Chia Seeds May Prevent Breast Cancer but Increase Prostate Cancer Risk
Despite the recent surge in interest in the health benefits of chia seeds, research investigating the role of chia seeds in cancer prevention is still limited. However, several studies have been conducted on the relationship between a diet rich in alpha linolenic acid and cancer. Alpha linolenic acid, also known as ALA, is a type of omega-3 fatty acid that is vital for human health. Foods like flaxseeds, hempseeds and soybeans supply a good amount of alpha linolenic acid, but chia seeds are the richest plant-based source of this essential fatty acid. For example, chia seeds deliver 8 times as much as ALA as soybeans, and 16% more than flaxseeds.
Chia seeds may lower breast and cervical cancer risk
A study published in the Journal of Molecular Biochemistry at the beginning of 2013 investigated the impact of alpha linolenic acid on certain breast cancer and cervical cancer cell lines. ALA was found to induce apoptosis in both breast cancer and cervical cancer cells, without damaging non-cancerous cells. Apoptosis is the body's natural way of getting rid of damaged or useless cells, but this mechanism is typically faulty in cancer cells, allowing them to grow uncontrolled.
Another interesting study – a case-control study conducted among a highly homogeneous population in Central France – analyzed biopsies of adipose breast tissue from 123 women with invasive non-metastatic breast carcinoma. A group of 59 women with benign breast cancer served as controls. The researchers found no link between breast carcinoma and fatty acids (saturates, monounsaturates, long-chain polyunsaturates n-6 or n-3), with one exception: an increase in alpha-linolenic acid was associated with a reduced risk of breast carcinoma. This study was published in the European Journal of Cancer in 2000.
In addition to alpha-linolenic acid, chia seeds are an excellent source of fiber and zinc, both which have cancer-fighting properties.
Tip: Make healthy breast cancer preventing smoothies by mixing chia seeds with vegetables and fruits that have anti-cancer properties (e.g. green tea, cherries, raspberries). Check out our page 20 Best Foods to Fight Breast Cancer for inspiration.
Can ALA in chia seeds inrease prostate cancer risk?
While current research on cancer and alpha-linolenic acid suggests that chia seeds – along with other foods rich in ALA – might provide protection against breast and cervical cancer, the evidence is quite different for prostate cancer risk. For example, a case-control study conducted among Spanish men and a meta-analysis of observational studies, both published in the early noughties, found a relationship between alpha-linolenic acid and an increased risk of prostate cancer. The risk appeared to be irrespective of the dietary source of ALA (e.g. animal vs plant-based sources).
However, a recent meta-analysis published in the American Journal of Clinical Nutrition in 2009 found evidence of publication bias in some of the earlier studies done on ALA and prostate cancer risk, and concluded that if there is an increased risk of prostate cancer associated with intake of ALA, that risk is likely to be small.