Sunday 27 March 2011

In search of the 'Elixir of Life'

It always amuses me and annoys me when a new 'miracle cure' enters the market promoting what I refer to as the proverbial 'elixir of life'. I have now had at least three people asking me for advice on the increasingly popular acai berry and its extracts, commercial blends of the juice containing freeze-dried extracts of this berry not to mention the numerous other proprietary products including health and beauty products such as cosmetics. But is there any validity to the manufacturers' claims and is there any scientific evidence to support such claims?


In attempting to answer this question, we need to start at the history and the context of all this fuss. The acai berry is reddish-purple berry plucked from the acai palm tree (Euterpe oleracea) which is native to Central and South America. It is the fruit of this palm that is harvested as food but the majority of it (about 80%) is really the seed. Therefore the most beneficial part (the outer part) is actually quite a small proportion of the whole fruit. The ripe fruit is a deep purple colour which also constitutes the pulp of the fruit. It is this fleshy part of the ripe fruit that is harvested as food.


Culturally, the locals consume acai combined with other foods such as tapioca or granola (a mix of rolled oats, nuts, honey and/or rice), serve it hot or cold or either salty or sweet depending on preference. Acai is also popularly used as a flavouring (eg. in ice cream, juices, sorbets and liquers). However, acai berry perishes within 24 hours but freezing has made it possible to transport it for commercial use. Additionally, freeze-drying the pulp has enabled manufacturers to add it to commercial blends of juices that include acai berry juice.


Demand for acai berry is so high and the recent surge in popularity has resulted in commmercial supplements, specifically formulated to retain the nutritional value of the fresh fruit itself. There are also various companies that market supplements that contain inferior levels of acai berry, coupled with exagerated claims of miracle weight loss and a number of other health claims, none of which have been proven.


Much of the scientific research on the acai berry has focussed on its antioxidants, long purported to protect against diseases caused by free radical damage. Antioxidants reduce the destructive power of free radicals and so may help lower the risks of diseases such as heart disease and cancer. Antioxidants are plentiful in red and blue/purple berries such as cherries, blueberries, blackcurrants, cranberries, pomegranate and blackberries to name but a few!


Ethical considerations and issues of sustainability

Many environmentalists were concerned that the expanding popularity of the acai berry, particularly in the US was depriving the Brazilian jungle dwellers of a protein-rich nutrient they have relied on for generations. However, this has been argued on the basis that acai farming actually enhances the subsistence of the harvesters providing a sustainable livelihood without damaging the Amazonian Rainforest. This ensures that the trees remain intact for this purpose rather than being cut down as the acai is a renewable resource and has been used in fact to reforest already degraded forest lands.
Investigating the Claims
The claims by some manufacturers of acai berry seem almost so extraordinary that it seems impossible that a small berry could possibly offer all these benefits. The list includes:



  • antioxidant properties 5 times that of blueberry - acai berry is very high in anthocyanins and flavonoids, already shown to have proven antioxidant activity. This also relates to the freeze dried acai pulp, seed extract and powder which contains notable quantities of these antioxidants

  • increased energy and stamina - by strengthening the immune system. The claim is that the body can then reserve the energy used for fighting infection to other uses. There is no evidence whatsoever of the immune mechanisms or cellular processes at work to make this happen

  • fighting obesity - it is asserted that the nutrient packed berry makes the body function more efficiently including the processing and burning of food. This is incredibly poor science as there is no evidence to suggest that eating a nutritious food increases the metabolic rate nor indeed to improve weight loss

  • preventing cancer - only one study so far has shown that acai is directly has anticancer activity by destroying the proliferation of human cancer cells in vitro. This doesn't mean that acai is a cure for cancer, but it does support the preventative function of antioxidants by strengthening cells and fighting damage from free radicals

  • protecting against heart disease - the berry contains essential fatty acids (omega 3 and 6) already shown to confer protection against heart disease

  • aiding digestion - the berry is high in fibre and a host of other nutrients that are beneficial to the gut

  • highly nutritious being packed with a host of vitamins, minerals, essential fat, phytosterols, antioxidants and fibre

  • improve sleep - there is no evidence of this but to be honest, if acai berry is being eaten in a bid to improve diet and lifestyle, then of course the general well-being is bound to improve and this will indirectly result in better attributes including sleep

Examining the evidence


The numerous and potential benefits of antioxidants have already been demonstrated in many previous studies therefore it is easy to see why the acai berry presents as a highly nutritious option. However, clever and aggressive marketing has fed into the mindset of those in perennial search of the elixir of life which has resulted in significant sales of the commercial preparations by some manufacturers making such extraordinary and unsupported claims. The cost of these preparations, particularly the juice blends are so ludicrously high that it is hard to believe that anyone would be foolish enough to buy them in the belief that the claims can all be met. However, it is not available in stores so it has clearly not passed the stringent checks of the relevant authorities, merely sold via what resembles a pyramid scheme. This should surely ring alarm bells?!


Conclusion


Comparative studies, particularly of the juice blends show that acai berry juice is no better than juices of the notable grape, blueberry or black cherry in its antioxidant content but is higher than cranberry, orange or apple (admittedly, manufacturers of the latter do not make the same health claims as the makers so acai juice blend!). Importantly, these commercial juice blends of acai do not disclose the pecentage of acai in them so it is hard to conduct a proper study into these claims. The extent to which polyphenols (as dietary antioxidants) promotes health is unknown as there is no credible evidence to indicate antioxidant activity for polyphenols in vivo. There is also some concern with some of the additives, particularly a preservative used in the juice blend which may present carcinogenic (cancer-promoting) properties although the quantities used in commercial preparations should be safe. In conclusion, it would be safe to say that acai berry is a nutritious fruit but no better or worse than any other red/blue/purple berry. As part of a healthy diet, it presents numerous benefits but to attribute these benefits to acai berry alone is poor science and until there is incontrovertible evidence to suggest otherwise, the jury is still out on this wonderful fruit.