Five a day: The truth
Five-a-day or pick-a-number-a-day
The five-a-day campaign is actually a different number-a-day campaign across more than 25 countries. The UK swears by five-a-day. The USA proposes nine-a-day: two and a half cups of vegetables and two cups of fruit every day. Australia suggests five portions of vegetables and two of fruit, where a portion of vegetables counts as 75 grams of cooked vegetables, one cup of salad vegetables, or one small potato and a portion of fruit would be one medium piece (150 grams), one cup of diced fruit pieces or canned fruit, or one cup fruit juice.
The European advice varies as follows: Denmark says eat six-a-day. The Irish have a food pyramid, not a plate (more American) and they go for four (plus)-a-day. The Swiss have five-a-day and tell citizens to go for a variety of colour in their choices. The Belgians and Austrians also favour five-a-day. Italy just says eat more fruit and vegetables – very libertarian. The Spanish have a pyramid with two rows to eat occasionally – the foods on these rows look like (red) meat, sausages, cakes and sweets – and then they have four rows to consume daily – in order of smallest to largest intake recommended – other meat/fish; dairy; fruit and vegetables and then grains. Hence, the Spanish have a free hand in choosing their number-a-day and they also have advice for moderate intakes of wine and beer along the side of their pyramid. The Greek food pyramid is simply called “The Mediterranean Diet” and they quantify three servings of fruit and six servings of vegetables a day. Latvia goes for percentages – 30% of daily intake should be in the form of fruit and vegetables. Germany (spot a centre of engineering expertise) has a three dimensional food pyramid indicating qualitative and quantitative nutritional information. They also have a staircase picture elsewhere on a public health website with fruit and vegetables on the bottom step (the largest group to be consumed); meat, fish and dairy on the next step; German sausages and whole grains on the next step and then other grains and finally junk on the final two steps.[i] This is getting closer to reasonable advice. I also heard anecdotally, from an attendee of the 2009 Amsterdam obesity conference, that the German delegates were recommending 500 grams of vegetables per day while fruit was not quantified. The Hungarians haven’t gone for a pyramid, or a plate – they have a house with no numbers apportioned. [ii]
Where did five-a-day come from?
So where did the pick-a-number-a-day all start? It started as the “National five-a-day for better health” program in 1991 as a public-private partnership between the National Cancer Institute (NCI) and the Produce for Better Health Foundation. The programme started in California, the sunshine state, and has become the world’s largest public-private nutrition education initiative. All States in the USA have a five-a-day co-ordinator and, as we can see above, the programme has spread as far as Australia and Latvia. (Five-a-day has since been trademarked by the National Cancer Institute).
The National Cancer Institute was established in 1937 and is the USA government’s principal agency for cancer research and training. The Produce for Better Health Foundation can be found at the web site “fruitsandveggiesmorematters.org” and their purpose is to get us to eat more fruit and vegetables. The conflict of interest chapter comes later, but we can’t move on without listing some of the sponsors of the Produce for Better Health Foundation:
– Logistics firms: C.H. Robinson Worldwide, Inc.; Caito Foods, Inc.; Capital City Fruit; Coast Produce Company and J&J Distributing.
– Specialist producers: Driscoll’s (berries); U.S. Highbush Blueberry Council (blueberries); Ocean Mist (artichokes and fresh vegetables); Giorgio (mushrooms); Columbine Vineyards (grapes); Nature sweet tomatoes; Potandon Produce (potatoes) and Paramount Farms (nuts and flavoured nut snacks).
– General fresh produce firms: W. Newell & Companies; Eurofresh Farms; Giumarra Companies; General Mills (Green Giant brand); Sun-Maid raisins and dried fruit; Kagome juices and Duda Farm Fresh Foods.
– Other: such as BASF (the world’s leading chemical company, and a provider of fungicides, insecticides and herbicides); Glad Products Company (containers, bags and ovenware); Nunhems USA (commercial vegetable seeds); The Kidney Cancer Association and McDonald’s.
