Fruit Juice and a link to increased cancer risk

Health & Body
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https://www.bmj.com/content/366/bmj.l2408

While CHOICE have been campaigning to have Added Sugars to be better identified in labelling, and there have also been calls to introduce a “Sugar” tax to address the use of sugar in both food and drinks, the above study has questioned even the usage of Fruit Juices that have not had sugars added. The results of the study linked to at the beginning of this post also point to these juices, as well as sugar laden soft drinks, increasing the risk of cancer in those who consume them:

" In a context where the World Health Organization is questioning the level of evidence of the scientific data supporting the implementation of a tax on sugary drinks, the results of this observational study based on a large prospective cohort suggest that a higher consumption of sugary drinks is associated with the risk of overall cancer and breast cancer. Of note, 100% fruit juices were also associated with the risk of overall cancer in this study. If these results are replicated in further large-scale prospective studies and supported by mechanistic experimental data, and given the large consumption of sugary drinks in Western countries, these beverages would represent a modifiable risk factor for cancer prevention, beyond their well established impact on cardiometabolic health. These data support the relevance of existing nutritional recommendations to limit sugary drink consumption, including 100% fruit juice,1287 as well as policy actions, such as taxation and marketing restrictions targeting sugary drinks, which might potentially contribute to the reduction of cancer incidence"

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It seems to me that ‘our’ ability to source and consume vast quantities of food types that were once impossible to do on such a scale or considered special treats and/or seasonal treats in much smaller amounts is a very recent thing in the context of human evolution - so likewise it seems to me no surprise to suggest it is likely to cause problems (and you didn’t sound surprised, but some do).

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Maybe straying to the side more than I should, but @draughtrider’s comment is right on. It would be interesting to see a list of foods available that have never been or are yet to be linked to a medical / health malady and are not contributing to poor environmental outcomes.

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Perhaps one result is due to how we consume the product. Eating fresh or preserved fruit vs a highly concentrated form of part of the fruit only.

The alternative is to suggest eating fruit increases the risk of some forms of cancer. Accepted good eating habits include fruit as an essential part of a healthy diet.

It would be interesting to understand the balance of a diet as a factor in the study outcomes.

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Yet another association of factor X and cancer, you can fill in your own X. I will get excited when we get beyond correlation and into causation and when dosage effects are observed. There may be something in it - who knows - but do we need another scare like this that may or may not be real?

There are already plenty of reasons to imbibe sweet drinks quite moderately or not at all depending on your situation. I don’t see this study contributing much to the public discourse.

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Computer modelling is on the verge of making that possible. There are already models with published and verified results whereby molecules are attributed with ‘personalities’ of how they act and react, and they are allowed to run in a molecular system without any levers or guidance by programmers. It takes very powerful computers, time and patience, and [big] budget and is still a way off from being useful across the ‘general purpose’, but still exciting.

A few years back I saw a graphical model of how Relenza reacts with a flu infection, done by the above technologies. It showed how the molecules interacted in a surprising way, but did not authoritatively show the ‘why’ it was so although once the interaction happened it could be explained why it helped reduce the infection.

It seems juices versus whole fruits as an issue might be enough of a focus in scope for an enthusiastic PhD team with sufficient sponsorship to look at.

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When I juice apples, oranges, grapefruits, pineapples etc, the whole fruit (but not the citrus or pineapple skins) goes in, so I can’t really see any difference between whole fruit and juice, other than the juice being mechanically squashed instead of my tongue and teeth squashing it.

OMG! :astonished:
Maybe it is mechanical squashing that causes cancer!

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Excepting you are not representative of all juicers and your product not of all juices, especially those bought at the grocer.

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Which demonstrates a problem with the conclusion, if juice specifics are not taken account of.

I know some commercial brands of orange and berry juices certainly include pulp, but some other juices are almost transparent.

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I have lingering concerns about the study.

Firstly, I agree with @syncretic that a correlation does not indicate a causation.

Secondly, the study looked at a self-selected (volunteer) & largely female cohort. American studies have shown that gender weighted (usually largely males) studies are NOT generalisable to both sexes. Equally ethnic biases in participants also blur result generalisation.

Thirdly, the study seemed to ignore the participants total consumption of sugar in all its forms focusing only on sugary drinks . It is possible that if all forms of sugar were considered, there would be no correlation at all, or it is possible that sugary drink consumption is just a marker for participants with higher sugar intakes?

Another thing that jumped out at me was that they did NOT find any correlation with artificially sweetened drinks. I seem to remember that we have seen on other threads here on the forum that there is no difference between the ‘natural’ and the ‘artificial’ sugars when it comes to the health impacts.

Let me conclude by saying that I am strongly opposed to the amount of sugar that is in processed food, and I think that something needs to be done to reduce this. Taxing only sugary drinks is not addressing the whole problem. Limits to the amount of sugar in all its forms in all processed foods needs to be addressed instead.

Unless governments are willing to take on the sugar industry, head on, the obesity epidemic will continue.

