I now have found two sources that indicate that copper induces fat loss. And each of those sources lists multiple other sources saying the same things, but different sources. The first lists 3 other sources. So this is a total of 6 sources now. Unfortunately, all these sources are only in 6 different animal studies: rabbits, ducks, hens, broiler chickens, mice, and cattle. Also, the amounts of copper are rather high. And these sources are relatively recent: 2017 and 2016.
Effect of dietary copper addition on lipid metabolism in rabbits July, 2017
Rabbits gained muscle and lost fat with up to 45 mg/kilo of copper added to their food, over 8 weeks. The food already had some copper, so it was 54 mg of copper per kilo of food in the highest copper group.
Humans eat about 3 kilos of food, from 2-4 kilos/day.
So the human equivalent of this copper was about 162 mg of copper/day, very roughly speaking. The rabbits took no co nutrients, and only 8 weeks. Not always applicable to humans. Humans have to slowly test.
In the rabbits, copper at the human equivalent of 162 mg/day was statistically better at lowering fat than half the amount of copper, roughly about 80 mg/day.
Copper increased the activity of numerous fat-burning enzymes:
“In the skeletal muscle, gene expression of CPT1, CPT2, LPL, FATP, FABP, and PPAR-α was significantly upregulated by copper treatment. … rabbits receiving the copper supplement had signiﬁcantly higher mRNA levels of CPT1, CPT2, HSL, and PPAR-α in the adipose tissue compared to the control group (p < 0.05).”
“In line with previous studies in ducks [Citation17], laying hens [Citation18], and broilers [Citation34], copper treatment increased body weight gain and muscle tissue growth in rabbits.”
“In conclusion, copper promoted skeletal muscle growth and reduced fat accretion.”
The high copper rabbits gained overall weight, but gained more muscle than the total weight of the fat that they lost. What’s very significant about that is the rabbits did not ever go to the gym!
Copper is key to fast metabolism, could help you burn fat naturally June, 2016
Further burnishing copper’s reputation as an essential nutrient for human health, researchers have found that the metal plays a key role in metabolising fat.
“We find that copper is essential for breaking down fat cells so that they can be used for energy,” said lead researcher Chris Chang, professor at the University of California – Berkeley.
“It acts as a regulator. The more copper there is, the more the fat is broken down,” Chang noted.
“We think it would be worthwhile to study whether a deficiency in this nutrient could be linked to obesity and obesity-related diseases,” Chang said.
“The researchers made the copper-fat link using mice with a genetic mutation that causes the accumulation of copper in the liver.
“The findings appeared online in the journal Nature Chemical Biology.
“The connection between copper and fat metabolism is not altogether surprising. The researchers actually found hints of the link in the field of animal husbandry.
“It had been noted in cattle that levels of copper in the feed would affect how fatty the meat was,” Chang said.
“This effect on fat deposits in animals was in the agricultural literature, but it hadn’t been clear what the biochemical mechanisms were linking copper and fat,” he noted.
My conclusion: ==> It is unknown how much copper humans may need to achieve similar results, if they can, at all!
My further thoughts: I feel there is significant evidence that copper should assist fat burning. For example, copper is needed to make ATP for energy, and copper is needed for increased oxygen metabolism, both of which should burn fat. Copper increases many hormones such as testosterone that should help burn fat. But copper also assists detox, which should also help burn fat. But if detox causes more mobilization of toxins than excretion, fat could increase, as the body will increase fat to trap toxins, too. This could mean that lower amounts of copper may tend to initially cause fat gain, and higher amounts of copper may more likely cause fat loss, and it is still yet unknown what these levels would be.
In the Olivares study of 20 mg copper over 6 weeks in humans, they did not test, nor note, any changes of fat, whether higher or lower, in people. They only looked at the potential for liver damage, and found none.
As an aside, Radmacher in the 1850’s did test up to 260 mg of copper to cure humans of diseases in the 1850’s, but this was also only short term doses, over about 3 weeks.