With the exception of The Kidney Cancer Association and, ironically, McDonald’s, the above represents a list of organisations that stand to benefit if there were a dictat from government that citizens should strive to eat (at least) five portions of fruit and vegetables every single day. Although we may mind less about tomatoes and berries being sponsored, than sugar and white flour, this is still a conflict of interest.
Why five-a-day? Why not? It’s a memorable number. It would have seemed achievable and it was the number of digits on one hand and, I would suggest, no more scientific than this. It was never the outcome of evidence based, thoroughly researched, scientific investigation. It was a marketing campaign – and the most successful nutrition marketing campaign that the world has seen.
Having been launched with no evidence whatsoever, there have been numerous attempts since to post-rationalise and to justify this worldwide campaign. It must be noted at the outset that this was never intended to be an obesity campaign. The involvement of the National Cancer Institute suggests that it was intended to be a programme to help with cancer in some non-quantified way. If it were designed as a general healthy eating campaign – to what end? It is difficult to know what this programme was intended to be, other than an excellent commercial venture for all the companies involved at conception. With no evidence at the time (or since), of any benefit from eating a certain number of fruits and vegetables each day, it is incredible to realise how far this marketing programme has gone. Now, as with so many other elements of our diet advice, we reiterate the slogan daily with no idea from whence it came.
The Colorado Department of Public Health reviewed the campaign and reported that, from the introduction of the five-a-day Day for Better Health Program in 1991 to 1998, the percentage of Americans who ‘knew’ that they should eat at least five servings of fruits and vegetables each day increased from 8% to 39% and the average consumption of fruits and vegetables increased from 3.9 to 4.6 daily servings per American.[iii] Most conveniently, in terms of dates, there was an article in the Journal of the American Medical Association (JAMA) in 1999 called “The Spread of the Obesity Epidemic in the United States, 1991-1998”. This reported that, during this period (when fruit and vegetable intake increased by nearly 20%), obesity increased by 50%, from 12.0% in 1991 to 17.9% in 1998.[iv] I’m not saying that five-a-day caused this, but it certainly didn’t help.
Five-a-day and cancer
Let us turn to the evidence for the condition that five-a-day was intended to help – cancer. In April 2010 a study was published in the Journal of the National Cancer Institute written by Paolo Boffetta, as the lead of a large group of European researchers.[v] The study sought to quantify if cancer risk were inversely associated with intake of fruit and vegetables. The article analysed data from the EPIC (European Prospective Investigation into Cancer) study, involving 142,605 men and 335,873 women for the period 1992-2000. This review of almost half a million people found that eating five portions of fruit and vegetables a day had little effect on cancer risk and the very small difference observed could be explained by other factors. The study also grouped participants into five categories from the lowest intake of fruits and vegetables (0 to 226 grams a day) to the highest intake (more than 647 grams a day). Significantly, the cancer risk did not vary between the five groups. The overall conclusion of the study was that: “A very small inverse association between intake of total fruits and vegetables and cancer risk was observed in this study. Given the small magnitude of the observed associations, caution should be applied in their interpretation.”
In November 2010, the UK part of the EPIC study published their findings in the British Journal of Cancer[vi]. Professor Tim Key concluded that: “The possibility that fruit and vegetables may help to reduce the risk of cancer has been studied for over 30 years, but no protective effects have been firmly established.”
