One of the most powerful polyphenols in olive oil is hydroxytyrosol. Consuming hydroxytyrosol is linked to benefits in neurological, cardiovascular, and metabolic health, and the compound has demonstrated anti-inflammatory, anti-cancer, neuro-protective, and immuno-protective effects. A recently published scientific review in the journal Foods examines the growing body of evidence supporting the characterization of hydroxytyrosol as a “functional food,” with emphasis on its effects on neurological and cognitive processes.
What is it?
Hydroxytyrosol (hi-droxy-TY-roh-sol), abbreviated as HXT, is a phenol, a natural chemical that is both water-soluble and attracted to fats, which means that it can pass through cell membranes. Its chemical structure also explains its strong antioxidant and anti-inflammatory properties. HXT occurs mainly in olives—olive oil, fruit, leaves, and pulp—as well as in red and white wines.
What does HXT do in the brain?
HXT interacts with the brain and its vascular (blood vessel) system in 3 ways: 1) as an antioxidant and anti-inflammatory agent, HXT helps prevent damage to cerebral blood vessels and improves their function; 2) lab studies show that, by reducing oxidation and inflammation, HXT helps maintain the proper functioning of the blood-brain barrier (BBB), a crucial filter inside the brain’s blood vessels that controls what substances enter and exit the brain; 3) in studies in humans, consuming HXT in the form of high-phenolic EVOO resulted in less “leakage” across the BBB and, as reflected in participants’ performance on cognitive tests, improved connectivity between brain regions.
HXT and its metabolites (the components of a substance that are formed when metabolic processes, such as digestion, break it down) are able to cross the BBB to interact with specific brain processes, enhancing protective activity and dampening inflammatory activity that is linked to depression and cognitive decline.
How much HXT is needed to obtain its benefits?
In studies in humans, the above benefits were observed with an HXT intake ranging from 7 to 15 mg/day. In terms of EVOO, this translates to a daily consumption of about 25 to 50 ml of high-phenolic olive oil, or ~2 to 3 tablespoons. Table olives—regardless of their color or brining—also provide an excellent source of HXT.
What’s next for HXT?
This body of promising evidence has intensified interest in the development of HXT-enriched foods and other ways of delivering this health-promoting compound. HXT is highly bioavailable, which means that, after it is consumed and digested, it is readily absorbed and transported by the body. So, for now—perhaps for always—the most effective, efficient, and delicious way to obtain the neuroprotective benefits of HXT is “food-first,” via high-phenolic EVOO.
Reference: Martínez-Zamora Z. Foods 2025;14(21):3624.
Cold Seafood Salad Recipe, Spotlight on Yuzu Rice Wine Vinegar, Overcooking Shellfish, Controlling High Blood Pressure, Plus Exercise and Your Appetite
I love elegant dishes that deliver on taste with a minimum of effort, and my take on a seafood salad is perfect at any time because the ingredients are always available—flash-freezing makes it possible to find them year-round in the freezer case. Another reason to love this dish is that it doesn’t call for any added salt, a contributor to high blood pressure. Read on for other ways to limit sodium in your diet.
Prepare an ice bath: Set out a very large bowl and fill it halfway with water, then add 2 cups of ice.
Step 2
Boil the shrimp in a large pot of water until pink, about 5 minutes; use a large strainer to scoop them out and into the ice bath to cool. Add the calamari rings to the boiling water and cook for 2 minutes; use the strainer to scoop them out and into the ice bath. Turn the heat in the cooking pot down to a simmer, add the scallops, cover, and take off the heat; wait 4 minutes, and then use the strainer to scoop them out and into the ice bath. After 5 minutes, drain the seafood and place in a serving bowl along with the tomatoes and onion rings.
Step 3
Whisk the olive oil, vinegar, and lemon juice in a small bowl. Add the parsley, then pour over the seafood. Toss lightly, taste, and season with pepper and more lemon juice as desired.
Yields 4 servings
Healthy Ingredient Spotlight
Yuzu Rice Wine Vinegar
Each year, as I contemplate the potential vinegar choices for the T. J. Robinson Curated Culinary Selections, I always want to include a rather exotic one to surprise and delight you. Yuzu Rice Wine Vinegar is exactly that.
