In response to Philip Boucher-Hayes' documentary

jh79 wrote: »

Never said you need meat in a balanced diet. I said that no study has shown that a plant based diet is better than a balanced diet with an appropriate amount of red meat.

If i am wrong put up a link to the study that says otherwise.

Red meat[edit]
A 2016 literature review reported that for 100g or more per day of red meat consumed, the risk increased 11% for each of stroke and for breast cancer, 15% for cardiovascular mortality, 17% for colorectal cancer, and 19% for advanced prostate cancer.[16]

In 2015 the International Agency for Research on Cancer concluded that red meat is probably (Group 2A) carcinogenic to humans,[17] reported that for each additional 100g (up to a maximum of approximately 140g)[18] of red meat consumed per day, the risk of colorectal cancer increased by 17%; there also appeared to be increased risk of pancreatic cancer and prostate cancer but the association was not as clear.[19] Put in perspective, in the UK, 56 out of 1000 people who eat the lowest amount of red meat will develop colorectal cancer (5.6%) while 66 out of 1000 high-red meat eaters will develop colorectal cancer (6.6%) (1.17 x 5.6 = 6.6).[20]

A 2013 meta-analysis found an increased risk of gastric cancer with higher consumption of red or processed meat.[21] Red meat itself contains certain factors that, under certain conditions, produce carcinogens like N-nitroso compounds (NOCs).[22]

The consensus on the role of red meat consumption to increased risk of cardiovascular diseases has changed in recent years. Studies that differentiate between processed and fresh red meat have failed to find a link between unprocessed red meat consumption and heart disease. A major Harvard University meta-study in 2010 involving over one million people who ate meat found that only processed meat had an adverse risk in relation to coronary heart disease (CHD).[23][24] The study suggests that the "differences in salt and preservatives, rather than fats, might explain the higher risk of heart disease and diabetes seen with processed meats, but not with unprocessed red meats." Some mechanisms that have been suggested for why red meat consumption might be risk factor for cardiovascular disease include: its impact on serum cholesterol,[25] that red meat contains arachidonic acid,[26] heme iron,[27] homocysteine,[28] and its high saturated fat content.

Several studies have found a correlation between unprocessed red meat and the occurrence of CHD and certain types of stroke and have controlled for various confounding risk factors.[29] A study of 84,000 women, over a period of 26 years, finds that those with the highest intake of unprocessed red meat, have a 13% increased risk of CHD.[29] Likewise a Harvard study published in 2012, studying mortality as a result of processed and unprocessed red meat consumption finds that one serving of either type of meat a day results in an increased risk of mortality of 13%,[30] while this ratio is indicative of cancer and cardiovascular (CVD) disease, the study indicates that of the 23,926 deaths[30] investigated during the course of the study, 5910 of them were related to CVD[30] and there was no statistical significance between the risk of unprocessed and processed red meats factors in the occurrence of CVD.[30] The disparity between metadata studies definitely need to be addressed, because while one points toward unprocessed red meat being insignificant in certain health risks, there are still correlations to be found in focused large cohort studies.[30][29]

Unprocessed red meat intake is tentatively associated with an increased risk of type II diabetes, but the link is weaker and less certain than the link between processed red meat and diabetes.[31] Other findings have suggested that the association may be due to saturated fat, trans fat and dietary cholesterol, rather than red meat per se.[32] One study estimated that “substitutions of one serving of nuts, low-fat dairy, and whole grains per day for one serving of red meat per day were associated with a 16–35% lower risk of type 2 diabetes”.[33]

jh79 wrote: »

The link between red meat and cancer and other illnesses is well established. But the quantities in the studies you referenced are quite large. A quick google brings up an NHS recommendation of 70g in total of red and processed meat per day.

Are there any studies that show this amount in a balanced diet carries more risks than a balanced whole plant based diet?

I don't think there are.

jh79 wrote: »

I doubt that 18% risk per 50g is from a starting point of zero. An increase of 50g from an average daily intake of 70g is a massive increase.

From what you posted earlier if 100,000 people practically doubled their intake daily there would be 10 extra incidences of cancer.

Also that 70g is an average daily intake. So over a week I could safely have 1 8oz steak, 1 Pork Chop, 8 sausages and 4 slices of ham. And the rest of the week i could eat chicken for my meat fix.

