Between 80 and 90% of all lung cancer are directly related to smoking. This direct link is explained by the fact that the chronic exposure of lung cells to the hundreds of carcinogenic compounds present in tobacco smoke repeatedly damages the DNA of these cells, which considerably increases (by 15 to 30 times) the risk of lung cancer.
10 to 20% of lung cancers affect non-smokers
Despite this well-documented role of cigarettes, only between 10 and 20% of lung cancer affect people who have never smoked in their life, which indicates that other factors may influence the development of this cancer. A poor diet, deficient in plants, could be one of these factors: several epidemiological studies have in fact reported that the abundant consumption of foods of plant origin rich in fibers was associated with a significantly reduced risk of lung cancer. A positive impact of plants is also suggested by the fact that a high fiber intake is associated with improved lung capacity as well as a reduced risk of chronic obstructive pulmonary disease and mortality due to respiratory diseases.
Reduce the risk of lung cancer with certain foods
The positive impact of fibers on health is due to their prebiotic properties, that is to say that they promote the implantation of beneficial bacteria in the colon. In the absence of oxygen, these bacteria feed on the fibers by fermentation and their metabolism then generates several molecules that positively influence the immune system, in particular certain short-chain fatty acids with anti-inflammatory activities. These benefits on immunity andinflammation can be increased by the presence of probiotics, which are friendly bacteria present in fermented foods (yogurt or sauerkraut cabbage, for example) and which can act in synergy with the resident bacteria. Since theinflammation chronic promotes the development of cancer, the simultaneous consumption of pre and probiotics could therefore represent a very interesting combination to reduce the risk of several types of cancer.
Anti-inflammatory action of pre and probiotics
This potential is particularly interesting with regard to the lung cancer : Previous studies have in fact shown that the fatty acids produced by intestinal bacteria can reach the lung via the bloodstream and significantly reduce the degree ofinflammation near lung cells.
An analysis of 10 studies carried out in several different regions of the globe (America, Europe, Asia) on a total of 1,445,850 participants suggests that this anti-inflammatory action of pre- and probiotics could actually result in a reduced risk of lung cancer. The researchers thus observed that the participants who consumed the largest quantities of fibers (30 g and more per day) had a 15% decrease in lung cancer compared to those who ate very little (10 g or less). Same conclusion for yogurt: people who consumed it regularly (80-100 g per day) saw their risk of lung cancer reduced by 19% compared to those who never ate it.
A 33% reduction in the risk of lung cancer
But the combination of the two provides even greater benefits: the participants who consumed the most fibers and yogurt had a risk of lung cancer decreased by 33%, compared to those whose diet was low in fibers and no yogurt. Remarkably, this protective effect is observed in non-smokers, ex-smokers and even smokers, suggesting that the anti-inflammatory effect generated by the metabolism of intestinal bacteria interferes with a crucial step in the development of this cancer.
Fiber and yogurt against lung cancer
In this sense, the authors observed that the association between the consumption of fibers and yogurt was even more pronounced for squamous cell carcinomas, a form of lung cancer whose progress is strongly influenced by theinflammation chronic. In short, in addition to their well-documented positive effects on reducing the risk of cardiovascular diseases and cancers of the digestive tract, fibers dietary may also play a protective role against lung cancer. This is another example of how increasing the intake of plants (fruits, vegetables, legumes, nuts, whole grain cereals) rich in fibers can lead to many health benefits.
Vieira AR et al. Fruits, vegetables and lung cancer risk: a systematic review and meta-analysis. Ann Oncol.; 27: 81-96.
McAleer JP and JK Kolls. Contributions of the intestinal microbiome in lung immunity. Eur. J. Immunol. 48: 39-49.
Yang JJ et al. Association of dietary fiber and yogurt consumption with lung cancer risk: a pooled analysis. JAMA Oncol.