Food & Fitness After 50: Research Roundup

Each day dozens of research studies appear in my inbox, peaking this old college professor’s interest. Last week, there were three studies that made me want to take a closer look: one published in an aging journal, one presented at an annual scientific conference, and one animal study in the journal Brain Structure and Function.  Let’s briefly talk about each one and how it might translates from the page to your plate.

Blueberries for Blood Pressure

1200-136890271-blueberriesThe blue color in blueberries is due to the presence of anthocyanins (pronounced ann-though-sigh-a-nins), a sub-group of plant chemicals knows as polyphenols. Fruits and veggies that are deeply colored red, blue, and purple are especially rich in anthocyanins. The study published in the Journals of Gerontology (gerontology is the study of aging) found that eating about a cup of blueberries twice a day lowered blood pressure similar to the lowering from taking common blood pressure meds. The effect on blood pressure was both acute (happened quickly) and chronic (over time). Researchers found that the anthocyanins relaxed blood vessels and reduced the stiffness that occurs in aging blood vessels. As we age, our blood vessels lose their elasticity making it harder to control blood pressure and increasing our risk for heart disease.

What does in mean for you?

Eat more blueberries! One cup of berries, whether fresh or frozen, has about 60 calories, making it a low-calorie addition to your diet. What it doesn’t mean is taking a blueberry concentrate supplement (yes, they do exist). Researchers note that blueberries are also rich in vitamins, minerals, and fiber and the synergistic action between them and the anthocyanins might also be a reason for their health promoting powers. So, food beats supplements!

Pomegranate: Can it juice your memory?

pom wonderfulPomegranate juice is rich in polyphenols called ellagitannins (pronounced eee-laj-ah-tan-ins). These antioxidant compounds are in plants to protect the plant, but when we eat the plant, their protectors come along for the ride. The research, presented at the 2019 meeting of the American Association for Geriatric Psychiatry, described how a daily serving of pomegranate juice improved visual learning and retention of learning in a year-long study with older adults, average age of 60. The study was a randomized, placebo-controlled, double-blind study; a design that is considered the gold standard in nutrition research. What that means is that study participants were randomly assigned to either drink 8-ounces of pomegranate juice or 8-ounces of drink that looked and tasted like pomegranate juice but contained none of the active polyphenols. Double-blind means that neither the participant nor the researchers knew who was getting the real juice or the placebo. Dr. Gary Small, director of the University of California (UCLA) Longevity Center, presented the current research at the scientific conference, building upon similar work that his group published in 2013 in the Journal of Evidence-Based Complementary and Alternative Medicine. In the 2013 study, a similar design was used but the study was short-term, only lasting one month, but the results were similar. So, the researchers wanted to know if a longer-term study would show memory benefits, and it did.

Researchers are not sure exactly what it is in the pomegranate juice that showed the positive results. One interesting theory is that the pomegranate juice works though the gut microbiome. The healthy bacteria in our gut can breakdown the ellagitannins to a compound that crosses the blood brain barrier, exerting its beneficial effect through the gut-brain axis.

What does it mean for you?

An eight-ounce bottle of pomegranate juice contains 2 whole pomegranates, so drinking the unsweetened juice gives you 650 to 700 milligrams of polyphenols. That’s a lot of good stuff in a little bottle. Pomegranate juice is tart, not sweet, so it might appeal to those of you who don’t like sweet, sugar-added beverages. Considering that most of us don’t eat enough fruit, 8-ounces of pomegranate juice is a good way to get more fruit and healthy polyphenols in our diet.

Vitamin D: Good for the Brain?

Vit DThe third study is on vitamin D deficiency on processing new information and retaining it for future recall. It was conducted with mice and I always cautioned my students to count the legs on the research subjects before considering if it is relevant to those of us on two legs, but this study is interesting in understanding vitamin D deficiency and the brain. Vitamin D is most often thought of as a bone-building nutrient because without enough vitamin D only 10-15% of dietary calcium is absorbed. Yet, vitamin D has many roles in the body, including cognition.

Older adults are considered “at risk” for vitamin D deficiency because our skin doesn’t convert sunlight to vitamin D as readily as it did when we were younger and vitamin D isn’t found naturally in a lot of foods. Some foods, like milk, are fortified with vitamin D, but many yogurts are not. (The only way to know if your favorite yogurt is fortified with vitamin D is to read the nutrition facts panel and ingredient list on the container.)  The recommended dietary allowance for vitamin D is 600 IU for those 51 to 70 years and 800 IU for those over 70. The upper limit is 4000 IU and many older adults take a supplement of 1000 IU to make sure they are getting enough vitamin D. Check with your doctor and ask if a vitamin D blood test is needed to tailor your vitamin D intake to your blood level.

