It’s not likely that you’ve heard of PQQ, or pyrroloquinoline quinone (say that three times fast!), but research is showing that this antioxidant with a funny name has the potential for wide-ranging benefits on many health fronts…

Liver Health

NAFLD or nonalcoholic fatty liver disease (too much fat in the liver, not from excessive drinking) is a growing epidemic that affects approximately three times as many American adults as diabetes. Unchecked, it can progress to cirrhosis and liver cancer and is predicted to become the leading cause of liver failure and death due to liver disease within the next two decades. Now, research at the University of Colorado Anschutz Medical Campus has found that PQQ can prevent the progression of NAFLD in mice and could hold the potential for stemming the disease in people.

Brain Health

A small clinical trial done in Japan showed that elderly participants who were given PQQ had better blood flow in the brain, so it’s possible that PQQ could help prevent the decrease in memory and attention that often comes with age.

Cholesterol Levels

A separate Japanese study found that PQQ decreased the LDL (“bad”) cholesterol levels in middle aged participants (40 to 57 years old) whose cholesterol levels were in the normal-to-moderately high range.

Bone Health

Osteoporosis is not limited to women—it’s also a health concern for older men. Researchers at the Nanjing Medical University in China showed that in the lab, PQQ holds the possibility of helping prevent osteoporosis in male mice caused by low testosterone (levels of the hormone naturally decline with age)—it helped prevent DNA damage and stimulated bone cell formation.


Despite all this research, study of PQQ is still in the early stage. All of these studies used supplements and were either lab tests involving mice (and very high doses of PQQ) or very small human clinical trials. That means that large, controlled studies on people are needed before experts can draw sweeping conclusions about PQQ’s effects on the human body. If these results continue to prove out, we might learn that adding PQQ to our diets could very well help protect the liver, keep bones and joints healthy, and improve brain function, said Karen Jonscher, PhD, associate professor at the University of Colorado and lead author of the study.

What about the PQQ supplements already on store shelves? Dr. Jonscher said that, according to GRAS (generally regarded as safe) notices from the FDA, commercially available PQQ taken once a day in a 10- to 20-milligram pill is well within the safe range—human studies have tested doses up to 60 mg per day short-term and 20 mg per day for 2 years with no adverse effects.

Even so, whenever you are considering taking a new supplement, particularly if you take any other medications or supplements, you should discuss it with your physician and even a pharmacist to learn of any known potential interactions or other concerns, Dr. Jonscher cautioned. And definitely do so if you’re interested in consuming higher levels of PQQ to fight a disease such as NAFLD.


Until we learn more about the most effective supplement dose of PQQ, eating foods high in the antioxidant can give you access to its potential benefits.

Good-for-you-foods that are also naturally high in PQQ include…

  • Green peppers
  • Spinach
  • Parsley
  • Kiwi
  • Papaya
  • Fermented soybeans (natto)
  • Tofu
  • Oolong and green tea

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