Category: News

Wild-caught halibut is experiencing a rise in a quality related defect that affects its market reputation. Consumers will order expensive halibut from restaurants, and the fish sometimes comes out nearly inedible. Why? This is due to a problem with the meat itself. “Chalkiness” of the meat has increased in recent years and may be due to both warming waters and stress placed on the fish during capture.  

Chalky halibut is a phenomenon where the protein inside the halibut becomes denatured. This results in a white, opaque appearance to the fillet, as opposed to the shininess consumers are used to. The meat itself often tastes tough and dry. However, it’s almost undetectable while undergoing processing and the ability to detect chalky halibut before it is served is difficult. Processors currently rely on pH tests, but the results can be inconsistent.  

Christina Dewitt, Director of the Seafood Research and Education Center at Oregon State University (OSU), and Angee Hunt, Assistant Professor at OSU, are working on a project together that can potentially help detect chalky halibut before it gets to the consumer.   

“I started looking into chalky halibut and began to understand the muscle chemistry of what was happening and why it was happening,” Dewitt said. “Chalky halibut might be caused by extreme stress—rapid lactic acid production. One of the ways that they detect chalky halibut is by measuring pH. There’s been some studies where they stress fish and they’ve demonstrated they can produce chalky halibut in those fish, and found that the pH of the meat is abnormally low as a result of that.”  

Dewitt and Hunt’s work, however, centers around the technology of bioimpedance. Bioimpedance is a non-invasive, rapid tool that sends out electrical currents that can detect certain qualities within a body, in this case, a fish’s body. For example, the equipment can detect tissue composition and function.  

“Typical bioimpedance is based on a technology that uses two different frequencies of electricity, and then they can use the resistance that occurs between those emitted frequencies to basically determine different things like the amount of fat content or the amount of degradation that’s occurring in the cell,” Dewitt said.  

Both Dewitt and Hunt will be traveling to Kodiak, Alaska, this summer to scan wild halibut for chalkiness using a bioimpedance device. In this study, alongside the current technology of pH detection, Dewitt is hopeful bioimpedance will prove more reliable. 

“We want to scan the fish [in Alaska] using our device,” Dewitt said. “We’ll probably scan it in a couple of different areas, and then they’re going to be collecting pH data on the fish. What we’re hoping is that when they pick it up using pH, we can definitely pick it up also [with bioimpedance]. We want to show that correlation, that the device can pick it up when it’s obvious.” 

For Hunt, she is looking forward to working directly with fishers and processors in Alaska. 

“This opportunity enables researchers to better understand the day-to-day challenges and identify opportunities for collaboration between industry and academia,” Hunt said.  

Next, their studies in Alaska will involve collecting data to correlate with the data that shows muscle degradation. Multi-frequency bioimpedance sensors can make it possible to capture shifts in electrical properties across a spectrum and detect tissue changes over time. Current commercial grade bioimpedance technology uses just one frequency to estimate impedance.  But their project will utilize a range of frequencies, from 1-200 kilohertz, to simultaneously evaluate quality changes.  

“We’re going to be scanning 100 frequencies, instead of just two, and looking to see if there is a relationship that the regular device can’t pick up,” Dewitt said. “We’re going to use both the research grade device and the commercial device that we have right now and take measurements side by side. We’re also going to collect the data from the plant, and then hopefully collect a small sample of the muscle that we can take with us to do some lab analysis on. The first stage of this is really to understand the frequencies that detect changes in the muscle structure when there is chalky halibut.” 

After the summer session in Alaska, there is still more to be done before the fish make it to the market. For Dewitt, there is an importance placed on gathering this data for statistical evaluation. By comparing these impedance values of frequencies, distinct patterns may emerge, allowing for a look into the physiological states or tissue responses across varying conditions. 

“And the next stage would be thinking forward, once you know the frequencies that respond the best to chalky halibut, then you would go back and try to sort those based on those frequencies and see how they perform,” Dewitt said. “And then collect samples from fish that are being predicted as having chalky halibut and finally test them to see if they confirm what we are thinking is going to happen.” 

It’s not just Alaska, either. Dewitt’s team is talking with local processors in Oregon and Washington. If there is chalky halibut coming in, they want to know about it and receive samples, if possible. The problem with chalky halibut that her team is trying to solve is ultimately stopping the fish from being received by the market. Dewitt and Hunt hope to improve its overall market competitiveness by catching it early with bioimpedance.  