Rice wine vinegar is such an important ingredient in Asian cooking. It’s made from sake, the beloved rice-based Japanese drink. The sake for this vinegar is American-made, a junmai-grade sake from California. Junmai means that it’s pure—nothing other than rice is added to the fermenting mixture. The rice wine is not seasoned, meaning it has no sugar added; it has just the mellowness that comes from aging.
For a completely one-of-a-kind creation, I had the idea to enhance this vinegar with yuzu. Yuzu is an Asian citrus fruit with a strong perfumed aroma and a highly complex flavor profile with notes of grapefruit, lemon, and mandarin orange—it’s tart, sweet, and floral all at the same time. Its thick and bumpy rind goes from green to yellow as it ripens, and its milky yellow juice has deep flavor. It took a lot of experimenting with proportions to find just the right balance of yuzu juice and rice wine so that both tastes would come through, and then it was rounded out with organic blue agave for a little bit of sweetness. The result is a sweet-tart vinegar with a flavor that will wow you as much as it did me.
Quick Kitchen Nugget
Don’t Overcook Shellfish
No one likes rubbery seafood—one bad experience can turn you off to these gifts from the ocean. It’s especially easy to overcook calamari and scallops since, unlike shrimp, their color doesn’t change dramatically when they’re done. However, they do go from translucent to opaque, often in just a few minutes. If you keep cooking beyond this point, they will become tough. Even if you scoop them out of the cooking liquid, the cooking process will continue until the heat dissipates, which is why I suggest dropping them in an ice bath right away.
Shrimp and whole lobsters will turn a bright red-orange as soon as they’re done. Seafood in the shell, like clams, mussels, and oysters, should be steamed on a rack over simmering water just until their shells open. This can take as little as 5 minutes or up to 10, depending on size, so keep watch. They don’t need the ice bath, but it should be used right away.
For Your Best Health
Controlling High Blood Pressure
Despite strong evidence that salt substitutes can safely lower sodium intake and reduce high blood pressure, very few Americans use them, according to preliminary research presented at the American Heart Association’s Hypertension Scientific Sessions 2025. A new analysis of nearly 20 years of national health data found that usage peaked at just over 5% and then declined, even among those with hypertension. Researchers say this represents a major missed opportunity to improve heart health.
High blood pressure occurs when the force of blood flowing through the blood vessels is consistently too high. High blood pressure can lead to other serious events such as heart attack and stroke. Data from 2017 to 2020 showed that 122.4 million American adults had high blood pressure and that high blood pressure contributed to more than 130,000 deaths. Too much sodium and too little potassium in the diet are risk factors for high blood pressure.
“Overall, less than 6% of all US adults use salt substitutes, even though they are inexpensive and can be an effective strategy to help people control blood pressure, especially people with difficult-to-treat high blood pressure,” said lead study author Yinying Wei, MCN, RDN, LD, and PhD candidate in the departments of applied clinical research and hypertension section, cardiology division, at UT Southwestern Medical Center in Dallas. “Healthcare professionals can raise awareness about the safe use of salt substitutes by having conversations with their patients who have persistent or hard-to-manage high blood pressure.”
Salt substitutes are products that replace some or all of the sodium with potassium. Potassium salt tastes similar to regular salt, except it can have a bitter aftertaste if it’s been heated. Many foods contain some sodium in their natural state; however, the largest amount of sodium comes from processed and packaged foods and meals prepared at restaurants. The American Heart Association recommends consuming no more than 2,300 mg of sodium a day, with an ideal limit of less than 1,500 mg per day for most adults, especially for those with high blood pressure. For most people, cutting back by 1,000 mg a day can improve blood pressure and heart health.
The investigation focused on people with high blood pressure, and an additional analysis was conducted among adults eligible to use salt substitutes, including people with normal kidney function and those not taking medications or supplements that affect blood potassium levels. Some salt substitutes contain potassium, and they can raise blood potassium to dangerous levels in people with kidney disease or those taking certain medications or potassium supplements. Excessive potassium can lead to irregular heart rhythms. People with high blood pressure who are thinking about switching from regular salt to a salt substitute should first consult with a healthcare professional.