Five-a-day and nutrition
One of the key arguments presented as justification for the five-a-day campaign (upon which the UK Department of Health alone has spent £3.3 million over the past four years), is that fruit and vegetables are highly nutritious.[1] We must stop making general and unsubstantiated claims like this. A worldwide instruction to citizens of tens of countries, across three continents, should be based on clear empirical evidence (and that evidence should have been tested and verified before any public health advice was issued). Aside from the fact that there is no such evidence for the health benefit of eating a particular number of a random selection of fruit and vegetables on any medical condition, let us analyse this ‘nutritious’ claim theoretically – starting with vitamins first:
We learned about the fat soluble vitamins, A, D, E and K, in Chapter Twelve of my book: The Obesity Epidemic. The pure form of vitamin A (retinol), vitamin D3 and vitamin K2 are only found naturally in animal foods (meat, fish, eggs and dairy products) and we can proceed on the basis that vitamin D can only feasibly be consumed naturally in animal foods (unless one can consume 2.2 kilograms of sunshine grown mushrooms in a fat delivery mechanism daily). Seeds, nuts and their oils are the best source of vitamin E. Even where fat soluble vitamins are found in plant sources, as the name suggests, they need a ‘fat’ delivery mechanism. K1 is found in green leafy vegetables and avocado is also a good source. Because of the absence of a ‘fat delivery mechanism’, the K1 in, say, spinach has a bio availability (availability to the body) of 4%, which increases to 13% if it is cooked in butter.[vii]
Vegetables have negligible or zero fat content, so no natural fat delivery mechanism. Two fruits do have a fat content – avocados and olives. If we compare the best source for each of A, D, E and K from avocado or olives, we find that 100 grams of olives delivers the equivalent of 20 micrograms of retinol (assuming that the body is capable of converting carotenes to retinol). Lamb’s liver delivers 7,392 micrograms of retinol per 100 grams. That means we would need to eat three kilograms of olives (4,350 calories) or eight grams of lamb’s liver (11 calories) to meet the recommended dietary allowance of vitamin A. Assuming again that our carotene conversion is optimal, 70 grams of carrots could provide the retinol equivalent, but we would need to eat them with (ideally) butter for this to be absorbed. For vitamin D, avocado and olives score zero; 100 grams of herring provides 40.7 micrograms. Avocado beats olives for vitamin E content – with 100 grams providing a respectable 2.1 milligrams. Sunflower seeds, however, provide 36.3 milligrams per 100 grams and almonds 24.7 milligrams. Avocado contains 21 micrograms of vitamin K1 per 100 grams, which is valuable, but no fruit or vegetable can provide K2.
The water soluble vitamins include the eight B vitamins and vitamin C. The best sources of the B vitamins are meat (especially organ meat), fish, milk and eggs. Whole grains and dried yeast are also a good source of B vitamins, but fruits and vegetables do not appear on lists of top sources of B vitamins. B12, of course, is only found in animal products and therefore must be taken as a supplement by vegans (vegetarians can get B12 in milk and eggs).
So we are left with vitamin C and fruit and vegetables do win the top spots here. Guavas and peppers provide the highest single source of vitamin C from fruits and vegetables respectively – with 228 milligrams per 100 grams for guavas and 183 milligrams per 100 grams for raw yellow peppers. However, as noted earlier in this chapter, the USDA database records many animal and nut sources of vitamin C and in substantial quantities. The more commonly consumed fruits don’t compare quite so favourably with, say, the 43 milligrams of vitamin C per 100 grams of chestnuts: apples have 4.6 milligrams per 100 grams and bananas 8.7 milligrams per 100 grams. So, we don’t even need fruits and vegetables for vitamin C, although they can be good sources of this vitamin.
On to minerals – if we look at the minerals with which people are more likely familiar: the best sources of calcium are dairy products and tinned fish; egg yolks, beef, cheese and liver are the best source of chromium; iron is best provided by organ meats; iodine is found in abundance in fish and kelp (seaweed); magnesium and manganese are plentiful in nuts and whole grains; good sources of selenium are organ meats, fish and shellfish and zinc is found in oysters, liver, meat, cheese and fish generally. Potassium is the one mineral for which fruits and vegetables are the best sources. Potassium, however, can also be found in all of nature’s foods, so we don’t need fruits and vegetables to obtain this mineral. Dried fruits and dark green vegetables are good sources of iron, but the organ meats are much better sources.
In conclusion, the statement in the Dietary Guidelines for Americans: “fruits and vegetables are excellent sources of vitamins” is not evidence based. A more accurate statement would be “low/zero-fat fruits are a good source of vitamin C and not much else; fruits with a fat content (avocado and olives) are poorer on vitamin C and better on other vitamins, but still no where near ‘excellent’; vegetables are often a better source of vitamin C than fruit and can also provide some useful fat soluble vitamins when eaten with fat.” For a short and accurate statement, the guidelines should have said “animal products are unbeatable nutritionally”.
Is five-a-day still a good idea despite having no evidence base?
