Five-a-Day still important

South Africa’s 5-a-Day for Better Health TRUST has responded to the findings of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study which found a modest association between vegetable and fruit consumption and cancer risk. It puts clarity to some of the issues raised by the study.

The 5-a-Day for Better Health TRUST says it would like to clarify some of the issues highlighted in the article… read on…

First of all, it’’s a pity that such a negative connotation was created in the headline of this article [sourced from and published in the UK Independent newspaper], which obviously doesn’’t allow for any context of information and is potentially damaging to readers who don’’t understand the broader sense of this study and its results.

Secondly, the data coming out of the EPIC study must be interpreted with care: the authors mention that the data should not be used for public health recommendations. EPIC is a prospective epidemiological study, and the number of subjects identified with cancer after the 8.7 year follow-up is really too small to stratify for different cancers and different groups (i.e. men, women, smokers, drinkers etc.)

The authors, therefore, looked at overall cancer risk and vegetable and fruit intake. They clearly showed a statistically significant inverse relationship, indicating that the higher the intake of vegetables and fruit, the lower the overall cancer risk. This in itself is remarkable because we would expect vegetables and fruit to ‘protect’ against specific diet-related cancers.

The protective effect showed in the study was relatively small. There may be methodological problems in the study responsible for this (as admitted by the authors) such as bias in reporting dietary intakes, the early stage of the study, the numbers of subjects etc. Another factor is that cancer is a multi-factorial disease, and diet is but one of the potential causative or protective factors.

Experts commenting on the study are quick to point out that while a 4% reduction in risk may not seem very significant, in public health terms it translates to thousands of people not getting cancer simply by eating more fruit and vegetables.

Also, in interpreting epidemiological data, one should be aware that it generally only shows associations between exposures (in this case vegetable and fruit intake) and outcomes (in this case cancer). Epidemiological means that it gives an indication of association between a specific health effect and its possible cause. The emphasis is placed on the words ‘association’ and ‘possible cause’. This means that these types of studies do not provide us with the convincing evidence needed in order to make policy and give recommendations.

For this level of certainty, well-designed peer reviewed intervention trials are required. In other words, we need other types of studies to indicate cause and effects and the magnitude of protection.

At present, the weight of the evidence from all types of studies suggests that eating sufficient quantities of vegetables and fruit every day will protect against cancer; the magnitude of this protection is not yet known. What we do know is that it will not necessarily prevent cancer, which emphasises that all the other preventative, healthy lifestyle messages must also reach the consumer –- one of the functions of the 5-a-Day for Better Health TRUST.

As study author, Dr Paolo Boffetta of the Mount Sinai School of Medicine in New York, cautions, this doesn’’t mean you should stop eating vegetables and fruit. He says there is still a great health benefit to be had from eating vegetables and fruit for a number of other reasons, such as reducing the risk of cardiovascular disease. “The researchers aren’’t saying that vegetables and fruit have no effect on cancer risk either; they’’re saying they’’re likely to be protective against cancer, although that protective effect is not likely to be large.

“We’’re pleased that the article mentioned some of the other beneficial health effects of eating your 5-a-day, which of course include improvement of overall nutritional status, improvement of micronutrient status, and protection against other non-communicable diseases such as overweight, obesity, heart disease, diabetes and stroke.”

Because while it’’s true that the case for vegetable and fruit consumption and its impact on cancer risk has weakened in recent years, the evidence of the impact of such consumption on weight gain has continued to strengthen. This indirect impact on cancer risk is just as important, since weight is one of the strongest diet-related cancer risk factors.

We know obesity increases cancer risk and that eating more vegetables and fruit in place of higher calorie foods decreases the risk of becoming obese. So vegetables and fruit can be said to have a preventative effect in that manner.

Note:

Information compiled by Prof. Este Vorster a trustee of 5-a-Day For Better Health TRUST and director of the north West University’’s Centre of Excellence for Nutrition and Leigh-Ann Silber also a trustee and registered dietitian.

About 5-a-Day:

Launched in September 1995, the 5-a-Day for Better Health TRUST is a non-profit organisation which aims, through education and promotion, to increase the consumption of vegetables and fruit in South Africa for better health –- from under-nutrition to over-nutrition.