The study did have some limitations, said the authors. First, information about salt substitute use was self-reported, so there may have been underreporting or misclassification. In addition, all types of salt substitutes were included in the analysis; therefore, the analysis could not specifically separate potassium-enriched salt from other types of salt substitutes. Finally, the survey data did not capture how much salt substitute the participants used.
“Future research should explore why salt substitute use remains low by investigating potential barriers, such as taste acceptance, cost, and limited awareness among both patients and clinicians,” said Wei. “These insights may help guide more targeted interventions.”
Salt substitutes aren’t the only options for adding more flavor to foods. According to the American Association of Heart Failure Nurses, pure herbs and spices, such as garlic, onion, and chili powder, are great choices. Just make sure you aren’t using garlic salt or onion salt.
Fitness Flash
Exercise and Your Appetite
Researchers at Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute (Duncan NRI) at Texas Children’s Hospital, Stanford University School of Medicine, and collaborating institutions recently shared new insights into how exercise helps with weight loss. They discovered a mechanism by which the compound Lac-Phe, which is produced during exercise, reduces appetite in mice, leading to weight loss. The findings appeared in Nature Metabolism.
“Regular exercise is considered a powerful way to lose weight and to protect from obesity-associated diseases, such as diabetes or heart conditions,” said co-corresponding author Yang He, PhD, assistant professor of pediatrics-neurology at Baylor and investigator at the Duncan NRI. “Exercise helps [people] lose weight by increasing the amount of energy the body uses; however, it is likely that other mechanisms are also involved.”
The researchers previously discovered that Lac-Phe is the most increased metabolite—a product of the body’s metabolism—in blood after intense exercise, not just in mice but also in people. They had also shown that giving Lac-Phe to obese mice reduced how much they ate and helped them lose weight without negative side effects. But until now, scientists didn’t fully understand how Lac-Phe helps suppress appetite.
“Understanding how Lac-Phe works is important for developing it or similar compounds into treatments that may help people lose weight,” Dr. He said. “We looked into the brain as it regulates appetite and feeding behaviors.”
The researchers studied two types of brain cells in mice: AgRP neurons, which stimulate hunger and are found in the arcuate nucleus of the hypothalamus, and PVH neurons, found in the paraventricular nucleus of the hypothalamus. Normally, AgRP neurons send signals that inhibit PVH neurons, making you feel hungry. But when AgRP neurons are turned off, PVH neurons become more active, reducing appetite.
The team discovered that Lac-Phe directly inhibits AgRP neurons, which in turn activates PVH neurons. This chain of events resulted in the mice eating less. The animals’ behavior remained normal, suggesting that Lac-Phe doesn’t cause unpleasant side effects. “We found that Lac-Phe acts on a protein on AgRP neurons called the KATP channel, which helps regulate cell activity. When Lac-Phe activates these channels in AgRP neurons, the cells become less active,” Dr. He said. “When we blocked the KATP channels using drugs or genetic tools, Lac-Phe no longer suppressed appetite. This confirmed that the KATP channel is essential for Lac-Phe’s effects.”
This research helped explain how exercise can naturally reduce appetite and improve metabolism. “The results also suggest the exciting possibility of targeting this newly discovered mechanism for weight management,” said co-corresponding author Yong Xu, PhD, currently at the University of South Florida.
Although this study focused on mice, the findings are promising for people. Future research will explore how Lac-Phe works in different metabolic states (like obesity vs. leanness), how it travels to the brain, and whether it can be used safely and effectively as a therapy.
Caprese Bites Recipe, Spotlight on Summer Squash, Foods that Lower Blood Pressure plus Exercise and Vitamin D Levels
Have a bumper crop of summer squash? Turn a Caprese salad into succulent morsels wrapped in slices of summer squash for a great light meal or party-ready hors d’oeuvres. If you’re a tea or chocolate lover, you’ll be pleased to read about the effects of a micronutrient found in them as well as in apples and grapes. Summer is a great time to add to vitamin D stores—a new study outlines how to better maintain levels come winter.
Baked summer squash strips are perfect for making finger food roll-ups. For this recipe, I’m filling them with the ingredients of a classic Caprese salad, one of my favorite seasonal dishes. Try to choose squash that are the same thickness from tip to base.
