Urbanized South Asians' susceptibility to coronary heart disease: The high-heat food preparation hypothesis.

Objective: Known risk factors do not fully explain the comparatively high susceptibility to coronary heart disease (CHD) in South Asians (Indian, Pakistani, Bangladeshi, and Sri Lankan populations in South Asia and overseas). The search for explanatory hypotheses and cofactors that raise susceptibility of South Asians to CHD continues. The aim of this study was to propose "the high-heat food preparation hypothesis," where neo-formed contaminants (NFCs) such as trans-fatty acids (TFAs) and advanced glycation end-products (AGEs) are the cofactors.

Methods: We reviewed the actions of AGEs and TFAs, the burden of these products in tissues and blood in South Asians, the relationship between these products and CHD, the effects of preparing food and reheating oils at high temperatures on NFCs, and the foods and mode of preparation in South Asian and Chinese cuisines.

Results: Animal and human studies show NFCs increase the risk for CHD. Evidence on the consumption and body burden of these products across ethnic groups is not available, and comparable data on the NFC content of the cuisine of South Asians and potential comparison populations (e.g., the Chinese with lower CHD rates) are limited. South Asians' cuisine is dominated by frying and roasting techniques that use high temperatures. South Asian foods have high TFA content primarily through the use of partially hydrogenated fats, reheated oils, and high-heat cooking. Reheating oils greatly increases the TFA content. In comparison, Chinese cuisine involves mostly braising, steaming, and boiling rather than frying.

Conclusion: We hypothesize that South Asians' susceptibility to CHD is partly attributable to high-heat treated foods producing high NFCs. Research to accrue direct evidence is proposed.