The 5-a-Day for Better Health TRUST encourages and challenges all South Africans to increase their intake of vegetables and fruit to at least five servings each and every day. Jane Badham, CEO of the 5-a-Day for Better Health TRUST explains, “”Our message is a positive one, it is about adding colour and variety to the diet in order to promote optimal health and prevent disease. Eating plenty of veggies and fruit is the one health message that science has positively linked to the prevention of many diseases from micronutrient deficiencies to diabetes, heart disease and cancer. And each day science is uncovering even more benefits from nature’s rainbow colours of vegetables and fruit.””

Key in the role of vegetables and fruit and health is the antioxidant effect that they exert and how they neutralise excess free radicals commonly generated by radiation, pollution, tobacco smoke and a high-fat diet, by donating one of their own electrons, thus ending a potentially cell damaging chain reaction within the body. It is that simple. Not surprisingly then that international and local health scientists and health organisations all agree and support the 5-a-Day message.

The World Health Organisation (WHO) “Global Strategy on Diet, Physical Activity and Health” sets the evidence based goals that we should all be striving for to improve the state of the world’’s health. One of the key dietary recommendations is the need to increase the world’s consumption of vegetables and fruit to at least 400g per day (five per day). The Medical Research Council (MRC) of South Africa shows that on average South Africans only eat about 205g of veg and fruit daily – falling far short of the global recommended minimum. Not surprisingly the South African Department of Health: Directorate of Nutrition has as one of its key dietary guidelines “‘Eat plenty of vegetables and fruit everyday’”.

Eating at least five, 80g servings of vegetables and fruit each day could positively and dramatically impact on the health status of all South Africans and has the potential to revert the deterioration in health that we have seen in the past years. Worldwide, the daily increased consumption of vegetables and fruit it is estimated, might save 2.7million lives a year. In fact it could reduce the burden of heart disease by 31%, stroke by 19% and some cancers by between 12% and 20%.

The MRC has found that 80% of adults 15 years and older eat less than the recommended five vegetables and fruit each day – in fact on average they only reach just under three servings a day. If one turns that into figures, in 2000 some 21 467 deaths in South Africa were attributable to low vegetable and fruit intake –- ranking it 10th out of 17 selected risk  factors for death. The recent MRC comparative risk assessment lists the low consumption of vegetable and fruit as one of the key factors adding to the burden of disease in South Africa and has great costs implications for our already stretched health services.

“”This is really tragic”,” says Badham “”as eating plenty of vegetables and fruit is such a positive message and we are as South Africans blessed with an abundant variety all year round. With just a little effort and without having to spend huge amounts of money, each and every South African can make a positive health change in their life by including 5-a-Day.”

Here are a 12 of the 5-a-Day for Better Health TRUS tips to increasing your daily intake of vegetables and fruit:

1. Start your day with a glass of 100% pure fruit juice.

2. Grab a fruit mid-morning snack – a crisp apple, a soft and juicy peach, a handful of raisins.

3. Choose vegetables and fruit in season as they are cheaper.

4. Stock your deep freeze with frozen vegetables for when you need a quick vegetable solution.

5. Double your normal serving of vegetables.

6. Page through your recipe books and experiment with new ways of preparing vegetables – be adventurous.

7. Cut up an apple or place a bowl of dried fruit near where your child is playing for an energy and nutrient dense snack rather than biscuits and other high fat snack foods.

8. Serve sliced and chilled fruit (mango, watermelon, melon, berries) for dessert alone or together with a sorbet.

9. Add vegetable kebabs (onions, mushrooms, peppers, baby tomatoes, baby marrow) and banana in their skins to the braai menu.

10. When making a tomato and onion gravy why not also add mushrooms, beans and finely chopped carrots.

11. Try new salad ingredients and experiment with adding fruit to salads – add sprouts, blanched broccoli florets, radishes, blanched asparagus, celery, pepperdews, baby spinach leaves, herbs, apple, pear and melon.

12. Blend fruit into a smoothie by whizzing up a banana with some frozen mixed berries and a dollop of yoghurt. There are so many variations – be creative. Serve as breakfast or an energising drink during the day.