- Researchers investigated the therapeutic effects of beer hop extracts on Alzheimer’s disease pathology.
- They noted that beer hops have antioxidant effects that may be useful in preventing the condition.
- They concluded that further research is needed for their findings to influence Alzheimer’s prevention strategies.
Around 6.5 million Americans aged 65 years and older have Alzheimer’s disease, according to the Alzheimer’s Association. By 2050, they estimate this figure may reach 12.7 million.
Preventative strategies are key for tackling the condition. Diet is often considered a promising preventive target, as natural molecules in foods, and nutraceuticals may be able to interfere with biochemical events that underlie pathology.
Further study of hop extracts in relation to Alzheimer’s pathology could lead to novel treatments and prevention strategies for the condition.
Recently, researchers investigated the effects of hop extracts on human cell lines and a worm model of Alzheimer’s.
They found that certain hop extracts may inhibit the build-up of amyloid beta proteins in the brain — a key marker of Alzheimer’s disease.
“The study is exciting and further supports the power of dietary interventions for the prevention of Alzheimer’s disease,” Dr. Michael L. Alosco, associate professor of neurology at Boston University, not involved in the study, told Medical News Today.
“Importantly, the message should not be that drinking hoppy beer can lead to brain-based benefits or prevent Alzheimer’s disease. The benefits of the hops chemicals are likely to be diluted when combined with alcohol and the caloric ingredients found in beer,” he highlighted.
“Nonetheless, the study provides potential insights into disease mechanisms of Alzheimer’s and identifies novel preventative and therapeutic targets,” he explained.
The current study appeared in ACS Chemical Neuroscience.
When asked what led the researchers to investigate compounds from hops in relation to Alzheimer’s, Dr. Alessandro Palmioli, assistant professor of organic chemistry at the Department of Biotechnology and Bioscience at the University of Milan Bicocca, Italy, one of the study’s authors, told MNT “it’s a long story.”
“We started many years ago by studying some natural and synthetic molecules that were able to counteract the early stages of this disease. With a view to early prevention, we wondered if these molecules could not be routinely taken with the diet. So our studies focused on the search for bioactive molecules present in food and edible plants,” he explained.
“Hops are very rich in polyphenolic compounds, and for this reason, it is historically used for the production of beer, but also for the preparation of herbal teas and infusions, and its uses in traditional medicine are known. In recent years we have also collected interesting results on coffee, sage, Radix Imperatoriae (the root of masterwort), cocoa, and cinnamon extracts.”
– Dr. Alessandro Palmioli
For the study, the researchers screened and compared the activities of four different hops commonly used in the preparation of beer and herbal tea:
- Cascade (HC)
- Saaz (HS)
- Tettnang (HT)
- Summit (Hsu).
Overall, they identified 42 compounds from the hops. These mainly included compounds linked to reducing blood sugar levels and antioxidant activity.
The researchers next evaluated the hop extracts’ antioxidant activity in human cell lines of neuroblastoma — a type of cancer that develops from immature nerve cells.
They found that HT had the most effective antioxidant and radical scavenging activities.
In further tests, the researchers analyzed the ability of each hop extract to inhibit amyloid beta accumulation.
They found that all hop extracts could inhibit the build-up of amyloid-beta proteins, although HT was the most potent and HC the least.
Next, the researchers further isolated different components of the hops to investigate their individual properties.
In doing so, they found that polyphenols from HT were the most potent anti-amyloidogenic compounds in the hop extracts due to their antioxidant effects.
Meanwhile, other tests showed that hops might also protect against amyloid-beta neurotoxicity by regulating cellular signaling and activating autophagy- the recycling of damaged cellular components.
Finally, the researchers observed the compounds’ activity in worm models of human amyloid beta accumulation to see how they behave in vivo.
To do so, they compared the effects of HT and doxycycline (doxy) — a common antibiotic known to act against amyloidogenic proteins- in reducing amyloid-beta protein-induced paralysis in the worms.
In the end, they found that HT protected worms from amyloid-beta paralysis in a dose-dependent manner.
They additionally noted that certain doses of HT and doxy produced similar anti-paralytic effects in worms. While 50 micrograms per milliliter of HT reduced amyloid-beta-induced paralysis by 36.3%, 100 micromoles of doxycycline reduced paralysis by 43.1%.
The researchers concluded that their results point towards the development of nutraceuticals that may prevent Alzheimer’s.
When asked about the study’s limitations, Dr. Palmioli noted that the findings are based on preclinical results and that their efficacy in humans remains unknown.
He noted, however, that