Even if eating a certain number of portions of fruit and vegetables a day does nothing beneficial for cancer and even if the vitamin and mineral analysis does not bode well for fruit and vegetables being a major benefit to health generally, does the five-a-day campaign still have merit? As I write about obesity, I will answer from that perspective. I can only conclude that five-a-day has not been a worthwhile campaign and I present the following arguments as to why it has in fact been deleterious:
1) There is an opportunity cost of having spent so much time and money embedding a message that has not helped obesity (to be fair it was never intended to) when the benefits of embedding an equally simple, but far more effective message, could have transformed the obesity epidemic. The single public health message, which could have made an immense difference, would have been “eat real food.”
2) If the message had been “swap five-a-day”, rather than “eat five-a-day”, this could have helped – provided that junk were swapped out and not meat, fish, eggs, dairy and nutritious foods. My personal experience, working exclusively in the field of obesity, is that people are trying to eat five-a-day in addition to everything else they are eating, not instead of. This can only worsen obesity and, of course, obesity has worsened dramatically since the launch of five-a-day.
3) As if it is not bad enough that people are trying to get their five-a-day on top of everything else, the means by which they are doing this is disastrous for obesity. People are adding more processed food into their diet trying to get their five-a-day. If you review internet advice sites for ‘how to get your five-a-day’, adding sweet corn to (white flour) pizza is one suggestion, eat tinned (syrupy) fruit is another, fruit juices and fructose rich drinks are frequently recommended. We are eating even more processed food trying to get our five-a-day, which is to our overall detriment.
4) Five-a-day is not helpful for the increasing number of people who are increasingly carbohydrate sensitive/insulin resistant and for whom fruit and high-carbohydrate vegetables are best avoided.
5) Finally, for anyone who is overweight (that’s two thirds of the ‘developed’ world), unlimited (green) vegetables and salads should be encouraged, but fruit/fructose is best avoided.
The first lesson in nutrition sets out that the body needs macro nutrients (fat, protein and carbohydrate – the need for the latter is debatable) and micro nutrients (vitamins and minerals). The best providers of the essential macro nutrients are animal foods – meat, fish, eggs and dairy. The best providers of vitamins and minerals are animal foods again, with seeds and a few non animal foods (kelp and peppers) being useful. The most nutritious foods on the planet, therefore, are animal foods.
Where is the logic for our governments and dietitians telling us to replace the most nutritious foods on the planet with the one macro nutrient that we arguably don’t even need, and certainly don’t need in the quantities currently recommended? How can our dietitians be so enthusiastic about processed foods, so lacking in micro nutrients that they are invariably fortified? How did we get to the situation that low calorie is more important than high nutrition?
The attack on real food occurs at the highest level. Here is an extract from the Chief Medical Officer’s report for England 2009 (published April 2010): “Meat, butter, cream and cheese can play a part in a healthy balanced diet. In excess they can cause health problems. Their high level of saturated fat finds its way into our diet in biscuits, cakes and pastries, as well as in meat” (my emphasis). If any meat, butter, cream or cheese have ‘found their way’ into processed foods: a) this didn’t happen by magic – food manufacturers put them there; b) they will be the most nutritious ingredients in the end product; and c) this means that we need to avoid the processed foods themselves and not any real foods that may happen to be within them. This is rather like saying that grade A students are bad, because they might find their way into crime.
Is there a five-a-day that would be worthwhile?
After all this, is there a perfect five-a-day? I set about doing what should have been done before any of this started. I went back to the USDA nutrition database and tried to get the Recommended Dietary Allowances (RDAs) from just five foods. This can be achieved with 100 grams of liver, 200 grams of sardines, 200 grams of whole milk, 100 grams of sunflower seeds and 200 grams of broccoli (1,300 calories). There will be infinite combinations of real foods that can provide the RDAs, but I started from the ones known to be highly nutritious.
