Category: Dementia

A version of the Mediterranean diet reduces memory loss and slows down brain shrinkage.

The green Mediterranean diet, which is plant-based and enriched with polyphenols and low in meat, appears to slow down age-related brain atrophy.

Although factors such as aging and obesity can cause shrinkage of the brain cells leading to cognitive decline and dementia, certain diets can help to prevent brain atrophy.

To test that, a clinical trial examined the impact of a high-polyphenol Mediterranean diet (GREEN-MED) on age-related brain atrophy.

The trial ran for 18 months involving 284 obese participants who were divided into three groups (healthy dietary guidelines, Mediterranean diet, and GREEN-MED) combined with aerobic exercise.

Participants also underwent whole-brain MRI scans at the start and end of the study.

All participants received physical activity (PA) programs and free gym membership.

Besides PA sessions, the healthy dietary guidelines group received regular nutritional counselling sessions promoting healthy diets.

The Mediterranean diet (MED) and the GREEN-MED groups had to follow a low calorie diet; 1200-1400 kcal per day for women and 1500-1800 kcal per day for men.

Their everyday diet was low in carbohydrates, rich in vegetables, including fish and poultry instead of red meat, and 28 grams of walnuts, containing 440 mg of polyphenols.

In addition to these, the GREEN-MED group drank 3 to 4 cups of green tea per day, and their dinner was a green shake of Mankai duckweed containing 800 mg of polyphenols.

The results showed that brain shrinkage was reduced significantly in those who followed either the MED or GREEN-MED diets.

The effect was even greater in the GREEN-MED group, particularly for those over age 50, suggesting the diet is neuroprotective.

The study’s authors wrote:

“The beneficial association between MED and age-related neurodegeneration might be partially explained by the abundance of polyphenols in plant-based food sources which have antioxidant and anti-inflammatory metabolites.

Polyphenols can cross the blood-brain barrier (BBB) reduce neuroinflammation and induce cell proliferation
and adult-onset neurogenesis in the hippocampus.”

The authors concluded:

“Our findings might suggest a simple, safe, and promising avenue to slow age-related neurodegeneration by adhering to a green-Mediterranean diet.”

A different study also found that the Green Med diet is better than the traditional Mediterranean diet since it reduces the odds of developing diabetes and heart disease even more.

The study was published in The American Journal of Clinical Nutrition (Kaplan et al., 2022).

Just six minutes of this exercise improves memory while reducing the risk of Parkinson’s and Alzheimer’s disease.

The reward for doing 6 minutes of high-intensity workout is a brain that is more resilient to aging, Alzheimer’s disease, and Parkinson’s disease.

According to a study, short intervals of vigorous exercise improve the production of a protein involved in brain function related to memory, learning, and flexibility.

Our brain has the ability to learn, adapt, and function through a process known as neuroplasticity.

Brain-derived neurotrophic factor (BDNF) is the particular protein that boosts neuroplasticity and protects neurons.

Past research has suggested that higher levels of BDNF enhance memory storage, memory formation, improve learning processes, and increase cognitive function.

BDNF’s capability of protecting nerve cells has encouraged researchers to find out if this protein can slow brain aging.

Dr Travis Gibbons, the study’s first author, said:

“BDNF has shown great promise in animal models, but pharmaceutical interventions have thus far failed to safely harness the protective power of BDNF in humans.

We saw the need to explore non-pharmacological approaches that can preserve the brain’s capacity which humans can use to naturally increase BDNF to help with healthy aging.”

The team wanted to see if either calorie restriction or exercise or both have any effect on BDNF production.

For this, they compared the factors below to examine the solo and joint impacts:

• 90 minutes of low-intensity cycling
• Six minutes of high-intensity cycling intervals
• Fasting for 20 hours
• Fasting with exercise

Short but vigorous exercise appeared to be the most effective approach for elevating BDNF levels compared with light exercise or fasting with or without prolonged low-intensity workouts.

