What does meat increase or decrease over time?

An analysis of more than 80,000 people over 8 years suggests what happens to the risk of premature death when a change in meat consumption.

Most of us know that eating red meat is not very good for you. Think: An increased risk of type 2 diabetes, cardiovascular disease, certain types of cancer and premature death. And adding processed red meat like bacon, hot dogs and sausages gives you even more: An increased risk of chronic obstructive pulmonary disease, heart failure and hypertension.

It is therefore logical that the increase or decrease in meat consumption has an impact over time. This is precisely what a team of researchers from the United States and China decided to determine. The problem was that they wanted to understand the risks independent of the initial consumption of red meat, and in particular the risk of mortality.

For the research, the team used data from 53,553 nurses aged 30 to 55 years of the famous cohort study, the Nurses' Health Study (NHS), and 27,916 sex health professionals male aged 40 to 75 years. Professional monitoring study (HPFS). All were free of cardiovascular disease and cancer at the beginning of the study.

They measured increases or decreases in red meat consumption over the last eight years and then tracked health and mortality data for eight years. What they found will probably not surprise anyone. From the study:

In two large potential cohorts of US women and men, we found that an increase in red meat consumption over eight years was directly associated with the risk of death over the next eight years and was independent of the initial consumption of red meat and concomitant changes in lifestyle. This association with mortality was observed with increased consumption of processed and unprocessed meat, but was higher for processed meat.

Unsurprisingly, also from the study:

A decrease in the total consumption of red meat and a simultaneous increase in the consumption of skinless nuts, fish, poultry, dairy products, eggs, whole grains or vegetables over eight years was associated with a lower risk of death over the next eight years.

They say that research suggests that a source change of protein or eating healthy plant-based foods such as vegetables or whole grains can improve longevity. And these results were also relevant in the short-term (four years) and longer-term (12 years) studies.

So, what impact did they find? After adjustment for age and other potentially influential factors:

• Increase in total consumption of red meat (processed and unprocessed) from 3.5 servings a week or more over a period of eight years has been associated with a 10 percent more risk of death in the next eight years.
• Increase consumption of processed red meat such as bacon, hot dogs, sausages and salami 3.5 servings a week or more was associated with a Risk of death increased by 13%.

They found that associations were consistent across different age groups, levels of physical activity, food quality, smoking and alcohol consumption.

In the meantime, they found that:

• The exchange of a portion of red meat a day for one serving of fish a day for eight years was linked to a 17% less risk of death in the next eight years.

Which seems to me quite significant. This being an observational study, the cause can not be explicitly established; In addition, as noted by the authors, the members of these two cohorts were primarily Caucasian registered health professionals, so the results may not be more widely applicable. Nevertheless, the data cover a broad band of people over a long period, with many dietary assessments and lifestyle factors, with similar results between the two cohorts.

Given all the previous evidence linking red meat consumption and poor health, it is logical to think that the increase in consumption would be linked to an increased risk of mortality. The results provide "a practical message to the general public about how dynamic changes in red meat consumption are associated with health," they conclude. "A change in protein source or eating healthy plant-based foods such as vegetables or whole grains can improve longevity."

The study, Association of Changes in Red Meat Consumption with Total and Cause-specific Mortality in American Women and Men: Two Prospective Cohort Studies, was published in The BMJ.