6–12 prunes a day may lower inflammation, protect bones

New research finds that the anti-inflammatory benefits of prunes may help protect bones in older women. Westend61/Getty Images
  • In the United States, approximately 10 million people over the age of 50 have osteoporosis, with a further 34 million at risk of the disease.
  • Health experts are looking for safe, affordable treatments with fewer negative side effects than conventional medications.
  • In a study of dietary interventions, researchers in Pennsylvania found that prune consumption could reduce inflammatory markers associated with bone density.

Osteoporosis is the most common bone disease. It causes the bones to lose mass and become porous and fragile, especially in older adults.

This increases the risk of fractures and lasting effectsTrusted Source such as persistent pain and collapsed spine.

Osteoporosis affects every genderTrusted Source, but it occurs more often among older females. Further, bone fractures due to osteoporosis happen more frequently among postmenopausal people than in premenopausal individuals.

As the ovaries stop functioning during menopause in females, estrogen levels decrease. This sets off an increase in inflammation throughout the body which can contribute to bone loss.

New research from the Integrative and Biomedical Physiology Program and the Departments of Nutritional Sciences and Kinesiology at The Pennsylvania State University (Penn State) discusses how prune consumption affects inflammatory markers associated with bone loss.

This work suggests that women can lower inflammation by eating six to 12 prunes a day.

Lead author Janhavi Damani, MS, a graduate student at Penn State’s Huck Institute of the Life Sciences, presented her team’s findings at the Experimental Biology 2022 meeting of the American Physiological Society. The conference took place April 2–April 5 in Philadelphia, PA.

Melissa M. Markofski, PhD is an assistant professor in the Department of Health and Human Performance at the University of Houston in Texas. She was not involved in the study.

In an interview with Medical News Today, Dr. Markofski mentioned: “What we know is that there’s a strong link between [prolonged] high levels of inflammation [and] chronic diseases, especially osteoporosis.”

She also noted: “Inflammation is linked between the immune system and bone health, and we know that in a state of high inflammation people [with] high inflammatory markers [have] an increased likelihood for developing osteoporosis, especially women.”

Prunes and polyphenols

Polyphenols are active plant compounds with antioxidant properties. They help prevent or combat cell damage from free radicals, unstable molecules that are byproducts of metabolic processes and that can result in oxidative stress.

Prunes, which are rich in polyphenols, have demonstrated their antioxidant and anti-inflammatory properties in other studies.

Damani and her team studied 106 women ages 55-75 years with low bone mineral density scores, an indication of osteoporosis. The researchers aimed to evaluate how 12 months of prune consumption could affect inflammation levels.

One group of these people ate about six prunes every day for 12 months, and another group ate about 12 prunes daily for 12 months. A control group did not eat any prunes during this time.

All the participants consumed calcium and vitamin D supplements as well, as “standard of care.”

Checking blood samples before and after the trial, the researchers observed significant reductions in inflammatory markers in the participants who ate prunes compared to the control group.

Lead author Damani commented:

“Our findings suggest that consumption of six to 12 prunes per day may reduce pro-inflammatory mediators that may contribute to bone loss in postmenopausal women. Thus, prunes might be a promising nutritional intervention to prevent the rise in inflammatory mediators often observed as part of the aging process.”

Before purchasing prunes in bulk, it may be helpful to acknowledge several limitations to this research.

The study sample size was quite small, and the participants were assessed for only 12 months.

Frederick Singer, MD is a professor of endocrinology and director of the endocrine and bone disease program at the Saint John’s Cancer Institute at Providence Saint John’s Health Center in Santa Monica, CA. He was not involved in this research.

Dr. Singer noted that, although prunes “appear to show some effect on anti-inflammatory factors” in this study, the research did not include bone density measurements. That data would have been more beneficial, he felt.

He also argued that a bigger, more long-term study is warranted.

Drs. Markofski and Singer wondered if a daily dose of dozen prunes is realistic or healthy for most people. Dr. Markofski expressed concern that 12 prunes contain about 36 grams of sugar, the same amount “in a scoop of ice cream.”

Another significant consideration about this study is the funding. The authors acknowledge that the California Prunes Board sponsored their work.

Sherry Ross, MD is an OB-GYN and women’s health expert at Providence Saint John’s Health Center in Santa Monica, CA. She was not involved in this study.

Speaking with MNT, Dr. Ross was pleased that the study supports eating prunes to help lower the risk of osteoporosis. She agreed that diet can play a huge role in this effort:

“Osteoporosis, a silent disease, affects millions of women every year. Estrogen, calcium, and vitamin D are part of the building blocks important in keeping bone tissue healthy and strong. Prevention is the perfect way to avoid weak bones, which put you at risk for osteoporosis.”