The 6-minute high-intensity workouts increased serum concentration of BDNF by five times.

Prolonged low-intensity cycling showed a slight increase in serum levels, from 336 pg/L to 390 pg/L, while fasting had no effect.

Such contrasting findings might be due to a cerebral substrate switch, the brain’s fuel source shifting from glucose to either ketone bodies or lactate.

It appears that the brain switches from glucose to lactate during exercise, leading to production of BDNF, while fasting causes an increase in ketone body delivery to the brain.

Platelets are tiny blood cells that store BDNF and exercise increased numbers of platelets by 20 percent compared to fasting.

The team also want to find out whether intermittent fasting with exercise would have a greater influence on BDNF and cognitive functions.

Dr Gibbons added:

“We are now studying how fasting for longer durations, for example up to three days, influences BDNF.

We are curious whether exercising hard at the start of a fast accelerates the beneficial effects of fasting.

Fasting and exercise are rarely studied together.

We think fasting and exercise can be used in conjunction to optimize BDNF production in the human brain.”

The study was published in the journal The Journal of Physiology (Gibbons et al., 2023).

The food that protects against cognitive decline.

Eating seafood once a week, or food that contains omega-3 fatty acids, may protect against age-related memory loss.

The study found that people who ate seafood less than once a week had a steeper mental decline with age.

Dr Martha Clare Morris, who led the study, said:

“This study helps show that while cognitive abilities naturally decline as part of the normal aging process, there is something that we can do to mitigate this process.”

For the research, 915 people were followed for around 5 years.

They all came from retirement communities and public housing in Illinois and their average age was over 80.

All had memory tests and reported how much seafood they ate.

This included foods like fish cakes, tuna sandwiches, shrimp and crab.

The results showed that people who ate more seafood had better semantic memory: this is something like general knowledge.

Consuming more seafood was also linked to stronger perceptual skills.

The study was published in the journal Neurology (van de Rest et al., 2016).

The types of fruit that can reduce cognitive aging and lower the risk of Alzheimer’s in midlife.

Daily consumption of strawberries or blueberries may lower the odds of dementia and Alzheimer’s disease in middle-aged men and women.

According to a study, both strawberries and blueberries contain effective antioxidants that help prevent the risk of late-life dementia.

Midlife adults can get the optimal health effect if consuming at least one cup of whole strawberries or blueberries per day.

Anti-aging antioxidants

A group of antioxidants called anthocyanins are responsible for the red, purple, or blue pigments of fruits and flowers.

Studies show that these antioxidants, due to their anti-inflammatory effect, can lower the risk of heart disease, type-2 diabetes and cancer.

Berries are rich in anthocyanins and several nutrients such as ellagic acid, that is known for its anti-aging effects, and improving memory and other cognitive skills.

Professor Robert Krikorian, the study’s first author, said:

“Both strawberries and blueberries contain antioxidants called anthocyanins, which have been implicated in a variety of berry health benefits such as metabolic and cognitive enhancements.

There is epidemiological data suggesting that people who consume strawberries or blueberries regularly have a slower rate of cognitive decline with aging.”

Slow cognitive decline

Around half of the American adult population with prediabetes are middle-aged.

This group are more vulnerable to memory loss and cognitive decline.

Past research has suggested that eating strawberries can boost cardiovascular health by improving insulin sensitivity and lowering blood glucose levels.

This study investigated whether strawberry consumption provides any health benefit in overweight middle-aged individuals with self-reported cognitive decline.

Professor Krikorian said:

“This study assessed whether strawberry consumption might improve cognitive performance and metabolic health in this population, and if so, whether there might be an association between cognitive enhancement and reduced metabolic disturbance.”

One cup of strawberries

The participants in this study received every day a sachet of strawberry powder, equal to one cup of whole strawberries, for 3 months.

During the study period, the participants took various tests to measure their cognitive abilities such as long-term memory, as well as their emotional state such as mood, anxiety, and depressive symptoms.

