Category: Dementia

This ingredient is linked to double the rate of memory decline and problems with thinking.

Eating a diet spiced with chillies is linked to an increased risk of dementia.

People who eat more than 50 g of chillies per day suffer double the rate of memory decline and problems with thinking.

The decline is even greater for chilli eaters who are slim.

The findings come on the back of some positive coverage for spicy foods, including linking them to longer life, lower blood pressure and other benefits.

Dr Zumin Shi, the study’s first author, said:

“Chili consumption was found to be beneficial for body weight and blood pressure in our previous studies.

However, in this study, we found adverse effects on cognition among older adults,”

The study included over 4,000 Chinese adults who were tracked over 15 years.

The spicy foods tracked included both fresh and dried chilli peppers, but not black pepper or capsicum (often known as sweet peppers or bell peppers).

Dr Shi said:

“Chili is one of the most commonly used spices in the world and particularly popular in Asia compared to European countries.

In certain regions of China, such as Sichuan and Hunan, almost one in three adults consume spicy food every day.”

The active ingredient in chillies is capsaicin, which is what produces the burning sensation when consumed, or when coming into contact with any tissue.

Capsaicin has been linked to weight loss as it is thought to speed up the metabolism and increase fat loss.

The study was published in the journal Nutrients (Shi et al., 2019).

Normally people’s brains shrink by about 5% every decade after the age of 40 but this could be prevented.

Exercise increases brain size and so may help stop brain shrinkage with age.

In some of the best evidence to date, exercise was shown to increase the size of the hippocampus, a brain structure critical for memory and other functions.

So far, studies have mostly shown the connection between exercise and brain size in rodents.

Shrinking brain size

Researchers followed people aged 24 to 76 for up to two years in a range of separate studies.

They looked at the effects of walking, cycling, treadmill running and general aerobic exercise.

Most people did around 2-5 sessions per week.

The results showed that left hippocampul volume was increased in people who exercised.

Dr Joseph Firth, the study’s first author, said:

“When you exercise you produce a chemical called brain-derived neurotrophic factor (BDNF), which may help to prevent age-related decline by reducing the deterioration of the brain.

Our data showed that, rather than actually increasing the size of the hippocampus per se, the main ‘brain benefits’ are due to aerobic exercise slowing down the deterioration in brain size.

In other words, exercise can be seen as a maintenance program for the brain.”

Preventing brain shrinking with age is possible

The study reviewed 14 separate clinical trials, including brain scans from 737 people.

This is some of the most definitive evidence yet published of the beneficial effects of exercise on brain health.

Normally people’s brains shrink by about 5% every decade after the age of 40.

Exercise is one of the few interventions proven to slow this process down.

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The study was published in the journal NeuroImage (Firth et al., 2018).

Reducing this behaviour could decrease the risk of dementia.

Too much sitting down is linked to a thinner brain in regions critical to memory formation.

Reducing sedentary behaviour could also decrease the risk of dementia.

Even high levels of physical activity were not enough to offset the damaging effects of sitting down for long periods, the researchers found.

The study’s authors conclude:

“In this preliminary study of middle-aged and older adults, self-reported hours per day spent sitting, but not physical activity level, was associated with less thickness in the MTL [the medial temporal lobe] substructures.

These findings are novel and require further exploration in longitudinal studies and analysis of mediating mechanisms.

Better understanding the effects of sedentary behavior on our brains is important given the global epidemic of physical inactivity and sedentary lifestyles.”

For the study, 35 middle-aged people were asked about their physical activity and had their brains scanned.

More sedentary people had thinner medial temporal lobes.

The medial temporal lobe is involved in the formation of new memories.

The authors write:

“Several lines of evidence suggest that sedentary behavior may be a risk factor for the development of age-related cognitive impairment.

A detailed projection of the effect of risk factors on Alzheimer’s disease (AD) prevalence suggests that approximately 13% of AD cases worldwide may be attributable to sedentary behavior.

A 25% reduction in sedentary behavior could potentially prevent more than 1 million AD cases globally.”

The study was published in the journal PLOS ONE (Siddarth et al., 2018).