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This idea that whole fruit is different to juice solely because of the pulp content and therefore juice with pulp is good bothers me. Has anybody considered that the difference is the dose? People are much more likely to drink large amount of pre-prepared juice (with or without pulp) than the equivalent in whole fruit.

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The whole study is a fairly detailed explanation of the results. They address variables in their testing:

" Discussion

We found that an increase in sugary drink consumption was positively associated with the risk of overall cancer and breast cancer. When the group of sugary drinks was split into 100% fruit juices and other sugary drinks, the consumption of both beverage types was associated with a higher risk of overall cancer. In contrast, no association was detected between artificially sweetened beverage consumption and the risk of cancer in this study. These results were robust after a wide range of sensitivity analyses."[My highlighting]

" Sensitivity analyses

Further adjustments for several indicators of the quality of the diet did not substantially modify the findings, nor did any other sensitivity analyses (appendix 11). Results remained stable when applying a bootstrap approach to account for extra variation (subdistribution hazard ratio for a 100 mL/d increase in sugary drink consumption 1.18, 95% confidence interval 1.02 to 1.34 for overall cancer; 1.23, 1.02 to 1.60 for breast cancer). Appendix 12 shows that cause-specific Cox proportional hazard models provided similar results."

There is much more discussion in the report of sampling, statistical modelling, sample sizes etc.

In regards to whole fruits and fruit juices they made note of this " Of note, despite their overall healthy and natural image in the general population, and some studies suggesting lower health risks compared with sugar sweetened beverages,55 56 57 58 100% fruit juices generally contain high levels of simple sugar (median=10.3 g/100 mL in this study, sometimes higher than regular soda),59 and their glycaemic indexes are higher than that of whole fruits.60"

They also reference a number of other studies which have found correlation between sugary drinks and cancers:

" Comparison with other studies

Except for pancreatic cancer (non-significant, six prospective studies, 2010),52 no meta-analysis was performed by the World Cancer Research Fund/American Institute for Cancer Research on the association between sugary drinks and the risk of cancer. A meta-analysis showed no link between the consumption of sweetened,29 carbonated beverages and the risk of overall cancer and specific locations, unlike our findings. However, this meta-analysis, funded by one of the biggest soda producing companies, did not show the isolated associations in sugary drinks and artificially sweetened beverages, which might have impaired the possibility to detecta potential role of sugar (main driver of the associations in our study). Genkinger and colleagues observed an increased risk of pancreatic cancer associated with sugar sweetened carbonated soft drink consumption in the framework of the Pooling Project (14 cohorts),24 and Navarrete-Muñoz and colleagues observed no association in the EPIC cohort.27

Data are scarce regarding other cancer sites, notably for breast cancer. The two published prospective cohorts were consistent with our findings; Hodge and colleagues observed an increased risk of breast cancer associated with sugary drinks (Melbourne Collaborative Cohort Study, participants aged 40 and over, 946 cases).22 This association was only observed for postmenopausal breast cancer. In contrast with our results, Makarem and colleagues observed no association with breast cancer (Framingham Offspring cohort), which might result from a lack of statistical power (124 cases).23

In line with our results, a recent meta-analysis observed no association for the risk of colorectal cancer,28 even though statistical power was limited for this cancer in our cohort. Results are contrasted regarding prostate cancer in the literature: in line with our findings, no association was observed for sugar sweetened and artificially sweetened sodas in a meta-analysis combining two prospective studies.29 Consistently, no association was observed in the Framingham Offspring cohort for sugary drinks,23 but an increased risk was observed for 100% fruit juices; however, statistical power was also limited in this study (157 cases). Sweetened beverage intake was associated with an increased risk of gallbladder cancer in the Swedish Mammography Cohort and Cohort of Swedish Men.25 Sugary drinks were associated with increased risk of endometrial cancer in the Swedish Mammography Cohort.26 The limited number of cases did not allow us to perform site-specific analyses for these cancer locations in our cohort.

Lastly, and in line with our results, two recent prospective studies observed an increased risk of obesity-related cancers and adiposity-related cancers associated with sugary drink consumption.2223 Furthermore, associations were observed between fruit juice intake and an increased risk of thyroid carcinomas,53 and in the EPIC cohort between citrus fruits and juices and increased risk of basal cell and squamous cell carcinomas of the skin.54"

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I wonder does anyone actually only consume citrus fruit and juice, and no other fruit? They found in that final reference an inverse relationship between SCC and BCCs for non citrus fruits and juices.

" In contrast, consumption of non-citrus fruit and juice appeared to be inversely associated with risk of BCC and SCC."

Does consuming apple juice as well as orange juice cancel out to no increased risk of those cancers? I think it would be very difficult to untangle it all!

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No idea but the researchers stated they hoped others would also conduct studies to further prove or disprove their findings. It appears to date to have not been a much studied area but more evidence seems to be building to a stronger association. One of the studies that found no links was actually funded by a large Soda drink company, I would guess this may point to some perceived bias in that study.