Ingredients
Two 6- or 7-inch yellow summer squash or zucchinis
Extra virgin olive oil
Coarse sea salt
8 ounces fresh mozzarella
12 cherry tomatoes, more as needed, halved
Basil leaves, to taste
Garlic chives (optional)
Balsamic vinegar of Modena
Freshly ground black pepper, to taste
Directions
Step 1
Preheat your oven to 375°F. Use the straight blade of a box grater or a mandoline to slice the squash into lengths about 1/8-inch thick. Each squash should yield about 8 slices.
Step 2
Arrange the squash slices on a rimmed sheet pan lined with parchment paper and lightly brush with olive oil, then sprinkle with salt. Bake for about 15 minutes until soft but not browned. Remove the pan from the oven and let cool.
Step 3
Cut the mozzarella into thin lengths; they should be about the width of each squash slice and a third as long. Center a piece of mozzarella on a squash length, top with a cherry tomato half, pressing it in to anchor it, and then with a basil leaf. Roll up the squash and tie it with a chive or secure it with a toothpick. Arrange the bites on a serving dish and drizzle with balsamic and more olive oil. Sprinkle on salt and black pepper to taste.
Yields 4 to 8 servings
Healthy Ingredient Spotlight
Summer Squash
Whether you’re choosing yellow squash or zucchini, these thin-skinned veggies are very versatile—they can be enjoyed raw or cooked and don’t need peeling. A key difference between the two varieties is size. While most yellow squash are on the short side, zucchini can be short or long, thick or thin. Similarities include their nutritional profile with good amounts of vitamins A and C, potassium and magnesium, and fiber. When shopping, choose firm vegetables without soft spots and treat them with care because those thin skins can get nicked or bruised easily.
Quick Kitchen Nugget
Storing Summer Squash
Summer squash will keep for up to a week in the crisper drawer of your fridge, wrapped in paper towel and then in a cloth vegetable bag for protection.
For Your Best Health
Foods that Lower Blood Pressure
A study from the University of Surrey in the UK has found that naturally occurring compounds called flavan-3-ols, a subgroup of flavanols, may improve blood pressure and the health of blood vessels. The research, published in the European Journal of Preventive Cardiology, analyzed data from 145 randomized controlled studies and found that regular consumption of flavan-3-ols, found in cocoa, tea, apples, and grapes, can lead to a reduction in blood pressure readings, particularly in people with elevated or high blood pressure. In some cases, the average blood pressure-lowering effects were comparable to those seen with some medications.
Flavan-3-ols were also found to improve the function of the endothelium, the inner lining of blood vessels, which is crucial for overall cardiovascular health. This improvement occurred independently of blood pressure changes, suggesting a broader positive impact on the circulatory system.
“The findings are encouraging for those looking for accessible ways to manage their blood pressure and support their heart health through enjoyable dietary changes,” said Dr. Christian Heiss, lead author of the study and professor of cardiovascular medicine at the University of Surrey. “Incorporating small amounts of commonly consumed foods like tea, apples, dark chocolate, or cocoa powder into a daily balanced diet could provide beneficial amounts of flavan-3-ols. While not a replacement for prescribed medications or medical advice, including more flavan-3-ol-rich foods in a daily routine could be a valuable addition to a healthy lifestyle, especially for those with higher blood pressure. These are findings that, although promising, require ongoing investigation.”
Fitness Flash
Exercise and Vitamin D Levels
With all its outdoor activities, summer is a great time to naturally boost the body’s vitamin D levels. But how can you maintain those levels come winter? A study from the University of Bath, University of Birmingham, University of Cambridge, and others in the UK, published in Advanced Science, has found that regular moderate-intensity exercise helps maintain crucial vitamin D levels during the darker months.
Participants who were either overweight or obese and who completed a 10-week indoor exercise program over winter experienced significantly smaller drops in vitamin D levels compared to those who didn’t exercise, even though their body weight was deliberately maintained. The program involved four sessions per week: two treadmill walks, one longer steady-state bike ride, and one high-intensity interval bike session.
Notably, exercise completely preserved the body’s active form of vitamin D (1,25(OH)₂D₃), which plays a key role in supporting bone health, the immune system, and various organs. Previous studies suggested that vitamin D supplements alone do not help maintain this active form.
