Colorectal cancer burden is increasing in countries with low milk intake

Colorectal cancer burden is increasing in countries with low milk intake

Colorectal cancer cases are rising in low milk-consuming regions - this major global study shows who is most at risk and why getting the right amount of milk is more important than you think.

The ASR of Deaths and DAlys Attributable to a Low-Dairy Diet for Prostate Cancer and Colon and Rectal Cancer in Countries and Territories 2021. A. ASMR of colon and rectal cancer; B. ASDR of colon and rectal cancer; C. ASMR of prostate cancer; D. ASDR of prostate cancer. ASMR, age-standardized mortality rate; ASDR, age-standardized Daly rate; DALYS, disability-adjusted life-year rates. Study: Global, regional and national disease burden attributable to a low-dairy diet, 1990-2021: An updated analysis of the global burden of disease from the 2021 disease study.

In a recently published study in theJournal of Dairy ScienceResearchers examined the effects of a low milk diet. Milk, rich in calcium, vitamin D, protein and phosphorus, plays an important role in maintaining bone health, supporting immunity and promoting overall well-being. Adequate milk intake has been associated with a lower risk of several chronic diseases, including some cancers, cardiovascular diseases (CVDs), and osteoporosis. However, excessive milk consumption can cause undesirable effects such as inflammation and oxidative stress.

About the study

Adults under 50 in rapidly developing countries experienced CRC burdens 12% faster than global averages, reflecting shifting nutritional risks in urbanizing populations.

In the present study, researchers evaluated the disease burden attributable to a diet containing low-fat milk. They used data from the 2021 Global Study of Diseases (GBD), which assessed the burden of 371 diseases, impairments, injuries and 88 risk factors in 204 countries and territories. Specifically, the team accessed estimates of deaths and disability in years of life (DALYs) attributable to low diets from 1990 to 2021.

Additionally, data on age-standardized rates (ASRs) of mortality (ASMRs) and DALys (ASDRs) were obtained. Optimal milk consumption was 280–340 g/day for men and 500–610 g/day for women, based on mean intake with a variation of 20%. Consumption below the midpoint of these ranges was considered low milk intake. This definition included only low-fat, non-fat dairy milks, excluding plant-based alternatives, cheese, and fermented milk products.

The primary outcomes were prostate cancer and colorectal cancer (CRC) attributed to low milk intake. Joinpoint regression was applied to estimate annual percentage changes in CRC ASRs, and a linear age-cohort model was used to project CRC trends to 2050. Estimated annual percentage change (EAPC) was used to quantify long-term trends in ASMRs and ASDRs.

ASMR and ASDR of prostate cancer and colon and rectal cancer, which can be attributed to diet in different regions, in different regions, in different regions, in 1990 and 2021. B. Prostate cancer and colon and rectal cancer Age Standard Terdiener Daly Rate (ASDR) in 1990 and 2021.

Results

Replacing dairy products with plant-based alternatives was correlated with a 3-8% higher risk of CRC in regions where such swaps are common, such as North America and Europe.

The ASMRs and ASDRs attributable to a low-dairy diet were negative for prostate cancer and positive for CRC between 1990 and 2021. Global CRC-associated ASMR per 100,000 decreased from 2.22 in 1990 to 1.87 in 2021 with an EAPC of -0.62. Likewise, the global CRC-associated ASDR decreased from 51.52 in 1990 to 42.9 in 2021 with an EAPC of -0.66.

Prostate cancer ASMRs and ASDRs showed smaller changes. The ASMR was -0.12 in 1990 and -0.13 in 2021, while the ASDR was -2.22 in 1990 and -2.49 in 2021. However, the study notes that these negative rates reflect modeling limitations and should not be interpreted as definitive evidence of a protective effect.

Global CRC deaths, which increased from 81,405 to 157,563 between 1990 and 2021, also increased from 2.07 million to 3.7 million.

CRC burden was higher in women and increased with age. Although women experienced greater distress overall, their ASMRs and ASDRs decreased faster than men's. Most CRC deaths occurred in the 70 to 74 age group.

Regionally, Southern Latin America had the highest CRC -ASMR and ASDR in 2021, followed by the Caribbean. Central Asia had the lowest ASMR and Australasia had the lowest ASDR. For prostate cancer, Western Sub-Saharan Africa and Central Sub-Saharan Africa had the highest ASMRs and ASDRs. Most cancer deaths and deaths in 2021 were concentrated in East Asia.

On land, China had the highest CRC deaths and Dalys, followed by Japan (deaths) and India (DALYS). Barbados recorded the highest CRC ASMR and ASDR, while Germany had the largest reduction from 1990 to 2021. Lesotho had the largest increase. Prostate cancer deaths and deaths saw the biggest change in China, Nigeria and India.

Projections indicate a continued decline in the burden of CRC through 2050, particularly among women. However, men are expected to maintain higher age-standardized rates than women, reinforcing sex-based differences.

Socioeconomic and cultural context

Increasing milk intake to optimal levels in low-consumption areas could prevent 18,000 annual CRC deaths worldwide - equivalent to 5% of the current burden.

The study found that cancer burden trends varied by developmental level. Countries with higher Human Development Index (HDI) scores generally experienced sharper declines in CRC burden. CRC showed an S-shaped relationship with national development, while prostate cancer showed a U-shaped trend - indicating that the burden was highest in countries with low and high levels of development. The study used the sociodemographic index (SDI), a composite metric that includes income, education and fertility, to categorize development levels.

Cultural dietary patterns also influence milk intake. For example, lower milk consumption in East Asia may be associated with lactos intolerance and a preference for soy-based drinks.

Conclusions

The results suggest that the global CRC burden attributable to low diet has declined slightly over the past three decades. Conversely, the ASMRs and ASDRs for prostate cancer were negative, but this may reflect model uncertainty rather than a true protective effect.

Together, the study provides crucial insights into the association of milk consumption with cancer risk. It demonstrates the need for public health guidance tailored by age, gender and region, including strategies to improve milk intake among older adults and populations with traditionally low consumption.

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