5 interesting studies: Kombucha, meat, and more

Nutrition science moves fast. So, to help you keep up, we’ll summarize five recent studies that we think are interesting.

So, let’s get to it.

1. Kombucha may lower blood sugar

Fermented foods can help support your gut microbiome. Can they also help support your general metabolism?

According to a recent pilot study on kombucha — a fermented sweet tea — they might.

What did they do?

The researchers recruited 12 people with type 2 diabetes. The participants consumed either kombucha or a placebo drink every day for 4 weeks. For the following 8 weeks, they drank neither.

The scientists measured the participants’ blood sugar levels at the start of the study and after the first and fourth weeks.

What did they find?

• After 4 weeks of kombucha: The participants’ blood sugar levels were lower than they had been at the start of the study.

• After 4 weeks of the placebo: There was no significant difference in blood sugar levels.

What should you do?

This was a very small study, so scientists need much more research to confirm the effect. 

However, kombucha can be a healthy addition to your diet. It may or may not reduce your blood sugar levels, but it will probably support your gut health.

2. Limit processed meat

Processed meat has gotten a lot of bad press in recent years, and a new paper adds to the pile-on.

What did they do?

The researchers looked for links between different types of meat and cardiovascular disease.

They followed almost 2,000 people for an average of 20 years. None of the participants had cardiovascular disease at the start of the study.

What did they find?

According to the analysis, around:

• 38% of the participants rarely or never ate meat 

• 31% ate mostly red meat

• 19% ate mostly white meat

• 12% ate mostly processed meat

During the follow-up period, compared with those who rarely or never ate meat:

• Those who ate mostly processed meat had a higher risk of developing cardiovascular disease.

• Those who ate mostly white meat had a reduced risk of developing cardiovascular disease.

What should you do?

Research into white meat and health has been inconclusive so far. But generally, experts agree that eating it in moderation is fine.

Surprisingly, the scientists behind the recent study found no links between red meat and increased cardiovascular risk.

Red meat may also be linked to cancer risk. So, if it’s your thing, you should enjoy it just once in a while. 

The present study’s authors explain that their participants had a relatively low intake of red meat. This may be why there was no link with heart disease.

3. Does more protein provide more gains?

If you're passionate about boosting your biceps and developing your deltoids, you probably pay attention to your protein intake.

Because protein bars, shakes, and powders are everywhere, it’s easy to think that we’re not getting enough protein. 

Still, there’s a lot of confusion, especially among people looking to increase muscle size.

It’s easy to imagine that the more protein you eat, the bigger your muscles will get. A recent study investigates whether this is true.

What did they do?

The scientists recruited 48 men with an average age of 26 who regularly did resistance training.

The study ran for 16 weeks. During this time, half of the participants consumed 1.6 grams of protein per kilogram of body weight per day, and the rest consumed double that amount.

For reference, the recommended dietary allowance (RDA) of protein for adults is 0.8 g per kg of body weight.

The researchers followed the participants for 16 weeks and measured their muscle growth, endurance, and strength.

What did they find?

There was no significant difference between the two groups, in terms of muscule size or strength. 

So, the extra protein didn’t seem to boost muscle growth.

What should you do?

If you’re eating a well-balanced, varied diet, you’re probably already getting enough protein. 

So, unless you’re training incredibly hard, you probably won’t see any benefits from upping your protein intake.

For a fascinating protein deep dive, try this episode of the ZOE Science & Nutrition podcast.

4. Are you a ‘weekend warrior’?

Current guidelines recommend getting at least 150 minutes of moderate-to-vigorous physical activity each week.

But fitting exercise into your daily routine can be tough when you’re juggling kids, pets, work, family events, and so on. As a result, many of us squeeze in our exercise at the weekend.

What did they do?

The team analyzed data from almost 90,000 people. Each wore a device to measure their physical activity.

During the analysis, the scientists split the participants into three groups:

1. Inactive people: They got less than 150 minutes of physical activity per week.

2. Weekend warriors: They got at least 150 minutes of physical activity per week — and at least half of it happened over 1–2 days.

3. People active throughout the week: They got at least 150 minutes of physical activity, and it was spread more evenly across the week.

The researchers then compared the participants’ risk of cardiovascular events, like heart failure and stroke. 

What did they find?

• People in the active groups had a lower risk of cardiovascular events than those in the inactive group. 

• There was no significant difference between the weekend warriors and those who were active throughout the week.

What should you do?

In short, get active when you can. As far as your heart health is concerned, it doesn’t seem to matter whether you squeeze in your exercise at the weekend or do it throughout the week.

If you’d like to know how much cardio you need, try this podcast episode.

5. Sage for hot flashes?

Though almost half of us experience menopause, research into this transition is seriously lacking.

One of the most common symptoms is hot flashes. These can significantly reduce the quality of life — for example, by interfering with sleep and mood.

Recently, scientists asked whether sage really can improve hot flashes.

What did they do?

The team pooled data from existing research and performed a meta-analysis. In all, they identified four relevant studies, which included 310 participants in total.

What did they find?

Sage supplements:

• didn’t reduce the severity of hot flashes 

• did reduce the frequency of hot flashes 

However, the authors note that scientists need to carry out larger trials to confirm the results.

What should you do?

If hot flashes affect you, sage might be worth trying. However, high doses can cause side effects. So, it’s worth speaking with a doctor before you start.

That’s all for this edition. Join us next time for more fascinating nutrition insights from the latest scientific papers.