5 fascinating studies: Sleep, blood pressure, and more

Hundreds of scientific papers get published each day. It’s nearly impossible to stay on top of.

So, to keep you in the loop, we’ll outline five recent nutrition science studies that we think are interesting. We’ll explain what the researchers have discovered and what it means for your health.

So, let’s dive in.

1. Polyphenols and sleep 

Polyphenols are plant compounds that help feed your gut bacteria and support your health. But can they help manage sleep disorders? A recent study investigates.

What did they do?

The scientists collected data from 10 previous studies, which included a total of 334 people with mild sleep complaints, insomnia, or sleep disorders.

What did they find?

Participants consuming polyphenol supplements or polyphenol-rich foods fell asleep 4.4 minutes quicker and slept for 13 minutes longer. 

However, sleep quality and efficiency didn’t improve. 

Sleep "quality" refers to how well-rested you feel after a night’s sleep.

And sleep "efficiency" is how much time you spend sleeping, compared with how much time you spend in bed.

What should you do?

Though scientists need to confirm these results, if you have trouble sleeping, eating more polyphenol-rich foods might help. 

And because these foods are good for your overall health anyway, it’s worth a try. 

2. Can magnesium help you sleep?

Sticking with sleep, our next study investigates whether magnesium supplements help improve your slumber.

Though some previous research hints at links between magnesium and sleep, the findings so far have been inconclusive. 

What did they do?

The scientists pooled data from nine studies on magnesium and sleep, which included 7,582 participants in total.

What did they find?

The team concluded that there was a link between higher magnesium intake and better sleep quality. 

And women who consumed the most magnesium were less likely to nap during the day than those who consumed the least.

But overall, the evidence wasn’t particularly strong, so the authors call for larger, longer studies.

What should you do?

In general, ZOE believes that it’s better to get your nutrients from whole foods, rather than supplements. That way, you get the benefits of the whole plant.

Magnesium might help improve your sleep, so if you want to up your intake, try these healthy, high-magnesium foods:

  • pumpkin seeds

  • chia seeds

  • almonds

  • spinach

  • cashews

  • peanuts

  • black, edamame, or kidney beans

3. Garlic and rheumatoid arthritis

Rheumatoid arthritis (RA) is an inflammatory condition that causes pain in your joints. It affects an estimated 18 million people worldwide.

Experts believe that oxidative stress — a buildup of harmful free radicals — plays a part in how RA develops. 

Your body naturally produces free radicals, and you have antioxidant systems that keep them in check. But if they build up, they can cause damage.

Because garlic has antioxidant properties, a new study asks whether garlic could improve symptoms of RA.

What did they do?

The study included 70 women with RA and ran for 8 weeks. The researchers split them into two groups: One took garlic tablets every day, and the other took a placebo. 

What did they find?

Blood tests suggest that those taking garlic had higher levels of antioxidants and lower levels of free radicals.

Also, the participants in the garlic group reported an increased quality of life and less pain after moving around.

What should you do?

Scientists need to confirm the results with longer, larger trials. But if you have RA, it won’t hurt to add more garlic to your cooking. 

And even if you don’t have RA, garlic adds a welcome punch to your meal and counts toward your 30-plant goal.

4. Can a plant-based diet slow aging?

Our next study asks whether a healthy plant-based diet might slow biological aging

What’s biological aging? Your chronological age is the number of years you've been alive. And your biological age is a measure of how well your body is functioning. 

So, if you’re 30 but you only eat fast food, smoke, and watch TV, your biological age might be 45. Conversely, if you’re 45, but you eat well, don’t smoke, and exercise regularly, your biological age might be 30.

What did they do?

The researchers used data from 10,191 people. Over 8 years, they assessed how slowly or quickly the participants’ biological ages were advancing.

Then, they matched these “aging trajectories” against the participants’ diets.

What did they find?

People with healthy, plant-based diets aged more slowly and were less likely to die during the 8-year follow-up period.

What should you do?

Scientists need to repeat these findings to confirm the results. But this is just the latest study showing the wide-ranging benefits of a plant-based diet.

So, whether it slows your biological clock or not, eat more plants

5. Diet, salt, and blood pressure

High blood pressure, also called hypertension, is common. Globally, it affects over 1 billion people.

Scientists know that reducing your salt intake can help bring your blood pressure down. 

But can you get even better results by reducing salt intake and having a healthy diet? A new study investigates.

What did they do?

The researchers split 240 participants into four groups, and the last was the control group:

  1. salt-restricted diet

  2. salt-restricted diet plus the Dietary Approaches to Stop Hypertension (DASH) diet 

  3. salt-restricted diet plus the Mediterranean diet

  4. just dietary advice

The DASH diet is similar to the Mediterranean diet — it focuses on vegetables, fruits, nuts, and whole grains. But it also features more potassium, magnesium, and calcium, as well as reduced salt.

What did they find?

After 3 months, people in groups 2 and 3 had larger decreases in blood pressure, compared with groups 1 and 4. The effect was most pronounced for group 3.

What should you do?

The DASH diet and the Mediterranean diet both focus on eating more whole plant foods and reducing the intake of ultra-processed foods.

So, if you have hypertension, reducing your salt intake and trying one of these dietary approaches might benefit you. 

Overall, the Mediterranean diet can be a healthy choice for many people. But we’re all different. 

So, find a dietary pattern that suits you and your body. To find out how you respond to food, start by taking our free quiz.


A randomized, double-blind, placebo-controlled clinical trial, evaluating the garlic supplement effects on some serum biomarkers of oxidative stress, and quality of life in women with rheumatoid arthritis. International Journal of Clinical Practice. (2020). https://pubmed.ncbi.nlm.nih.gov/32159257/ 

Association between plant-based dietary pattern and biological aging trajectory in a large prospective cohort. BMC Medicine. (2023). https://link.springer.com/article/10.1186/s12916-023-02974-9 

DASH vs. Mediterranean diet on a salt restriction background in adults with high normal blood pressure or grade 1 hypertension: A randomized controlled trial. Clinical Nutrition. (2023). https://pubmed.ncbi.nlm.nih.gov/37625311/ 

Effects of polyphenol-rich interventions on sleep disorders: A systematic review and meta-analysis. Current Research in Food Science. (2023). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9972497/ 

Hypertension. (n.d.). https://www.who.int/health-topics/hypertension 

Magnesium. (2022). https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ 

Magnesium intake and sleep disorder symptoms: Findings from the Jiangsu Nutrition Study of Chinese Adults at five-year follow-up. Nutrients. (2018). https://www.mdpi.com/2072-6643/10/10/1354 

Oxidative stress in rheumatoid arthritis: What the future might hold regarding novel biomarkers and add-on therapies. Oxidative Medicine and Cellular Longevity. (2019). https://www.hindawi.com/journals/omcl/2019/7536805/ 

Rheumatoid arthritis. (2022). https://www.who.int/news-room/fact-sheets/detail/rheumatoid-arthritis 

Scoping review of the association of plant-based diet quality with health outcomes. Frontiers in Nutrition. (2023). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10447911/ 

The role of magnesium in sleep health: A systematic review of available literature. Biological Trace Element Research. (2022). https://link.springer.com/article/10.1007/s12011-022-03162-1