“The bad part about chalky halibut is sometimes it gets past the plant,” Dewitt said. “It gets past the distributor and only shows up once the consumer gets it, so it begins to give a bad reputation to halibut, [which usually] has a good reputation, but it loses its reputation each time it gets consumer complaints. There’s a lot more of it showing up, and it got past all these different players. Ideally, you would take some preventable steps. It shouldn’t get to the consumer.”  

At all of these different levels of processing halibut, chalky halibut is a thorn in the side of halibut production. There is a huge need to detect it early. Dewitt and Hunt are on a mission to prove that bioimpedance could work for this.  

“Using the bioimpedance machine we hope to be able to detect the quality differences between individual chalky and non-chalky halibut,” Hunt said. “Early detection will allow each type to be directed to the appropriate processing to maximize utilization, consumer experience, and economic value of halibut harvests.” 

By Maia LeClair, SIRF intern

Typically, medical interventions like chemotherapy and radiation are used as a bulwark against cancer, but what you eat in a day can play more of a role than you would think in fighting this common disease. Specifically with prostate and breast cancer, certain additions to a healthy diet can provide boosts to either prevention, continued efforts against the growth of cancer, or post-cancer health. 

Some recent research studies, available on the Seafood Industry Research Fund (SIRF) website, looked in depth on how incorporating Omega-3 fatty acids into a diet can be useful against cancer. Omega-3s are essential fats that support heart and brain health and are found in fatty fish such as salmon, trout, sardines and tuna. Due to providing these anti-inflammatory properties, its use against cancer is scientifically intriguing. 

One article, titled “Feasibility of Investigational Procedures and Efficacy of a Personalized Omega-3 Dietary Intervention in Alleviating Pain and Psychoneurological Symptoms in Breast Cancer Survivors,” discusses how breast cancer patients sometimes struggle with psychoneurological symptoms (PNS) after treatment and deal with high inflammation. Omega-3s are anti-inflammatory. By correlating the two together, researchers from University of Connecticut conducted a study which showed that a diet of high Omega-3s in breast cancer survivors can have a “significant decrease in pain, perceived stress, sleep, depression, and fatigue over the course of intervention.” 

Similarly, in another study by the University of Connecticut, titled “Dietary Consumption Patterns in Breast Cancer Survivors: Pilot Evaluation of Diet, Supplements, and Clinical Factors,” the aim was to evaluate dietary quality in a cohort of breast cancer survivors. In this study, results found that many women are not meeting recommended dietary guidelines. Yet the results also indicated that by incorporating a high amount of Omega-3s, including in supplements, it promoted better nutritional consumption patterns and improved overall health during survivorship after cancer.  

Both studies point to the impact Omega-3s can have on the body. Increased consumption of Omega-3s can be an aid against the sometimes obstructive aftereffects of battling breast cancer. Eating more seafood is a good step to take on the road to full recovery.  

Men can also experience positive effects from a diet of Omega-3s. Dr. William Aronson, at UCLA, spends time researching how Omega-3s can delay the progression of prostate cancer. His continued efforts are reflected in two research papers: “Effect of Omega-3 Fatty Acid Diet on Prostate Cancer Progression and Cholesterol Efflux in Tumor Associated Macrophages” and “High Omega-3, Low Omega-6 Diet with Fish Oil for Men with Prostate Cancer on Active Surveillance.”  Preclinical and clinical translational research supports the role of an Omega-3 fatty acid diet for prostate cancer prevention and treatment, according to the study.  

In this study, men on active surveillance for prostate cancer were randomly assigned to one of two groups: a control group or a group on the high Omega-3 diet. After one year, they were evaluated to observe the change of the Ki-67 index which is a protein marker for cancer growth. A high amount of Ki-67 in the body suggests a higher rate of progression of prostate cancer. An increased intake of fish and other foods high in Omega-3s, with a lowered intake of Omega-6s, such as corn oil, safflower oil, and fried foods, showed a decrease in the biomarker Ki-67, which is positive. 

