Erythrocyte membrane n-3 PUFA are inversely associated with breast cancer risk among Chinese women.

The relationship between erythrocyte membrane n-3 PUFA and breast cancer risk is controversial. We aimed to examine the associations of erythrocyte membrane n-3 PUFA with odds of breast cancer among Chinese women by using a relatively large sample size. A case-control study was conducted including 853 newly diagnosed, histologically confirmed breast cancer cases and 892 frequency-matched controls (5-year interval). Erythrocyte membrane n-3 PUFA were measured by GC. Logistic regression and restricted cubic spline were used to quantify the association between erythrocyte membrane n-3 PUFA and odds of breast cancer. Erythrocyte membrane α-linolenic acid (ALA), docosapentaenoic acid (DPA) and total n-3 PUFA were inversely and non-linearly associated with odds of breast cancer. The OR values (95 % CI), comparing the highest with the lowest quartile (Q), were 0·57 (0·43, 0·76), 0·43 (0·32, 0·58) and 0·36 (0·27, 0·49) for ALA, DPA and total n-3 PUFA, respectively. Erythrocyte membrane EPA and DHA were linearly and inversely associated with odds of breast cancer ((EPA: ORQ4 v. Q1 (95 % CI) = 0·59 (0·45, 0·79); DHA: ORQ4 v. Q1 (95 % CI) = 0·50 (0·37, 0·67)). The inverse associations were observed between ALA and odds of breast cancer in postmenopausal women, and between DHA and oestrogen receptor+ breast cancer. This study showed that erythrocyte membrane total and individual n-3 PUFA were inversely associated with odds of breast cancer. Other factors, such as menopause and hormone receptor status, may warrant further investigation when examining the association between n-3 PUFA and odds of breast cancer.

Serum levels of n-3 PUFA and colorectal cancer risk in Chinese population.

Circulating n-3 PUFA, which integrate endogenous and exogenous n-3 PUFA, can be better used to investigate the relationship between n-3 PUFA and disease. However, studies examining the associations between circulating n-3 PUFA and colorectal cancer (CRC) risk were limited, and the results remained inconclusive. This case­control study aimed to examine the association between serum n-3 PUFA and CRC risk in Chinese population. A total of 680 CRC cases and 680 sex- and age-matched (5-year interval) controls were included. Fatty acids were assayed by GC. OR and 95 % CI were calculated using multivariable logistic regression after adjustment for potential confounders. Higher level of serum α-linolenic acid (ALA), docosapentaenoic acid (DPA), DHA, long-chain n-3 PUFA and total n-3 PUFA were associated with lower odds of CRC. The adjusted OR and 95 % CI were 0·34 (0·24, 0·49, Pfor trend < 0·001) for ALA, 0·57 (0·40, 0·80, Pfor trend < 0·001) for DPA, 0·48 (0·34, 0·68, Pfor trend < 0·001) for DHA, 0·39 (0·27, 0·56, Pfor trend < 0·001) for long-chain n-3 PUFA and 0·31 (0·22, 0·45, Pfor trend < 0·001) for total n-3 PUFA comparing the highest with the lowest quartile. However, there was no statistically significant association between EPA and odds of CRC. Analysis stratified by sex showed that ALA, DHA, long-chain n-3 PUFA and total n-3 PUFA were inversely associated with odds of CRC in both sexes. This study indicated that serum ALA, DPA, DHA, long-chain n-3 PUFA and total n-3 PUFA were inversely associated with odds of having CRC in Chinese population.

Association of dietary intake of n-3 polyunsaturated fatty acids with breast cancer risk in pre- and postmenopausal Chinese women.

OBJECTIVE: This study aimed to evaluate the associations between breast cancer risk and intake of n-3 polyunsaturated fatty acids (PUFAs) and/or n-3 PUFA subclasses in Chinese women, and determine whether these associations varied with menopausal status or clinical characteristics. METHODS: A hospital-based case-control study including 1,589 cases and 1,621 age-frequency-matched controls was conducted. Dietary data were assessed by a validated food frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals were obtained using multiple unconditional logistic regression models after controlling for potential confounders. RESULTS: Higher intake of marine n-3 PUFAs and total n-3 PUFAs was associated with lower risk of breast cancer, with adjusted OR quartile 4 v.1 (95% confidence intervals) of 0.68 (0.55-0.84) and 0.56 (0.42-0.75), respectively. Dietary a-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid were also inversely associated with breast cancer risk, with adjusted ORs (95% confidence intervals) of 0.51 (0.38-0.70), 0.68 (0.55-0.84), 0.68 (0.55-0.85), and 0.76 (0.61-0.94), respectively. In stratified analyses, these inverse associations between risk and dietary n-3 PUFAs were more evident among premenopausal women and women with ER+, PR+ and ER+PR+ tumors. A decreased risk of breast cancer was significantly associated with increasing n-3 PUFA intake in obese/overweight women, but not in women of normal weight. There was a significant interaction between linoleic acid and marine n-3 PUFAs. CONCLUSIONS: High intake of n-3 PUFAs and n-3 PUFA subtypes was associated with a lower risk of breast cancer, especially among premenopausal women and women with ER+ and/or PR+ subtype breast cancer.