For interest, I repeated the experiment for a vegetarian diet and the biggest challenge became vitamin D. The RDAs could be met with five foods: 500 grams of whole milk, 450 grams of eggs (10 medium eggs), 300 grams of spinach, 250 grams of raw mushrooms grown in sunshine and 50 grams of sunflower seeds (1,360 calories). Dietary advisors applaud people for choosing a vegetarian diet, but then tell them to avoid eggs and to consume low-fat milk. It then becomes practically impossible for a vegetarian to meet even minimal nutritional requirements. I had returned to eating meat and fish before the research for this part of the book, but, this exercise gave me great concern about what lasting damage I may have done to my health during years of not eating meat and fish. Gwyneth Paltrow may also be re-evaluating her diet after sharing her medical experience on her health website (June 2010). Paltrow’s vitamin D levels were tested by doctors in New York, following a “pretty severe” bone fracture and they “turned out to be the lowest they had ever seen.”[viii]
Vegans can’t get B12 naturally and they would need to eat 2.25 kilograms of (raw sunshine grown) mushrooms in a fat delivery mechanism (e.g. vegetable oil) to get the ‘adequate intake’ for vitamin D and an unusual food like oriental dried radishes to get their calcium – and to repeat this daily. For completeness, the five vegan foods would be 2.25 kilograms of mushrooms, 175 grams of porridge oats, 25 grams of sunflower seeds, 100 grams of oriental dried radishes and 300 grams of spinach (in more vegetable oil) and a vitamin B12 supplement. Without the calories in the vegetable oil, the vegan basket adds up to 1,644 calories – the highest of all three sample ways of getting our nutritional requirement.
In my book The Obesity Epidemic: What caused it? How can we stop it? I show how the RDAs can be met with a basket of nine-foods-a-day (liver, sardines, eggs, whole milk, sunflower seeds, oats, cocoa, spinach and broccoli). One of the problems of trying to pick just five foods is that we end up with many vitamins and minerals over, or under, represented in our diet. We should consume a wide variety of nature’s food. This nine-a-day would be ideal, but the list of foods is not catchy enough for a marketing campaign, which, after all, is what this was. This ‘perfect’ basket also wouldn’t lead to a large increase in fruit and vegetable consumption – which is what the 1991 meeting attendees were no doubt keen to achieve.
The biggest tragedy of five-a-day is that we missed the opportunity to deliver a message that could have made a difference to our health and weight. The drive to eat five fruits and vegetables a day would have been far better directed (and still could be) towards eating more of the most nutritious foods each day. Meat (ideally liver), fish (ideally oily), milk (whole), sunflower seeds and broccoli would be the optimal five-a-day. Mum and granny were right.
(This is an extract from The Obesity Epidemic: What Caused it? How can we stop it?)
[1] Fruit is also widely promoted for its antioxidant properties: a) the antioxidant role in the body is best played by vitamin E and b) if we reduce our exposure to free radicals (processed food, pesticides, smoking, pollution etc), we need fewer antioxidants.
[i] http://www.fet-ev.eu/index.php?option=com_content&task=view&id=58&Itemid=116
[ii] The UK, USA and Australian references are in The Obesity Epidemic (below for convenience). The other countries are detailed at the following site: http://www.eufic.org/article/en/page/RARCHIVE/expid/food-based-dietary-guidelines-in-europe/
USA: http://www.health.gov/dietaryguidelines/dga2005/document/default.htm (These have been updated in the 2010 Dietary Guidelines for Americans since The Obesity Epidemic was published.)
UK: http://www.nhs.uk/livewell/5aday/pages/family.aspx
Australia: http://www.nhmrc.gov.au/guidelines/publications/n29-n30-n31-n32-n33-n34
[iii] http://www.cdphe.state.co.us/pp/copan/5-a-day/5ADAY.html
[iv] Ali H. Mokdad; Mary K. Serdula; William H. Dietz; Barbara A. Bowman; James S. Marks; Jeffrey P. Koplan, “The Spread of the Obesity Epidemic in the United States, 1991-1998”, Journal of the American Medical Association, (1999).
[v] Paolo Boffetta et al, “Fruit and vegetable intake and overall cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)”, Journal of the National Cancer Institute, (April 2010).
[vi] http://www.nature.com/bjc/journal/vaop/ncurrent/full/6606032a.html
[vii] www.nutritiondata.com
[viii] http://goop.com/newsletter/88/en/ – Gwyneth Paltrow’s personal web site.
