Health risks of excessive Red meat consumption


Numerous observational studies have associated a high intake of red meat with an increased risk of heart disease and cancer.

In contrast, a high intake of fruits and vegetables is linked with a reduced risk of heart disease and cancer.

A recent observational study investigated whether high intakes of fruits and vegetables would counterbalance the link between red meat intake and poor health. Here is a summary of its findings.

Background

Observational studies suggest that eating a lot of red meat may increase the risk of diabetes, heart disease, certain types of cancer and premature death (12345).

These associations are quite consistent across studies and populations. However, observational studies have a major weakness — they cannot prove causality.

As a result, scientists are still not entirely sure if high red meat intake itself is harmful or if other factors related to high red meat intake are responsible (16).

The unhealthy lifestyle habits sometimes associated with high red meat intake include:

  • Lower-quality diet (78).
  • Low consumption of fruits and vegetables (9).

Nevertheless, some scientists believe that certain components of red meat, especially in processed red meat or overcooked meat, may at least partially explain these associations.

Accordingly, some observational studies have linked processed meat with adverse health effects but not unprocessed, fresh red meat (51011).

Researchers have hypothesized that eating a lot of fruits and vegetables might partially offset the harmful effects of high red meat intake (9).

This hypothesis is supported by evidence indicating that high meat intake does not increase the risk of death when intake of fruits and vegetable is comparable to that of vegetarians (1213).

Article Reviewed

This observational study investigated the association of red meat intake with the risk of death from chronic disease at different levels of fruit and vegetable intake.

High red meat intake and all-cause cardiovascular and cancer mortality: is the risk modified by fruit and vegetable intake?

Study Design

This observational study examined whether high intakes of fruits and vegetables could offset the adverse health effects of red meat intake.

The researchers evaluated data from two large prospective studies, including a total of 74,645 Swedish men and women.

Food intake was evaluated using self-administered questionnaires asking how often people consumed fruits, vegetables, fresh meat or processed meat.

Fresh meats included fresh and minced pork, beef and veal, whereas processed meat included sausages, hot dogs, salami, ham, processed meat cuts, liver pate and blood sausage.

Bottom Line: This was an observational study investigating whether high intakes of fruits and vegetables can counterbalance the negative health effects of high red meat intake.

Finding 1: Red Meat Was Linked With an Increased Risk of Death

The study showed that eating a lot of red meat increased the risk of death from heart disease by 29% and the overall risk of death by 21%. However, it was not significantly associated with an increased risk of death from cancer.

The chart below shows the percent changes in the risk of death, compared to the lowest quintile of red meat consumption (less than 46 grams per day).

Interestingly, these associations were largely reduced when limiting the analyses to non-processed (fresh) red meat, suggesting that processed meat may be to blame.

Bottom Line: The study showed that a high intake of red meat, especially processed red meat, was significantly linked with an increased risk of death from heart disease or other causes.

Finding 2: Eating Fruits and Vegetables Didn’t Reduce the Health Risks of Red Meat Intake

The researchers discovered that red meat intake was associated with an increased risk of death, irrespective of how many fruits and vegetables people were eating.

The harmful effects of red meat were clearly dose dependent. The higher the intake, the more likely the participants were to die during the follow-up period.

Additionally, this association of red meat with death was independent of education status or unhealthy lifestyle habits, such as smoking or alcohol consumption.

The researchers also found that fruit and vegetable intake was not associated with total red meat intake or the intake of processed meat.

In other words, those who ate a lot of red meat didn’t necessarily eat less fruit and vegetables (FV), as shown in the chart below.

However, a high fruit and vegetable intake wasn’t associated with reduced risk of death from heart disease or other causes.

Bottom Line: High red meat intake was consistently associated with an increased risk of death at all levels of fruit and vegetable intake.

Limitations

The study’s main limitation was its observational design – it couldn’t demonstrate causality.

Second, food intake was self-assessed using food frequency questionnaires (FFQs), which are often inaccurate.

In addition, the questionnaires didn’t ask about lamb and game meat intake, which might have skewed the results.

Third, the study revealed no protective effects from fruit and vegetable consumption. This might explain why they didn’t counterbalance the increased risk associated with red meat intake.

Summary and Real-Life Application

In short, this observational study indicates that eating a lot of fruits and vegetables does not counterbalance the harmful effects of high red meat intake.

However, since the study had a few limitations, its findings should be taken with a grain of salt. The results need to be confirmed in future studies.