The strawberry-treated group experienced a significant reduction in memory interference.

Professor Krikorian said:

“Reduced memory interference refers to less confusion of semantically related terms on a word-list learning test.

This phenomenon generally is thought to reflect better executive control in terms of resisting intrusion of non-target words during the memory testing.”

Furthermore, the strawberry-treated participants also experienced less depressive symptoms.

Professor Krikorian said the positive effects can be due to:

“…enhanced executive ability that would provide better emotional control and coping and perhaps better problem-solving.”

Lowering brain inflammation

Other studies have found that higher consumption of strawberries improves metabolic measures such as lowering insulin levels.

Professor Krikorian pointed out:

“Those studies generally used higher dosages of strawberry powder than in our research, and this could have been a factor.”

It seems the improvement of cognitive function by eating strawberries could be due to decreased brain inflammation.

Professor Krikorian said:

“Executive abilities begin to decline in midlife and excess abdominal fat, as in insulin resistance and obesity, will tend to increase inflammation, including in the brain.

So, one might consider that our middle-aged, overweight, prediabetic sample had higher levels of inflammation that contributed to at least mild impairment of executive abilities.

Accordingly, the beneficial effects we observed might be related to moderation of inflammation in the strawberry group.”

Related

• One cup of cranberries a day reduces the risk of neurodegenerative disorders.
• Lingonberry juice lowers blood pressure in the long-term.
• Flavonoid-rich foods can reduce blood pressure levels.
• Blackcurrants are found to improve mood.

The study was published in the journal of Nutrients  (Krikorian et al., 2023).

It is thought that the vitamin helps clear the brain of the characteristic tangles of proteins that form in dementia.

Taking vitamin D supplement could decrease dementia risk, a large study suggests.

People who took vitamin D supplements lived for longer without developing dementia and overall had a 40 percent lower risk of developing the disease.

Adequate vitamin D levels have been repeatedly linked to lower dementia risk by research (1, 2, 3, 4).

One study has even suggested that adequate levels of vitamin D could prevent almost one-in-five cases of dementia (Navale et al., 2022).

However, the link remains somewhat controversial, with other studies finding no connection (also: Owusu et al., 2018).

Professor Zahinoor Ismail, the study’s first author, acknowledged the contradictory findings from past studies:

“We know that vitamin D has some effects in the brain that could have implications for reducing dementia, however so far, research has yielded conflicting results.

Our findings give key insights into groups who might be specifically targeted for vitamin D supplementation.

Overall, we found evidence to suggest that earlier supplementation might be particularly beneficial, before the onset of cognitive decline.”

Vitamin D and dementia

For this study, data from over 12,000 participants in the US National Alzheimer’s Coordinating Center was analysed.

Just over one-third were taking vitamin D supplements.

The results showed that vitamin D supplementation was associated with a reduced dementia risk in all groups.

However, the connection was stronger in women and people who had no pre-existing cognitive deficits, such as mild cognitive impairment.

Similarly, carriers of the APOEe4 gene appeared to benefit more from vitamin D supplementation.

The APOEe4 gene significantly increases the risk of developing dementia.

It is thought that vitamin D helps to clear the brain of the characteristic tangles of proteins that form, known as amyloid and tau.

Dr Byron Creese, study co-author, said:

“Preventing dementia or even delaying its onset is vitally important given the growing numbers of people affected.

The link with vitamin D in this study suggests that taking vitamin D supplements may be beneficial in preventing or delaying dementia, but we now need clinical trials to confirm whether this is really the case.

The ongoing VitaMIND study at the University of Exeter is exploring this issue further by randomly assigning participants to either take vitamin D or placebo and examining changes in memory and thinking tests over time.”

Despite these findings, it is not recommended to take high levels of vitamin D as a preventative measure.

Recommended doses are 600 IU per day for people under 70 and 800 IU for those over 70.

The study was published in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring (Ghahremani et al., 2023).