If there was a particular way of eating that could give you the best chance possible of keeping your mind healthy and sharp into older age, would you want to adopt it? Well there is, and it is called the MIND diet. Designed by medical researchers to help reduce the risk of dementia and loss of brain function as you age, the research base into it is growing. In this podcast, I’ll look closer at the evidence behind the MIND diet and give you all the key foods that are part of it.
Of all the diseases linked with ageing, it would be those of cognitive decline such as Alzheimer’s disease which accounts for two-thirds of cases of dementia that are the most devastating for the person and their family. Worldwide, from 1990 to 2016, the number of people with dementia doubled with cases now approaching 50 million. So this is a really significant problem across the globe.
There is no single cause of dementia, but it is estimated that about one-third of cases of Alzheimer’s disease worldwide are attributable to modifiable risk factors, many of which are nutrition and lifestyle dependent. These include depression, obesity, hypertension, and type 2 diabetes.
One factor that is considered a culprit is oxidative stress and inflammation and here, diet has a big role to play. Antioxidants came to the public’s attention in the 1990s when scientists began to understand that free radical damage was involved in the early stages of heart disease, cancer, vision loss, and a host of other chronic conditions. Some studies showed that people with low intakes of antioxidant-rich fruits and vegetables were at greater risk for developing these chronic conditions than were people who ate plenty of those foods.
There is though very mixed and inconsistent evidence that nutritional supplements such as vitamin B-group vitamins, vitamins C, D or E and omega–3 polyunsaturated fats play a protective role when given in isolation. Yet observational evidence points to a diet containing foods high in phytonutrients offering some degree of protection. And the disconnect here is that antioxidants are not just one molecule, they represent a property that is part of many vitamins and minerals.
There are thousands of chemicals that have some potential antioxidant activity and these compounds are called polyphenols. There are over 8,000 different types of polyphenols found in fruits, vegetables, grains, legumes, tea and coffee. And these polyphenols are far more than antioxidants as they can also regulate cell growth and death, increasing the activity of enzymes involved in removing harmful substances from the body, and also decrease inflammation
Taken together, it strongly advocates for a food-first approach if nutrition is to have a role in halting cognitive decline, rather than taking nutrient supplements in isolation.
This leads me in to just what are the characteristics of a diet that could be linked to reducing the risk of dementia. And here we have what has been termed the MIND diet which was developed over many years and was first published in the medical literature in 2015 by a team at Rush University Medical Center in the United States.
And by diet here, I mean ‘way of eating’ not ‘weight loss’. MIND is an acronym for Mediterranean-DASH diet Intervention for Neurodegenerative Delay. It combines characteristics of a Mediterranean-style diet with the DASH diet where DASH stands for Dietary Approaches to Stop Hypertension. The DASH diet can lower high blood pressure which is a risk factor for Alzheimer’s disease. And on top of this, the MIND diet also includes foods specifically relevant to brain health.
Here is what a MIND diet could look like:
- Lots of leafy green vegetables and other kinds of vegetables
- Berries eaten at least twice a week
- Wholegrains eaten each day
- Fish and poultry
- Legumes
- Nuts
- And to round out the Mediterranean flavour, olive oil and if, you’re partial to it, some red wine.
The diet also limits how much red meat and highly processed discretionary foods like sweets and fast food. I’ll also put a link in the show notes to a nice article on the MIND diet so you can get more details on the foods in it, but my list here is pretty much your self-assessed checklist. www.nia.nih.gov/health/what-do-we-know-about-diet-and-prevention-alzheimers-disease
Now it all sounds good in theory, but just how much research is there to support eating close to what the MIND diet advocates for and real-world brain benefits? While most of the research here is observational, only in the last month a review paper has brought all of this research together in one place. And there were 13 studies altogether. And surprisingly, one of those studies was a randomised controlled trial which removes many of the biases that exist in drawing just upon observational research. And I’ll link to this review in the show notes. https://pubmed.ncbi.nlm.nih.gov/33989093
And here were the key findings: all of the included studies pointed in the direction that following the MIND diet was positively linked to specific aspects of cognition and cognitive function in older adults. And here was the key finding for me: the MIND diet was actually superior to other plant-rich diets which on their own have lots of health merits and that includes the Mediterranean and DASH diets on their own and even vegetarian diets.
I was especially interested to look at details of the one RCT included as doing long-term RCTs in the area of diet and cognition is very hard to do because of the time frames needed. The intervention study involved just 37 healthy women who were obese and followed either a calorie-reduced version of the MIND diet or a standard calorie-controlled diet for 3 months.
It was found that the MIND diet significantly improved working memory, verbal recognition memory, and attention compared with women in the control group. There was also some evidence that there were positive physical changes in the brains of women following the MIND diet. So, while this was indeed a small study, it is exciting to get this sort of real-world benefit seen in such a trial that removes many of the other factors that can cause bias in observational research.
There are so many positive things to be said about the sorts of foods that feature in the MIND diet. Whether you’re young or old, it is never too late to make some small changes to what you eat that could have long-term health benefits for your body, and mind.
So that’s it for today’s show. You can find the show notes either in the app you’re listening to this podcast on if it supports it, or else head over to my webpage www.thinkingnutrition.com.au and click on the podcast section to find this episode to read the show notes.
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I’m Tim Crowe and you’ve been listening to Thinking Nutrition.