A snapshot of the latest research on diet, exercise, and more

Here's the latest research on cannabidiol, irritable bowel syndrome, type 2 diabetes and more.

• How to keep your mind sharp as you age
• Is CBD harmful?
• Can you lower risk of diverticulitis?
• Is red meat better than beans?
• Does gluten cause IBS symptoms?
• Can living near a golf course increase risk of Parkinson's?
• Do GLP-1 drugs harm vision?
• Do potatoes raise type 2 diabetes risk?

How to keep your mind sharp as you age

What can keep the old noggin in shape as you get older?

Scientists randomly assigned 2,111 people aged 60 to 79 who were at risk for cognitive decline to either a “structured” or a “self-guided” intervention. (“At risk” meant that they were sedentary, had a suboptimal diet, and had at least two risk factors like high blood pressure or being male.)

The structured intervention included 38 team meetings, exercise training at a gym, advice on the MIND diet, social engagement, online cognitive training using BrainHQ, and a biannual review of risk factors. The self-guided group got general healthy lifestyle advice and $75 gift cards at six team meetings, plus annual clinic visits.

After two years, global cognitive scores rose in both groups, but significantly more in the structured group. Of the scores’ three components, executive function—but not processing speed or episodic memory—improved more in the structured group.

What to do

Keep your mind and body active.

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Is CBD harmful?

Could high doses of cannabidiol (CBD) pose a risk to your health?

Researchers randomly assigned 151 healthy people to get CBD (2.3 milligrams per pound of body weight per day) and 50 to get a placebo. (The CBD was Epidiolex, a drug that’s approved to treat certain seizures.)

After 28 days, liver enzyme levels were 3 times the upper limit of normal in 8 of the CBD takers (and in no placebo takers). Two met the criteria for potential drug-induced liver injury by day 21, and 5 met that criteria by day 28. (All levels returned to normal after discontinuing CBD.)

What to do

Don’t assume that high doses of CBD are safe for everyone.

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Can you lower risk of diverticulitis?

A healthy lifestyle may curb your risk of diverticulitis (inflamed pouches in the colon), whatever your genetic risk.

Scientists tracked 179,564 people for roughly 20 years. Five “lifestyle factors”—eating more red meat, eating less fiber, doing little exercise, being a current or past smoker, or having excess weight—were each linked to a 9 to 44 percent higher risk of diverticulosis.

Moreover, people with none of those factors had roughly half the risk—even if their genetic risk was high—compared to people with all five factors.

What to do

This study can’t prove that a healthy lifestyle cuts the risk of diverticulitis, but whaddya got to lose?

And don’t worry that nuts, seeds, or fruit with edible seeds causes diverticulitis. In yet another study, they didn’t.

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Is red meat better than beans?

Scientists randomly assigned 102 men to get equal amounts of protein from either:

• 27 oz. per week (about 4 oz. a day) of red or processed meat or
• 7 oz. per week (1 oz. a day) of red or processed meat plus 33 to 44 oz. per week (5 to 6 oz. a day) of beans and peas. 

After 6 weeks, LDL (“bad”) cholesterol fell by 7 points in the bean eaters and rose by 6 points in the meat eaters. The bean eaters also lost 2 pounds.

What to do

Cut back on beef and pork...for your health and the planet’s.

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Does gluten cause IBS symptoms?

Does gluten or wheat trigger symptoms of irritable bowel syndrome (IBS), as many people believe?

Researchers randomly assigned 28 of those people to get wheat, purified gluten, and sham (gluten-free, wheat-free) diets for 1 week each with 2 weeks in between. (The study was partly funded by Nestlé’s research arm.)

The three diets led to no differences in the worsening of IBS symptoms overall or in symptoms like bloating or abdominal pain.

What to do

Don’t assume that gluten and wheat trigger your IBS symptoms. But a diet low in FODMAPs (which include wheat plus many other foods) may help curb IBS symptoms.

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Can living near a golf course increase risk of Parkinson's?

Do pesticides that are used on golf courses raise the risk of Parkinson’s?

Researchers looked at the home addresses of 419 people with Parkinson’s disease (cases) and 5,113 people without Parkinson’s (controls).

Those who lived within 1 mile of a golf course were twice as likely to have Parkinson’s than those who lived more than 6 miles away. People whose tap water came from service areas with a golf course also had double the risk.

What to do

Far more studies are needed to know if the pesticides used on golf courses boost the risk of Parkinson’s. Stay tuned.

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Do GLP-1 drugs harm vision?

Do GLP-1 drugs like semaglutide (sold as Ozempic or Wegovy) raise the risk of vision loss caused by age-related macular degeneration (AMD)?

Scientists compared the health records of 46,334 people with diabetes who were prescribed GLP-1 drugs for at least six months to the records of 92,668 people with diabetes who weren’t prescribed GLP-1 drugs. All were aged 66 or older.

Over 2½ years, the risk of neovascular (wet) AMD was 2.2 times higher in the GLP-1 takers. However, the risk was still low—2 out of every 1,000 people taking a GLP-1 drug versus 1 out of every 1,000 people who didn’t take a GLP-1 drug.

What to do

It’s too early to know if GLP-1 drugs raise the risk of AMD, because something else about people who take them may explain the results. It’s also possible that other diabetes drugs—like metformin or sodium-glucose cotransporter-2 inhibitors—lower AMD risk.

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Do potatoes raise type 2 diabetes risk?

Are white potatoes unhealthy? It depends.

Researchers tracked 205,107 people without diabetes for roughly 25 years.

Those who ate french fries at least 5 times a week had a 27 percent higher risk of developing type 2 diabetes than those who rarely ate fries. However, those who ate baked, boiled, or mashed potatoes or potato chips at least 5 times a week had no higher risk of diabetes. (The study didn’t look at sweet potatoes.)

What to do

If eating fries raises diabetes risk—something this kind of study can’t prove—then how the potatoes are cooked may be what matters. Then again, something else about the people who eat fries may explain the link. 

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