Ageing And Brain Function

 

What is ageing?

 

People tend to think that ageing is only associated with the elderly. However, it's truer to say that ageing begins from birth. Adopting anti-ageing measures can never start too early.

 

The rate of ageing is due to a combination of factors: influences from our genes as well as influences from our lifestyle and the environment. We cannot change our genes, but we can change our lifestyle by looking at what we eat and what activities we do. For instance, antioxidants, including those we get from our diet, play an important role in slowing down the ageing process (Bibliography Ref: 80, 81).

 

The earliest signs of ageing include wrinkles and grey hair. Later on, tissues, organs and systems in the body, such as the heart and brain, stop working as well as they used to. When the brain starts to age, we develop a poorer memory and have less control over our body movement.

 

How might fruit help the ageing process?

 

Emerging research by Dr Ghosh and colleagues at Horticulture and Food Research Institute of New Zealand1 into the protective effect of food components on nerve cells found that the phenolic components found in blackcurrant out-performed the corresponding compounds found in other fruit such as blueberry and boysenberry. Dr Ghosh’s studies suggest that the antioxidant ability of blackcurrant is such that the anthocyanins and the other components such as the procyanidins not only protected the nerve cells (neurons) from oxidative stress but also helped to regenerate the bodies own defence systems.

 

Dr Joseph and his colleagues in Tufts University recently revealed that feeding older rats with blueberry, strawberry or spinach extracts significantly improved short-term memory. They also found that blueberry extract improved the rats' body balance, co-ordination and running speed (Bibliography Ref: 82, 83). Interestingly, a blackcurrant extract was found to significantly prolong the life span of 'older dying' mice (Bibliography Ref: 84).

 

Dr Josephs group have been instrumental in many of the studies focussed on the beneficial effect of fruit derived polyphenolics with respect to neural-related disease such as Alzheimers, Parkinsons and Dementia2. Their detailed human cell studies have shown that supplementation with soft fruit polyphenolics, such as anthocyanins, flavanol, catechins and hycroxy cinnamic acids, resulted in the prevention of a variety of age-related deficits including cognitive performance whilst increasing incidences of neurogenesis (the creation of new nerve cells) and neuroplasticity, the ability of the brain to change with learning.

 

More recently, model studies were undertaken to look at the effect that the polyphenolic components within soft fruit, such as blueberry and boysenberry, had on memory, locomotion and anxiety3. Interestingly the experiments with a rat model demonstrated that these components showed significant improvements to short-term memory, one of the symptoms related to Alzheimer’s disease.

 

Further support as to the ability of the fruit polyphenolic compounds to reduce oxidative stress and thereby reduce the effect of associated diseases and pathologies comes from recent studies with hippocampal cells (believed to play a central role in memory)4. Compounds commonly found in blackcurrant, like catechin and anthocyanidins, were found to exhibit protective effects when the cells were stressed.

 

Other researchers found that this protection extended to the protection of nerve cells exposed to common products of ageing5. Low density lipoproteins are involved in cholesterol transport in the body but they are susceptible to oxidation during our normal ageing processes leading to the production of oxidise LDL (oxLDL). This was shown to enter nerve cells leading to DNA breakdown and ultimately cell death, However polyphenolic compounds similar to those found in blackcurrant exerted a protective effect and reduced neurodegeneration. Further, more detailed, studies by this group under Prof Rice Evans in King’s College London showed that the procyanidins (significant components of blackcurrants) and their metabolites inhibit cell death induced by oxidative stress6.

 

Corroboration of proanthocyanidins as beneficial dietary components was reflected in the report by Bagchi et al7 who reported that these compounds exhibit a broad scale protective effect in many different cell types. An early patent claimed that blackcurrant juice may have the potential to prevent neurodegenerative diseases (conditions due to brain ageing or failing over time) such as Parkinson's disease (Bibliography Ref: 85).

 

Most of these studies have not been carried out in humans because we take a long time to age, so laboratory models were used instead. Whilst these studies give us an early indication of the anti-ageing properties of blackcurrants and berry anthocyanins, more research in humans is required to confirm these effects

 

1Ghosh et al., (2006) Effects of anthocyanins and other phenolics of boysenberry and blackcurrant as inhibitors of oxidative stress and damage to cellular DNA in SH-SY5Y and HL-60 cells. Journal of the Science of Food and Agriculture. 86, 678-686.

 

2Lau et al. (2005) The beneficial effects of fruit polyphenols on brain aging. Neurobiology of Aging, 26(1), 128-132. Galli et al. (2006) Blueberry supplemented diet reverses age-related decline in hippocampal HSP70 neuroprotection. Neurobiology of Aging, (27), 344-350. de Rivera et al. (2005) The effects of antioxidants in the senescent auditory cortex. Neurobiology of Aging, (In Press), Rabin et al. (2005) Effects of age and diet on the heavy particle-induced disruption of operant responding produced by a ground-based model for exposure to cosmic. Brain Research, 1036, 122-129 Youdim and Joeseph (2001) A possible emerging role of phytochemicals in improving age-related neurological dysfunctions: a multiplicity of effects. Free Radical Biology and Medicine, 30, 583-594.

 

3Maria Rosana Ramirez et al. Effect of lyophilised Vaccinium berries on memory, anxiety and locomotion in adult rats Pharmacological Research, Volume 52, Issue 6, December 2005, Pages 457-462

 

4Ishige et al. (2001) Flavonoids protect neuronal cells from oxidative stress by three distinct mechanisms Free Radical Biology and Medicine, 30(4) , 433-446

 

5Schroeter et al. (2000) Phenolic antioxidants attenuate neuronal cell death following uptake of oxidized low-density lipoprotein. Free Radical Biology and Medicine. 29(12) 1222-1233

 

6Spencer et al. (2001) Epicatechin and its in vivo metabolite, 3«-O-methyl epicatechin, protect human fibroblasts from oxidative-stress-induced cell death involving caspase-3 activation Biochem. J. 354, 493-500

 

7Bagchi et al. (2000) Free radicals and grape seed proanthocyanidin extract: importance in human health and disease prevention. Toxicology, 148, (2-3), 187-197.