Key findings:
People who exercised saw a smaller drop in their overall vitamin D levels over winter—about 15 percent compared to a 25 percent drop in those who didn’t exercise.
Those who exercised kept healthy levels of the active form of vitamin D, which helps support the immune system and bone health.
Weight was kept stable throughout the study, indicating the effect was due to exercise—not weight loss.
To ensure sunlight didn’t skew the results, the study ran between October and April, when natural vitamin D production from sunlight is minimal in this part of the UK, and participants were asked to avoid supplements.
A previous study from the team showed that a single workout can briefly boost vitamin D levels. This is the first one to show that regular cardio exercise can maintain basal circulating vitamin D levels and offer lasting protection during the winter months.
As Oly Perkin, PhD, lead author and lecturer from the Centre for Nutrition, Exercise and Metabolism at the University of Bath explained, this is the first study to show that exercise alone can protect against the winter dip in vitamin D. It’s a powerful reminder that we still have lots to learn about how exercise benefits our health.
Very Berry Chocolate Bars Recipe, Spotlight on Dark Chocolate, The Differences Between Dark and Milk Chocolate, Melting Chocolate in the Microwave, Outdoor Exercise and Air Quality
Healthy foods aren’t only about whole grains and vegetables. Some can satisfy a sweet tooth, too. That’s because foods like berries and dark chocolate have a wide category of nutrients called flavonoids. Read about newly discovered benefits in the first research piece I’m sharing…then indulge in one of these chocolate bars! With summer upon us, it can be enjoyable to exercise outdoors, but air quality could be a concern. The tips below will help you make smart choices.
Olive oil enhances dark chocolate by adding a fresh, slightly herbal taste. Raspberries and pistachios add layers of flavor and texture. Tip: Blueberries and almonds are another great combo.
Ingredients
3 ounces raspberries
8 ounces dark chocolate discs or pieces, preferably 70% cacao
2 tablespoons extra virgin olive oil
1 ounce shelled, unsalted pistachios
Directions
Step 1
Rinse the raspberries and pat dry with paper towels; set aside.
Step 2
Melt 6 ounces of the chocolate in a glass bowl placed over simmering (not boiling) water, stirring with a silicone whisk or spatula until fully melted. Carefully remove the bowl from the heat and place on a towel or hot pad on your counter. A few pieces at a time, add in the rest of the chocolate. This tempers it, or brings it down in temperature, so that the finish of the chocolate bars will be shiny. (If you have an instant-read thermometer, the chocolate on the stove should reach about 118°F and go down to 90°F after you add in the rest.) Stir in the olive oil until fully incorporated.
Step 3
Line a cookie sheet with waxed paper. Pour out the tempered chocolate in three sections and use an offset spatula to smooth each one out to a 4-by-3-inch rectangle (don’t worry about being too exact).
Step 4
Sprinkle equal amounts of raspberries and pistachios on each bar. Let the chocolate harden in a cool spot for two or more hours, then use a spatula to transfer to a glass container. Store in the fridge and enjoy within 3 days.
Yields 3 bars
Healthy Ingredient Spotlight
The Differences Between Dark and Milk Chocolate
Each type of chocolate has its fans, with some people loving both. But for the better nutritional profile, dark is the winner. First, it tends to have less sugar, though there are sugar-free versions of both. Second, dark chocolate is vegan friendly since it doesn’t contain any milk solids—it’s naturally dairy free. Another edge: it has up to two or three times the antioxidants called flavanols, a type of flavonoid, found in milk chocolate (see For Your Best Health below to learn why that matters). This is thanks to its higher percentage of cocoa solids or cacao, so always look for labels that give this information. There’s no FDA-mandated minimum of cocoa solids for dark chocolate, but many makers list this along with a description of the chocolate’s flavor profile, which is important for bakers. Those cocoa solids also give dark chocolate a much richer flavor than milk chocolate.
Quick Kitchen Nugget
Melting Chocolate in the Microwave
This is an easy way to melt chocolate without using the stovetop: Place three-quarters of the needed amount in a microwave-safe bowl and microwave on the 50% setting for 30 seconds to 1 minute at a time, checking between bursts. When the chocolate has melted, add the reserved chocolate to the bowl, let it sit for a minute, then fold it together with a spatula. As the additional chocolate melts, it will also bring down the temperature of the microwaved chocolate.
