- Guayusa and lion’s mane are two natural dietary supplements that may have health benefits.
- Usually taken as a tea made from the leaves, guayusa is a plant in the Ilex (holly) family. Lion’s mane is a mushroom, used for culinary purposes, which can also be taken as a supplement.
- Studies have suggested that both have antioxidant and anti-inflammatory properties, alongside other health benefits.
- A new study has found that they might also enhance mood and cognitive function.
Many people take supplements to enhance their health and wellbeing, but while animal studies have demonstrated their positive effects, there is little conclusive evidence of their efficacy in people.
Guayusa is from a tree in the holly family, Ilex guayusa, which grows widely in South America. People have been drinking it as a tea in the western Amazon for centuries.
- antioxidant activity
- anti-inflammatory effects
- cardiovascular protection
- anti-obesity and anti-diabetic effects
- neuroprotective activity.
Lion’s mane is a white, spherical mushroom (Hericium erinaceus). In Asia, it is used for both culinary and medicinal purposes, and it is becoming increasingly available as a supplement, because of its reported health benefits. The extract can be taken as capsules, liquid, tablet or powder.
Studies have suggested that benefits of lion’s mane may include:
- antioxidant and anti-inflammatory properties
- supporting immune function
- relieving anxiety and depression
- lowering cholesterol
- cancer prevention or treatment
- controlling blood sugar
- cognitive benefits.
Until now, evidence for these benefits has been largely from animal studies.
A new study now suggests that both supplements may enhance mood and cognition in people. The study is published in the journal Nutrients.
Kelsey Costa, a registered dietitian and nutrition consultant for the National Coalition on Healthcare, not involved in this research, commented on the study for Medical News Today:
“The study’s findings align with previous research suggesting cognitive benefits from these natural compounds. However, we should approach these results with cautious optimism given the study’s limited size and funding source — Applied Food Sciences Inc., the makers of AMT [the guayusa supplement]. This introduces the potential for bias in the study design and interpretation of results.”
A total of 40 people took part in the study — 22 female and 18 male particiapants. All were aged between 18 and 50 years, were in good health, had a
Participants underwent one screening visit and three test visits. At the screening visit, researchers assessed their health and diet, and participants did practice neuropsychological assessments to familiarize themselves with the processes for the test visits.
For 24 hours before each test visit, participants had to eat exactly the same diet and avoid exercise and alcohol. In addition, they were told to avoid caffeine for 12 hours, and fast for 8 hours before the test visit.
On arrival for each test visit, they were randomly allocated to receive placebo, 650 mg guayusa extract (AMT: AmaTea® Max), or 1 gram (g) Nordic-grown lion’s mane.
They completed baseline testing to assess mood, focus, mental clarity, concentration, ability to be productive and tolerate stress, and happiness (using the Subjective Happiness Scale), before taking the supplement, after 60 minutes and after 120 minutes.
At each time point, participants also underwent neuropsychological assessments, which assessed reaction time, mental processing, cognitive control, and attention. Researchers also checked their blood pressure and heart rate.
Researchers found that both supplements improved reaction time, with lion’s mane having a greater effect at 120 minutes than 60, suggesting a delayed response after ingestion.
The two supplements had some different effects, with lion’s mane appearing to have some more lasting effects than guayusa. This finding is backed up by a study that suggests lion’s mane given over an 8-week period decreased depression, anxiety, and sleep disorders in a group of people with overweight or obesity.
Guayusa significantly improved mental clarity, focus, concentration, mood, and productivity at 60 and 120 minutes post ingestion, and the ability to tolerate stress at 60 minutes. Lion’s mane improved subjective ratings of happiness at 60 minutes and this effect persisted to 120 minutes, whereas guayasa improved this only at 120 minutes.
The researchers caution that guayusa did raise both diastolic and systolic blood pressure by, on average 5mmHg, but that it remained within the normal range for healthy blood pressure.
“Guayusa has caffeine and similar derivatives. These are essentially stimulants, which we know can boost cognitive performance,“ Prof. Maryann Amirshahi, medical director of the National Capital Poison Center, not involved in this study, explained to MNT.
“Guayusa and lion’s mane also contain antioxidants — these are chemicals that prevent damage to nerves and other cells. There are many different chemicals in both of these, so it is hard to say which one, or a combination of them is what boosts cognitive performance,” she noted.
Prof. Amirshahi nevertheless cautioned that the study had some limitations: “An important limitation of a recent study is that they only looked at cognitive performance at 2 hours. We do not know how long these effects last and if they are offset by poor sleep. We also do not know how effective or safe they are with longer term use.”
Costa further explained some of the effects:
“As noted by the authors, caffeine appears as a key factor in the observed cognitive improvements associated with AMT. […] Essentially, caffeine boosts alertness by lessening alpha band frequency power, subsequently improving focus and visual information sensitivity.”
“In the case of lion’s mane, the researchers suggest the
The authors suggest that further studies using
Prof. Amirshahi warned that:
“While both of these supplements are recognized by the Food and Drug Administration as ‘GRAS’ (Generally Recognized as Safe), there are some important caveats. Supplements are not required to undergo the rigorous testing that FDA approved medications do. What that means is that we do not know as much about how effective a particular supplement is. Also, little safety information is collected about supplement products.”
Costa concurred, noting that “[t]he compounds present in guayusa tea and lion’s mane are generally considered safe for most people, but it’s always important to consider individual health conditions and potential interactions with other substances.”
“Consulting a healthcare professional before starting any new supplement regimen is recommended,” she added.