To increase my risk of bowel cancer by 18% i would need to eat double that! Even if that 70g figure is revised downwards (if new research says it is necessary), I can just fill that gap with chicken.

As i previously stated there is no evidence (that i am aware of) that a balanced diet that includes 70g of red or processed meat per day carries any extra health risks than a balanced whole plant based diet.

Non-linear dose-response meta-analyses revealed that colorectal cancer risk increases approximately linearly with increasing intake of red and processed meats up to approximately 140 g/day, where the curve approaches its plateau. The associations were similar for colon and rectal cancer risk. When analyzed separately, colorectal cancer risk was related to intake of fresh red meat (RR for 100 g/day increase  = 1.17, 95% CI  = 1.05−1.31) and processed meat (RR for 50 g/day increase  = 1.18, 95% CI  = 1.10−1.28). Similar results were observed for colon cancer, but for rectal cancer, no significant associations were observed.

Background

The evidence that red and processed meat influences colorectal carcinogenesis was judged convincing in the 2007 World Cancer Research Fund/American Institute of Cancer Research report. Since then, ten prospective studies have published new results. Here we update the evidence from prospective studies and explore whether there is a non-linear association of red and processed meats with colorectal cancer risk.

jh79 wrote: »

Just read it now and it does not start from 0g. Even the graph in the paper does not go through the origin.

It is a big assumption to make that it is linear beyond the data analysed which is what you are doing.

Toxicity is never linear from 0 up you will have a plateau at both the lowest and highest concentration. It this case a plateau is observed at the highest concentrations.

While i'm not a clinical scientist the authours conclusion suggests i may be correct in my interpretation. They say red meat intake should be limited not removed completely ,this not the conclusion you would make if the data supported an increased risk for consumption levels above 0g.

jh79 wrote: »

Also if we take the lowest data point and the 100 g above that equates to an 18% increase, is this even a clinically significant increase. An increase of 18% of a small number could fall within error limits. At the lower levels the risk is obviously smaller.

Our estimates are consistent with those reported in the 2007 WCRF/AICR expert report [15], where the risk increase of colon cancer was 37% for every 100 g/day increase in red and processed meats, and the risk increase of colorectal cancer was 29% for every 100 g/day increase in red meat, and 21% for every 50 g/day increase in processed meat.

An analysis of data from 10 studies estimated that every 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by about 18%.

The cancer risk related to the consumption of red meat is more difficult to estimate because the evidence that red meat causes cancer is not as strong. However, if the association of red meat and colorectal cancer were proven to be causal, data from the same studies suggest that the risk of colorectal cancer could increase by 17% for every 100 gram portion of red meat eaten daily.


What types of cancers are linked or associated with eating processed meat?
The IARC Working Group concluded that eating processed meat causes colorectal cancer. An association with stomach cancer was also seen, but the evidence is not conclusive.

The accumulated evidence from prospective studies supports that red and processed meats intake is associated with increased risk of colorectal, colon, and rectal cancers. The risk increase in colorectal cancer estimated in linear dose-response models was 14% for every 100 g/day increase of total red and processed meats, 25% in colon cancer, and 31% in rectal cancer. These results are consistent with those of the highest versus lowest meta-analyses. In non-linear models, colorectal cancer risk appears to increase almost linearly with increasing intake of red and processed meats up to approximately 140 g/day. Above this level, the risk increase is less pronounced.

Red meat intake (assessed separately from processed meat) was associated with increased risk of colorectal and colon cancers, but the association with rectal cancer was not statistically significant. Similarly, processed meat intake was related with risk of colorectal and colon cancers, but not with rectal cancer. The lack of association with rectal cancer is in contrast with the results observed when red and processed meats were combined into a single food item, where similar associations with colon and rectal cancers were observed. This may be due to a lower number of studies in the analyses of rectal cancer than in those of colorectal and colon cancers.

jh79 wrote: »

I'm not critising the above i'm critising your hypothesis that this data says that a plant based diet is better than a meat eaters at 70g per day. Nothing you have posted supports that theory.

jh79 wrote: »

Any commemt to make on the fact that the study compared cancer rates to zero rather the the base rates?

Water John wrote: »

What is a processed meat? Ham, Steak, Chops?