“Whether you are in your 20’s, 30’s, or 40’s, making sure you have enough daily dietary calcium is an important step in building strong bones and preventing this disease that affects older women. Lifestyle changes including eating a well-balanced and colorful diet rich in calcium, vitamin D, and regular exercise helps establish healthy bones and should be started in puberty and adolescence.”

Eating 1 avocado daily could lower cholesterol

Incorporating avocados into one’s diet can have many health benefits. Zoran Djekic/Stocksy
  • Diet is an essential component of health, and eating a varied diet can help with well-being and quality of life.
  • Avocados can be part of a healthy diet and can provide people with some helpful nutrients.
  • A new study found that eating one avocado a day did not contribute to weight gain, may lower bad cholesterol levels, and increase diet quality.

The latest food trends and diets are constantly changing and it can be hard to keep up. Some experts are now tailoring their research to the health benefits of specific foods. One of these food items is the avocado.

A recent studyTrusted Source published in the Journal of the American Heart AssociationTrusted Source evaluated the impact of eating one avocado daily compared to a habitual diet.

Although the researchers did not find much difference between the control and intervention groups, they found that the participants who ate an avocado daily had lower bad cholesterol levels and improved their diet quality.

It is also important to point out that the Hass Avocado Board funded the research.

People can get cholesterol from food, but the body also makes cholesterol. There are two main typesTrusted Source of cholesterol: Low-density lipoprotein (LDL) and high-density lipoprotein (HDL). It is essential to keep cholesterol levels, in particular LDL (sometimes called “bad” cholesterol) levels, below a certain amount to prevent adverse health outcomes like stroke or coronary artery disease.

Nutritional expert Dr. Brian Power, who was not involved in the study, explained to Medical News Today how blood cholesterol levels and heart health are connected.

“Convincing evidence from studies paints a picture of blood cholesterol levels being important for heart health. Elevated levels are an important risk factor for cardiovascular disease, including cerebrovascular disease and coronary heart disease.”
— Dr. Brian Power

Research is ongoing about what factors influence cholesterol levels and how people can modify their diets to keep their cholesterol at healthy levels and improve their overall diet. One area of interest is how specific foods impact health.

For example, eating avocados may help maintain healthy cholesterol levels. Avocados also contain several helpful vitamins like vitamin C and K, and they are a good source of fiber.

The study in question was a randomized trial and examined the health benefits of eating one avocado daily over six months. Researchers wanted to see if eating a daily avocado helped people to reduce visceral adiposity in participants with an elevated waist circumference (“a waist circumference of ≥35 inches for women and ≥40 inches for men”).

They also looked at the impact on several other health outcomes, including cholesterol levels, body weight, body mass index, and health-related quality of life.

To be included in the study, participants had to have an elevated waist circumference and regular consumption of two or fewer avocados per month. The intervention group (505 participants) consumed one avocado daily, while the control group (503 participants) continued their typical diet. Researchers collected data about dietary intake at the start of the study and at 8, 16, and 26 weeks and used MRI scans to look at levels of visceral adipose tissue or the body fat that lines abdominal organs.

Researchers found that there weren’t many significant differences between the control and intervention groups. The exception was in cholesterol levels. The intervention group had lower total cholesterol levels and lower “bad” cholesterol levels.

There were also slight differences in diet between the two groups, with the intervention group having higher healthy eating index scores. The intervention group took in higher levels of fiber and fat and lower levels of carbohydrates and protein.

In addition, researchers also found no significant differences between the groups regarding weight gain, indicating that incorporating a daily avocado did not contribute to weight gain.

Study author Dr. Alice H. Lichtenstein noted that adding superfoods or health foods to one’s diet did not necessarily translate into significant health benefits.

“The study found that simply adding a ‘healthy food’ in terms of fats and nutrients, in this case, an avocado, to one’s diet did not result in clinical benefits. However, there were no negative effects, and it was associated with a benefit, an improvement [in] overall diet quality.”
— Dr. Alice H. Lichtenstein

This study had some limitations. For example, researchers did not collect data about participants’ medications. Second, participants were only observed over six months, and a longer time frame could have seen different results, particularly in terms of visceral adipose tissue.

Researchers also conducted the study during the COVID-19 pandemic, which may have influenced participants’ lives. They had a high retention rate for participants, but not everyone who started the study completed it. Some data collection, such as about diet, relied on participant reporting, so there is a risk for errors.

Dr. Power noted that the study is a reminder that there is no one “fix it” food when it comes to a healthy diet.

“[The study’s] important message is that focusing on single foods is not a substitute for maintaining healthy dietary patterns as a whole. That said, irrespective of any modest benefit on cholesterol, anything that encourages people to consume more fruit and vegetables as a part of an overall balanced diet is to be welcomed.”
— Dr. Brian Power

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