Young overweight man with towel resting in park

(© New Africa -

LUND, Sweden — New research indicates that young men who gain a significant amount of weight at an early age increase their likelihood of developing prostate cancer by nearly a third. Scientists in Sweden suggest that weight gain during a young man’s teens and twenties increases the risk of developing lethal tumors later in life.

The findings come from an analysis of over a quarter-million participants for an average of 43 years. This could be instrumental in combating the second deadliest cancer among men. According to the American Cancer Society, doctors in the United States will diagnoses roughly 288,300 new cases of prostate cancer in 2023.

“Knowing more about the factors that cause prostate cancer is key to preventing it. The only well-established risk factors, such as increasing age, a family history of the disease, and several genetic markers, are not modifiable, making it vital to identify risk factors that can be changed,” says Dr. Marisa da Silva, the study’s lead author from Lund University, in a media release. “This makes it essential to identify risk factors that can be altered.”

While many prostate cancers grow slowly and may not harm a man during his lifetime, others are aggressive and difficult to treat, quickly spreading to other organs. Previous studies have established a strong link between these cancers and excess body fat. However, the underlying reasons have been unclear, and many studies relied on body fat measures from a single point in time, neglecting to assess the cancer’s aggressiveness.

“Previous research has implicated elevated concentrations of insulin-like growth factor-1 (IGF-1), a hormone that is involved in cell growth and development, with an increased risk of prostate cancer,” explains Dr. da Silva. “Levels of this hormone are raised in people with obesity and a steep increase in weight may fuel this elevation and the development of the cancer.”

Obesity: Doctor measuring obese man's stomach.
(© Kurhan –

The research team analyzed data from 258,477 men who had their weight measured at least three times between the ages of 17 and 60 as part of the Obesity and Disease Development Sweden (ODDS) study. All participants were free of cancer at the time of enrollment from 1963 to 2014 and were followed until 2019. Prostate cancer diagnoses and deaths during this period were recorded.

A total of 23,348 participants were diagnosed with prostate cancer, and 4,790 died from the disease. The average weight gain was highest early in life — 1.6 pounds annually from ages 17 to 29, 0.75 pounds annually from ages 30 to 44, and 0.5 pounds annually from ages 45 to 60. This trend displayed a connection with both the development and aggressiveness of prostate cancer.

Weight gain of 1.1 pounds annually throughout a man’s life increased the risk of aggressive and fatal prostate cancer by 10 percent and 29 percent, respectively. Further analysis revealed that the link was most significant between the ages of 17 and 29. A young man gaining 2.2 pounds annually during this period has a 13 and 27-percent increased risk of aggressive and fatal prostate cancer, respectively.

The Swedish researchers concluded that preventing weight gain during young adulthood may reduce the risk of aggressive and fatal prostate cancer.

“We do not know if it is the weight gain itself or the long duration of being heavier that is the main driver of the association that we see. Nevertheless, one must gain weight to become heavier, so preventing a steep increase in weight in young men is imperative for the prevention of prostate cancer,” Dr. da Silva concludes.

The study authors presented their findings at the European Congress on Obesity in Dublin, Ireland.

South West News Service writer Mark Waghorn contributed to this report.

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