and the inhabitant organisms (gut biota) are able to take in and use the components of the turmeric plant pieces including curcumin, and then the animal benefits from this by digesting them in turn. Ruminants are very much more efficient at digesting plant materials. And equines too are better adapted at absorbing plant nutrients.
There is much scientific evidence (about 8,000 scientific citations if one cares to look in the scientific literature) to back up the tens of thousands of anecdotal experiences put forward in this group over the seven years. And there is a three-thousand-year history of these effects in eastern medicine. There is no real negative evidence. Just recently the sceptics TV show “Trust Me I am Doctor” produced real evidence that turmeric included in food had a significant effect on genes associated with inflammation, asthma and some forms of cancer - http://www.sbs.com.au/food/article/2017/01/27/daily-disease-fighting-ritual-michael-mosley-puts-turmeric-test
Here is a brief mention of the positive effects that can be backed up with scientific evidence and anecdotes:
ANTICOAGULANT: allowing blood to flow correctly and inhibiting abnormal blood clot formation (thrombosis). If already on anticoagulants your clotting needs to be monitored and the dose of these reduced or stopped.
ARTHRITIS: Curcumin inhibits the breakdown of cartilage and has been shown in some studies to be as effective as hydrocortisone and phenylbutazone in relieving the symptoms of arthritis such as inflammation, swelling and joint stiffness. Even better, it does so without the significant side-effects of those drugs, and has been shown to be safe at very large doses.
BLOOD PRESSURE: reduces and normalises blood pressure. Those on blood pressure reducing tablets need to monitor that and reduce dose.
CANCER: Curcumin defends the body against cancer via a number of actions: it detoxifies carcinogens thereby preventing the initiation of cancer cells; suppresses the progression of cancerous cells by inhibiting their proliferation while simultaneously increasing their death and removal; and inhibits the spread of cancerous cells to other areas of the body. It can also reduce the side effects of chemotherapy treatment and enhance the action of some chemotherapy agents. Various studies have demonstrated either turmeric (as a whole food) or curcumin/curcuminoids (as isolates) to have beneficial results in preventing or treating a wide range of cancers. These include skin including melanoma, ovarian, breast, lung, oral, stomach, liver, colon and prostate cancers.
CARDIOVASCULAR EFFECTS: Curcumin improves the liver’s ability to clear the body of LDL (‘bad’ cholesterol), and increases the proportion of HDL (‘good’ cholesterol). In addition, it prevents the oxidation of both LDL and HDL (oxidised cholesterol leads to blood vessel damage and plaque build-up that can result in heart attack or stroke).
COGNITION and BRAIN health: Alzheimer’s Disease In addition to the anti-inflammatory and antioxidant protection turmeric/curcumin affords against neurodegenerative diseases, curcumin has been shown, after crossing the blood-brain barrier, to inhibit formation of the plaques between neurons (nerve cells) that disrupt brain function.
DIABETES: along with cinnamon and ginger, turmeric is effective at reducing blood sugar and increases insulin sensitivity and levels serum glucose. Enhances glucose uptake in skeletal muscle and other tissue. Need to monitor blood sugar levels and probably adjust insulin doses downwards. Improves insulin resistance condition.
DEPRESSION: mood lifting, mentally energising anecdotes are common in the TUG group page, and useful antidepressant. If already on antidepressants one needs to run it past your doctor because there can be some additive effects.
ENERGY: increases metabolic rate and normalises blood glucose and alertness. Diabetic animals fed curcumin not only had a significant reduction of blood cholesterol levels (LDL fraction) but also of blood triglycerides and phospholipids (elevated levels of both are associated with the disturbed lipid metabolism characteristic of diabetes).
FERTILITY: improves fertility in dogs, cattle, horses and presumably humans. Chicken egg production improved by 30%.
GASTROINTESTINAL TRACT: inhibit the growth of Helicobacter pylori a bacterium associated with both gastric & duodenal ulcer formation and gastric & colon cancers. Other studies have indicated that turmeric (at appropriate doses) can enhance the healing of gastric ulcers via an increase in gastric wall mucus production. Further, turmeric has been shown to have an antispasmodic effect on the gastro-intestinal tract. In addition, turmeric and curcumin have been investigated and found to be protective against Inflammatory Bowel Disease.
LIVER health: Turmeric has a liver-protecting action. It both prevents and repairs liver damage. It protects the liver from inflammation and improves ‘the clearing function of the liver when it has been damaged and dramatically increases the clearance of alcohol from the system. Best hangover cure but even better when in the system prior to a night out.
SKIN, nails and hair growth: significant reduction of itchiness in skin of humans, horses and dogs. Improves quality of fingernails and hair in humans and hooves of horses. Deepens coat colour in horses. Counteracts sunburn even after redness appears. Does this by antioxidant effect e.g. scavenges radiation induced, reactive, free, radicals.
WEIGHT LOSS: above effects contribute to significant weight loss.
WOUND HEALING: promotes rapid healthy healing of wounds
As well as all the above, turmeric has demonstrated the ability to suppress cataract development, and have a topical anti-fungal effect.