We’ve all heard the saying, “an apple a day can help keep the doctor away,” but now scientists are suggesting adding something else to your daily routine to reduce the risk of bowel cancer.

Researchers from the University of Oxford have identified a key item that could protect against this deadly disease—and the good news is, it’s likely already in your fridge.

Their study, published in Nature Communications, examined 97 dietary factors and their link to bowel cancer risk, using data from 542,778 women who participated in the Million Women Study.

Bowel cancer, often referred to as the “silent killer” cancer—which the NHS defines as cancer occurring anywhere in the large bowel, including the colon and rectum—has been increasing among younger individuals in recent years. According to the American Cancer Society, it is the leading cause of cancer death in men and the second leading cause in women.

The Oxford research team discovered that out of all the factors analyzed, two had the greatest impact on altering bowel cancer risk.

Consuming the equivalent of a glass of wine daily was found to raise the risk of bowel cancer by 15 percent, whereas calcium appeared to have the opposite effect.

Researchers revealed that drinking a glass of milk each day could lower the risk of bowel cancer by nearly 20 percent.

Dr. Keren Papier, the study’s lead researcher, noted that more research is required but stated, “This is the most comprehensive single study ever conducted into the relationship between diet and bowel cancer, and it highlights the protective role of calcium in the development of this disease.”

The research indicated that an additional 300mg of calcium per day—roughly the amount in a 240ml glass of milk or two small pots of yogurt—was associated with a 17 percent reduction in bowel cancer risk.

It also found that calcium had a similar protective effect regardless of whether it came from dairy or non-dairy sources, implying that calcium itself was responsible for the benefit.

While researchers clarified that calcium from milk, yogurt, vegetables, and other sources all contributed, they noted that the study did not establish a clear link for cheese or ice cream, leaving it uncertain whether those sources would have the same impact.

The study also supported earlier findings that processed and red meat increase the likelihood of bowel cancer, with an additional 30g per day associated with an eight percent higher risk.

Sophia Lowes, senior health information manager at Cancer Research UK, which funded the research, emphasized the importance of prevention: “Bowel cancer is one of the most common cancers affecting people in the UK, which is why it’s so vital that we know how to prevent it.

“Maintaining a healthy, balanced diet, alongside keeping a healthy weight and stopping smoking, is one of the best ways to lower your risk of bowel cancer.

“This includes cutting down on alcohol and red and processed meat, and eating lots of fruit, vegetables and wholegrains.

“Dairy products like milk can also be part of a diet which reduces bowel cancer risk.

“We look forward to further research, including into the effects of specific ingredients like calcium, to ensure fewer people are impacted by this devastating disease.”