Skip to main content
The Globe and Mail
Support Quality Journalism.
The Globe and Mail
First Access to Latest
Investment News
Collection of curated
e-books and guides
Inform your decisions via
Globe Investor Tools
per week
for first 24 weeks

Enjoy unlimited digital access
Cancel Anytime
Enjoy Unlimited Digital Access
Canada’s most-awarded
newsroom for a reason
Stay informed for a
lot less, cancel anytime
“Exemplary reporting on
COVID-19” – Herman L
per week
for 24 weeks
Get full access to
Just $1.99per week for the first 24weeks
Just $1.99per week for the first 24weeks
var select={root:".js-sub-pencil",control:".js-sub-pencil-control",open:"o-sub-pencil--open",closed:"o-sub-pencil--closed"},dom={},allowExpand=!0;function pencilInit(o){var e=arguments.length>1&&void 0!==arguments[1]&&arguments[1];select.root=o,dom.root=document.querySelector(select.root),dom.root&&(dom.control=document.querySelector(select.control),dom.control.addEventListener("click",onToggleClicked),setPanelState(e),window.addEventListener("scroll",onWindowScroll),dom.root.removeAttribute("hidden"))}function isPanelOpen(){return dom.root.classList.contains(}function setPanelState(o){dom.root.classList[o?"add":"remove"](,dom.root.classList[o?"remove":"add"](select.closed),dom.control.setAttribute("aria-expanded",o)}function onToggleClicked(){var l=!isPanelOpen();setPanelState(l)}function onWindowScroll(){window.requestAnimationFrame(function() {var l=isPanelOpen(),n=0===(document.body.scrollTop||document.documentElement.scrollTop);n||l||!allowExpand?n&&l&&(allowExpand=!0,setPanelState(!1)):(allowExpand=!1,setPanelState(!0))});}pencilInit(".js-sub-pencil",!1); // via darwin-bg var slideIndex = 0; carousel(); function carousel() { var i; var x = document.getElementsByClassName("subs_valueprop"); for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } slideIndex++; if (slideIndex> x.length) { slideIndex = 1; } x[slideIndex - 1].style.display = "block"; setTimeout(carousel, 2500); } //

Green Chinese tea with grape fruit, beetroot, blueberries and raspberries full of antioxidant flavonoid goodness.

Brian/iStockPhoto / Getty Images

If berries, apples and tea aren’t part of your regular diet, consider adding them to your menu more often. According to scientists from Tufts University in Massachusetts, eating more of these foods plentiful in natural plant compounds called flavonoids can help guard against Alzheimer’s disease.

The good news: If your diet is low in flavonoids, the findings suggest it doesn’t take much to improve your intake to a potentially beneficial level.

Flavonoids are bioactive compounds found in fruits, vegetables, soybeans, flaxseed, dark chocolate, red wine and tea. They’re categorized into seven classes or types, each one having specific health properties.

Story continues below advertisement

The latest evidence

The study, published this month in the American Journal of Clinical Nutrition, examined the relationship between long-term flavonoid intake and the risk of dementia. Alzheimer’s disease is the most common form of dementia, making up 60 per cent to 80 per cent of cases.

While a number of studies have looked at links between diet and dementia over the short term, this one followed 2,801 people for two decades. At the study outset, participants were aged 59, on average, and free of dementia.

Flavonoid intake was measured every four years during the 20-year period. During that time, 193 participants developed dementia, 158 cases of which was Alzheimer’s disease.

A high intake of three flavonoid types was associated with a lower risk of dementia: flavonols (in apples, pears, berries, onions, kale, broccoli, tea), anthocyanins (berries, red grapes, red wine) and flavonoid polymers (tea, apples, cocoa, red grapes, berries, red wine).

Compared with a high intake, a low intake of flavonoids in berries was associated with a four-fold greater risk of developing dementia. A low intake of flavonoids from apples and tea was linked with twice the risk.

To arrive at these results, the researchers controlled for a number of risk factors for dementia, including smoking, physical activity, high blood pressure, high cholesterol, diabetes and overall diet quality.

Flavonoids are thought to improve blood flow in the brain and protect brain cells from inflammation and free radial damage. Flavonoids also play a role in removing toxins and other compounds in the brain that can interfere with cognitive function.

Story continues below advertisement

Which foods have flavonoids?

Top flavonoid contributors were tea, apples and pears for flavonols; blueberries, strawberries and red wine for anthocyanins; and tea, apples and pears for flavonoid polymers.

Participants in the highest intake category for flavonoids consumed, per day, 14.2 mg of flavonols, 16.4 mg of anthocyanins and 179 mg of flavonoid polymers.

To put these numbers in perspective, a medium red apple has 7 mg of flavonols and an eight-ounce cup of tea has 9.6 mg, while one cup of blueberries has 240 mg of anthocyanins (along with 16 mg of flavonols) and one cup of strawberries contains 41 mg.

A high intake of these three flavonoid types was equivalent to a monthly intake of 7.5 cups of berries, eight apples and pears and 10 cups of tea.

A low intake was equal to a monthly intake of no berries, one-and-a-half apples and no tea. Drinking a cup of tea each day and eating berries a few times a week would be enough to reach the higher flavonoid intake level.

Strengths, limitations

A credit to this study is that flavonoid intake was assessed repeatedly during the 20-year follow-up period. Had flavonoid intake been measured only once, at the beginning of the study, we wouldn’t know if participants’ intake had changed substantially over the 20 years.

Story continues below advertisement

The researchers also utilized a robust database that allowed for the capture of total flavonoid intake, rather than only a few types.

Limitations include the study’s observational design, which can’t prove that a higher flavonoid intake prevented dementia. As well, participants were white and of European descent so the findings may not apply to other populations.

Still, this new study adds to growing evidence that flavonoid-rich foods may offer cognitive benefits.

But let’s also not forget other healthy lifestyle choices that help guard against Alzheimer’s disease, including maintaining a healthy weight, being physically active, moderating alcohol intake and not smoking.

Leslie Beck, a Toronto-based private practice dietitian, is director of Food and Nutrition at Medcan.

Sign up for the weekly Health & Wellness newsletter for the latest news and advice.

Your Globe

Build your personal news feed

  1. Follow topics and authors relevant to your reading interests.
  2. Check your Following feed daily, and never miss an article. Access your Following feed from your account menu at the top right corner of every page.

Follow the author of this article:

Follow topics related to this article:

View more suggestions in Following Read more about following topics and authors
Report an error Editorial code of conduct
Due to technical reasons, we have temporarily removed commenting from our articles. We hope to have this fixed soon. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to If you want to write a letter to the editor, please forward to

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff.

We aim to create a safe and valuable space for discussion and debate. That means:

  • Treat others as you wish to be treated
  • Criticize ideas, not people
  • Stay on topic
  • Avoid the use of toxic and offensive language
  • Flag bad behaviour

If you do not see your comment posted immediately, it is being reviewed by the moderation team and may appear shortly, generally within an hour.

We aim to have all comments reviewed in a timely manner.

Comments that violate our community guidelines will not be posted.

UPDATED: Read our community guidelines here

Discussion loading ...

To view this site properly, enable cookies in your browser. Read our privacy policy to learn more.
How to enable cookies