Note: Chocolate melts better when it’s in smaller pieces. If you don’t want to have to chop up a block of chocolate, buy coin-shaped wafers from brands like Valrhona, Callebaut, and Guittard. Save chocolate chips for cookies because they’re made to not melt completely.
For Your Best Health
Flavonoid-rich Foods for Health
A recent study led by researchers from Queen’s University Belfast, Edith Cowan University Perth (ECU), the Medical University of Vienna, and Universitat Wien in Austria found that increasing the diversity of flavonoids in your diet—from foods like cocoa, tea, apples, and grapes as well as blueberries, strawberries, and oranges—could help prevent the development of health conditions such as type 2 diabetes, cardiovascular disease (CVD), cancer, and neurological diseases and offers the potential of living longer. Published in Nature Food, the study tracked over 120,000 participants from 40 to 70 years old for more than a decade.
ECU research fellow, first author, and co-lead of the study Benjamin Parmenter, PhD, made the initial discovery that a flavonoid-diverse diet is good for health. “Flavonoid intake of around 500 mg a day was associated with a 16% lower risk of all-cause mortality, as well as a ~10% lower risk of CVD, type 2 diabetes, and respiratory disease. That’s roughly the amount of flavonoids that you would consume in two cups of tea.”
Dr. Parmenter added that those who consumed the widest diversity of flavonoids had an even lower risk of these diseases, even when consuming the same total number of milligrams. For example, instead of just drinking tea, also enjoy berries, chocolate, and apples.
“We have known for some time that higher intakes of dietary flavonoids, powerful bioactives naturally present in many foods and drinks, can reduce the risk of developing heart disease, type 2 diabetes, and neurological conditions like Parkinson’s,” said study co-lead professor Aedín Cassidy, PhD, from the Co-Centre for Sustainable Food Systems and Institute for Global Food Security at Queen’s. “We also know from lab data and clinical studies that different flavonoids work in different ways—some improve blood pressure, others help with cholesterol levels and decrease inflammation. This study is significant, as the results indicate that consuming a higher quantity and wider diversity has the potential to lead to a greater reduction in ill health than just a single source.”
Professor Tilman Kühn, PhD, a co-lead author, noted that the importance of diversity of flavonoid intake hadn’t been investigated until now, making this study very significant, as the findings align with the belief that eating the rainbow is invaluable for maintaining good health. “Eating fruits and vegetables in a variety of colors, including those rich in flavonoids, means you’re more likely to get the vitamins and nutrients you need to sustain a healthier lifestyle,” he said.
The first-ever dietary guidelines for flavonoids were released recently, but this research goes one step further. “Our study provides inaugural evidence that we may also need to advise increasing diversity of intake of these compounds for optimal benefits,” Dr. Parmenter said.
“The results provide a clear public health message, suggesting that simple and achievable dietary swaps, such as drinking more tea and eating more berries and apples for example, can help increase the variety and intake of flavonoid-rich foods, and potentially improve health in the long term,” Dr. Cassidy added.
Fitness Flash
Outdoor Exercise and Air Quality
According to experts at ACE (American Council on Exercise), a leading certifier of fitness professionals, it’s important to know your local air quality before you go outside to exercise. When the air quality is bad, it can put your overall health at risk, cause increases in resting and exercise heart rate and blood pressure, worsen asthma, and decrease lung function and oxygen-carrying capacity. This is because, in part, your body’s natural air-filtration system process is less effective when you breathe through your mouth and more pollutants reach the lungs. This is true regardless of the cause of bad air quality, including wildfires, pollen, and even heavy traffic.
ACE has these suggestions:
Understand the risk-reward balance between physical activity and air pollution. On some days, it may be safer to bring your workout indoors or at least reduce the intensity at which you work out.
Pay attention to the air-quality index in your area. You can check it daily at airnow.gov.
Be mindful of when and where you exercise. Avoid heavily trafficked roads at peak commuting times, for instance. Look at pollen reports before you go out if you’re sensitive to this allergen.
Consider wearing a face mask. It will keep you from inhaling allergens and pollutants without impacting your performance.
