Daily Archives: 15 August, 2012

Chocolate can combat Alzheimer’s disease

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A DAILY dose of cocoa could be the secret to halting Alzheimer’s disease, researchers claim.

Scientists have found that the potent ingredient in chocolate can dramatically improve cognitive impairment.

Experts say pensioners should have some cocoa every day in a bid to keep dementia and Alzheimer’s at bay.

The key lies in health-boosting flavanols which are abundant in the sweet treat.

Flavanols are an antioxidant also found naturally in fruit and vegetables such as grapes, berries and apples, drinks including tea and red wine, and other plant-based foods.

Dr Giovambattista Desideri, who headed the research team, said: “This study provides encouraging evidence that consuming cocoa flavanols as part of a calorie-controlled and nutritionally balanced diet could improve cognitive function.

“Given the global rise in cognitive disorders, which have a true impact on an individual’s quality of life, the role of cocoa flavanols in preventing or slowing the progression of mild cognitive impairment to dementia warrants further research.”

Flavanols belong to a group of compounds called flavonoids which have been shown to help beat cancer, heart disease and the ageing process by protecting cells. They also mop up potentially harmful oxygen molecules in the body.

Researchers from the University of L’Aquila in Italy found that eating cocoa flavanols daily could improve mild cognitive impairment (MCI), the precursor to the brain condition.

chocolate_healthy_heart_lancastria

Dark chocolate

MCI is characterised by the memory loss that comes with ageing, which precedes full dementia. About 60 per cent of those with this impairment go on to develop Alzheimer’s.

In the new study, published in the journal Hypertension, 90 elderly people with MCI had 990mg (high), 520mg (intermediate) or 45mg (low) of a cocoa flavanol drink daily for eight weeks. Their diet was restricted to eliminate other sources of flavanols.

Tests for cognitive function included short-term memory, long-term episodic memory and processing speed.

Researchers found scores significantly improved in the ability to relate visual stimuli to motor responses, working memory, task-switching and verbal memory for those on the high and intermediate flavanol drinks.

Those who drank higher levels had significantly improved overall cognitive scores than those on lower levels.


Blood pressure and insulin resistance, where the hormone is less effective at lowering blood sugars, also decreased in those taking high and intermediate flavanol levels. Changes in insulin resistance explained about 40 per cent of the scores for improvements in cognitive function.

Dr Desideri said: “The positive effect on cognitive function may be mainly mediated by an improvement in insulin sensitivity.

“It is yet unclear whether these benefits in cognition are a direct consequence of cocoa flavanols or a secondary effect of general improvements in cardiovascular function.

“Larger studies are needed to validate the findings, figure out how long the positive effects will last and determine the levels of cocoa flavanols required for benefit.” Previous research has shown that chocolate and cocoa products can decrease the risk of dementia.

They may protect neurons from injury, improve metabolism and interact with the molecular structure responsible for memory, researchers said. Indirectly, flavanols improve brain blood flow.

Alzheimer’s occurs with a build-up of amyloid plaques, proteins that group together causing blockages and reducing normal brain functioning.

Dr Laura Phipps, of Alzheimer’s Research UK, said: “It would be useful to see more long-term studies to investigate the lasting effects. Ultimately we would need to see the results of large-scale trials to know whether cocoa flavanols could help prevent or delay dementia.”

Cancer tumour stem cell discovery

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Researchers have discovered the cells in tumours that seem to be responsible for the regrowth of tumours.

Three separate studies on mice appear to have confirmed the view that the growth of tumours is driven by so-called cancer stem cells.

The researchers claim to have resolved one of the biggest controversies in cancer research and say their work marks a “paradigm shift” in the field.

The studies have been published in the journals, Nature and Science.

Doctors often successfully reduce the size of tumours through various therapies, but often patients suffer a relapse and the tumour regrows.

Some researchers believe that this happens because therapies fail to eradicate a small proportion of cells that drive tumour growth known as cancer stem cells. They believe that these are the cells that should be targeted to eliminate the tumour forever.

Evidence for the existence of cancer stem cells has been weak. But now three separate groups of researchers working independently have found direct evidence of cancer stem cells driving tumour growth in brain, gut and skin cancers.

The suggestion is that the same may be true of all cancers which produce solid tumours.

Cancer cells

Cancer cells

According to Prof Cedric Blanpain of the Free University of Brussels, who led one of the studies, the results could pave the way for a new approach to treating many cancers.

“If these cells are indeed the cells that fuel tumour growth then maybe you can target these cells,” he told BBC News.

But that may be easier said than done. The newly-identified cancer stem cells are very similar to healthy stem cells responsible for growing and renewing tissue in the body. Any therapy to target cancer stem cells may also destroy healthy tissues. A priority for researchers will be to see if there are important differences between normal and cancer stem cells so that therapies can distinguish between them.

But according to Prof Hugo Snippert of the University Medical Centre in Utrecht, who led the study into intestinal tumours, the confirmation that these cells exist is an important step in future cancer research.


“Many argued that these cells did not exist. But we have shown for the first time there is such a thing as a cancer stem cell and that tumours are maintained by them,” he said.

Prof Luis Parada of the University of Texas, who led research that identified stem cells in brain tumours in mice, said he believed there would now be a new approach to developing new treatments for solid tumour cancers.

“Cancer stem cells change the paradigm. The goal of shrinking tumours may well turn out to be less important than targeting the cancer cells in that tumour.”

Dr Michaela Frye, a Cancer Research UK scientist based at the University of Cambridge, said: “These results add even more weight to the theory that cancers are driven by a distinct group of cells called cancer stem cells. Because cancers are proving to be so complex, we don’t yet know how relevant this research in mice is to humans, but it gives us new insights into how cancers might develop and why they can sometimes grow back after therapy.”