Obesity, Diabetes, high glucose levels and similar have already been positively linked to certain cancers with high sugar diets often driving those causal problems as well, this study among a few others has tried to see if sugar alone may be creating increased cancer risk outside of those already determined causes. The results appear to support this linkage. Perhaps the sugar drives mechanisms to push towards mutation and thus cancer (sort of speeding up the engine until it malfunctions).

On reading some of the Citrus Fruit and BCC SCC study the following may be the reason Citrus Fruit was a driver “Animal experiments have demonstrated the photocarcinogenic properties of furocoumarins, a group of naturally occurring chemicals that are rich in citrus products.” & “Our findings support positive associations between citrus consumption and risk of cutaneous BCC and SCC in two cohorts of men and women, and call for further investigations to better understand the potential photocarcinogenesis associated with dietary intakes.”

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All I get from this is that they are pretty confident of the association that they found. That does not address the question of cause and effect.

During WW2 much study was done on conditions that produced success or failure in the air war. This was of great interest as if your bombers destroyed more of theirs on the ground and your fighters keep their fighters off your bombers you were well in front.

One study showed a very strong positive correlation between allied bomber effectiveness and bad weather over the target. All the experts said that was mad as bad weather gave poor visibility which made accurate bombing much more difficult or impossible. There was no doubt that the statistics were valid and highly significant.

Bad weather meant the enemy fighters couldn’t find the bombers (in the days before radar) and often stayed home rather than waste fuel. The absence of enemy fighters was more important to outcomes than bad visibility.

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Usually one research paper isn’t enough to verify a particular finding, and as indicated in the paper, additional research may be needed to substantiate the hypothesis. Usually additional independent research (by another party) is needed to qualify the initial findings.

Mass media has been known to jump at the findings from one set of research results and broadcasting the results as unequivocal evidence. Later on other research papers either support the initial findings or disprove them. The media often doesn’t retract statements made when later proven to be misguided/mis-interpreted.

It is always best to wait for additional research to paint a picture and before hanging ones hat.

Notwithstanding this, it is known that obesity or over-consumption of one food type can lead directly to diseases or other health impacts. Long term consumption of high sugar foods, whether from added sugar or that in naturally high in sugar, is known to have health consequences/complications …this is an unequivocal fact.

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As I said in my opening post this study has found an increased risk of cancer from high sugar drinks. They state they don’t know the actual pathway/pathways but the risk is increased. This is not the first linkage of sugary drinks to cancer. Indeed, from the report it was noted how other studies had also found increases of certain cancers from high sugar drinks eg Genkinger & Colleagues linking of sugar drinks to increased risk of Pancreatic cancer in the Pooling Project, Hodge & Colleagues link Breast cancer in the Melbourne Collaborative Cohort Study, Sweetened beverage intake was associated with an increased risk of gallbladder cancer in the Swedish Mammography Cohort and Cohort of Swedish Men, Sugary drinks were associated with increased risk of endometrial cancer in the Swedish Mammography Cohort. There have already been enough linkages between Obesity, Adiposty, Diabetes II, and cancers in humans that they are known risk factors…they increase the risk but not always is there the clear evidence of why they do it, so they label it an increased risk factor. High Sugar intake via drinks including 100% fruit juice in the study I first linked to, has found that Sugary drinks are an increased risk factor, the why is not yet clear but the risk was able to be determined. Now they are asking that others re-test their work by doing studies to firm up or disprove their findings. But there is certainly a clear link between sugar intake & disorders such as Obesity, Adiposty, Diabetes and other problems eg https://www.thelifestudy.org/public/life-p/2012/AP10-006_Brinkley_Total%20and%20Abdominal%20Adiposty%20are%20associated%20with%20Inflammation_2012.pdf.

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I wonder if the cancer link is due to the sugar itself, or the resulting obesity. IE consumption of sugar in excess of calorific/energy requirements resulting in fat deposition.

Some athletes consume large amounts of sugar- they have to when burning over 30000kJ in a day! And yet exercise is a known preventative of cancer, shown in numerous studies.

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The study used analysis to address those factors and they found that sugar itself was a problem…high sugar drinks that is. This is why the study is somewhat novel in that previously not much research (or nearly none) had been done into purely the high sugar concentrations. The study was over a 9 year period and involved over 100,000 volunteer participants. I think that most people don’t use the amount of energy doing a high level of physical activity some athletes would undertake. Hence a risk factor for people but not perhaps a risk when used in high energy activities. A question worth asking them?? Looking at a general population the risk was increased but this is a general population. A high energy consuming athlete is not a “normal” for this purpose. But once they cease the high energy lifestyle they would probably become more normal as per the risk factors. This is not to say they don’t increase risks of other problems from the high intensity activities.

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I’ll have to class myself as abnormal then :wink: I’ve certainly done quite a few days with well in excess of 30000kJ worth of energy expenditure when cycling. Some do it much more often than I do.

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