Overall, whether someone has breast cancer, prostate cancer, or just looking to eat healthier, eating more foods high in Omega-3s should be encouraged. Dr. Aronson is continuing to study these effects and other researchers are too, as delaying cancer progression and reducing inflammation in the human body are top goals many have in the fight against cancer. People with prostate or breast cancer can benefit from these findings and with a simple change to certain aspects of their diet may find many encouraging outcomes.

By Maia LeClair, SIRF intern  

Catching cancer early and treating it fast is one of the leading drivers of investment, research, and study in the field of cancer research. With so many affected by cancer every year, clinical trials indicating actionable steps for patients, while not necessarily a cure, can still be a lifeline. The concern for many with cancer is the threat of metastasizing, or fast-growing tumors unwilling to be halted. But are there other considerations in what could play a role in the progression of cancer? Dr. William Aronson, a Professor at UCLA in the Department of Urology, has dedicated years to the study of how Omega-3s, a type of fatty acid easily found in fish, can be used within a diet to slow the progression of prostate cancer. His recent study, titled High Omega-3, low Omega-6 diet with fish oil for men with prostate cancer on active surveillance: the CAPFISH-3 randomized clinical trial, can be found on the Seafood Industry Research Fund (SIRF) website.  

Dr. Aronson’s work typically focuses on the quantity of dietary fat, omega-3 fatty acids from fish oil, caloric restriction, green tea, and lycopene in a diet. He conducts clinical research on the role of these nutritional elements in the treatment of prostate cancer. His research has focused on the general efficacy of incorporating these elements into one’s diet. And what he’s found seems to be positive.  

“The background is that in our animal models and in prior short-term clinical studies, we’ve clearly seen the potential for dietary fat changes combined with fish with Omega-3 fats for delaying prostate cancer progression,” Aronson said.  

His studies, which date back more than 25 years, are driven by this look into how diet affects one’s health, while having a type of mindset of “you are what you eat.”  

“There have been epidemiologic studies suggesting that increased fish intake delays the progression of prostate cancer,” Aronson said. “The studies for prevention are actually less clear, but there are very nice prior studies that involve fish intake for delaying progression.” 

In this case, the studies conducted showed results of how increased fish intake, while lowering fat intake of ingredients, such as corn oil, safflower oil, and fried foods, significantly lowered the biomarker protein Ki-67, which can predict prostate cancer progression. Ki-67 is a protein on the surface of cancer cells which is a marker for cells actively dividing and the cancer growing. Prostate cancers with higher Ki-67 levels are more likely to spread outside the prostate leading to cancer progression and limiting life expectancy 

 Dr. Aronson’s study observed the rates of Ki-67 significantly declined because of the changed diet.  

“We found that through this dietary intervention, which involved increased fish intake, we were able to lower the Ki-67 level in prostate cancer cells in these patients, as compared to a control group,” Aronson said. 

Dr. Aronson said in prior studies, he and his team found that the omega-3 fats actually inhibit a cell in the immune system that prostate cancer uses to promote its own growth. They are interested in applying this favorable effect of fish-derived omega-3 fats in future clinical trials with the hope of slowing the progression of more advanced prostate cancer. 

Ultimately, these studies and clinical trials are encouraging dietary changes in the hope of slowing the progression of this cancer, which is the second leading cause of cancer in men. Due to its high prevalence, Aronson said the key is to share these findings with clinicians and patients who might benefit from them. 

For Dr. Aronson, these clinical trials are the culmination of years of hard work. Working with funding from the National Cancer Institute and private donors has all led up to the end results of this particular trial.  

“To see our positive findings was so gratifying,” Aronson said. “In that moment when the statisticians let us know our favorable results, that was really among the most exciting moments in my career. We believe our findings will be of tremendous benefit to our patients with prostate cancer.” 

Dr. Aronson and his team are presently analyzing the samples from the patients, both blood and tissue samples, to further understand exactly how the fish-based intervention had such a positive impact.   

“We’ve got some hard work ahead of us,” Aronson said. “Our findings were positive, but there’s more work to be done.” 

Science and technology are ever evolving, and Aronson isn’t stopping here. He believes the future will hold more concrete ways of prevention and treatment for cancer with diet and lifestyle changes. For now, Aronson’s findings help create hope. It is exciting that incorporating more seafood, one of the easiest meals to cook, into one’s diet can have benefits that go past the usual health food conversations and potentially have a direct impact on the progression of prostate cancer.  

By Maia LeClair, SIRF intern