Low-Grade Inflammation, Diet Composition, and Health: Current Research Evidence and Its Translation

The scientific study of nutrition tends to be very complex, and it is often difficult to disentangle the various effects of diet on health. Even the best-intentioned dietary research studies typically require a very large sample size, and this can be a particular issue when trying to draw meaningful conclusions about the potentially modifiable effects of nutrition on health, specifically in the area of inflammation. This is important because, even among those individuals who appear to be generally healthy and do not display overt signs of inflammation, low-grade chronic inflammation can still be present. This type of inflammation tends to be the precursor to many serious health conditions, particularly cancer.

What Is Low-Grade Inflammation?

Chronic, low-grade inflammation is present when there is an accumulation of immune cells, mainly neutrophils, in the walls of body organs as a result of persistent infection or irritation. This type of inflammation is largely invisible to the naked eye, and there are no specific clinical symptoms associated with it. However, it can still be problematic for an individual as it tends to be the precursor to many serious health conditions (e.g., cancer).

As mentioned above, there are often no specific clinical symptoms associated with low-grade inflammation. However, those who are affected can be more susceptible to infections, and this can significantly impact their quality of life. In addition, there is also the potential for the long-term effects of low-grade inflammation to be much more serious, especially for children, as this type of inflammation can have lasting effects on their health. This is why it is important to identify and combat low-grade inflammation whenever possible, especially in childhood. Interestingly, research suggests that nutrition can play an important role in modulating this type of inflammation. Certain foods and nutrients, such as the spices ginger and turmeric, has been shown to be effective in reducing neutrophil infiltration in the intestinal walls, and subsequent low-grade inflammation. Other research suggests that fruits and vegetables can protect against low-grade inflammation in the first place.

Can Food Affect Inflammation?

Yes, food can affect inflammation. Specifically, foods rich in vitamin A (e.g., retinoids) have been shown to possess anti-inflammatory activity, and foods rich in vitamin C (e.g., grapefruit) have been shown to possess anti-oxidant activity, both of which can affect inflammation. In addition, there is some evidence that vitamin E (e.g., Tocotrienol), the carotenoids (e.g., lycopene), and the polyphenols (e.g., caffeic acid, (–) curcumin, epicatechin) can also affect inflammation. Interestingly, these compounds are often found in foods that are high in antioxidants, such as fruits and vegetables, indicating a potential ‘good’ role that these foods can play in modulating inflammation, at least in part, through their antioxidant content.

Current Research Evidence

It is well known that diet can affect inflammation. A recent systematic review and meta-analysis by Wang and colleagues examined the effects of dietary intake on serum high-sensitivity C-reactive protein (hsCRP) among healthy individuals. In this review, the authors examined the effects of different dietary patterns on hsCRP among more than 200,000 adults from 20 randomized controlled trials. The results of these studies showed that a diet rich in vegetables, fruits, and whole grains significantly reduced the levels of hsCRP compared to diets high in fats and processed foods. The results of this review provide strong support for the link between diet and inflammation.

Further Reading

The above review by Wang and colleagues is a great place to start for anyone wanting to better understand the connection between diet and inflammation. In addition to providing a comprehensive summary of the evidence regarding the effect of diet on inflammation, it also serves as a helpful reminder that nutrition is a complex area, and it is often difficult to determine exactly how a particular food or nutrient affects health. This is because it is often difficult to determine the relative importance of confounding variables, such as the types of food consumed and the quantities, as well as other factors, such as sleep quality and the levels of physical activity, among others.

Another great reference for anyone wanting to learn more about nutrition and inflammation is the book “Nutrition and Health” by Dr. Daniel E. Siegel (New York: Penguin). This is an excellent resource that provides a detailed summary of what is known regarding the relationship between diet composition and health. In addition, it also provides the reader with an understanding of how various nutritional compounds can affect the human body, both positively and negatively. Lastly, the information regarding the role of nutrition in health is often complicated, and it can be difficult to discern the various factors involved and the various conditions in which it may or may not be beneficial, thus making it a useful reference for the curious mind, as well as a good place to start for anyone wanting to learn more about the topic.

In summary, nutrition is an area of scientific research that can have a significant impact on an individual’s health. It is often difficult to determine exactly how a particular food or nutrient affects health, especially in the case of low-grade inflammation. However, it is still very much possible to reduce inflammation, even at an early age, through nutrition. This is because persistent infections and irritations can still be found in many parts of the world, particularly in underdeveloped countries, and the majority of individuals, regardless of their economic status, live in these regions. Hence, it is still very much possible to avoid many of the diseases and conditions that are linked to low-grade inflammation. This is why nutrition can play such an important role in modulating this type of inflammation. In particular, it can be key in helping to prevent many kinds of cancer, as this type of inflammation can be the precursor to many different types of cancer, particularly gastrointestinal cancer.