What does it mean for you?

Choose vitamin D-rich foods, either naturally occurring or fortified (for an extensive list of vitamin D in foods click here.)

Bottom Line

Eat more deeply colored fruits and veggies, including blueberries and pomegranate juice, to get healthy plant compounds in your diet. And, choose vitamin D rich foods, like salmon or tuna, and fortified milk, yogurt, and cereals. Here is my breakfast plan:

  • 1 cup of Greek yogurt (choose a brand fortified with Vitamin D)
  • 1 cup of fresh or frozen blueberries and ½ cup of high fiber breakfast cereal mixed into yogurt
  • 8-ounces of pomegranate juice

While the research is promising, this breakfast may or may not improve my brain health, but it gives me a great start to the morning with three servings of fruit and a good dose of fiber in a calcium and vitamin D-rich breakfast bowl. And, did I mention it tastes great?

For more information on how foods and fitness affect brain health check out Food & Fitness After 50.

Copyright © 2019 [Christine Rosenbloom]. All Rights Reserved.

Disclosure, I am on a clinical nutrition advisory board for POM Wonderful, but I was not asked to write about pomegranate juice or compensated to write this post. 

Food & Fitness After 50: Foods for a Healthy Gut: Part 1

onion_home_graphicWe hear a lot about gut health, probiotics, prebiotics and foods that contain them, but it seems like there are more questions than answers on what it means to have a healthy gut. When I talk to older adults, gut health is bound to come up. I sat down with a gut health expert, Jo Ann Hattner, to ask some questions and seek clarity. Jo Ann has over thirty years of experience as a Registered Dietitian Nutritionist in clinical academic settings primarily at Stanford University Medical Center where she focused on gastroenterology and nutrition. Currently, she is the owner of Hattner Nutrition in San Francisco, CA. She is author of the book Gut Insight: Probiotics and Prebiotics for Digestive Health and Well-Being.

We covered so much content in our interview, that this will be a two-part post so that you have time to “digest” all the material! The first post will discuss gut health and the gut microbiome,  and stay tuned next week for information about pre-and probiotic foods, and fermented foods, and dispel some myths about pre-and probiotics.

We hear a lot about a “healthy gut.” What makes a gut healthy?

Let’s start with the function of the gut. Basically, the gut is responsible for three big things: digestion, absorption, and elimination. So, your gut takes the foods and fluids you eat or drink and breaks them down into smaller pieces (digestion) so that we can transfer those smaller units into the blood stream (absorption) where they can travel to various parts of the body that need them. Then, the leftover parts that don’t get digested and absorbed get passed through the large intestine, the colon, where the fibers are fermented and the waste products are excreted (elimination.) A healthy gut tolerates a wide of foods and eliminates waste with ease. And, a healthy gut makes a healthy body. So, our gut nurtures our body, and to nurture our gut we need to eat foods that are rich in prebiotics and probiotics.

We also hear a lot about the human microbiome? What is the human microbiome and is it the same thing as the gut microbiome?

When you hear the words “human microbiome” it refers to all the microbial communities that live in and on our bodies. Scientists study the role they play in human health and disease. The gut microbiome or gut microbiota is the microbial communities that live in the gastrointestinal tract or the gut.

Many researchers and scientists consider the gut microbiome as the regulator or the control center of our biology. The gut microbiome has been shown to have an effect on immunity, obesity, inflammatory bowel diseases, and even central nervous system function. Emerging research tells us that our gut microbiome communicates with our brain (called the “gut-brain connection”). So, the phrase “gut instinct” may describe how our gut talks to our brain!

Can we change our gut microbiome by the foods we eat?

The basic pattern of our gut microbiome is established at birth and in early life. Babies delivered by C-section are exposed to different microflora than those delivered through the birth canal. And, breast milk contains important pre- and probiotics that help establish an infant’s gut microbiome. Even a parent’s caress and kiss transmit bacteria to the baby, as well as touches from friends and the family pet. Researchers believe that not only is the number of bacteria in our gut important, but also the diversity or having many different strains of bacteria, are best for good health. Currently, scientists don’t know if we can permanently change our gut microbiome or if the changes seen with eating probiotic foods just create a temporary change.

Stay tuned next week for Part 2 of this post, when we answer questions about specific foods that are rich in pre-and probiotics, fermented foods, and dispel some myths.

Jo Ann Hattner is one of the experts we interviewed for Food & Fitness After 50, available at Amazon.